EFFECT OF SOME CHLORIDES ON THE PROPERTIES OF SAND-LIME PRODUCTS

The effect of some chlorides such as CaCl2, KCl and NaCl on the hardening of calcium silicate was studied. Compressive strength, bulk density and porosity of the products autoclaved at 16 atm for 6 h were determined. The rate of reaction was also followed by the determination of combined water, free lime and free silica contents and the hydrated phases were identified by DTA technique. The results showed that the compressive strength as well as bulk density decreased and the porosity increased by the addition of chlorides. The reacted silica and free lime contents decreased with an increase in amounts of NaCl and KCI, and free lime content increased with the increase of CaCl2. The combined water content decreased in the presence of the salts. The amount of combined water in the product was in the order CaCl2 greater-than-or-equal-to NaCl > KCI.