CIVIL WORK AT RAILWAY SIDING FOR INSTALLATION OF APPROACH TO WFM AT JOBNER INSTALLATION

CIVIL AND STRUCTURAL WORKS.

1. The method of measurement shall be as per latest revision of IS:1200 unless otherwise

2. Providing and operating necessary measuring and testing devices and materials including all

consumable are included in the scope of work. No separate measurement or payment for testing

the work shall be made and rates quoted for various items shall be deemed to include the cost

of such tests, which are required to ensure specific quality.

3. All materials shall be of standard quality, manufactured by renowned concerns conforming

to Indian Standard or equivalent and shall have IS mark as far as possible unless otherwise

approved by the Site-in-charge, prior to procurement and use. The Contractor shall furnish

manufacturer's certificates for the materials supplied by him when asked for. Further to that he

shall get the materials tested from an approved lab if

asked for by the Site-in-charge. The cost for all the tests and test certificate shall be borne by

the contractor. Any materials procured or brought to site and not conforming to specifications

and satisfaction of Site-in-charge shall be rejected

4. Wherever referred to in this tender document, only the latest revision which shall be in force

till the completion of work, of specifications, Codes of Practice and other publications of

Bureau of Indian Standards shall be applicable.

5. Wherever the contractor executes civil and structural works involving building, equipment

foundations, supporting structures, pipe racks etc., the following works are deemed to have

been included in the quoted rates for various works.

a) Marking of centre lines of foundations.

b) Marking of top levels of foundations, floors etc. and establishment of reference lines, bench

marks on various floors, platforms etc.

c) Preparation of "As built" scheme of structural foundations, equipment foundations etc.

6. The schedule of rates, specifications and drawings shall be read

in conjunction with each other and in case of conflict amongst

them, clarification shall be obtained from the Site-in Charge,

whose decision shall be final and binding.

SPECIFICATION FOR MATERIALS

Water used for cement concrete, mortar, plaster, grout, curing or washing of coarse aggregate

shall be clear and free from excess amounts of oil, acids, alkalis, organic matters or other

harmful substances in such amounts that may impair the strength or durability of the structure.

Potable water shall generally be considered satisfactory for preparation of mortar, concrete mix

and curing of brickwork, plaster, concrete etc.

The Site-in-charge may require the Contractor to get the water tested from an approved

laboratory at latter's expense and in case the water contains excess of acid, alkali or salt etc.,

the Site-in-charge may refuse to permit its use.

Coarse and fine aggregates for concrete shall conform in all respects to IS:383.

Aggregates shall be obtained from a source known to produce these satisfactorily. These shall

be chemically inert, hard, strong, dense, durable, clean and free from excess amounts of alkalis,

vegetable matter and other deleterious substances. Flaky and elongated pieces shall not be used.

Coarse aggregate is aggregate most of which is retained on 4.75 mm IS sieve. It shall have a

specific gravity not less than 2.6.

Fine aggregate is aggregate most of which passes through 4.75 mm IS sieve but not more than

ten percent (10 %) pass through 150 micron IS sieve.

The Site-in-charge may require the Contractor to carry out tests at the

Contractor 's expense, in accordance with IS : 516 (Methods of test for

strength of concrete )and IS:2386 (Methods of test for aggregates for

3.0 SAND FOR FILLING

Sand for filling shall be medium coarse hard, strong free from any organic and deleterious

materials. Any sand (Fine/Coarse) proposed, shall be used only after it is approved by the Site-

The cement used shall be ordinary Portland cement conforming to IS:269 or Portland

Pozzolana Cement Conforming to IS : 1489 (Part-I, 1991) or Portland Slag Cement

Conforming to IS:455 unless otherwise specified.

RECEIPT AND STORAGE OF CEMENT BAGS

It must be ensured that the cement being received at site is as fresh as possible by checking the

batch no. with the supplier's test certificate which should accompany the cement. Generally

cement more than 120 days old shall not be used. Before receiving cement it should be ensured

that a proper cement godown is constructed by the contractor.

The godown shall be weather tight, and of proper ventilated structure. Wooden battens or ball

is shall be laid on the floor so that a gap of atleast 15 cm is available between the floor and

cement bags. The cement bags may be stacked upside down at least once in 60 days to avoid

slump formation. While receiving cement following precautions must be taken.

Bags should not be wet /partially or fully set. The cement shall be stored as per IS :4082-1977.

Relevant excerpts of IS:4082 are as given below. At least 60 cm space should be kept between

walls and stacks. Cement bags should be stacked close so as to avoid air circulation to the

extent possible. Maximum 10 bags shall be stacked in one stack. Cement of different types and

brands shall be kept in separate stacks to ensure usage on first in first out basis. For extra safety

in monsoon, polythene sheet shall be used to cover the bags.

All reinforcement and structural steel shall conform to the following:

5.1 REINFORCEMENT STEEL

- IS : 1139 Hot rolled deformed bars

- IS : 1786 Cold twisted bars

- IS : 432 Mild Steel round bars (Grade - I)

- IS : 1566 Hard drawn steel wire fabric.

5.2 STRUCTURAL STEEL

- IS : 226/2062 Hot rolled sections and plates

- IS : 1079 Cold formed light gauge sections

- IS : 432 Mild Steel round bars (Grade - I)

- IS : 4923 Hollow sections (rectangular or square)

5.3 OTHER BARS AND SECTIONS:

Any other type of reinforcement bars and structural sections specified on the drawings shall

conform to respective Indian Standard Codes.

The reinforcement and structural steel shall be stored in such a way as to avoid and prevent

deterioration and corrosion.

SPECIFICATION FOR EARTHWORK

1.0 CLASSIFICATION OF SOIL

1.1 SOFT/LOOSE SOIL

Generally any soil which yields to the ordinary application of pick and shovel or to phawra or

other ordinary digging implement; such as sand, silt, loam, clay, peat etc.

1.2 HARD/DENSE SOIL

Generally any soil which requires the close application of pick, or jumper or scarifier to loosen

such as stiff clay, gravel and cobble stone.

1.3 SOFT/DISINTEGRATED ROCK

Rock or boulder may be quarried or split with crowbar. This will also include laterite & hard

1.4 HARD ROCK (REQUIRING BLASTING)

Any rock or boulder for the excavation of which blasting is required.

1.5 HARD ROCK (REQUIRING CONTROLLED BLASTING)

Due to any reason, if general blasting is prohibited, then for excavating these rocks, controlled

blasting as approved by the Site-in-charge shall be used.

1.6 HARD ROCK (BLASTING PROHIBITED)

Hard rock requiring blasting as described under 1.4 but where blasting is prohibited for any

reason and excavation has to be carried out by chiselling, wedging or any other agreed method.

2.0 BACKFILLING MATERIAL

Backfilling material shall be as approved by the Site-in-charge. Back filling of excavations in

trenches, foundations and elsewhere shall consist of one of the following materials as the Site-

in-charge may direct in each location.

(ii) Selected earth from heaps or brought from borrow areas.

(iii) Stone/gravel

(v) Lean concrete

The material shall be free from rubbish, roots, hard lumps and any

other organic material.

3.0 EARTHWORK IN EXCAVATION

Excavation shall be carried out in any material encountered on the site to the lines, levels and

contours shown on the detailed drawings and the Contractor shall remove all excavated

materials to soil heaps on site or transport for use in filling the site or stack for reuse as directed.

Excavated material shall not be deposited within 1.5M from the top edge of the excavation.

The sides of the excavation may be cut sloping or shored and strutted to hold the face of earth

as per site requirements and as directed by the BPCL's Site-in-charge. The Contractor shall

remove all vegetation, shrubs etc. encountered during excavation. Foundation pits/trenches

shall not be excavated to the full depth unless construction is imminent. The last 15 cm depth

of the excavation shall not be removed until concreting work is imminent. The full depth may

at the discretion of the Site-in-charge be excavated and the bed covered with a seventy five

(75) mm (minimum) thick (or as indicated on the drawing) layer of lean concrete 1:5:10 mix

(1 Cement: 5 Coarse Sand: 10 Crushed Stone Aggregates) or as specified in schedule or rates.

The Contractor shall provide suitable drainage arrangement to prevent surface water from any

source entering the foundation pits at his own cost.

Where excavation is made in excess of the depth required, the Contractor shall at his own

expense, fill upto required level with lean concrete 1:5:10 mix or as decided by Site-in-charge.

