泡沫混凝土与钢丝粘结性能试验与模拟

为研究埋入深度与基材密度对钢丝拔出力的影响,试验制备3种不同容重泡沫混凝土,将3种埋入深度的镀锌钢丝垂直埋置在3种基材中.养护7 d,进行钢丝从泡沫混凝土中拔出试验,得到拔出力与拔出位移的关系曲线.结果分析表明:同容重等级泡沫混凝土,钢丝埋入深度越长,拔出力越大,拔出位移也越大;相同埋入深度下,泡沫混凝土容重等级越大,钢丝拔出力也越大,拔出位移也越大.为模拟钢丝拔出行为,基于试验数据建立了钢丝从泡沫混凝土中拔出的3阶段模型,模型计算结果与实测试验结果吻合良好.用该模型可模拟不同埋入深度的钢丝从不同容重的泡沫混凝土中拔出行为.基于模型计算,得到不同容重泡沫混凝土钢丝拔出力峰值与埋深的对应关系,以及钢丝数量与所能提供粘结强度的对应关系.

Test and simulation on pull-out behavior of steel wire in foam concrete

Three kinds of foam concretes with different density were used and three different embedment lengths of wires were selected to study the pull-out behavior of steel wire from foam concrete. After 7 days of curing, steel wire was pull-out from the foam concrete. Test data including pull-out force and wire-end displacement were obtained. Experimental results show that pull-out peak load and corresponding wire end slippage increase with the embedment length and density of foam concrete. Based on the test results, a pull-out model of wire from foam concrete is developed with assumption of three stage bond strength assumptions. The model results are well agreed with the test results. The developed model can simulate pull-out behavior of steel wire with different embedment length. Base on this model, relationships of steel wire pull-out strength versus embedment length and pull-strength versus number of steel wires in foam concretes can be obtained.