冻融环境下煤矸石混凝土毛细吸水性能

摘要

The capillary water absorption of coal gangue concrete(CGC) and ordinary concrete(OC) was studied under the action of freeze-thaw,and ASTM C1585-13 was introduced to measure the water absorption rate of hydraulic cement concrete.The effects of freeze-thaw cycles and coal gangue replacement rate on the capillary water absorption of CGC were analyzed,and the prediction model of the initial water absorption rate of CGC under the action of freeze-thaw was established.Results show that with the increase of the coal gangue replacement rate under the same freeze-thaw environment,or with the increase of the freeze-thaw cycles number under the same coal gangue replacement rate,the cumulative water absorption,the initial water absorption rate and the capillary water-absorbing capacity will all increase respectively;the capillary water-absorbing capacity of CGC is greater than OC;the CGC has a strong response to freezethaw cycles.The predict model of the initial water absorption rate of CGC under the freeze-thaw environment was established by regression analysis,which has a relatively high computation precision.The model can be used to predict the capillary water absorption properties of CGC,which provides theoretical support for the research on frost resistance of CGC.%采用ASTM C1585-13测量水硬水泥混凝土吸水率的标准试验方法,研究了煤矸石混凝土(CGC)和普通混凝土(OC)在冻融环境下的毛细吸水性能,分析了冻融循环作用及煤矸石取代率对CGC毛细吸水性能的影响机理,建立了冻融环境下CGC初始毛细吸水率预测模型.结果表明:冻融环境相同时,煤矸石取代率越大,CGC的累积吸水量就越大,初始毛细吸水率也越快,毛细吸水性能越强;冻融环境不同时,冻融循环次数越多,相同煤矸石取代率的CGC累积吸水量越大,初始毛细吸水率越快,毛细吸水性能越强;CGC的毛细吸水能力比OC强;CGC对冻融循环作用响应强烈.通过回归分析建立的冻融环境下CGC初始毛细吸水率预测模型计算精度较高,可用于预测CGC的毛细吸水性能,为CGC的抗冻耐久性研究提供理论依据.