石灰岩机制砂石粉含量对混凝土抗盐冻性能的影响

Effect of Micro-fines Content of Limestone Manufactured Sand on Deicer-Salt Resistance of Concrete

摘要:

为消除石灰岩机制砂对混凝土抗盐冻性能影响的疑虑，对比研究了石灰岩机制砂中石粉含量为0%、3%、5%、7%、10%、15%、20%时混凝土的抗盐冻剥蚀性能。结果表明：机制砂中存在一定量的石粉可以提高机制砂混凝土的力学性能和抗盐冻性能，C30路面混凝土的最佳石粉含量为7%~10%，C50路面混凝土的最佳石粉含量为3%~5%；混凝土的饱水度随着机制砂中石粉含量的增加而降低，石粉未降低混凝土的抗氯盐化学侵蚀性能，进一步表明石灰岩机制砂中的石粉不会降低混凝土的抗盐冻性能。

Abstract:

In order to eliminate doubts about the effect of limestone manufactured sand on the deicer-salt resistance of cement concrete， a comparative study was conducted on the influence of limestone manufactured sand with micro-fines content of 0%， 3%， 5%， 7%， 10%， 15% and 20% on the deicer-salt resistance of concrete. The results show that the appropriate amount of micro-fines in limestone manufactured sand can improve the mechanical properties and deicer-salt resistance of manufactured sand concrete. When the micro-fines content is 7%-10%， C30 pavement concrete has the best deicer-salt resistance， while C50 pavement concrete has the most suitable micro-fines content of 3%-5%. Moreover， the degree of water-saturation in concrete decreases as the micro-fines content in the manufactured sand increases， and the micro-fines in the manufactured sand does not reduce the concrete’s resistance to chloride salt chemical erosion， further indicating that the micro-fines in the limestone manufactured sand does not lower the deicer-salt resistance of concrete.