1.交通运输部公路科学研究院;2.中交一公局第四工程有限公司南宁分公司
中央级公益性科研所基本科研业务费专项资金项目（2019-9014）
1.research institute of highway, ministry of transport.;2.CCCC First Highway Engineering Co., Ltd. Nanning Branch
为消除石灰岩机制砂对路面混凝土抗盐冻性能影响的疑虑,对比研究了不同石粉含量石灰岩机制砂对C30和C50两组强度等级路面混凝土抗盐冻性能的影响规律。结果表明：石灰岩机制砂中含有适量的石粉可以改善机制砂混凝土的力学性能和抗盐冻性能,当石粉含量为7%~10%时,C30路面混凝土具有最佳的抗盐冻性能,而C50路面混凝土最适宜的石粉含量为3%~5%,同时,石灰岩机制砂中石粉含量对混凝土饱水度和抗CaCl2和NaCl化学侵蚀性能进一步证实石粉的微集料作用,在适量的石粉情况下,提升了混凝土的密实性,降低了混凝土的饱水率,提高了混凝土抗盐冻性能。
In order to eliminate doubts about the impact of limestone manufactured sand on the deicer-salt resistance of pavement cement concrete, a comparative study was conducted on the influence of limestone manufactured sand with different micro-fines contents on the deicer-salt resistance of pavement cement concrete, using C30 and C50 strength grades as benchmarks. The results showed 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 cement concrete has the most suitable micro-fines content of 3%~5%. At the same time, the micro-fines content in limestone manufactured sand further confirms the micro aggregate effect of micro-fines on the water saturation and resistance to CaCl2 and NaCl chemical erosion of concrete. With an appropriate amount of stone powder, the compactness of concrete is improved, the degree of water-saturation of cement concrete is reduced, and the deicer-salt resistance of cement concrete is improved.
