NEHRP Clearinghouse

Title
Interface Shear Capacity of Concrete Surfaces Used in Strengthening Structures.
File
PB87148193.pdf
Author(s)
Bass, R. A.; Carrasquillo, R. L.; Jirsa, J. O.
Source
National Science Foundation, Washington, DC. Directorate for Engineering., December 1985, 92 p.
Identifying Number(s)
PMFSEL-85-4
Abstract
The repair and strengthening of buildings for improved seismic resistance is becoming an increasingly challenging task for design engineers who are looking for an economical alternative to the rapidly rising cost of new construction. The main objective of the work described herein is to investigate the strength and load-deflection characteristics of the interface connection between new concrete cast against existing concrete. Thirty-three full scale push-off type 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 interface at several locations were measured. The peak strength, the degradation of strength with repeated load cycles, and increasing deflections were observed. Special attention was given to determining the failure mechanism along the interface.
Keywords
Structural engineering; Maintenance; Reinforced concrete; Retrofitting; Shear properties; Dowels; Buildings; Earthquake engineering; Concrete structures; Shear tests; Cyclic loads; Tests