Lowering of water table by well-point pumping shall be paid separately. The Contractor shall

make necessary arrangements for lighting, fencing and other suitable measures for protection

against risk of accidents due to open excavation at his own expense. Where the excavation is

to be carried out below the foundation level of an adjacent structure, the precaution to be taken

such as under pinning, shoring and strutting etc. shall be determined by the Site-in-charge. No

excavation shall be done unless such precautionary measures are carried out. The payment for

such precautionary measures shall, however, be made separately unless the rate for such

measures are specifically included in the rates for items of excavation. Loose or soft bed ground

encountered in excavation at the required depth shall be excavated to a firm bed and difference

made up to the required level with lean concrete 1:5:10 mix or as decided by the Sitein-

charge. Any obstacle encountered during excavation shall be reported immediately to the Site-

in-charge and shall be dealt with as instructed by him. Removal of buried pipes or cables shall

be done with prior permission of BPCL's Site-in-charge and the Contractor shall provide

all measures to protect the same. Cost of such protective measures are deemed to be included

in the rates for various items of excavation. The Contractor shall not undertake any concreting

in foundation until the excavation pit/trench is approved by the Site-in-charge.

3.1 The specification for earthwork shall also apply to excavation in rock in general. The

excavation in rock shall be done such that extra excavation beyond the required width and

depths as shown in drawing is not made. If any extra excavation particularly in depth is made

by the Contractor during the excavation operation, the Contractor shall make up such extra

excavations with concrete 1:5:10 mix to the required levels and shaped at no extra cost to the

3.2 In case of hardrock requiring blasting, the provisions mentioned below

shall be strictly followed.

4.0 MEASUREMENT

Payment for earth work in excavation shall be made on cubic meter (m3) basis on the

measurement of volume of pit/trench of excavation as per IS:1200 . The rate shall include cost

of all the operations of blasting, making all arrangements for dewatering, removal and disposal

of surplus earth.

The contractor shall intimate BPCL's Site-in-charge as soon as different soil classifications are

met with. Joint levels shall be taken as to the levels of different soil classifications and volumes

shall be worked out on the basis of levels only. Where levels of different strata cannot be clearly

marked and defined, the contractor shall stack soils separately for measurement purpose and

then dispose it off as directed. If soil of any classification other than that specified in the SOR

is met with during the excavation, the decision of the Site-in-charge as to the classification of

the soil, levels of the strata and their location shall be binding on the contractor.

In the above case, the total quantity of excavation shall be computed from the measurement of

pit/trench excavated. The hard rock and soft rock shall be measured separately from the

relevant stacks and each shall be reduced by 50% for voids, and paid under the relevant items.

The balance, i.e. the total quantity of excavation minus the reduced (for voids) quantity of

excavation for rocks shall be paid as soft/hard soil as per the direction of the BPCL's Site-in-

charge. However the maximum payment shall be limited to the volume of the excavated

pit/trench asapproved.

SHORING AND STRUTTING

The shoring and strutting of the sides to withhold the face of excavation pits/trenches shall be

done as approved by the Site-incharge. Payment for shoring/strutting shall be made on square

meter basis as separate items.

GENERAL PROCEDURE/INSTRUCTIONS

FOR EARTH FILLING IN

DEPOTS/INSTALLATION

1.0 The procedure for earth filling can be divided into following:

1. Quantity of earth filling.

2. Evaluation of earth.

3. Filling procedure.

4. Compaction Test procedure.

5. Measurement of earth filling.

1.1 Quantity of earth filling

To arrive at the quantity of earth to be filled at a particular site, the HFL of the area is transferred

from some permanent bench mark (Railway, Culvert, Bridge etc.) to site and the area

earmarked for filling is divided into no. of grids of 10, 15, 20, 25M spacing depending on

the size of the plot. The reduced levels of various grid points are taken with the help of dumpy

level and are plotted on the land development drawing. Depending on the finished ground level

of the area, the quantity of earth is calculated. The procedure for using dumpy level is as follows

Dumpy level is an instrument with which difference of levels of any 2 points can be found out.

It is very commonly used in surveying for finding the levels and for plotting the contours. From

any known level e.g. permanent benchmark level of any point can be found out. With the help

of dumpy level a horizontal plane (Line of collimation) is formed which is tangent to mean sea

level and by taking height of different points to this line of collimation, level of each point can

For taking level of any point w.r.t. the known Bench Mark (BM), with dumpy level, first take

the height of B.M. reading, you get the level of line of collimation and by reducing the height

of particular point from B.M's reading you get the level of that particular point.

There are two methods of recording the measurements.

(a) Collimation System (H.I.): In this method the level of collimation is found out and then

for each point the reading is reduced and level is found out e.g.

Stn. Chainage Reading Collim- Reduced

Back Inter Fore HI

Sight Sight Sight

To check, if the difference of sum of back sight and fore sight-reading is equal to difference of

1st & last B.M. reading, It is OK

b) Rise & Fall Method:

In this method rise and fall of each point is added or subtracted from B.M. reading to get the

level of particular point e.g.

Stn. Chainage Reading Rise Fall Reduced

Back Inter Fore

Sight Sight Sight

To check the calculation and reading - close the reading on some known B.M. The difference

of back sight and fore sight reading, rise and fall readings and first and last B.M. reading should

be same. If they are not same then adjust the difference in all the readings.

For checking Dumpy Level and correcting the line of collimation, Dumpy level is kept at mid

location of 2 staff locations and, say reading on both the staff is taken as a & b. Then the dumpy

level is shifted in same line towards one staff and then say the reading on both the staff is taken

as a' and b'. If the difference of a, b and a, 'b' is same, the D.L. is OK. If it is different then

adjust diaphragm screw and check by repeating the process.

1.2 Evaluation of Earth

Before finally selecting the particular soil for filling from a quarry, the properties of earth are

tested to ensure its suitability.

(a) Procedure for Testing Soils

For selecting earth for earth filling following tests are conducted to check the suitability of

earth for filling purpose as per IS:2720 (Part-V)

(b) Liquid Limit (LL)

It is the minimum amount of water required to be added to a soil that will just make it to flow

like liquid when jarred slightly:

Wt. of wet soil - Wt. of dry soil

Wt. of dry soil

Most clay soils have LL around 50 - 90%. If sand or silt is added to

clay, its LL is lowered.

(c) Plastic Limit (PL)

It is the moisture content at which a thread of soil can be rolled without

breaking until it is only 3 mm in diameter, when it just begin to

crumble under pressure exerted by hand.

Sands, gravel and peat do not possess plasticity and their PL is zero.

Average PL of clay is 45 while that of silts is

Plasticity Index (PI) = LL - PL

Liquidity Index (LI) = Natural moisture content - PL

(d) Acceptability Criterion

(i) LI & PI should be less than 30 for good soil.

(ii) It should also be checked that the organic impurity level of

selected earth is not more than 2 - 3%.

(iii) Soil having laboratory maximum dry density of less than

gm/cc shall not be used.

(e) Testing Frequency

One test for every 3000 m² of earth filled is required to be carried out.

1.3 FILLING PROCEDURE

Depending upon the depth of earth filling in an area, the numbers of layers are decided. At few

selected points, a reference (constructed of 16mm dia reinforcing bar grouted in cement

concrete) flag with depth of earth filling layers marked on it is installed. Filling is carried out

with approved material in layers, not exceeding 30 cms of loose thickness; watering and rolling

Compaction to 90-95% of maximum dry density can be achieved by any of the following

(I) Using Road Rollers upto capacity of 10MT.

(ii) Using hand rollers.

(iii) Using sheep's foot Roller (can compress upto 35 kg/cm sq.)

(iv) Using Rammer (weighing 3.3 - 4.0 kg).

As per practical experience, Sheep’s foot roller is best suited for earth compaction, while

rammer is best suited for sand. When areas are large, road roller could also be used effectively

in combination with sheep's foot roller. It should be noted that water flooding should always

be avoided while compacting the earth.

1.4 COMPACTION TEST PROCEDURE

The compaction test procedure is as follows:

(a) Laboratory Test

First a test is conducted in laboratory to find density/moisture relation by proctor compaction

test. For this test, cylindrical metal mould of 4" dia x 4 1/2" ht. is used in which soil is filled in

3 equal layers with 24 blows of 2.5 kg. hammer from a height of 30 cm. By changing the

percentage of moisture, we get different dry densities, which can be plotted in the form of

curve. From this curve, relation between maximum dry density and moisture content can be

(b) Procedure of Calculation Dry Density of Soil Samples

The internal volume (Vc) of the core-cutter in ml. shall be calculated from its dimensions which

shall be measured to the nearest 0.25 mm. The core cutter shall be weighed to the nearest gram.

(Wc) A small area approximately 30 cm square of the soil layer to be tested shall be exposed

and levelled. The steel dolly shall be placed on top of the cutter and the latter shall be rammed

down into the soil layer until only about 14 mm of the dolly protrudes above the surface, care

being taken not to rock the cutter. The cutter shall then be dug out of the surrounding soil, care

being taken to allow some soil to project from the lower end of the cutter. The ends of the soil

core shall then be trimmed flat to the ends of the cutter by means of the straight edge. The

cutter containing the soil core shall be weighed to the nearest gram (Ws)

The soil core shall be removed from the cutter and a representative sample shall be placed in

an air-tight container and its moisture content (W) determined as per IS:2720 (Part-II) -

Note: It is necessary to make a number of repeat determinations and average out results, since

the dry density of the soil varies appreciably from point to point. The number of determinations

should be such that an additional one should not alter the average significantly.

