Appraising structures affected by the alkali–aggregate reaction

Abstract

This paper presents the appraisal of structures affected by the alkali–aggregate reaction (AAR) and is based on the overall philosophy and principles that have already been established in a Rilem report to be published. This report is part 2 of the recommendations on diagnosis and appraisal that have been developed in the frame of the Rilem technical committee 219-ACS. It recommends that, from the start of an investigation, there should be close links between the materials science team inspecting and testing for diagnosis and the structural engineers carrying out an appraisal. This paper first describes the initial appraisal that is based on site investigations (cracking index, global deformation and environment analysis) and the laboratory investigations on the cores taken from the structure (mechanical testing, residual expansion tests) in order to obtain a severity assessment of the structure. Then it presents the structural assessment that includes the severity rating of the structural elements and the structural assessment based on a numerical modelling referring to Larive's law.