Macro- and micro-indicators of ASR in concrete pavement Available to Purchase

Alkali–silica reaction produces deterioration of concrete, visible on the macro- and micro-scale. Macro-indicators of alkali–silica reaction are important in the field inspection of concrete. Micro-indicators help to verify the presence of alkali–silica reaction and make it easier to distinguish ASR from other degradation mechanisms. Three parameters were determined to evaluate the deterioration of concrete pavements: the specific length of cracks measured on the pavement surface; the specific length of cracks in the drill cores; and the volume of alkali–silica gels and microcracks in thin sections. According to these indicators, it was possible to distinguish two types of pavement degradation: degradation mainly associated by ASR and degradation connected with another mechanism. The macro- and micro-indicators linked the deterioration to alkali–silica reaction in six sites on the Czech highways. One site was attributed to another degradation mechanism. The rock types (and/or quartz recrystallisation of aggregates) affecting ASR were determined.