Monitoring of Damage Due to Alkali Silica Reaction in Concrete at Different Temperatures by Using Non-destructive Testing Methods

One of the factors influencing ASR is temperature and researches have been done on relating temperature and ASR expansion. However, the relationship between temperature, ASR expansion and damage is still not clearly understood. Additionally, non-destructive testing (NDT) methods have proven that they can be used in detecting ASR in mortar and plain concrete. In this context, this research aims to use NDT to monitor damage induced by ASR in concrete with a goal of establishing a relationship between temperature, ASR expansion and damage. This aim was achieved by experiments of ASR in plain concrete cylindrical specimens exposed to temperatures of 20, 38 and 60 ℃ while fully immersed in water. The specimens’ expansions were measured by a length comparator. The damage was monitored by NDT methods of linear vibration analysis, resistivity and permittivity. The results showed a rapid ASR expansion at 60 ℃ from beginning while at 38 ℃, a latent expansion at first then rapid expansion later can be observed. The static and dynamic elastic modulus were sensitive to ASR damage as they reduced with ASR progression compared with compressive strength that did not show a reduction with ASR development. In electromagnetic tests, permittivity was found to be more sensitive to the detection of ASR compared with resistivity. The monitoring is still in progress and final results will be used in ASR modelling towards developing better monitoring for concrete structures affected by ASR.