椰壳纤维再生混凝土抗折强度试验研究

摘要

Coconut fibers recycled concrete is mixed by use of orthogonal test,the best mix proportion for breaking strength is obtained.Comparison is done to the reference concrete which is not added into coconut fibres.The stepwise regression equation for breaking strength is founded,microanalysis for destroyed concrete is done.Five factors are selected,they are recycled aggregate dosage, fly ash substitution amount,super-plasticizer water-binder ratio.The result shows that the most important factor in five factors which affect concrete breaking strength is water binder ratio,the breaking strength for recycled concrete improves more than reference concrete. The precision of stepwise equation is very high,R=0.917,it can be used to predict the strength of recycled concrete.According to microanalysis,it is found that coconut fibers combine with recycled concrete very close,breaking strength improves very obviously.The workability and strength of recycled concrete mixed by the more excellent mix proportion can satisfy the quality request of general engineering.%采用正交试验方法进行设计配制椰壳纤维再生混凝土,选择了配制椰壳纤维再生混凝土抗折强度的最优配合比,和未掺加椰壳纤维的基准混凝土进行比较.建立了抗折强度逐步回归分析方程,并对破坏后的混凝土进行微观分析.试验结果表明,在再生骨料取代量、粉煤灰取代量、椰壳纤维掺量和水胶比、高效减水剂五个影响因素中,对再生混凝土28 d抗折强度的影响最主要的影响因素是水胶比.再生混凝土的抗折强度比基准混凝土提高较多;所建立的逐步回归分析方程精度高,R=0.917,可用于拟合预报再生混凝土的抗折强度.通过微观分析,发现再生混凝土和椰壳纤维结合紧密,抗折强度提高显著.经正交试验确定的最佳配合比设计的再生混凝土和易性和强度均能满足一般工程要求.