连续配筋混凝土多指标配合比设计方法

采用MEPDG软件分析了连续配筋混凝土路面路用性能对于混凝土抗压强度、干缩应变、温缩系数等参数的敏感性。通过室内试验研究了水泥用量、水灰比等混凝土配合比组成参数对路面设计参数的影响。根据均衡设计的理论, 建立了连续配筋混凝土多指标配合比设计方法, 推荐了各配合比组成参数的范围, 并建立了水灰比与混凝土干缩应变、温缩系数间的回归方程及弯拉强度与抗压强度间的关系式。分析结果表明:连续配筋混凝土配合比设计的控制指标宜包括抗压强度、干缩应变和温缩系数, 水泥浆含量宜小于22%, 最大公称粒径宜为19.0~26.5mm。根据多指标的配合比设计方法得到的混凝土能更好地满足连续配筋混凝土路面的性能要求。

Mix proportion design method with multiple indexes for continuously reinforced concrete

The sensibilities of continuously reinforced concrete pavement (CRCP) performances on concrete parameters such as compressive strength, drying shrinkage strain and temperature shrinkage coefficient were analyzed by using MEPDG software. The influences of mix proportion parameters of cement content, water-cement ratio etc on pavement design parameters were studied through laboratory tests. According to balanced design theory, the mix proportion design method with multiple indexes for continuously reinforced concrete was set up. The appropriate scopes of mix proportion parameters were recommended, the regression formulae of water-cement ratio with drying shrinkage strain and temperature shrinkage coefficient were established, and the formula of flexural-tensile strength and compressive strength was also established. Analysis result indicates that compressive strength, drying shrinkage strain and temperature shrinkage coefficient are fitted to be control indices of mix proportion design method for continuously reinforced concrete. The mass content of cement slurry should be less than 22%. Nominal maximum aggregate size should be 19.0-26.5 mm. It is shown that the concrete designed according to the mix proportion design method with multiple indexes can better satisfy the performance requirement of CRCP.