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

Abstract:

In order to study the improving mechanical behavior of composite girder on the hogging moment zone with post combined prestressed concrete slab, especially on the concrete cracking property in this range, two composite girders, one being common composite girder and the other composite girder with post combined prestressed concrete slab, were designed and fabricated, on which static tests 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 that for serviceability limit state of composite girder with post combined prestressed concrete are 3.87 times and 5.38 times of those of common composite girder respectively, which indicates that adopting post combined prestressed concrete slab for composite girder can significantly improve the resistance cracking ability in the negative zone of composite girder.

Key words:composite girder; negative moment; concrete slab; cracking; prestress; test