机制砂掺量对水泥混凝土力学性能影响研究

Research on the influence of manufactured sand proportion on the mechanical properties of cement concrete

合理控制水泥混凝土的机制砂掺量是改善混凝土工作性能的有效措施。文章结合潍坊地区实际工程,研究机制砂掺量对水泥混凝土性能的影响,在相同水灰比下向天然河砂中掺配5种比例的机制砂,制备水泥混凝土试块,测试其和易性和抗压强度。结果表明:机制砂掺配比例为50%时,坍落度下降速率最快,初期坍落度相对于未掺配机制砂的混凝土减少了11.9%,1 h后坍落度减少了15.7%,但仍能满足坍落度要求;水泥混凝土7、28 d的抗压强度相对于未掺机制砂的水泥混凝土分别提高了约3.4%、5.5%;综合考虑和易性、抗压强度以及经济性,推荐机制砂掺配比例≤50%。

Reasonable control of the amount of manufactured sand in cement concrete is an effective measure to improve the performance of concrete.Based on the actual project in a certain area,this article studies the influence of the amount of manufactured sand on the performance of cement concrete.Under the same water-cement ratio,natural river sand is mixed with 5 kinds of manufactured sand for cement concrete test block,to test the workability and compressive strength of cement concrete.The results show that when the blending ration of manufactured sand is 50%,the slump decline rate is the fastest.The slump is initially reduced by 11.9%compared with the concrete without manufactured sand and then it is reduced by 15.7%after 1 hour,but it can still meet the slump requirements;the compressive strengths of 7 d and 28 d of cement concrete are increased by 3.4%and 5.5%,respectively,compared with cement concrete without manufactured sand.Considering workability,compressive strength and economy,it is recommended that the blending ratio of manufactured sand does not exceed 50%.