The bulk density (Db), that is, the weight of the wet soil per cubic metre shall be calculated

from the following formula:

Ws = weight of soil and core-cutter in g,

Wc = weight of core-cutter in g, and

Vc = volume of core-cutter in ml.

The dry density Dd, that is, the weight of the dry soil per cubic metre

shall be calculated from the following formula:

Db = bulk density, and

w = moisture content of the soil (percent)

Dry density thus calculated should be 90-95% of max. dry density

determined by lab. test.

1.5 MEASUREMENT OF EARTH FILLING

Earth filling should be calculated meticulously to avoid any complications at the latter date.

The various methods of area calculations are as follows:

(1) Average Ordinate Rule

(2) Trapezoidal Rule.

(3) Simpson's Rule.

We shall compare only Trapezoidal rule and Simpson's rule as Average

Ordinate rule is not accurate.

Trapezoidal Rule: The rule is based on the assumption that the figures are trapezoids.

Simpson's rule: It assumes that the short lengths of boundary between

the ordinates are parabolic arcs.

Area of the figure = L [ (Ol + On) + 4 (O2 + O4 + .........On-1) + 2 (O3 +

This rule is applicable only when the number of divisions of the area is even and total number

of ordinates is odd. If there is an odd number of divisions (resulting in even number of

ordinates), the area of the last division must be calculated separately and added to equation.

The results obtained by the use of Simpson's rule are more accurate than trapezoidal rule.

Earth Volume Calculation: This can also be done by using

(i) Prismoidal formula or Simpson's rule for Volume

(ii) Trapezoidal formula.

Prismoidal formula

Here also it is necessary to have an odd number of cross sections. If there are even number of

sections, the end strip must be treated separately, and volume between the remaining section

be calculated by Prismoidal formula.

Trapezoidal Formula

For Volume Calculation, we should use only Simpson's rule (Prismoidal formula) as this is

more accurate than Trapezoidal formula. Sample Calculations of area and volume are enclosed

in Annexure-I for reference.

SPECIFICATION FOR EARTH WORK IN FILLING

1.0 MATERIAL FOR EARTHWORK

1.1 Only Material considered suitable by the Site-in-Charge shall be employed for the

construction and that considered unsuitable shall be disposed off, as directed at his own cost

and no claim for compensation will be entertained.

1.2 The CONTRACTOR shall give the samples of Earth he proposes to use for filling along

with the following characteristics of the samples to Site-in-Charge, prior to collection and use,

for approval. The tests for following characteristics shall be done in a laboratory/test house as

approved by Site-in-Charge.

(i) Mechanical analysis for grain size distribution as per IS:2720 part IV.

(ii) Liquid limit as per IS:2720 Part V.

(iii) Plastic limit as per IS:2720 Part V.

(iv) Moisture density relationship as per IS:2720 Part-VII.

1.3 The material (soil) used for filling shall be free from boulders lumps, tree roots, rubbish or

any organic deleterious matter.

1.4 Material (soil) having plasticity index less than 20 shall be used for filling purpose.

1.5 Soil having laboratory maximum dry density of less than 1.5 gms/cc shall not be used.

1.6 Care shall be taken to see that unsuitable waste material is disposed off in such a manner

that there is no likelihood of its getting mixed with

the material proposed to be used for filling.

2.0 CUTTING TREES

2.1 All trees having girth between 30 cms and 120 cms and which are not marked for

preservation, shall be cut down and their roots dug up to a depth of 1 metre from the existing

2.2 All holes or hollows produced by digging up roots shall be carefully filled with approved

material (soil) including all leads and lifts, rammed and compacted to obtain 90% of maximum

laboratory dry density of soil and levelled as directed.

2.3 All uprooted trees shall be stacked or disposed off as directed by Sitein- Charge.

Cutting of trees above 30 cms girth shall be paid per number. The rate quoted shall include

cutting, uprooting, removing the trees within plant boundary as directed, including filling holes

or hollows produced by removal of roots etc. as per specifications.

3.0 CLEARING AND STRIPPING

3.1 The areas including depressions, where filling or cutting is to be carried out shall be cleared

and stripped completely of bushes, roots, vegetation, plantation trees, shrubs, trees upto 30 cms

girth, organic and other objectionable materials. All these shall be completely uprooted and

virgin soil exposed and not merely scrapped at the surface. The roots of trees of girth upto

cms shall be removed to a minimum depth of 1 M below existing ground level and holes,

hollows filled up with selected approved available earth within all leads and lifts, and

compacted to obtain 90% of laboratory dry density of soil and levelled as directed by Site-in-

Charge. All soft patches must be worked out to remove soft soil and selected approved Earth

Must be filled back and the areas (areas coming under filling) compacted to obtain 90% of

maximum laboratory dry density of soil, as per IS:2720 Part-VII. The depth of stripping shall

be generally 50 to 150 mm, as decided by Sitein-Charge.

3.2 Material obtained from clearing shall be stacked or disposed off as directed by Site-in-

No separate payment shall be made for clearing, stripping and disposal of Materials obtained

from clearing. This shall be considered as part of Cutting Work in areas of cutting and Filling

work in areas of Filling and the rates quoted under the respective items.

4.0 EARTHWORK IN FILLING

4.1 After clearing, stripping and consolidation of areas, spot levels at intervals and pattern as

decided by Site-in-Charge shall be taken jointly and filling shall commence only after the levels

are signed by the CONTRACTOR as a token of his acceptance. Approved fill Material shall

be spread in uniform layers not exceeding 30 cms. in loose depth. The Contractor has to make

his own approach and access roads from the borrow area to the demarcated filling areas. BPCL

does not guarantee any passage way or right of way for the Contractor's work other than

available at site. No claim shall also be admissible to the CONTRACTOR on account of his

having to take longer leads or routes for earth movement, than envisaged by him, either due to

any road cuttings, non-availability of routes, or any other grounds whatsoever. In case total

filling required in any area consists of earth both from borrow areas and available approved

excavated material from within plant area, then joint levels, shall be taken before commencing

filling with earth from borrow area. However, earth from Borrow areas required for filling can

be used only after the available earth from excavation within demarcated area has been utilised

and clearance to this effect obtained from the Site-in- Charge.

4.2 All clods, Lumps, etc. shall be broken before compaction.

4.3 Successive layers of filling shall not be placed until the layer below has been thoroughly

compacted to satisfy the requirements laid down in this specification.

4.4 Prior to Rolling, the moisture content of Material shall be brought to within plus or minus

2% of the Optimum Moisture Content as described in IS:2720 Part VII. The moisture Content

shall preferably be on the wet side for potentially expansive soil.

4.5 After adjusting the Moisture Content as described the layers shall be thoroughly compacted

by either sheep foot roller or power driven roller or vibratory roller as approved by Site-in-

Charge till the specified maximum laboratory dry density is obtained.

4.6 Each layer shall be tested in field for density and accepted by Site-in- Charge subject to

achieving the required density before laying the next layer. A minimum of one test per 500 M2

for each layer shall be conducted.

4.7 If the layer fails to meet the required density, it shall be reworked or the material shall be

replaced and method of construction altered as directed by Site-in-Charge to obtain the required

4.8 The filling shall be finished in conformity with the alignment, levels, cross-section and

dimensions as shown in the drawing. Earthen embankment shall be filled 300 mm more on

both sides, where height is more than 1M, and this extra filling shall be dressed, after

compaction, in conformity with alignment, level, cross-section and dimension as shown in the

drawing to achieve proper compaction in the slope. No extra payment shall be made in this

4.9 Extra Material shall be removed and disposed off as directed by the Site-in-Charge.

4.10 Tolerances

General site grading including cutting and filling in depressions shall- be carried out to within

up down tolerance of ± 5 cms of final lines grades and slopes.

Payment for filling shall be made on Cubic Metre of Volume calculated on the basis of cross

section plotted from the levels of ground, where filling is to be carried out and the levels

reached after filling is duly consolidated, volume being calculated by Prismoidal formula. In

case of simultaneous cut and fill operation, wherever specified, payment shall be made on the

basis of one composite rate for cutting and filling, all other details about measurement etc.

remaining same as above. No extra payment shall be made towards testing charges.

SPECIFICATION FOR PLAIN AND

REINFORCED CEMENT CONCRETE

1.0 Construction of plain and reinforced concrete works shall be in accordance with IS:456 and

other relevant codes mentioned therein.

