全珊瑚海水混凝土配合比设计及评价方法

Mix Proportion Design and Evaluation Approach of Coral Aggregate Seawater Concrete

针对南海岛礁大规模海防工程建设过程中资源短缺的问题,设计地域适用性较强的全珊瑚海水混凝土。通过正交试验方法和基于信噪比的田口方法,研究总胶凝材料用量、预吸水率、砂率和净水胶比对全珊瑚海水混凝土抗压强度的影响;验证田口方法的优越性,确定各因素对全珊瑚海水混凝土抗压强度的影响程度,并加以量化;提出多因素共同作用下全珊瑚海水混凝土抗压强度的多元非线性回归模型。结果表明:基于信噪比的田口方法优于传统正交试验方法。最优全珊瑚海水混凝土设计组合为:总胶凝材料用量550 kg·m^-3,预吸水率5%,砂率50%,净水胶比0.25;各因素影响程度从大到小依次为:预吸水率、净水胶比、砂率和总胶凝材料用量。预吸水率的贡献率最大,为67.6%;净水胶比次之,为17.8%;砂率的贡献率较小,仅为0.7%。回归模型的建立对指导制备高强全珊瑚海水混凝土具有十分重要的意义。

For the sake of relieving the resource shortage in the construction of large-scale coastal defense projects in reef of the South China Sea, coral aggregate seawater concrete (CASC) with better regional applicability was designed. We employed the orthogonal test and the signal-to-noise ratio (SNR) based Taguchi method to explore the impact of total cementitious material content, pre water absorption rate, sand rate and net water to binder ratio on compressive strength of CASC. Then we verified the superiority of Taguchi method, confirmed and quantified the influe- nce degree of various factors on compressive strength of CASC, proposed a multivariate nonlinear regression model on compressive strength of CASC. The results show that the SNR based Taguchi method exhibited great superiority to conventional orthogonal test. The optimum design parameters of CASC turned out to be the total cementitious material content of 550 kg·m^-3 , pre water absorption rate of 5%, sand rate of 50%, and net water to binder ratio of 0.25. The influence degree of pre water absorption, net water to binder ratio, sand rate and total cementitious material content on CASC decreased successively. Specifically, the contribution of pre water absorption rate accounted the largest proportion (67.6%), followed by net water to binder ratio (17.8%), and sand rate (0.7%). The establishment of regression model show exceeding significance to guide the preparation of high-strength CASC.