掺加辅助胶凝材料高性能混凝土抗压强度研究

Study on Compressive Strength of High Performance Concrete with Auxiliary Cementitious Materials

采用激光粒度仪分析矿渣粉与粉煤灰的颗粒级配,使用二元线性回归法对二者的掺配比例进行优化,形成微观级配上无限接近最优密实度分布的辅助胶凝材料。将这种辅助胶凝材料按照高性能混凝土设计原则,采用不同水胶比、不同掺量进行混凝土试配和成型,并检测其工作性和力学性能,同时将其与单纯使用P·O 42.5普通硅酸盐水泥的混凝土对比。由结果可知,在水胶比低于0.40的情况下,使用P·O 42.5普通硅酸盐水泥和上述辅助胶凝材料时,按28d为标准设计龄期,混凝土强度可以满足C25~C75的设计要求。同时,和完全使用P·O 42.5普通硅酸盐水泥的混凝土进行比较,掺30%辅助胶凝材料的高性能混凝土在强度上基本都高于完全使用纯水泥的混凝土,实现了等量甚至超量替代,且在价格上辅助胶凝材料的价格低于普通硅酸盐水泥。

The particle size distribution of slag powder and fly ash is analyzed by laser particle size analyzer,and the mixing ratio of slag powder and fly ash is optimized by binary linear regression method to form an auxiliary cementitious material which is infinitely close to the optimal density distribution in the micro gradation.According to the design principle of high-performance concrete,this auxiliary cementitious material is used for concrete trial mixing and molding with different water cement ratio and different mixing amount,and its workability and mechanical properties are tested.At the same time,it is compared with the concrete using ordinary Portland 42.5 cement.According to the experiment,when the water binder ratio is lower than 0.40,when the ordinary Portland 42.5 cement and the above auxiliary cementing materials are used,the concrete strength can meet the design requirements of c25-c75 according to the standard design age of 28d.At the same time,compared with the concrete completely using ordinary Portland 42.5 cement,the high-performance concrete mixed with 30% auxiliary cementitious materials is basically higher in strength than the concrete completely using pure cement,achieving equal or even excessive replacement.In terms of price,since the price of auxiliary cementitious materials is lower than that of ordinary Portland cement.