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CAER Seminars

An experimental testing system for fiber reinforced polymer(FRP) strengthened concrete panels under uniform pressure loads

Dr. Jeffrey Helm,
Lafayette College
Easton, PA

Wednesday, January 14, 2009 10:00am
Ben Bandy Conference Center
Center for Applied Energy Research

Though numerous experimental studies have been conducted on the use of externally-bonded glass and carbon fiber reinforced polymers to externally strengthen reinforced concrete beams, columns, and joints, relatively little experimental work has been conducted on the external strengthening of two-way slabs in flexure. Two-way slab testing is necessary because the influence of complex stress fields and membrane action cannot be anticipated from the previous experimental work conducted on beams.

A testing system to investigate the response of large, 2-m by 2-m, fiber reinforced polymer (FRP) strengthened concrete slabs, to uniform pressure loads has been developed. The system combines a test frame that employs pressurized bladders to produce a uniform load on the lower, compressive side of the concrete panels while the upper, tensile surface is imaged by two three-dimensional digital image correlation (DIC3D) systems. From the images taken of the panel under load, full-field displacement and strain fields are measured. The test program studies the effects of various types of fiber reinforcement and the effect of fiber orientation on the strength and rigidity of the concrete panels.

This talk will cover the basis of three-dimensional digital image correlation for the measurement of surface displacement and strain, the development of the slab test system and preliminary results from the experimental studies.