Title: Experimental Device to Study Cracking and Deterioration of Concrete

Author(s): D. Breysse, B. Gerard and M. Lasne

Publication: Symposium Paper

Volume: 145

Issue:

Appears on pages(s): 1013-1032

Keywords: concretes; cracking (fracturing); deterioration; durability; mechanical couplers; permeability; specimens; structural design; tension tests; Structural Research

DOI: 10.14359/4475

Date: 5/1/1994

Abstract:
Cracking of concrete, whatever its origin (mechanical, physicochemical, thermal, ...) is a factor accelerating the deterioration of the material. The knowledge of the transfer properties of sound concrete and of cracked concrete is essential for predicting its durability since the deteriorating mechanisms (freezing, corrosion, lixiviation) are related by the flow of aggressive (liquid or gas) agents through the porous body. An experimental system has been developed with the purpose of estimating the increase in permeability resulting from mechanically induced cracking. A specimen of concrete is subjected to uniaxial or biaxial tension, and the water permeability is measured in the direction perpendicular to the axis of loading. The tests are designed and monitored to collect data useful for modeling of concrete structures: the material is in tension (and not in compression, as it is more classical in studies of damage-permeability coupling), and the permeability is measured with open cracks. The response in tension being unstable, the geometry of the specimen has been designed with great care, using knowledge previously accumulated in ``PIED" uniaxial diffused damage tension test. It results that the transfer properties are evaluated in the most unfavorable context. The way the specimen has been designed for these measurements is detailed, then the experimental frame (triaxial press ASTREE) is presented, and some experimental results on preliminary tests are given.