2.0 GRADES OF CONCRETE

Unless otherwise specified, the grades of concrete shall generally be as per table given below.

GRADE COMPRESSIVE

OF 15 CM CUBE AT

28 DAYS (N/SQ. MM)

The compressive strength is defined as the strength of material below which not more than 5%

of test results are expected to fall.

3.0 TYPE OF CONCRETE MIX

The concrete shall be either nominal mix or design mix as defined in IS:456. Unless otherwise

specified, all lean concrete shall be nominal mix and all structural concrete shall be design mix.

3.1 NOMINAL MIX

This concrete shall be made by adopting proportions of materials as specified in table given

GRADE TOTAL QUANTITY PROPORTION OF FINE QUANTITY OF

OF DRY AGGREGATES AGGREGATE TO COARSE WATER PER50

BY MASS PER 50 KG AGGREGATE (BY WEIGHT) OCEMENT

OF CEMENT(KG)(MAX) LITERS

M 5 800 Generally 1:2 but

subject to an upper

limit of 1:1.5 and

lower limit of 1:2.5

3.2 DESIGN MIX CONCRETE

The mix shall be designed to produce the grade of concrete having the required workability

and characteristic strength not less than appropriate values given in para 2 above.

3.3 PROPORTIONING

Proportioning shall mean the process of determining the proportions of the various ingredients

to be used to produce concrete of the required strength, workability, durability and other

properties. BPCL's Site-in-charge shall verify the strength of the concrete mix, before giving

his sanction for its use. However, this does not absolve the Contractor from his responsibility

as regards achieving the prescribed strength of the mix. If during the execution of the work,

cube tests show lower strengths than required, the Site-in-Charge shall order fresh trial mixes

to be made by contractor. No claim to alter the rates of concrete work shall be entertained due

to some changes in mix variations. Preliminary mix designs shall be established well ahead of

the start of work.

3.4 MAXIMUM DENSITY

Suitable proportions of sand and different sizes of coarse aggregates for each grade of concrete

shall be selected to give the maximum density as nearly as practicable. This shall be determined

by mathematical means, laboratory test, field trials and suitable changes in aggregate gradation.

3.5 WATER CEMENT RATIO

Once a mix, including its water-cement ratio, has been determined and specified for use by the

Site-in-charge, the water-cement ratio shall be maintained. The Contractor shall determine the

water content of the aggregates frequently as the work progresses, and the amount of mixing

water shall be adjusted so as to maintain the specified watercement ratio.

3.6 CONSISTENCY

The concrete shall have consistency such that it shall be workable in the required position and

when properly vibrated it flows around reinforcing steel all embedded fixtures etc.

3.7 WORKABILITY

The concrete mix proportion chosen should be such that the concrete is of adequate workability

for the placing condition and can be properly compacted with the means available. The

suggested ranges of values of workability of concrete measured in accordance with IS :

are indicated below.

PLACING CONDITIONS DEGREE OF VALUES OF

Concreting of shallow Very low 20-10 seconds, vee-bee

sections with vibration time or 0.75 - 0.80

compacting factor

Concreting of lightly Low 10-5 seconds , vee-bee time

reinforced section with or

vibration 0.80 -0.85 , compacting

Concreting of lightly Medium 5-2 seconds , vee-bee time

reinforced sections without or

vibration , or heavily 0.85-0.92 ,compacting

reinforced sections with or

vibration 25-75 mm, slump for

Concreting of heavily High Above 0.92, compacting

reinforced sections without or

vibration 75-125 mm, slump for

*For smaller aggregate the values will be lower.

In proportioning concrete , the quality of both cement and aggregate should be determined by

weight. Where the weight of cement is determined on the basis of weight of cement per bag, a

reasonable number of bags should be weighed periodically to check the net weight. Water

should be either measured by volume in calibrated tanks or weighed. Any solid admixtures that

may be added, may be measured by weight; liquid and paste admixtures by volume or by

weight. Batching plant, where used, shall conform to IS : 4925. All measuring equipment shall

be maintained in a clean serviceable condition, and their accuracy periodically checked.

4.1 Except where it can be shown to the satisfaction of the Site-in-charge that supply of

properly graded aggregate of uniform quality can be maintained over the period of work, the

grading of aggregate should be controlled by obtaining the coarse aggregate in different sizes

and blending them in the right proportions when required, different sizes being stacked in

separate stock piles. The grading of coarse and fine aggregate shall be checked frequently, the

frequency for a given job being determined by the Site-in-charge to ensure that the specified

grading is maintained.

4.2 Under special circumstances, change from weigh batching to volume batching may be

permitted by BPCL's Site-in-charge on specific request from the Contractor.

4.3 The amount of the added water shall be adjusted to compensate for any observed variations

in the moisture contents in both fine and coarse aggregates. For the determination of moisture

content in the aggregates, IS : 2386 (Part-III) may be referred to. To allow for the variation in

weight of aggregates due to variation in their moisture content, suitable adjustments in the

weights of aggregate shall also be made. In the absence of exact data, only in the case of

nominal mixes, the amount of surface water may be estimated from the values given in

SURFACE WATER CARRIED BY AGGREGATE

AGGREGATE APPROXIMATE QUANTITY OF SURFACE

Litres/M3 Percentage by weight

Moderately Wet Sand 80

Moist gravel or crushed rock 20-40 1.25 -

Very wet Sand 120

5.0 CONCRETE MIXING.

The concrete mixing shall be carried out in an approved type of mechanical mixer. The mixing

shall be continued until there is a uniform distribution of material and the mass is uniform in

colour and consistency. If there is segregation, after unloading from the mixer, the concrete

shall be remixed.

Mixers shall comply with IS:1791 and shall be maintained in satisfactory operating condition

. Mixer drum shall be kept free of hardened concrete and blades shall be replaced when worn

down more than ten percent (10%) of their depth. Should any mixer at any time produce

unsatisfactory results , leak mortar or cause waste of materials , its use shall be promptly

5.2 MIXING TIME

Mixing time shall be as indicated in the following table. Excessive mixing requiring additions

of water shall not be permitted. Time shall start when all solid materials are poured in the

revolving mixer drum, provided that all or the mixing water shall be introduced before

onefourth of the mixing time has elapsed. The Site-in-charge may, however, direct a change in

the mixing time, if he considers such a change necessary.

CAPACITY MINIMUM MIXING TIME

2 Cu.M or less 1-1/2 Minutes.

3 Cu.M 2-1/2 Minutes.

5 Cu.M 3 Minutes

All records and charts for the batching and mixing operations shall be prepared as specified

and as per the instructions of the Site-in-charge.

5.3 HAND MIXING

Normally hand mixing of concrete shall not be permitted. However this may be allowed by the

Site-in-charge in special cases (such as far away isolated places). Ten percent (10%) extra

cement shall have to be added to the normal mix when mixed by hand .It shall be carried out

on a water tight platform and care shall be taken to ensure that mixing is continued until the

mass is uniform in colour and consistency. No extra payment shall be made to the Contractor

for mixing by hand or for using extra cement due to hand mixing.

Admixtures shall be used in concrete only with the approval of the Site-in-charge.

5.5 TRANSPORTATION

All concrete shall be conveyed from the mixer to the place of final deposit as rapidly as possible

in suitable buckets, dumpers, containers or conveyors which shall be mortar leak tight. Care

shall be taken to prevent the segregation or loss of the ingredients and maintaining the required

5.6 PLACING AND COMPACTION

Before placing concrete all soil surfaces upon which or against which concrete is to be placed

shall be well compacted and free from standing water, mud or debris. Soft or yielding soil shall

be removed and replaced with lean concrete or with selected soils and compacted to the density

as directed by Site-in-charge. The surface of absorbing soil (against which concrete is to be

placed) shall be moistened thoroughly so that moisture is not drawn from the freshly placed

concrete. Concrete shall not be placed until the framework, the placement of reinforcing steel,

embedded parts etc. have been inspected and approved by the Site-in-charge. Any accumulated

water on the surface of the bedding layer shall be removed by suitable means before start of

placement. No concrete shall be placed on a water-covered surface. Concrete shall be

discharged by vertical drop only and the drop height shall not exceed 1.5 M. Concrete shall be

deposited as near as practicable in its final position to avoid rehandling. Concrete shall be

placed in successive horizontal layers.

