THE EFFECT OF SODIUM CARBONATE ON ELEVATED TEMPERATURE RESISTANCE OF CEMENT MORTARS CONTAINING NATURAL ZEOLITE

Abstract

In this paper, the effect of sodium carbonate (Na2CO3) on the flexural and compressive strength of cement mortars containing natural zeolite subjected to high temperatures were examined. The results obtained from the tests were compared with the reference mortars. In the mortar mixtures, sand and water quantities were kept constant. Water/binder and sand/binder ratios were 0.5 and 3.0, respectively. In the mixtures, the crushed sand was used and ordinary Portland cement (OPC) was replaced with 5, 10, 15 and 20% natural zeolite by weight. For activation of zeolite, sodium carbonate having 7% Na dosage was used as an activator. The findings showed that the resistance of mortars subjected to high temperatures were dependent on the temperature level, and that the fire resistance of zeolite mortars was higher than that of mortar made with OPC only. Additionally, it was seen from the test results that Na2CO3 used for activation in zeolite mortars led to a decrease in the flexural and compressive strength values after the high temperatures.