The Effect of Temperature on the Expansions of Concrete Caused by Alkali-Aggregate Reaction
In this paper，the effect of environmental temperature on alkali-aggregate silica reaction (ASR) of the concrete using reactive coarse aggregate is described. The sodium hydroxide NaOH of 8.16kg/? is added to the concrete in order to accelerate ASR. The expansions caused by ASR of the concrete are measured at environmental temperature of 80℃ hot water，60℃ and 40℃ underwater and fog room，and 20℃ underwater for 180 days. And，ASR repression effects by lithium nitrite under different temperatures are also examined. As a result of this study，in case of concrete exposed in water at 80℃，the expansion of concrete caused by ASR occurred at earliest time，and reaction velocity was highest，too，but the quantity of expansion in the long term was smaller than that in case of concrete in water or fog room at 60℃ and 40℃. In case of concrete exposed in water at 20℃，the expansion of concrete did not occur. ASR repression effects caused by lithium nitrite were extremely large at all the temperatures.