All struts, stays and braces (serving temporarily to hold the forms in correct shape and

alignment pending the placing of concrete at their locations) shall be removed when the

concrete placing has reached an elevations rendering their service unnecessary. These shall

not be buried in the concrete. Concrete shall be thoroughly compacted with vibrators and fully

worked around the reinforcement, embedded fixtures and into corners of form work before

setting commences. In no case this shall be subsequently disturbed. Methods of placing shall

be such as to preclude segregation. Care shall be taken to avoid displacement of reinforcement

or movement of formwork. Unless otherwise approved, concrete shall be placed in single

operation to the full thickness of slabs, beams and similar members. Concrete shall be placed

continuously until completion of the part of the work between construction joints or as directed

by the Site-in-charge. The method of placing and compaction employed in any particular

section of the work shall be to the entire satisfaction of the Site-incharge. During hot weather

(atmospheric temperature above 40 oc) or cold weather (atmospheric temperature below 5 oc),

the concreting shall be done as per the procedure set out in IS:7861. Concrete that has been left

standing and become stiffened shall not be deposited in the work.

5.7 ITEMS EMBEDDED IN CONCRETE

Concreting shall not be started unless the electrical conduits, pipes, fixture etc., wherever

required, are laid by the concerned agency. The Contractor shall afford all the facilities and

maintain co-ordination of work with other agencies engaged in electrical and such other work

as directed by the Site-in-charge. Before concreting, the Contractor shall provide, fabricate and

lay in proper position all metal inserts, anchor bolts, pipes etc. (which are required to be

embedded in concrete members) as per relevant drawings and directions of Site-in-charge.

6.0 REQUIREMENT OF CONCRETE EXPOSED TO

SULPHATE ATTACK

Concentration of Type of Min.

Sulphates Cement Cement

In soil In Water

Less than Less than OPC 280

0.2 to 0.5 300 to OPC or 330

0.5 to 1.0 1200 to Super 330

7.0 CONSTRUCTION JOINTS

7.1 Construction joints shall be provided in position as shown or described on the drawings or

as directed by the Site-in-charge. Such joints shall be kept to the minimum. These shall be

straight and at right angles to the direction of main reinforcement.

7.2 In a column, the joint shall be formed about 100 mm to 150 mm below the lowest soffit of

the beams framing into it. Concrete in a beam and slab shall be placed throughout without a

joint but if the provision of a joint is unavoidable, the joint shall be vertical and located within

1/3 to 1/4 of the span. This is to be done to ensure that joint is located at the point of minimum

7.3 When stopping the concrete on a vertical plane in slabs and beams, an approved stop board

shall be placed with necessary slots for reinforcement bars. The construction joints shall be

keyed by providing a triangular or trapezoidal fillet nailed on the stop board. When concrete is

stopped on a horizontal plane, the surface shall be roughened and cleaned after the initial set .

7.4 When the work has to be resumed on a surface, which has hardened, such surface shall be

roughened to expose the tips of the coarse aggregate by hacking it. It shall then be swept clean

and thoroughly wetted. For vertical joints neat cement slurry shall be applied on the surface

before it is dry. For horizontal joints the surface shall be covered with a layer of mortar about

10 to 15 mm thick composed of cement and sand in the same ratio as the cement and sand in

concrete mix. This layer of cement slurry or mortar shall be freshly mixed and applied

immediately before placing the concrete.

7.5 Where the concrete has not fully hardened, all laitance shall be removed by scrubbing the

wet surface with wire or bristle brushes, care being taken to avoid dislodgement of particles of

aggregate. The surface shall be thoroughly wetted and all free water removed. The surface shall

be coated with neat cement slurry. On this surface, a layer of concrete not exceeding 150 mm

in thickness shall first be placed and shall be well rammed against old work, particular attention

being paid to corners and close spots , work thereafter shall proceed in normal

8.0 SEPARATION JOINT

Separation joint shall be obtained by using an approved alkathene sheet stuck on the surface

against which concrete shall be placed.

9.0 EXPANSION JOINT

Expansion joints in structures shall be formed in positions and to the shapes shown in relevant

drawings. Joints shall be filled with material as stipulated in drawings/schedule of rates/Tender

10.0 PROTECTION OF FRESHLY LAID CONCRETE

Newly placed concrete shall be protected by approved means from rain, sun and wind. Concrete

placed below the ground level shall be protected from falling earth during and after placing.

Surface shall be kept free from contact with such ground or with water draining from such

ground during placing of concrete for a period of atleast 3 days. The ground water around

newly poured concrete shall be kept to an approved level by pumping or other means.

Curing of concrete shall be in accordance with IS : 456. Concrete shall be cured by keeping it

continuously wet for the specified period of time to ensure complete hydration and hardening.

Curing shall be started after 8 hours of placement of concrete and in hot weather after 4 hours.

Curing shall be assured by use of an ample water supply in pipes, with all necessary appliances

such as hose, sprinklers etc. A layer of sacking, canvass, hessian, or other approved material

that will hold moisture for long periods and prevent loss of moisture from the concrete shall be

used as covering. Type of covering which would stain, disfigure, or damage the concrete during

and after the curing period shall not be used. The Contractor shall have all equipment and

materials required for curing on hand and ready for use before concrete is placed. For curing

the concrete in pavements, floors, flat roofs or other level surfaces the ponding method of

curing is preferred after the expiry of first 24 hours during which (i.e. first 24 hours) the

concrete shall be cured by use of wet sacking, canvass, hessian etc. The minimum water depth

of 25 mm for ponding shall be maintained. The ponded areas shall be kept continuously filled

with water and leaks, if any , shall be promptly repaired.

12.0 DAMP PROOF COURSE - (DPC)

The 40 mm thick Damp Proof Course shall consist of plain cement concrete of nominal mix

1:2:4 by volume (1 Cement : 2 Coarse Sand : 4 Crushed Stone Aggregates ) with 10 mm and

down size graded aggregate, unless otherwise specified. The Damp Proof Course shall be laid

at plinth level of brick walls, flush with the floor surface and shall not be carried across

doorways. Before laying, the top surface of wall should be thoroughly cleaned and watered.

The D.P.C shall be laid in layers of 20 mm thickness retaining the edges by necessary formwork

and shall be well tamped and trowelled to smooth finish. The layer shall be cured by keeping

the surface wet for 40 hours and after it has dried, two coats of hot bitumen of grade 85/25

conforming to IS:73 shall be applied over it at the rate to 1.7 Kg/M2. Over this, the second

layer 20 mm thick concrete shall be laid and cured as described in case of the first layer and

two coats of hot bitumen at the rate of 1.7 Kg/M2 shall be applied again in a similar manner.

Over this, dry sharp sand shall be sprinkled evenly.

13.0 FINISHING OF CONCRETE

On striking the formwork, all surface defects such as bulges, ridges and honey-combing etc.

observed shall be brought to the notice of the Sitein- charge. The Site-in-charge may, at his

discretion allow rectification by necessary chipping and packing or grouting with concrete or

cement mortar. However, if honeycombing or sagging are of such extent as being undesirable,

the Site-in-charge may reject the work totally and his decision shall be binding. No extra

payment shall be made for rectifying these defects, demolishing and reconstructing the

structure. All burrs and uneven faces shall be rubbed smooth with the help of carborandum

13.1 REPAIR AND REPLACEMENT OF UNSATISFACTORY

Repairs shall be made as soon as possible after the forms are removed and before the concrete

becomes too hard. Stone pockets, segregation patches and damaged areas shall be chipped out

and the edges undercut slightly to form a key. All loose material shall be washed out before

patching. A good bond between the patch and parent concrete shall be obtained by sprinkling

dry cement on the wet surface or by throwing mortar with force on to the wetted concrete, or

by brush in a coat of thick cement grout of about 1:1 (1 Cement:1 Sand) just before applying

the patching material. Before this has dried, the remainder of the patch shall be filled with

mortar or concrete, depending on the extent of the repair. Cement concrete/mortar used in

repair of exposed surfaces shall be made with cement from the same source as that used in

concrete and blended with sufficient amount of white Portland cement to produce the same

colour as in the adjoining concrete. The proportions of ingredients shall be same as those used

in parent concrete. The mortar shall be as dry as possible and well compacted into the cavity.

All filling shall be tightly bonded to the concrete and shall be sound, free from shrinkage cracks

after the filling has been cured and dried. For larger repairs to hardened concrete, necessary

formwork bearing tightly at the edges of the cavity shall be provided. Concrete shall be chipped

out to a depth of at least 100 mm. Mortar shall be scrubbed into all surfaces with a wire brush

before placing the concrete. Damaged reinforcement shall be adequately spliced with new steel

so as to maintain the original strength. Additional reinforcement, ifrequired in the patch, shall

be provided as per the instructions of Sitein-charge.

13.2 CURING OF PATCHED WORK

Immediately after patching is completed, the patched area shall be covered with an approved

non-staining water saturated material, which shall be kept wet and protected against sun and

wind for a period of 12 hours. Thereafter, the patched area shall be kept continuously wet by a

fine spray or sprinkling for not less than 10 days.

13.3 The use of an epoxy for bonding fresh concrete used for repairs shall be permitted at the

discretion of the Site-in-charge. Epoxy shall be applied in strict accordance with the

instructions of the manufacturer.

