Title: Shear transfer across new and existing concrete interfaces

Author(s): Robert A. Bass, Ramon L. Carrasquillo, and James O. Jirsa

Publication: Structural Journal

Volume: 86

Issue: 4

Appears on pages(s): 383-393

Keywords: concretes; dowels; epoxy resins; friction; grouting; repairs; shear strength; strengthening; Structural Research

DOI: 10.14359/2906

Date: 7/1/1989

Abstract:
An experimental program was designed to provide information on the interface shear capacities between new concrete cast against an existing concrete surface. Thirty-three full-scale, pushoff specimens were designed, constructed, and tested. Test variables included surface preparation, amount and depth of embedment of the interface reinforcement, reinforcement details in the new and existing concrete elements, and the compressive strength of both new and existing concrete elements. Testing consisted of repeated load cycles producing shear stresses along the plane of the concrete interface. Deflections along and across the concrete interfaces at several locations were measured. Peak strength, degradation of strength with repeated load cycles, and increasing deflections were observed. Special attention was given to determining the failure mechanism along the interface.