Strengthening Roof Slab of main academic building (Electrical, Civil, Humanities and Mathematics Deptt.) of Assam Engineering College, Guwahati under SOPD-G during the year 2024-25

Amount

Demolishing cement concrete manually/ by mechanical means including disposal of material within 50 metres lead as per direction of Engineer - in - charge. Nominal concrete 1:3:6 or richer mix (i/c equivalent design mix)

Providing and inserting 12mm dia galvanised steel injection nipple in honey comb area and along crack line including drilling of holes of required diametre (20mm to 30mm) up to depth from 30mm to 80mm at required spacing and making the hole & crack dust free by blowing compressed air, sealing the distance between injection nipple with adhesive chemical of approved make and allow it to cure complete as per direction of Engineer-In-Charge

Providing and injecting approved grout in proportion recommended by the manufacturer into cracks/honey-comb area of concrete/ masonry by suitable gun/pump at required pressure including cutting of nipples after curing etc. complete as per directions of Engineer-inCharge Stirrer mixed Acrylic Polymer of approved make @ 2% of weight of cement used) modified Cement slurry made with non shrink compound in concrete/RCC work

Epoxy injection grout in concrete/RCC work of approved make

Grading roof for water proofing treatment with Cement concrete 1:2:4 (1 cement : 2 coarse sand :4 graded stone aggregate 20mm nominal size)

Providing and fixing to the inlet mouth of rain water pipe cast iron grating 15 cm diameter and weighing not less than 440 grams.

Polyurethane based waterproofing system Base preparation 1. Providing and laying water proofing treatment to horizontal and vertical surfaces of podium slabs, including cleaning the surface with wire brush, treating all surface cracks coving preparation at wall - slab joint and preparation of surface in all aspects to receive the waterproofing. 2- Application of Primer: Apply Epoxy based primer over well prepared surface at 150-200 gm per Sq.Mtr. 3-Providing and applying Single component moisture cured polyurethane Elastomeric liquid water proofing coating like Nitoproof 600 PF of Fosroc/ Aquarm WPU 1K(E) of MYK or equivalent to achive a DFT of 1 mm over the entire horizontal area extending upto 300mm on the parapet wall and then terminated. Sprinkling quartz sand @ 200 gm/m2 while second coat of PU coating is still tacky for providing mechanical grip to facilitate installation of plaster on the veriical walls. The membrane will have the following technical parameters: Tensile Strength : 2 N/mm2(ASTM D412) Elongation at break : 500 % (ASTM D412) Punture resistance : 90 N (ASTM D 4833) Adhesion to Concrete: >2.0 N/mm (ASTM D 903) 4- Providing and laying 150 Gsm Geo fabric membrane as separation layer