The Study Of Bending Performance Of Recycled Concrete Floor

With the society’s values to recycle concrete increasing, the domestic and foreignresearch scholars in the research of recycled concrete continuously deepen and gained certainachivements.However most of the scholars focused on the aspects of material properties at thevery beginning.There is more and more studies on recycled concrete structure performanceand recycled concrete structure design method only in recent years.The author designed6recycled concrete one-way slabs, two two-way slabs, two ordinary concrete one-way slabsand one ordinary concrete two-way slab for the experimental research of recycled concreteslab flexural properties in this paper.The recycled concrete one-way slab experimental studyhas been completed.This study mainly focused on the influence of reinforcement ratio,thickness of recycled concrete slab for its flexual properties through the static test of recycledconcrete one-way slabs under vertical load. In this experiment the flexural capacity (thecracking load and ultimate load), load-deflection curves, strain of steel, concrete strain, crackdevelopment of recycled concrete one-way slabs of different thickness and differentreinforcement ratio were researched under the vertical load. At last,some proposals onrecycled concrete one-way slab design and the amendments of recycled concrete slab crackwidth calculation formula were putted forward.The research shows that the cross section work in the bending process of recycledconcrete one-way slabs is divided into three stages:elastic stage, cracks stage, yield stage.Ateach stage the average strain of cross section of recycled concrete one-way slabs basicallyaccord with the assumption of plane cross section.The ultimate load bearing capacity betweenrecycled concrete one-way slabs and normal concrete one-way slabs differs little.But thecracking load of recycled concrete slabs is smaller than that of common concrete slabs and themaximum crack width is far greater than ordinary concrete slabs.Calculating the cracking moment, ultimate bending moment, maximum crack width bythe ordinary concrete board calculation formula in the current" code for design of concretestructures"(GB50010-2010), it finds out that the ultimate bending moment of the recycledconcrete one-way slab can use the current specification to calculate. But in the presentstandard calculation of ordinary concrete slab cracking moment, maximum crack widthcalculation formula is not suitable for recycled concrete one-way slabs. The current standardformula needs to fix to caculate the recycled concrete one-way slabs.This paper also putforward the correction formula of maximum crack width of recycled concrete one-way slabs...