Description
Concrete structures in cold climates suffer from frost damage. The evaluation of frost resistance requires big samples, which is not suitable for structural assessment. Therefore, developing an evaluation method that induces minimal damage to the structure is necessary. The drilling powder method has been proven to cause minimal damage to the concrete (1 mm hole) and can be used to estimate the concrete compressive strength. In this study, this technique is further investigated on its applicability to evaluate concrete frost resistance. Concrete specimens were prepared with various water-to-cement ratios and amounts of air-entraining admixture. The extraction of concrete powder and freeze−thaw cycle exposure were performed on the specimens to evaluate the pore structures and frost resistance, respectively. Mercury intrusion porosimetry was used to evaluate the pore structures of the drilling powder. Additionally, the feasibility of the drilling powder method was investigated by comparing the obtained result with that of a 5 mm concrete core. The results showed that the drilling powder method can be used to evaluate the frost resistance of normal concrete. However, the 5 mm concrete core cannot be used to estimate the frost resistance owing to the variation in coarse aggregate portion in the small-sized sample. These results imply the potential use of the proposed method in minimal damage assessment.
