Comparison of Evolution of Pop-Out Damage by Mixed in Burnt Lime Nodules in Precast Concrete in Outside and Inside Exposure Conditions

Abstract In 2010 burnt lime blocks were accidentally mixed with limestone concrete aggregates at a Belgian limestone and lime production plant. The contaminated limestone aggregates were used in precast concrete factories. The concrete elements used in several constructions quickly showed pop-outs, caused by swelling of lime nodules. The appearance of pop-outs in suspected constructions was recorded. An extensive experimental program as well as on site observations have been made, to monitor the evolution of the pop-out phenomenon with time. The pop-out evolution in outside exposure conditions is compared to the evolution of pop-outs under inside climatic conditions. Outside, the phenomenon becomes marginal after about 2 years. In inside exposure conditions, the phenomenon still continues after 7 years, be it at a low rate.