Environmental Chemomechanics of Concrete

Abstract

The premature decay or deteriorartion of of concrete structures by various types of chemical degradation processes is one main cause of reduced lifespan expectation of civil infrastructure, including bridges, buildings, power plants, public and private facilities. This is the background for this paper on environmental chemomechanics of concrete. It is composed of two parts. The first part is devoted to multiple cross-effects between chemo-physical processes and deformation and cracking of deformable materials. A macroscopic thermodynamic approach is applied to thermo-chemo-mechanical couplings involved in the irreversible behavior of concrete subject to internal reactions. These couplings are set within a chemoplasticity framework, to address latent heat effects related to the exothermic or endothermic nature of chemical reactions, chemical shrinkage, hardening-softening due to internal pressures generated by chemical reactions, and chemical hardening as related to the increase of both the Young’s modulus and the strength of concrete. The second part is devoted to the design of structures affected by such coupling processes. It carries the analysis of the first part on to the structural scale of concrete engineering applications. Through a number of case studies of structures affected by the Alkali-Silica-Reaction and early-age concrete structures, we address the question, how to quantify the effect of thermochemo-mechanical couplings on the structural behavior.