基于正交试验的再生骨料混凝土强度研究

研究不同影响因素对再生骨料混凝土强度的影响是再生骨料混凝土研究领域的主要方面之一,对实际工程应用有着重要的意义。采用三因素、三水平的正交试验设计方法对再生骨料混凝土的配合比进行了试验设计,分析了每个因素水平对再生骨料混凝土配合比的作用及各个水平之间的差异,探讨了水胶比、再生骨料掺量、超细粉煤灰掺量等试验因素对再生骨料混凝土强度的影响规律和机理,并与基准混凝土对比。试验结果表明:无论早期与后期,水胶比是影响再生骨料混凝土强度的最主要因素,也是最显著因素;掺粉煤灰再生骨料混凝土的拉压比与同强度等级的高强混凝土相比有所提高,抗裂性能有所改善。采用多元回归分析的方法,建立了再生骨料混凝土强度与水胶比、再生骨料掺量、超细粉煤灰掺量的经验公式。

Study on the strength of recycled aggregate concrete based on orthogonal experiment

An orthogonal experimental design method involving three factors and three factor levels is adopted for the mix design of recycled aggregate concrete(RAC),and the effect of each factor level on mix proportion of RAC and the difference between each factor levels are analyzed.The influence and mechanism of different experimental factor,which includes water-binder ratio,percentage of recycled aggregate and ultra-fine fly ash(UFA)content,on the strength of RAC is studied and compared with normal concrete.The experimental results indicate that water-binder ratio is the most principal and significant influencing factor on the strength of RAC,regardless of age.Compared with the normal concrete,ratio of the splitting tensile strength to the compression strength of recycled aggregate concrete with fly ash is increased,and the cracking resistance improved.An empirical relationship among the strength of RAC,the water-binder ratio,the percentage of recycled aggregate and UFA content is proposed by using multivariate regression analysis.