用粉煤灰改善石灰石粉混凝土的氯离子扩散性

Effects of Fly Ash on the Chloride Diffusivity of Concrete with Limestone Powder

采用RCM法测定混凝土试件的氯离子扩散系数,研究了石灰石粉单掺以及粉煤灰和石灰石粉双掺对混凝土抗氯离子渗透性能的影响.结果表明,混凝土中掺入石灰石粉对其抗氯离子渗透不利;粉煤灰能有效降低石灰石粉混凝土的氯离子扩散系数,提高其抗氯离子渗透能力;当混凝土中石灰石粉掺量为20%时,粉煤灰改善混凝土抗氯离子渗透性能的最佳掺量为20%.

In this paper, the effects of the addition of limestone powder and the mixed addition of limestone powder and fly ash on the chloride diffusivities were studied, by using RCM method. The results indicate that the chloride diffusion coefficients of concretes increase with the increasing of the replacement of the limestone powder. The addition of fly ash can effectively decrease the chloride diffusion coefficients of the concretes with limestone powder, thus improving their ability to counter chloride diffusion. The best improved ability for countering chloride diffusion is reached with the addition of 20% limestone powder as well as 20% fly ash.