STUDY OF HYDRATION AND CHLORIDE BINDING PROPERTIES OF SLAG-BLENDED CEMENT WITH DIFFERENT BLENDING RATIOS

摘要

In this study, after investigating several factors, it can be concluded that slag that is blended in Portland cement showsdifferent degree of reaction under different blending ratios, w/b, and curing temperatures, influencing the strengthdevelopment and chloride binding capacity. The degree of reaction tends to decrease as the blending ratio increases,contributing to the low strength at early age under 20°C curing. It can be compensated by increasing curing temperature.Slag blend performance up to 70% are good in case of 0.5w/b and 40°C, with quite near strength to OPC at early age.Among all, 20% and 50% slag blend perform better at 40°C curing temperature irrespective of w/b ratio. Regarding tochloride binding, at w/b 0.5, the capacity of slag blend is higher than OPC, but does not increase proportionally withincreasing slag ratio. At higher slag ratio, chemically bound chloride tends to increase more significantly than physicallybound. This is probably because of the aluminum in slag. The physically bound chloride, on the other side, tends to decreaseabove the slag ratio 50%, probably because of the low degree of reaction and less amount of C-S-H.