14.0 CEMENT WASH

If instructed by the Site-in-charge, the Contractor shall provide one coat of cement wash over

the concrete surfaces of foundation, pipe racks, columns, walls etc. which are not plastered.

Forms for concrete shall be of plywood or steel as directed by the Sitein-charge and shall give

smooth and even surface after removal thereof. If it is desired by the Site-in-charge, the

Contractor shall prepare, before commencement of actual work, design and drawings

forframework and get them approved by the Site-in-charge.

15.1 FORM REQUIREMENT

The formwork shall be true, rigid and adequately braced both horizontally as well as

diagonally. The forms shall have smooth and even surface and be sufficiently strong to carry

without deformation the dead weight of the green concrete, working load, wind load and also

the side pressure exerted by the green concrete. As far as practicable, clamps shall be used to

hold the forms together. Where use of nails is unavoidable minimum number of nails shall be

used and these shall be left projecting so that they can be easily withdrawn. Form joints shall

not permit any leakage. The formwork shall be strong enough to withstand the effect of

vibrations practically without any deflection, bulging, distortion or loosening of its

components. Forms for beams and slabs (span more than 6.0 m) shall have camber of 1 in

so as to offset the deflection and assume correct shape and line after deposition of concrete.

For cantilevers, the camber at free end shall be 1/100th of the projected length.

15.2 INSPECTION OF FORMS

Before concrete is placed, all forms shall be carefully inspected to ensure that they are properly

placed, sufficiently rigid and tight, thoroughly cleaned, properly treated and free from foreign

material. The complete formwork shall be inspected and approved by the Sitein- charge before

the reinforcement bars are placed in position. When forms appear to be unsatisfactory in any

way, either before or during the placing of concrete, the work shall be stopped until the defects

have been corrected as per the instructions of the Site-in-charge.

15.3 TREATMENT OF FORMS

The surfaces of forms that would come in contact with concrete shall be well treated with

approved non-staining release agents such as soft soap, oil, emulsions etc. Care shall be taken

that such release agents are kept out of contact with the reinforcement.

15.4 REUSE OF FORMS

Before reuse, all forms shall be thoroughly scrapped, cleaned, examined and when necessary

repaired and retreated before resetting. Formwork shall not be reused, if declared unfit or un-

serviceable by the Site-in-charge.

15.5 REMOVAL OF FORMS/ STRIPPING TIME

In the determination of time for removal of forms, consideration shall be given to the location

and character of the structures, the weather and other conditions including the setting and

curing of the concrete and material used in the mix. Forms and their supports shall not be

removed without the approval of the Site-in-charge. Methods of form removal likely to cause

overstressing or damage to the concrete shall not be adopted. Supports shall be removed in

such a manner as to permit the concrete to uniformly and gradually take the stresses due to its

own weight. In normal circumstances and where ordinary Portland cement is used, forms may

generally be removed after expiry of following periods and as per IS:456,

(1) Walls , columns and vertical faces 24 to 48 hrs as may of all structural members be decided

by the Site-in-charge.

(2) Slabs (props left under) 3 days.

(3) Beam Soffits (props left under) 7 days

(4) Removal of props under slabs :

Spanning up to 4.5 M 7 days.

Spanning over 4.5 M 14 days.

(5) Removal of props under beams and

Spanning upto 6 M 14 days

Spanning over 6 M and upto 9M 21 days

Over 9 M 28 days

15.6 STAGING/SCAFFOLDING

Staging/Scaffolding shall be properly planned and designed by the Contractor. The Contractor

shall get it reviewed by Site-in-charge before commencement of work.

16.0 REINFORCEMENT

Reinforcement shall be cut, bent to shape and dimensions as shown in the bar bending

schedules/drawings. In normal course the bar bending schedule shall be supplied to the

Contractor, however, in case, bar bending schedule is not provided , the Contractor shall

develop the same at no extra cost to the Owner and get it reviewed by the Site-incharge. The

Contractor shall check the bar-bending schedule (issued by the Owner) prior to fabrication and

satisfy himself about the correctness of the same.

16.1 STRAIGHTENING, CUTTING AND BENDING

Procedure for cutting and bending shall be as given in IS:2502.

16.2 PLACING AND FIXING

All reinforcement shall be cleaned of mill scale, loose rust, oil, grease or any other harmful

material before placing them in position. All reinforcement shall be fixed in correct position

and shall be properly supported to ensure that displacement will not occur when concrete is

placed. The reinforcement bars shall be tied at every intersections by two strands of 16 SWG

black soft annealed binding wire.

16.3 OVERLAPPING

Only bars of full length shall be used as shown in the drawings. But where this can not be done,

overlapping of bars shall be done as directed by the Site-in-charge. Where practicable, the

overlapping bars shall not touch each other, but these shall be kept apart by 25 mm or

times the maximum size of the coarse aggregate whichever is greater. But where this is not

possible, the overlapping bars shall be tied with two strands of 16 SWG black soft annealed

binding wire. The overlaps shall be staggered for different bars and located at points along the

span where neither shear nor bending moment is maximum.

16.4 WELDED JOINTS

Welding of reinforcing bars shall not be permitted without the written permission of the Site-

in-charge. Where welding is permitted, it shall be in accordance with the recommendations of

IS:2751 and IS:9417. Welded joints shall be located at suitable staggered positions. Tests shall

be made to prove that the joints are of the full strength of the bars.

16.5 SUBSTITUTION

When specified diameter of reinforcement bars is not available, the Contractor shall use other

diameter of reinforcement bars on written approval of the Site-in-charge.

Cover to reinforcement shall be as indicated on the drawings and in their absence as per IS:456

or directed by the Site-in-charge.

17.0 PRECAST CONCRETE

17.1 Specifications contained in clauses above regarding concrete, formwork and

reinforcement shall apply in addition to the clauses given as under. The Contractor shall get

the precasting bed approved by the Site-in-charge prior to the start of the work.

17.2 Necessary lifting hooks of 12mm diameter MS rounds shall be provided for handling as

indicated in the drawing or as directed.

17.3 Unless otherwise specified, the exposed surfaces of precast members shall be finished

smooth with 1:3 (1 Cement: 3 Sand) cement mortar. Surface used, as walkways shall be given

a non-skid finish

18.1 PLAIN AND REINFORCED CONCRETE

Payment for plain and reinforced cement concrete (cast in-situ) shall be made on cubic meter

basis of the volume of the actual finished work done or as per approved construction drawings,

whichever is less and shall be inclusive of providing pockets, openings, recesses of all sizes,

chamfers, fillets construction joints, cement wash, curing etc. The rates shall be deemed to

include complete cost of taking and testing concrete cubes and carrying out other tests as per

specifications and as directed by Site-in-charge. The rate shall however be exclusive of

reinforcement, metal inserts,pipe sleeves, and formwork. Where the strength of concrete mix

(nominal or design) as indicated by tests, lies in between the strengths of any two grades and it

is accepted by the Owner/Site-in-charge, such concrete shall be classified as a grade belonging

to the lower of the two grades between which it lies. The concrete giving lower strength than

specified may be accepted at reduced rates after satisfying the safety of the structure by

checking it with devices such as impact hammer, load test etc. or rejected entirely at the

discretion of the Site-in-charge. The rejected concrete shall be dismantled at no extra cost to

the owner and no payment shall be made for the concrete so rejected and the formwork and

reinforcement used for the same . In case the concrete of lower strength can be improved by

carrying out some strengthening measures entirely at the discretion of the Site-in-charge, then

the said measures shall be carried out by Contractor at his own cost. If the Contractor is able to

make up the strength to the required grade by such improvement measures ,payment shall be

made for the grade achieved. However, if the strength of concrete is not made up to the strength

of required grade , then no payment whatsoever shall be made for any improvement measures

undertaken by the Contractor and payment shall be made only for the lower strength if accepted

by the Site-in-charge. Deductions for openings, pockets etc. shall be as specified in relevant

Indian Standard Codes.

Unless otherwise specified, payment for formwork shall be on square meter basis of the actual

area in contact with the concrete cast. The rates shall be inclusive of keeping the formwork for

the full period as specified in the above clauses and removing the same after the period

is over. No extra payment shall be made for providing scaffolding/staging.

Superior quality formwork for exposed/architectural concrete work shall be measured and paid

separately under the relevant item in the schedule of rates.

