新型装配式GRC-PC复合墙板收缩试验与应力分析

Shrinkage experiment and stress analysis on the new type of pre-fabricated GRC-PC composite wallboard

为探究GRC-PC复合墙板的收缩性能,通过浇筑纯GRC墙板与3组GRC-PC复合墙板,连续监测、记录其收缩应变并进行对比分析。根据试验结果,计算墙板的表面应力,并校核墙板抗裂性能。研究表明复合墙板在进入收缩阶段后,GRC板会受到混凝土的约束作用,收缩应变值远小于自由收缩的GRC板,减小幅度超过了70%;混凝土内埋入钢丝网片、增大墙板尺寸和室内温湿度都会在不同程度上影响复合墙板的收缩应变;3组复合墙板的表面最大应力分别为4.24,6.13,8.13 MPa,均不超过GRC抗拉强度估算值,墙板具有较好的抗裂性能。

In order to explore the shrinkage performance of GRC-PC composite wallboards,one GRC wallboard and three GRC-PC composite wallboards were casted to continuously monitor and record their shrinkage strain values for comparative analysis.The surface stress values of wallboards were calculated based on the experiment data to examine crack resistance of wallboard.Results showed that the shrinkage strain values of the composite wallboards were far lower than that of the free shrinking GRC wallboard after entering the shrinking stage since the GRC boards of the former ones were constrained by the cement;steel mesh embedded in the concrete slab increase of wallboard sizes and in-door temperature as well as humidity all impact the shrinkage strain of composite wallboards to varying degrees;the maximum stresses values on the surface of three composite wallboards were 4.24,6.13 and 8.13 MPa,respectively.The wallboards has superior crack resistance as stress values of composite wallboards were all less than the estimated tensile strength of GRC.