不同掺合料对C80机制砂混凝土性能的改善效果分析

Analysis of improvement effect of different admixtures on the properties of machine-made sand C80

为推动机制砂在高强高性能混凝土中的工程应用,开展了石灰石粉、微珠粉等活性掺合料对机制砂高强高性能混凝土性能的影响研究。研究表明:石灰石粉可显著改善C80机制砂混凝土的工作性,其力学性能早期发展较快,且具有较高的弹性模量。机制砂混凝土的劈裂抗拉强度、轴心抗压强度与抗压强度的比值分别为0.065、0.88,机制砂制备的高强混凝土脆性并没有发生显著变化。活性掺合料可显著降低机制砂高强混凝土的氯离子扩散系数,且石灰石粉与矿渣粉和硅灰混掺对高强混凝土抗氯离子侵蚀性能的提升效果更佳。

To promote application of machine-made sand in high strength and high performance concrete,the influence of active admixtures(such as limestone powder,microsphere powder)on the performance of machine-made sand high strength and high performance concrete were studied.The results show that limestone powder can significantly improve the workability of C80 concrete.Mechanical properties of C80 concrete developed rapidly in early stage,and had higher elastic modulus.The ratio of splitting tensile strength and axial compressive strength to compressive strength of machine-made sand were 0.065 and 0.88.The brittleness of machine-made sand concrete did not change significantly.Active admixture can significantly reduce chloride diffusion coefficient of mechanical sand concrete,the effect of mixing limestone powder with slag powder and silica fume on the improvement of chloride ion erosion resistance of mechanical sand concrete was better.