石灰石粉对不同强度等级混凝土性能的影响

Effect of limestone powder on properties of concrete with different strength grades

以石灰石粉等质量替代粉煤灰、超细粉煤灰,研究石灰石粉替代率对C30、C80混凝土工作性能、抗压强度及抗氯离子渗透性能的影响。结果表明,对C30混凝土,石灰石粉替代率为40%时,可以改善混凝土的流动性,混凝土60 d抗压强度较基准组提高了5.8%,电通量较基准组减小了46.1%。对C80混凝土,掺入石灰石粉会降低其7、28 d抗压强度,石灰石粉替代率为100%时,混凝土28 d抗压强度较基准组降低17.5%,电通量较基准组增大21.2%。掺入石灰石粉对C30、C80混凝土抗压强度和抗氯离子渗透性能呈现出截然相反的效果,石灰石粉更适合应用于低强度等级的混凝土,且替代率宜为40%。

Replace fly ash and ultrafine fly ash with limestone powder of equal mass,and study the effect of the limestone powder replacement rate on the workability,compressive strength,and chloride ion penetration resistance of C30 and C80 concretes.The results show that for C30 concrete,when the replacement rate of limestone powder is 40%,it can improve the fluidity of the concrete.The 60 d compressive strength of the concrete increased by 5.8%compared to the control group,and the electric flux decreased by 46.1%compared to the control group.For C80 concrete,the addition of limestone powder reduces its 7,28 d compressive strength.When the replacement rate of limestone powder is 100%,the 28 d compressive strength of the concrete decreased by 17.5%compared to the control group,and the electric flux increased by 21.2%compared to the control group.The addition of limestone powder has completely opposite effects on the compressive strength and chloride ion penetration resistance of C30 and C80 concretes.Limestone powder is more suitable for application in concrete with low strength grades,and the replacement rate should be 40%.