混凝土梁剪切徐变试验研究

针对混凝土桥梁剪切徐变问题,提出基于两点加载梁的剪切徐变测试方法。阐述了剪切徐变的测试原理,并推导剪切徐变系数的计算公式。采用数据补偿对温度及收缩的影响进行物理排除,对传感器的布置方案及数据误差的影响进行分析。以三组不同加载等级的试验梁为例,测试了混凝土梁的剪切徐变特性并给出规范系数的修正值。试验结果表明,我国现行规范对于轴向受力混凝土的徐变系数规定是可行的,剪切徐变系数则需乘以2.5~3倍的放大系数;三系数徐变公式修正法可为相关实验和计算提供参考。

Experimental Study on Long-term Shear Creep of Concrete Beam

According to shear creep of concrete bridge, test method based on two point loading concrete simple beam is proposed. Test principle of shear creep is discussed with analytical derivation of shear creep ratio. Effect of temperature and shrinkage is compensated by independent beam. And arrangement of gauge is analyzed as well as data error effect. Three gradual increase loading beams are tested and creep ratio of concrete beam is studied to modify the value in current Code. Results of experiment indicate: Chinese code for axial stress creep is suitable, while long-term shear creep ratio should consider a multiplier of 2.5~3. Modification method using three parameters can be referenced in similar test and computation.