Methodology for Waterproofing of Pu Waterbound Grout RequireThe particle size of OPC cement is 9.5 micron which is higher than 1 neno micron. The cement will fill up the capillary up to 9.5 micron and the remaining capillary track will remain unfilled. In the due course by the time when water passes through this track it increases the size of hole. Hence, we grout the whole surface by “PU WATERBOUND ” to resolve the problem as per Cement grouting method by prescribed above by Hydraulic injection pressure machine @ 60 PSI.
Concrete is naturally porous typically 10 to 18 percent air (extremes 2-60%). to make concrete "workable" a water/cement ration of 0.45-0.50 is used but cement only needs 0.25 w/c ratio for hydration. as concrete cures, the surplus water escapes to its surface where it evaporates. this bleeding water leaves a network of tiny capillaries pores. we cannot see the pores. their size ranges from 3nm (millionths of a part mm size) to 0.1mm (the diameter of a human hair ) .
the median is about 1 micron (1,000nm) but a water molecule is 3,000 times smaller (0.28 nm) by all logic, concrete should leak like a sieve so, what holds the water back? not the concrete but the physics of water it self. although not as viscous as molasses, it takes pressure to push water through dry microscopic pores. surface tension holds the blob of water inside the dry pore until its surface gets wet. but add a little water pressure during occasional rain storms or condensation on the interior and after a while, the pores gets wet and the concrete starts leaking. concrete is hygroscopic, it attracts water by sorption and once wet, the pores draw in ground water by wicking (capillary suction). but nothing holds back gases-invisible water vapor and gases flow right through the pores.)