MODIFICATION OF NATURAL ZEOLITE AND ITS INHIBITING EFFECT ON THE EXPANSION OF ALKALINE SILICA REACTION

摘要

By modification of natural zeolite, the modified zeolite (MZ) with higher alkaline cations exchange capacity was produced, with which the concentration of soluble alkaline in concrete was decreased considerably, and the expansion due to alkali-silica reaction (ASR) was controlled. It was seen from ASTM C441 standard that the ASR induced expansion was less than 0.1% when cement was substituted with 5% of the modified zeolite, while the percentage of fly ash and blast furnace slag with the same result was about 25% and 40% respectively. Physical properties of cement with 5% of modified zeolite were also tested, normal consistency, setting time, bending and compressive strength all met the requirement of Chinese national standard.