18.3 REINFORCEMENT

Payment for reinforcement bars shall be on the basis of weight in metric tons. The weight shall

be derived from the sizes and corresponding unit weights given in handbook of Bureau of

Indian Standards. Binding wire shall not be weighed nor otherwise measured. Measurements

for weight shall not include cutting allowance etc. Rate quoted for reinforcement should

include cost of supplying, decoiling, straightening, cleaning, cutting, bending, placing, binding,

welding if required and providing necessary cover blocks of concrete

18.4 PRE-CAST CONCRETE

Payment for precast concrete members shall be made on cubic metre basis of the volume of the

finished member. The rate quoted shall include cost of formwork, preparation of casting yard,

finishing as specified, curing, handling, fixing in position, breaking masonry and/or concrete

surfaces and making good the same etc. Reinforcement shall be paid separately under relevant

items. Lifting hooks shall be paid on the same basis as reinforcement . Metal inserts shall be

paid as per relevant clauses of Specification

18.5 DAMP PROOF COURSE (D.P.C)

Payment shall be made on square meter basis of the area laid inclusiveof formwork, curing,

providing and applying bitumen, supplying and spreading sand over bitumen etc.

SPECIFICATION FOR

1.0 CLASSIFICATION OF BRICK WORK

Bricks shall conform to IS:1077. Locally available best quality bricks with a minimum

compressive strength of 50 to 75 Kg/cm² conforming to the specification shall be used for

construction. The brickwork shall be classified as 50A class or 50-B class or 35 A class

(Locally available bricks) according to the classification of bricks used and the method of

laying. The sampling and testing of bricks shall be done in accordance with the procedure laid

down in IS :5454 and IS:3495 respectively.

2.0 CEMENT MORTAR

Cement Mortar shall be prepared by mixing cement, sand and water in specified proportions.

The mortar shall be used as soon as possible after mixing and before it has begun to set and in

any case within thirty (30) minutes after the water is added to the dry mixtures. Mortar unused

for more than 30 minutes shall be rejected and removed from the site of work.

2.1 PROPORTIONING

The unit of measurement for cement shall be a bag of cement weighing 50 kgs and this shall

be taken as 0.035 cubic meter (M3). Sand in specified proportion shall be measured on the

basis of its dry volume. In case of damp sand its quantity shall be increased suitably to allow

The mixing of mortar shall be done in mechanical mixer operated manually or by power. The

Site-in-charge may, however, relax this conditions at his discretion, taking into account the

nature and location of work, practicability of the use of these machines etc., particularly

keeping in view the utilization of mortar turned out in one operation of the mixer before its set

initially or where items involving small quantities are to be done or if, in his opinion, the use

of mixer is not feasible.

A) Mixing in Mechanical Mixer

Cement and sand in specified proportion shall be mixed dry thoroughly in a mixer. Water shall

then be added gradually and wet mixing continued for at least one minute. Care shall be

taken not to add more water than that which shall bring the mortar to the consistency of a stiff

paste. Only the quantity of mortar which can be used within 30 (thirty) minutes of its mixing

shall be prepared at a time. Mixer shall be cleaned with water each time before suspending

The measured quantity of sand shall be levelled on clean masonry platform and cement bags

emptied on top. The cement and sand shall be thoroughly mixed dry till the mixture is of a

uniform color. The quantity of dry mix, which can be used within 30 minutes, shall then be

mixed with just sufficient quantity of water to bring the mortar to the consistency of a stiff

3.0 PROCEDURE OF CONSTRUCTION

3.1 SOAKING OF BRICKS

Bricks shall be thoroughly soaked in clean water before use for at least two hours and until air

bubbles cease to come out. The soaked bricks shall be kept on wooden planks or bricks platform

to avoid earth being smeared on them. At the time of placing the bricks, they should be

Brickwork (one or more brick thickness) shall be laid in English Bond unless otherwise

specified. Half or cut bricks shall not be used except when needed to complete the bond. The

walls shall be taken up truly plumb; if battered, the batter is to be truly maintained. All courses

shall be laid truly horizontal and all vertical joints shall be truly vertical. The level and

verticality of the brickwork in walls shall be checked up at every one-metre interval.Brick shall

be laid with frogs upward. While laying, bricks shall be thoroughly bedded and flushed in

mortar and tapped into position with a wooden mallet and the superfluous mortar removed.

The walls of all structures shall be carried up regularly in all cases leaving no part one-meter

lower than another. If this cannot be adhered to, the brick work shall be raked back according

to bond (and not left toothed) at and angle not more than 45o but raking back should not start

within 60 centimetres of a corner. The brickwork shall not be raised more than 14 courses per

day. All iron fixtures, pipes, conduits, holdfasts of doors and windows etc. which are required

to be built in walls, shall be embedded in cement mortar or in cement concrete as specified, in

their correct position as the work proceeds.

Joints shall be restricted to 6 mm in 50 A class brick work and 10 mm in 50 B class and 35 A

class brick work. After the work the faces of the brickwork shall be cleaned (the very day, the

brick work is laid) with wire brush and all mortar droppings removed.

Green work shall be protected from rain by suitable covering. Masonry work as it progresses

shall be kept thoroughly well watered on all faces for al least 10 days after completion. The top

of masonry work shall be left flooded at the close of the day by forming fillet of mortar 40 mm

high round the edges of top course and filled with water.

4.0 SCAFFOLDING/STAGING

Staging/Scaffolding shall be properly planned and designed by the Contractor. The Contractor

shall get it reviewed by Site-in-charge before commencement of work.

5.0 HALF BRICK MASONRY

5.1 Brickwork shall be of half brick thickness and reinforced with 40 x 3 mm thick MS flats as

The work shall be done exactly in a similar manner as brickwork of one or more brick thickness

except that all courses shall be laid with stretchers. Before laying, the reinforcement bars shall

be straightened and thoroughly cleaned. Half the mortar thickness for the bedding joint shall

be laid first and then MS rounds embedded (one on each face of the brick work) maintaining a

side cover of 12 mm mortar. Subsequently the other half of the mortar thickness shall be laid

covering the reinforcement fully. The reinforcement bars shall be carried at least 150 mm into

the adjoining walls. At the junction of two walls, the brick shall, at each alternate course, be

carried into each of the respective walls so as to thoroughly unite the work. The brickwork shall

not be raised more than 14 courses per day. All required fixtures shall be embedded in cement

mortar or concrete as specified in their correct position as the work proceeds.

6.1 Payment for brick masonry work (of one or more brick thickness) shall be made on cubic

metre basis on the volume of actual work done.

6.2 Payment for half brick masonry work shall be made on square meter (M2) basis on the area

of actual work done and shall include cost of supplying and fixing reinforcement in position.

6.3 The rate of brick masonry work shall be inclusive of all labour, material, sampling and

testing, scaffolding/staging, soaking of bricks raking of joints, curing, providing recesses and

openings, embedding fixtures etc.

SPECIFICATION FOR

1.0 RANDOM RUBBLE MASONRY

Stone shall be of approved quality and type. It shall be hard, sound, uniform in colour and free

from decay and weathering. Unless otherwise approved, stones from one single quarry shall be

used for any one work. The length of the stone shall not exceed three times the height and the

breadth on base shall not be greater than 3/4 th the thickness of wall and not less than 15 cms.

The height of stone may beup to 30 cms.

Stone shall be hammer-dressed on the face, the sides and the beds. The "bushing" (projection)

on the face shall not project more than 40 mm on an exposed face and 10 mm on the face to be

All stones shall be wetted before use. The wall shall be carried up truly plumb or to specified

batter. Every stone shall be carefully fitted to the adjacent stones so as to form neat and close

joints. Stones may be laid at random without being brought upto any level courses except at

plinth, window sills and roof level. The bond shall be obtained by fitting in closely the adjacent

stones and by using bond stones. Face stones shall extend and bond well into the backing.

These shall be arranged to break joints as much as possible and to avoid long vertical

lines of joints. Hearting (interior filling) of the wall face shall consist of rubble stones with

thickness not less than 100 mm in any direction, carefully laid, hammered down with a wooden

mallet into position and solidly bedded in mortar. Chips and spawls of stones shall be used

wherever necessary to avoid thick mortar beds or joints and at the same time ensuring that no

hollow spaces are left anywhere in the masonry.The masonry in a structure shall be carried

regularly. Where the masonry of one part has to be delayed, the work shall be raked back at

an angle not steeper than 45 degree.

Bond or through stone running right through the thickness of wall shall be provided in the walls

having thickness upto 600 mm. If the walls are thicker than 600mm, two or more bond stones

overlapping each other by at least 150 mm shall be provided in a line from face to back.

Atleast one bond stone or a set of bond stones shall be provided for every 0.5 sq.m. of wall

Stones shall be so laid that all joints are fully packed with mortar. Facejoints shall be 20 mm

thick. The joints shall be struck flush and finished at the time of laying when plastering and

pointing is not required. If walls are to be plastered or pointed, joints shall be raked to a depth

of 20 mm (minimum) during the progress of work when the mortar is still green. For the faces

of walls that are not to be plastered, stone surfaces shall be cleared of mortar splashing to give

uniform appearance.

