Effects of alkali-silica reaction on the shear behavior of reinforced concrete beams without transverse reinforcement

Alkali-silica reaction, or ASR, is a common deterioration mechanism that subjects concrete to internal expansive stresses. Previous research on the structural effects of ASR has shown that if a structure is effectively confined by reinforcement (e.g., three-dimensional reinforcement configuration), it is unlikely that its performance will be compromised by the development of ASR. On the other hand, in structures that are not effectively confined by reinforcement (e.g., no transverse reinforcement present, such as slabs and walls), unrestrained expansion occurs in the direction that is lacking restraint, possibly introducing a structural vulnerability. Multiple laboratory studies have been conducted to identify the structural implications of ASR in reinforced concrete. However, large-scale tests on ASR-damaged concrete elements without transverse reinforcement have not been found in the literature and the structural implications of ASR on that type of elements therefore remain uncertain. The research described in this dissertation studied the effects of ASR-related damage on the shear behavior of full-scale structural concrete elements without transverse reinforcement. The main objective was to quantify the effects that different severity levels of ASR had on the shear strength and behavior of the test specimens. This objective was accomplished through a full-scale experimental program. A total of ten specimens modeled after typical structural walls were fabricated in the laboratory and subsequently tested in shear, at different target levels of ASR expansion. The development of ASR was facilitated through the use of known reactive materials and aggressive conditioning regimes. The progress of specimen deterioration was monitored and correlated to structural test results. Structural test results did not reveal any deficiencies in the shear performance of the specimens at any level of ASR-related expansion examined in this test program. Based on the results of this research, several recommendations were made for the assessment of ASR-related deterioration and residual shear strength of ASR-affected structures in the fieldCivil, Architectural, and Environmental Engineerin