抗振混凝土收缩及抗裂性能研究

针对桥梁加固维修中行驶车辆对桥梁产生的车桥耦合振动作用直接影响水泥混凝土性能,本文通过对抗振混凝土的常规收缩变形以及平板法约束收缩开裂试验研究不同钢纤维掺量、凝结时间、温度等因素对抗振混凝土干燥收缩和温度收缩大小的影响。试验结果表明,钢纤维的掺入明显改善混凝土的干燥收缩和温度收缩,振动对混凝土影响得到有效控制;振动后混凝土裂缝明显比未振动混凝土裂缝增多,而添加钢纤维后混凝土裂缝数量及宽度显著降低,钢纤维在混凝土中延缓了裂缝的发展;并确定钢纤维掺量1%为最佳掺量。

Study on shrinkage and crack resistance of anti-vibration concrete

In view of the direct influence of vehicle-bridge coupling vibration on the performance of cement concrete during bridge reinforcement and maintenance, this paper studies the influence of different steel fiber content, setting time and temperature on the drying shrinkage and temperature shrinkage of anti-vibration concrete through the tests of conventional shrinkage deformation of anti-vibration concrete and restrained shrinkage cracking of plate method. The test results show that the drying shrinkage and temperature shrinkage of anti-vibration concrete are affected by different steel fiber content, setting time and temperature. The addition of steel fibers can obviously improve the drying shrinkage and temperature shrinkage of concrete, and the influence of vibration on concrete is effectively controlled; the cracks of concrete after vibration are obviously more than those of non-vibration concrete, while the number and width of cracks of concrete after adding steel fibers are significantly reduced, and the development of cracks in concrete is delayed by adding steel fibers; and the optimum content of steel fibers is determined to be 1%.