Permeability of concrete under thermal and compressive stress influence; an experimental study

Material Technology Innsbruck (MTI), University of Innsbruck, Technikerstraße 13, 6020 Innsbruck, Austria

Abstract

In recent years the permeability was found as one of the main parameters affecting the durability of concrete. Especially in concrete at high temperatures in case of fire loading, the interaction of thermal/mechanical loading and fluid transfer strongly influences degradation of mechanical properties within concrete and spalling of near-surface concrete layers. To understand the change in transport properties of concrete, a new experimental setup was developed, allowing us to conduct permeability tests under uniaxial compressive loading up to 20 MPa and thermal condition up to 350 °C. Based on the obtained results, the effect of both mechanical and thermal loading on the effective transport properties is highlighted and relations to more simplified test setups, disregarding mechanical loading and/or conducting the permeability test at room temperature giving the residual permeability, are established.