机制砂的级配对超高性能混凝土性能的影响

Effect of gradation of mechanical sand on the performance of ultra-high performance concrete

随着超高性能混凝土在建筑领域的应用增多,其成本较高问题逐渐突出。为降低超高性能混凝土成本,利用机制砂配制超高性能混凝土,研究机制砂的级配对超高性能混凝土力学性能及微观形貌的影响。结果表明:采用机制砂可配制出工作性能良好,28 d抗折、抗压分别大于30、160 MPa的试样;机制砂与水泥石基体结合紧密,钢纤维在水泥石基体中分布均匀,致密均匀的结构使试样的力学性能得到较大的提高。

With the increase in the application of ultra-high performance concrete(UHPC)in the construction industry,the high cost of UHPC has gradually become a prominent problem.In order to reduce the cost of UHPC,the UHPC was prepared by using mechanical sand and the effects of gradation of manufactured sand on the mechanical properties and the micromorphology of UHPC were studied.The results showed that the samples with good workability can be prepared by using the machine-made sand,and the 28 days flexural and compressive strength ofthe samples were greater than 30 MPa and 160 MPa,respectively.In addition,the mechanical sand is tightly combined with the cement stone matrix and the steel fibersare evenly distributed in the cement stone matrix.Accordingly,the compact and uniform structure greatly improves the mechanical properties of the samples.