Title: Comparison of Analytical with Experimental Internal Strain Distribution for the Pullout Test

Author(s): William C. Stone and Nicholas J. Carino

Publication: Journal Proceedings

Volume: 81

Issue: 1

Appears on pages(s): 3-12

Keywords: concretes; cracking (fracturing); finite element method; nondestructive tests; pullout tests; strength; stress analysis.

DOI: 10.14359/10634

Date: 1/1/1984

Abstract:
Axisymmetric, two-dimensional, linear-elastic finite element solutions for the internal strain distribution of the pullout test were compared with experimental data from two large-scale tests. Good agreement was found between experimental and analytical strains up to the load which caused first cracking in the laboratory specimens. Within the un-cracked stress region where the fracture surface develops, state is triaxial tension-tension-compression. Tensile stresses are directed in the circumferential and the radial directions, while the compressive stresses are dircted parallel to a line from the pullout insert disk to the reaction ring. For a 70 deg apex angle, the principal compressive stress trajectories were nearly parallel to the measured failure surface in the physical test. This behavior suggests that the stresses formation which are of the failure surface is dominated by the tensile present. Because of the complex state of stress during the test, it is unlikely that pullout strength is directly related to compressive strength. It is proposed that the good correlation comes about because both the pullout strength and the compressive strength of concrete are related primarily to the tensile strength the mortar.