An Analysis on Shear Strength of PC Hollow Beam Based on MCFT Theory
In order to study the shear strength of prestressed concrete hollow beams,based on the tests on shear strength of prestressed concrete hollow beams carried out for 6 times,the crack development and ultimate shear strength of slab beam are analyzed.The equivalent spacing method is proposed to determine the stirrup spacing of prestressed concrete hollow slab beams.The theoretical calculation model for slab and beam is established with modified compression field theory(MCFT),and the validity of the models is verified by comparing with the test results.A lot of parameter analysis is carried out to study the influence of concrete strength,steel strength and other parameters on shear strength of inclined section.The result shows that(1)the ratio between the calculated shear strength at the loading point and the test shear strength is 0.71,the ratio between the calculated shear strength at the midpoint of the shear span and the test shear strength is 0.99,and the ratio between the calculated shear strength and the test shear strength at the support position in the pure shear state is 1.11;(2)the number of fully bonded prestressed reinforcement increases from 2 to 10,and the shear strength of prestressed concrete hollow slab beams increases by 21.7%under the bending and shearing;(3)with the increase of the number of prestressed tendons,the effect of the effective prestress size on the shear strength is more significant,when the bending moment is 100 kN·m,the shear strength of 2 prestressed tendons and 6 prestressed tendons increase by 10.2%and 15.3%respectively,when the effective prestress increases from 186 to 1395 MPa,the shear strength of ten prestressed tendons increases by 20.3%.
bridge engineeringshear strengthMCFT theoryprestressed concrete hollow beambending and shearing
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