Development of a reaction signature for combined concrete materials factors

Abstract

The main objective of this study is to provide a methodology of testing concrete materials as a combination to assist engineers to effectively mitigate alkali–silica reaction (ASR) in concrete. This involves capturing the combined effects of concrete materials (water cement ratio, porosity, supplementary cementitious materials, etc.) through a method of testing to allow the formulation of mixture combinations resistant to ASR leading to an increase in the life span of concrete structures. Thus, a kinetic model is proposed to determine concrete/aggregate ASR characteristics which are calculated using a mathematical numerical analysis. To relate the effect of material combinations to field performance, the aggregate and concrete characteristics are combined using two mathematical models. The first model predicts the activation energy (Ea) of the aggregate at levels of alkalinity similar to field conditions. The second model, generated using the Juarez-Badillo transform, connects the ultimate expansion of the concrete and aggregate, the water cement ratio, and the fly ash content to the Ea of the rock. It is expected that the knowledge gained through this work will assist government agencies, contractors, and material engineers, to select the optimum mixture combinations that fits best their needs or type of applications, and predict their effects on the concrete performance in the field.