后结合预应力组合梁负弯矩区混凝土开裂性能试验

为了研究后结合预应力技术改善混凝土桥面板组合梁在负弯矩作用下的受力性能,特别是混凝土的开裂性能,设计制作了2根组合梁(一根是常规混凝土桥面板组合梁,另一根是后结合预应力混凝土桥面板组合梁),进行了2根组合梁的静力试验.测试了在不同荷载作用下组合梁的变形、不同截面上构件的应变分布、混凝土的裂缝、钢与混凝土之间的相对滑移以及极限承载力等.试验结果表明:后结合预应力混凝土板连续组合梁的初始开裂荷载和正常使用状态的极限荷载分别是普通连续组合梁的3.87倍和5.38倍,说明采用后结合预应力混凝土桥面板能够大大提高组合梁负弯矩区混凝土的抗裂性能.

Experimental Studies on Cracking Behavior of Post combined Prestressed Concrete Slab in Hogging Zone of Composite Girder

In order to research the improving mechanical behavior of composite girder on the hogging moment zone with post-combined prestressed concrete slab, especially for the concrete cracking property in this range, two composite girders, one is common composite girder and another is composite girder with post-combined prestressed concrete slab, were designed and fabricated, also the static tests on two girder were conducted. The main mechanical behaviors including girder deformation, strain distribution, concrete cracks, relative slip between steel and concrete, bearing capacity etc were tested. The testing results show that the load for initial concrete cracking and the load for serviceability limit state of composite girder with post-combined prestressed concrete are 3.87times and 5.38times those of common composite girder respectively. It is tested that the method of adopting post-combined prestressed concrete slab for composite girder can improving the resistance cracking ability in the negative zone of composite girder significantly.