The Forming Principle of Reflection Cracks of Composite Lay in old Bridge Reinforcement

摘要

In order to study the transverse reflection crack of concrete composite lay in old bridge reinforcement, aiming at the forming process of the reflection crack, the theoretical model of its peak tensile stress and its separation distance is presented, and its forming mechanism is analysed. Based on the theoretical model, the influence of the thickness overlay, and constraint under the concrete composite lay are studied to the transverse reflection crack. Based on these researched results, the peak tensile stress and its separation distances is calculated by given theoretical model, and the results reveal shrinkage cracks rely on the restraint condition, elastic modulus, shrinkage ratio and the thickness of the composite-slab.