WATERPROOFING OF PORTLAND-CEMENT MORTARS WITH A SPECIALLY DESIGNED POLYACRYLIC LATEX

Polymer modified portland cement mortars, with polymer/cement ratios up to 0,20 (w/w) have been studied, in respect to their mechanical and waterproofing characteristics. The polymer here developed, characterised by low water absorption, improves the workability, the flexural strength and the resistance to penetration of water and salt solutions of the modified mortars. These effects become remarkable over a certain amount of polymer (p/c ratios> 0,05). The air entrainement due to the polymer has a negative influence on the compressive strength but increases the freeze-thaw resistance. A comparison with the traditional superplasticizers and waterproofing admixtures, which impart hydrophobic properties to hardened mortars and concretes is also presented.