Seismic behavior of frost-damaged squat RC shear walls under artificial climate environment: a further experimental rese
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(2020) 20:106
ORIGINAL ARTICLE
Seismic behavior of frost‑damaged squat RC shear walls under artificial climate environment: a further experimental research Xian‑Liang Rong1,2 · Shan‑Suo Zheng2 · Yi‑Xin Zhang2 · Li‑Guo Dong2 · Huan Liu2 · Kuang‑Yu Dai3 Received: 12 March 2020 / Revised: 17 May 2020 / Accepted: 10 June 2020 © Wroclaw University of Science and Technology 2020
Abstract In cold environment, the damage of freezing and thawing poses a great threat to the safety of concrete structures. In this study, six frost-damaged squat reinforced concrete (RC) shear walls were subjected to low cyclic reversal loading to investigate the effects of axial compression ratio, concrete strength and freeze-thaw cycles (FTCs) on the seismic performance of squat RC shear walls. The seismic behavior of the test specimens was evaluated in terms of the frost action at the microstructure level, frost-heave crack patterns, damage processes, failure patterns, hysteretic behaviors, skeleton curves, deformations, and energy dissipation capacities. It shows that the boundary elements and distributed reinforcements had obvious restraining effects on the development of frost-heave cracks. The FTC action weakened the load-carrying capacity, energy dissipation capacity, and shear resistance capacity of the walls. When the number of FTCs is kept at 200, with the increase of the concrete strength, the gel structure (C-S-H) gradually evolved from fibrous to nets, also the width and number of frost-heave cracks started to reduce, and the distribution of frost-heave cracks evolved from the middle of the specimen to the perimeter. Moreover, the energy dissipation capacity and the ratio of the shear displacement on the whole displacement after cracking loading condition started to increase. Keywords Cold climate · FTCs · Seismic performance · Squat RC shear wall · Axial load ratio · Concrete strength
1 Introduction As a key issue, climate affects the construction and development of reinforced concrete buildings [1–3]. The frost action is challenging the safety of RC buildings in many countries with a cold climate [4]. In the last several decades, reinforced concrete (RC) members in cold areas have experienced substantial deterioration from the surface to the inside due to freeze-thaw cycles (FTCs) [5]. In the northern regions of China, RC members are repeatedly subjected to FTCs every year [6]. In Canada, the infrastructure in cold * Xian‑Liang Rong [email protected] * Shan‑Suo Zheng [email protected] 1
College of Civil Engineering, Tongji University, Shanghai 200092, China
2
School of Civil Engineering, Xi’an University of Architecture and Technology, Xi’an 710055, China
3
Department of Civil and Environmental Engineering, University of Auckland, Auckland, New Zealand
regions is rapidly deteriorating [7]. In America, freeze-thaw action has become a major factor in the deterioration of the mechanical properties of RC structures built in extremely cold areas, such as North Dakota [8]. It shows a vital challenge which concerns
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