再生混凝土抗压强度试验及回归分析

Experimental and Regressive Analysis on Compressive Strength of Recycled Concrete

为了研究再生混凝土抗压强度的影响因素,进一步确定抗压强度与影响因素之间的关系模型,采用实验室废弃C30混凝土试块制备成连续粒径级配的再生骨料(5~31.5mm),用这种再生骨料部分取代天然骨料配制的混凝土试样进行抗压强度试验,考察因素包括:水灰比、再生粗骨料取代率、龄期及其交互作用因素,选用正交表L27(313)安排试验。结果表明,影响再生混凝土抗压强度的主要因素是龄期,其次为再生粗骨料的掺入量,最后为水灰比;而交互作用因素的影响为:粗骨料取代率与水灰比交互作用影响最大,龄期与粗骨料取代率的交互作用影响最小。对正交试验结果采用回归理论分析,建立了影响再生混凝土抗压强度因素的非线性回归模型,并结合方差分析,对回归方程显著性进行了检验。

In order to study influencing factors of compressive strength on recycled concrete and relational model between concrete compressive strength and influencing factors,recycled coarse aggregate in the range of 5 31. 5 mm was obtained from waste samples of C30 in the laboratory through dealing and orthogonal table L27（ 313） was adopted to arrange the test by fully taking into account of these factors influencing cube compressive strength on recycled concrete such as water-cement ratio,the replacement of recycled coarse aggregate,the age,and the interaction between one factor and the other. The results indicate that the main factor affecting the compressive strength of recycled concrete is the age,the replacement of recycled coarse aggregate,and water-cement ratio. The order of the interaction function is as follows： the replacement rate and water-cement ratio,water-cement ratio and the age,the replacement rate and the age. Based on orthogonal test results and regression analysis,the equation was established by these factors mentioned above. According to analysis of variance,regression equation was examined.