ABSTRACT
Deterioration of concrete due to Alkali-Silica Reaction (ASR) can result in loss of serviceability and load-carrying capacity of concrete structures. Therefore, understanding mechanism of influence of ASR on concrete structures, as well as detection and evaluation of ASR are important topics. However, number of testing methods for ASR is limited, and, in regards to prestressing concrete structures, studies of influence of prestressing on behavior of ASR-damaged concrete are also rare. The present paper focuses on evaluation of concrete damaged by ASR and subjected to different levels of prestressing force. Concrete specimens with different levels of applied prestressing force were produced using the same amount of reactive aggregates. After 11 years of deterioration, the specimens were tested using several elastic wave-based methods of Non-Destructive Testing (NDT), including ultrasonic travel time tomography, ultrasonic pulse velocity method and acousto-ultrasonic method. Elastic wave velocity-based methods of NDT appeared to be not sensitive enough for evaluation of influence of prestressing on ASR, while results of acousto-ultrasonic method showed good correlation with the level of prestressing force and results of crack mapping. Results of the study allowed propose methods of NDT, which can be used for evaluation of ASR damage in concrete and influence of prestressing on ASR-damaged concrete.
