长期荷载作用下的自密实混凝土梁卸载后的静力试验研究

对12根经过长期荷载作用卸载后的自密实与振捣混凝土梁进行了静力试验研究。试验结果表明自密实混凝土品质优良,同组梁实测结果的离散性较小。混凝土成型工艺、养护条件对长期作用的自密实与振捣混凝土梁卸载后再次加载构件的荷载-挠度曲线、破坏形态、裂缝分布以及极限承载力没有大的影响。预加应力的作用使得梁的裂缝宽度、裂缝延伸高度及裂缝分布范围大大减小。采用连续梁的结构形式可以显著减小结构挠度,提高结构的极限承载力。本文采用现有的计算方法对试验梁进行了理论分析,理论计算结果与试验结果吻合良好。

Experimental research on self-compacting concrete beams under static loading after long-term actions

This paper reports the test results of 12 beam specimens including 8 SCC simple beams and 2 vibrated concrete simple beams and 2 SCC continuous beams under static loading after long-term actions.The test results indicate that the variability of test results for the same group of SCC beams are very small,accounting for good quality of SCC.Casting technique and curing condition of concrete have little effect on the load-deflection relationship,load carrying capacity,mode of failure and distribution of cracks in simple beams.The cracks of perstressed beams are much smaller in width,height and distribution than those of non-prestressed beams.The adoption of structural type of continuous beam can significantly reduce the deflection of beams,while grealtly increase the ultimate load.The existing calculation method can be used to analyse the tested beams. The calculated results are in good agreement with those from the test.