钢木组合早拆模板整体抗压破坏试验

为研究新型钢木组合立柱早拆模板体系的稳定性,完成了由小径原木及钢管斜撑形成的纵向4列、横向6排新型早拆模板结构,并进行了足尺抗压破坏试验.考虑加载类型和持荷时间对结构稳定性及破坏的影响,分析了构件力和位移的变化规律,得出该试验单元破坏模式为杆件平面外失稳,且局部构件发生强度破坏.试验结果表明:该体系模板实际浇筑速度不应过快,加快模板周转时间十分有利于小径木原木应力的恢复,应加强浇筑期间的监控;节点水平约束对结构稳定起重要作用,构造措施必不可少;存在初始缺陷较严重的小径原木明显降低结构稳定性,应注意薄弱部位的安装位置.

Compressive failure test of the full steel undersize-log formwork with early-removal substructure

To investigate the stability of the new full steel undersize-log formwork with early-removal substructure, 4-bay-5-row which were made up of the logs and steel tubes as a test unit were prepared to study the compressive failure test. The loading patterns and time which affected the substructure were considered, the supports force and deformation were analyzed, and the failure modes that were out-plane bucking and strength failure were observed in some members. The experimental results show that the pouring concrete actual speed should not too fast, and speeding up the turnover time of this formwork is available to reinstate the stress of this log. The members during pour concrete should be monitored. The structural measures and horizontal restraints of joints are absolutely essential, and the logs which are serious imperfection can obviously decrease the stability of the new formwork, so that attention should be paid to the weak parts of the installation location.