Influence of alkali-silica reaction on the shear capacity of reinforced concrete beams with minimum transverse reinforcement

Journal Article · Wed Feb 24 00:00:00 EST 2021 · Engineering Structures

DOI:https://doi.org/10.1016/j.engstruct.2021.112020· OSTI ID:1850485

Aryan, Hadi ^[1]; Gencturk, Bora ^[2]

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1. Univ. of Southern California, Los Angeles, CA (United States). Sonny Astani Dept. of Civil and Environmental Engineering; Univ. of Southern California, Los Angeles, CA (United States)
2. Univ. of Southern California, Los Angeles, CA (United States). Sonny Astani Dept. of Civil and Environmental Engineering

A growing number of critical concrete infrastructure are affected by alkali-silica reaction (ASR) damage such as the Seabrook Nuclear Power Plant in New Hampshire, Parker arch-gravity dam in Arizona, and several highway bridges in California and Texas. ASR causes expansion and cracking and degrades the concrete mechanical properties. Despite a wealth of material level studies there is still limited large-scale experimental data regarding the effects of ASR on reinforced concrete (RC) members. Due to the brittle nature of the shear failure in RC structures, this study focuses on the shear response of full-scale ASR damaged RC beams with minimum shear reinforcement. Six RC beams were built with different levels of ASR susceptibility and conditioned in different environments during which continuous expansion monitoring was performed. The beams all contained reactive fine aggregate (sand) and two of them had additional alkali, 1.25% by weight of cement, to accelerate ASR. The highest expansion rate of the beams happened during the first 150 days and the expansions stayed constant after 240 days and 330 days for beams conditioned in outdoor and laboratory conditions, respectively, until the last measurement at 575 days. The highest expansion, 0.4%, was seen in the beams with additional alkali and conditioned outside with regular water spray. Out of the six beams, three were selected at different levels of ASR damage and two shear tests were performed on the minimally reinforced spans close to the ends of each beam. Results indicated that beams gain shear strength from ongoing cement hydration in the presence of moisture for ASR expansions less than 0.2%. Compared to one of the beams with 0.2% ASR expansion, one of the other samples with 0.4% expansion lost 6% of its shear strength, 25% of its shear stiffness, and showed about two times larger shear cracks and shear deformations at peak load. Finally, the shear reinforcement yielded at 20% less load in the beam with 0.4% expansion compared to the beam with 0.2% expansion.

• Research Organization: Univ. of Houston, TX (United States)
• Sponsoring Organization: USDOE; USDOE Office of Nuclear Energy (NE)
• Grant/Contract Number: NE0008438
• OSTI ID: 1850485
• Alternate ID(s): OSTI ID: 1815223
• Journal Information: Engineering Structures, Journal Name: Engineering Structures Journal Issue: C Vol. 235; ISSN 0141-0296
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
Alkali-silica reactivity
Concrete degradation
Engineering
Long-term monitoring
Shear failure