Fracture of Reinforcing Steels in Concrete Structures Damaged by Alkali-Silica Reaction-Field Survey, Mechanism and Maintenance-

Abstract

Instances of reinforcing steel fracture in concrete structures damaged by the alkali-silica reaction (ASR) have been discovered recently in Japan. As long as reinforcing steels are not broken due to ASR-caused expansion, the safety of a structure is considered not to be seriously compromised. However, the safety of a structure becomes questionable when the confinement of concrete becomes degraded due to the fracture of reinforcing steel bars. Therefore, it is important to clarify the mechanism of the fracture of reinforcing steel bars and develop methods for detecting steel bar fractures and strengthening concrete structures damaged by ASR. This paper describes the fracture of reinforcing steels in the case of concrete structures damaged by ASR in the Kansai area in Japan. It then introduces the results of investigation on the fracture mechanism, nondestructive testing methods, and repair and strengthening methods for damaged concrete structures.

Influence of Random Cracks on the Shear Behavior of Reinforced Concrete Beams Containing Steel Fibers

“…This fact was observed and reported by Miyagawa et al 5) The effect in reducing the amount of expansion agent can be seen in a reduction of the maximum surface strain (Fig. 12) a reduction in the crack width ( Table 4) as well as in a more uniform distribution of the crack width on the surface of the beam (Fig.10).…”

Alkali–silica reaction: Current understanding of the reaction mechanisms and the knowledge gaps

“…Swelling of this gel leads to stress development and potentially, cracking of concrete. ASR is a major durability problem of concrete, and continues to damage important structures, including dams and hydraulic structures, pavements, bridges, walls, barriers, and nuclear/power plant structures [3][4][5][6][7][8][9][10][11][12][13].…”

Effects of Fly Ash on Mechanical Properties of PC Girder Using Reac-tive Andesite Aggregates

“…Moreover, the influence of ASR on the flexural loading capacity of preloaded and cracked beams was also perceived to be insignificant. The fracture mechanism of reinforcing steels in the case of concrete structures damaged by ASR was studied thoroughly by Miyagawa et al (2006). The authors introduced the results of the investigation on the fracture mechanism, nondestructive testing methods, and repair and strengthening methods for damaged concrete structures.…”