Title:
Experimental Testing to Determine Concrete Fracture Energy Using Simple Laboratory Test Setup
Author(s):
Joshua Martin, John Stanton, Nilanjan Mitra, and Laura N. Lowes
Publication:
Materials Journal
Volume:
104
Issue:
6
Appears on pages(s):
575-584
Keywords:
experimental testing; finite element analysis; fracture energy; nonlinear analysis
DOI:
10.14359/18961
Date:
11/1/2007
Abstract:
Nonlinear finite element analysis can complement experimental investigation and provide insight into the behavior of reinforced concrete structures. The development of a finite element model of a concrete structure typically requires specification of the concrete tensile strength, fracture energy, the shape of the post-peak tensile response curve, and other material parameters. Previous research has resulted in a number of different tests for determining fracture energy and post-cracking response. Because test specimens exhibit extremely brittle response, these methods typically require the use of a very stiff, closed-loop test machine so that load can be applied under displacement control. A study recently completed at the University of Washington employed the fracture energy test method recommended by RILEM, with test specimens modified to include counterweights and with an open-loop testing machine. The fracture energy and post-cracking response data generated from these tests fall within the range typically observed for the RILEM-type tests. Additionally, nonlinear finite element analyses performed using these data to calibrate the concrete constitutive models reproduced, with acceptable accuracy, the load-displacement response observed in the laboratory.