分别用粉煤灰、矿渣粉按比例等量取代部分水泥,制作混凝土试块,在覆膜状态下通入蒸汽养护,测试各龄期混凝土试块的抗压强度与劈拉强度。结果表明:在70℃覆膜蒸养条件下,随着粉煤灰掺量的增加同一龄期混凝土试块的抗压强度与劈拉强度均呈下降趋势,且试块养护7~28d的抗压强度增长率比脱模(9h)~3d强度增长更为明显;当粉煤灰掺量在10%~20%时劈拉强度下降较为平缓,掺量大于20%时劈拉强度的下降较为迅速;在相同的养护条件下,掺加矿渣粉对混凝土力学性能有先增大后减少的趋势,当取代率为20%时混凝土试块的抗压强度与劈拉强度均达到最大值,且矿渣粉取代率的改变量对劈拉强度的影响大于抗压强度。
With the fly ash and slag powder in proportion to replace part of cement,making concrete test block in the film under the state through the steam curing in order to test the age of concrete block compressive strength and splitting tensile strength.The results showed that at 70 ℃coated steam curing condition,with the increase of fly ash content at the same age,the concrete compressive strength and tensile strength were decreased,and the growth rate of compressive strength of 7-28 dwas more obvious than that of mold release to 3d;When the content of the powder coal ash was 10%-20%,the tensile strength decreased slightly,and the splitting tensile strength decreased rapidly when the dosage was greater than20%.Under the same curing condition,the mechanical properties of concrete increased first and then decreased.When the replacement ratio was 20%,the compressive strength and splitting tensile strength of concrete test block reached the maximum value and the change of the replacement rate of slag powder was greater than the compressive strength.