Performance Study On The Local Compression Of Reactive Powder Concrete Under Anchorages

The compression transmitted from the anchor plate will cause vertical compression and lateral expansion to the internal concrete in prestressed anchorage system.And the local lateral expansion will be constrained by the outer concrete,so various deformation and restraint influence each other,which makes the stress and deformation of anchorage zone concrete very complicated.The problems of local compression of concrete directly decide the security of the prestressed concrete structure and the reliability of the whole construction structure,and they affect the normal use and service life of the structure engineering.The complexity and the importance of the problems of local pressure of anchorage zone concrete,make it a key link in the process of prestressed concrete structure design and calculation.The large increase in the compressive strength and bending strength of reactive powder concrete(RPC)can make the structure effectively decrease its size under the same conditions,and make the structure light-duty come true.Therefore,RPC materials can effectively improve the ability of bridge cross in the bridge engineering.At the same time,the decrease of the structure size also makes the problems of RPC materials under the local compression of prestressed structure become more prominent and complex.Specific research works in this dissertation are described as follows:(1)This paper expounds the mechanism configuration and mechanical properties of reactive powder concrete(RPC),and respectively summarizes the research status of prestressed anchorage local compression about normal concrete and RPC materials;This paper introduces the existing local compression damage theory of ordinary concrete.(2)This paper aims to discuss the effects of three parameters,including curing condition,the amounts of steel fibers,and the ratio of block area to bearing area,to the local compression bearing capacity of RPC specimens.18 axial compressive specimens are tested and from which failure modes,crack patterns,and load-displacement relationships are obtained.We will reveal the working mechanism and failure mechanism of RPC specimens.(3)This paper aims to discuss the effects of three parameters,including the variety of indirect reinforcements,the ratio of reinforcements,and the ratio of the bearing plate area to the core concrete area,to the local compression bearing capacity of RPC specimens.14 axial compressive specimens are tested and from which failure modes,crack patterns,load-displacement relationships and strain distribution are obtained.We will reveal the working mechanism and failure mechanism of RPC specimens.(4)By introducing the constitutive relations of RPC under different curing conditions and steel fiber contents,the nonlinear finite element model under local compression was built and the nonlinear analysis of load process was completed based on ABAQUS software.(5)An uniform formula that respectively calculates the local compression bearing capacity of concrete and indirect reinforcements,is established by considering the existing formulas and the influence rules of the different parameters mentioned above.