Post casting residual strength development of new generation inorganic binders using different South African silica sands

摘要

The paper investigates the performance of two local silica sands using a new generation modified sodium silicate binder. The binder is a water glass based system. It is used as a one-component liquid binder in the range between 1.5 and 3.0 mass %. The hardening can be realized with CO_2 gassing, liquid ester hardeners or with heat and heated air. Three curing methods of the sodium silicate were considered which CO_2, ester and heat are. The methodology followed consisted of sand characterization and residual strength measurement of strength specimen exposed to heat after curing. The test results revealed the profound influence of the sand properties on the residual strength of the sand. Because of the difference of properties of the two sands, they behave differently with the same sodium silicate binder.