Title: Shear Transfer Behavior in Concrete and Polymer Modified Concrete Two-Layered Systems with Application to Infrastructure Rehabilitation and New Designs

Author(s): Edward G. Nawy

Publication: Symposium Paper

Volume: 89

Issue:

Appears on pages(s): 51-90

Keywords: beams (supports); bond (concrete to concrete); composite construction (concrete to concrete); cracking (fracturing); deflection; loads (forces); polymer-portland cement-concrete; shear properties; shear stress.

DOI: 10.14359/6243

Date: 12/1/1985

Abstract:
Research is reported on the shear transfer between normal concrete and polymer modified concrete. The experimental program was designed to verify the general theory of shear transfer mechanism for concrete and to evaluate the necessary constants of the theoretical expressions. The general theory presented covers structural members with (i) no shear reinforcement, (ii) moderate shear reinforcement and (iii) high shear reinforcement. Four groups of specimens were tested. Group A specimens were used to investigate the relation between intrinsic bond shear transfer capacity and the strength of the composite materials (PMC and concrete). No transverse steel was used in these specimens. Group B specimens contained various amounts of shear reinforcement at the shear interface. Group C specimens were cast monolithically using ordinary concrete to serve as control specimens. Group D were control specimens made up of cast-in-place concrete over precast concrete. They were designed to evaluate the "apparent cohesion" of such elements, for the purpose of comparison with Group A specimens. The investigation will also present the extension of application of the theory to two-layered beams. Results of tests of 16 simply supported beams will be presented, where the principal parameter is the variation of the top PMC layer thickness. The major aspects to be presented are the load-deflection and cracking behavior, the mode of failure of the beams, the contribution of PMC to the strength of the composite beam, the initation and progress of slip in the interface of the two layers, frictional shear resistance of the unreinforced concrete-PMC interface, and the effect of using shear reinforcement to prevent any slip and shear failure.