Payment for stone masonry work shall be made on cubic metre (M3) basis on the volume of

actual work done and the rates shall be inclusive of all labour, material, scaffolding/staging,

wetting out of stones, raking out joints, curing, providing recesses and openings, embedding

2.0 COURSED RUBBLE MASONRY

Stones shall be as specified in 1.1.

Face stones shall be hammer dressed and to be squared on all sides and joints so as to give

them approximately rectangular block shape. The bed joint shall be rough chisel dressed, true

and square for at least 60mm back from the face and the side joints for at least 40 mm, such

that no portion of the dressed surface is more than 6 mm from a straight edge placed on it. The

remaining portion of stones shall not project beyond the surface of the bed and side joints. The

"Bushing" on the face shall not project more than 40 mm on exposed face and 10 mm on

the face to be plastered.

All stones shall be wetted before use. The walls shall be carried up truly plumb or to specified

batter. All courses shall be laid truly horizontal and all vertical joints shall be truly vertical.

The stones shall be laid in horizontal courses and each course shall be of equal height. The

height of each course shall not be less than 150 mm and not more than 300 mm. Face stones

shall be laid as alternate headers and stretchers. Stones shall break joint atleast half the height

of the course. No face stone shall be less in breadth than its height and at least one third of the

stones shall tail into the work for length not less than twice their height. The hearting of interior

filling of the wall shall consist of flatbedded stones carefully laid on their proper beds or joints

of mortar and at the same time ensuring that no hollow spaces are left anywhere in the masonry.

Chips not more than 10% of quantity of stone masonry may be used where necessary to fill

interstices between adjacent stones to avoid thick beds or joints of mortar. The masonry in

structure shall be carried up regularly, but where breaks are unavoidable, the joint shall be

raked back at an angle not exceeding 45 degree.

Same as for random rubble masonry except that a bond stone or a set of bond stones shall be

inserted 1.5 to 1.8 m apart, in every course.

All bed joints shall be horizontal and all side joints vertical. All joints shall be full of mortar.

Face joints shall not be more than 10 mm thick. When plastering or pointing is not required to

be done, the joints shall be struck flush and finished at the time of laying. Otherwise the joints

shall be raked to a minimum depth of 20 mm during the progress of work when the mortar is

still green. The joint shall be either flush or struck. Raised or cut-pointing, shall be done with

cement mortar 1:3 using wooden mould/template of minimum 12 mm depth for uniformity.

SPECIFICATION FOR

PLASTERING AND POINTING

1. CEMENT PLASTERING

1.1 PREPARATION OF SURFACE

The surface to be plastered shall be thoroughly cleaned so that it is free from dust, dirt, oil,

salts, etc. On cement concrete surfaces, the surface shall be cleaned with wire brush and

scarified by lines with trowel. The surface in both cases shall be washed properly and kept wet

for 4 hours before plastering is commenced.

The mortar of specified mix shall be used.

1.3 APPLICATION OF PLASTER

Plaster shall be started from top and gradually worked down towards floor. It shall not, at any

place be thinner than specified. To ensure even thickness, plaster of about 15cm x 15cm shall

be first applied horizontally and vertically at not more than 2 metre interval over the entire

surface to serve as gauges. The surfaces of these gauged areas shall be truly in the plane of

finished plaster surface. The mortar shall then be laid on the wall or other surfaces between the

gauges and finished even. All corners shall be rounded to a radius of 25 mm unless otherwise

specified. The Contractor shall not be paid for any extra thickness of plaster done than as

specified. The plastering thicknesss hall generally be as under unless otherwise specified.

For internal wall - 12 mm thick in CM 1:4 External wall - 15 or 19 mm thick in CM 1:4 in two

coats For underside of roof - 6 mm thick in CM 1:3

Curing shall start 24 hours after the plaster is laid. It shall be kept were for 7 days. During this

period it shall be suitably protected from all damages at the Contractor's expenses by such

means as approved by the Site-incharge.

1.5 Any cracks which appear in the surface and all portions which sound hollow when tapped,

or are found to be soft or otherwise defective, shall be cut out in rectangular shape and redone

as directed by the Sitein- charge.

1.6 Wherever specified, standard water proofing compound as approved by the Site-in-charge

shall be added to the mortar at the rate of 3% or as specified by the manufacturer by weight of

Cement for which the rate shall be specified separately in the schedule of rates.

Payment for plastering shall be made on square metre basis, irrespective of particular thickness

of plaster. For openings of area less than 0.5 metre square no deduction and no payment shall

be made for jambs, sills, soffits etc. For opening of area between 0.5 sqm and 3.0 sqm. each

deduction shall be made at 50% of the opening area and no payment made for jambs, soffits

etc. For openings of area above 3 sqm.each , deduction shall be made for full area of opening

but Jambs, Soffits and Sills, shall be measured. All measurements shall be separately made for

each face. The rate of plastering shall include the cost of providing drip moulds/bands,

scaffolding, swing etc. needed for the work with labour and material all complete.

2.0 SAND FACE PLASTER

2.1 PREPARATION OF SURFACE

The surface to be plastered shall be thoroughly cleaned so that it is free from dust, dirt, oil, salts

etc. On cement concrete surfaces, the surface shall be cleaned with wire brush and scarified by

lines with trowel. The surface in both cases shall be washed properly and kept wet for 4 hours

before plastering is commenced.

2.2 Sand face plaster shall consist of two layers. The first layer generally 7mm average thick

cement plaster with cement mortar of 1:4 mix (1 cement : 4 sand) shall be rough finished. Over

this a second layer of average 13 mm thick of cement sand plaster in the proportion of 1:2 mix

shall be applied. The second layer of plaster shall be laid only after first layer has sufficiently

dried.The surface of sand plaster shall be finished rough with sponge or as directed by the Site-

The plaster shall be thoroughly cured for 7 days as directed by Site-incharge.

2.4 Any cracks which appear in the surface and all portions which sound hollow when tapped,

or are found to be soft or otherwise defective, shall be cut out in rectangular shape and redone

as directed by the Sitein- charge.

Payment for plastering shall be made on square metre basis, for the particular thickness of

plaster. Deduction shall not be made for Jambs, Sills and soffits measured for opening of area

less than 0.5 sqm. each. For opening of area between 0.5 sqm. and 3.0sqm. each, deduction

shall be made at 50% of the opening area and no payment made for jambs, soffits, sills etc. For

openings of area above 3 sqm. each, deduction shall be made for full area of opening but jambs,

soffits and sills shall be measured. All measurements shall be separately made for each face.

The rate shall include the cost of providing drip moulds/bands, scaffolding and swing etc.,

needed for the work with labour and material all complete.

3.0 ROUGH CAST CONCRETE FACING/AGGREGATE

3.1 The surface shall be prepared as for cement plaster and then 2 cm backing coat of cement

mortar 1:3 (1 cement:3 sand) shall be applied. Subsequently a top coat, 13mm average thick of

cement and stone chips mixture in proportion 1:3 (1 cement : 3 stone chips10mm size and

below) shall be applied by throwing the mixture on top with trowel to produce uniform rough

Payment shall be made on square metre basis. The rate shall include the cost of scaffolding,

swing etc. With labour and material all complete.

4.1 TYPE OF POINTING

Pointing shall be of the type specified such as "Flush", "ruled" and "Raised and cut" etc.

4.2 PREPARATION OF SURFACE

The Joints shall be brushed clean of dust with wire brush and wetted thoroughly for 6 hours

before pointing is commenced.

Mortar of specified mix shall be used conforming to the schedule of rates.

4.4 APPLICATION & FINISHING

The mortar shall be pressed into raked out joints with pointing trowel and finished either flush,

sunk or raised according to type of pointing specified in the drawings or as directed. The

superfluous mortar shall be cut off from the edges of the lines and the surface of masonry shall

be cleaned of all mortar finish to be free of slack spots, cut faces and other blemishes. Finished

work of pointing shall be to exact size and shape stipulated and edges shall be straight, neat

The pointing shall be kept wet for 7 days. During this period it shall be suitably protected from

Payment shall be made on basis of area of brick wall pointed with deductions for voids as per

clause 1.7. The rate shall include cost of all material and labour involved in all the operations

including the cost of scaffolding etc. Required for work.

4.7 POINTING ON RANDOM RUBBLE STONE MASONRY

In recessed pointing, the mortar shall be simply struck off with a trowel and the work left

showing the natural irregularities in line and surface of the stones themselves. Other

specification shall remain as above for pointing. In case of raised pointing, it shall project from

the well facing with its edges cut parallel so as to have a uniformly raised band about 6mm

raised and width 10mm or more as directed showing the natural irregularities in line and surface

of stones themselves. Other specifications shall remain same as per above specifications of

Payment shall be made on square metre basis of the surfaced pointed with deductions for voids

as per clause 1.7. The rate shall include cost of all materials and labour involved in all the

operations including the cost of scaffolding etc. required for the work.