Li Changyong, Zhao Minglei, Zhang Xiaoyan, Li Jie, Li Xiaoke, Zhao Mingshuang
International Joint Research Lab for Eco-Building Materials and Engineering of Henan, School of Civil Engineering and Communications, North China University of Water Resources and Electric Power, Zhengzhou 450045, China.
School of Engineering, RMIT University, Melbourne, VIC 3003, Australia.
Materials (Basel). 2021 Feb 26;14(5):1107. doi: 10.3390/ma14051107.
To determine the validity of steel fiber reinforced expanded-shale lightweight concrete (SFRELC) applied in structures, the shear behavior of SFRELC structural components needs to be understood. In this paper, four-point bending tests were carried out on reinforced SFRELC beams with stirrups and a varying volume fraction of steel fiber from 0.4% to 1.6%. The shear cracking force, shear crack width and distribution pattern, mid-span deflection, and failure modes of test beams were recorded. Results indicate that the shear failure modes of reinforced SFRELC beams with stirrups were modified from brittle to ductile and could be transferred to the flexure mode with the increasing volume fraction of steel fiber. The coupling of steel fibers with stirrups contributed to the shear cracking force and the shear capacity provided by the SFRELC, and it improved the distribution of shear cracks. At the limit loading level of beams in building structures at serviceability, the maximum width of shear cracks could be controlled within 0.3 mm and 0.2 mm with the volume fraction of steel fiber increased from 0.4% to 0.8%. Finally, the formulas are proposed for the prediction of shear-cracking force, shear crack width, and shear capacity of reinforced SFRELC beams with stirrups.
为确定钢纤维增强膨胀页岩轻混凝土（SFRELC）在结构中应用的有效性，需要了解SFRELC结构构件的抗剪性能。本文对配有箍筋且钢纤维体积分数在0.4%至1.6%之间变化的钢筋SFRELC梁进行了四点弯曲试验。记录了试验梁的抗剪开裂力、剪裂缝宽度及分布规律、跨中挠度和破坏模式。结果表明，配有箍筋的钢筋SFRELC梁的抗剪破坏模式从脆性转变为延性，且随着钢纤维体积分数的增加可转变为弯曲破坏模式。钢纤维与箍筋的协同作用提高了SFRELC的抗剪开裂力和抗剪承载力，并改善了剪裂缝的分布。在建筑结构梁正常使用极限荷载水平下，随着钢纤维体积分数从0.4%增加到0.8%，剪裂缝的最大宽度可控制在0.3mm和0.2mm以内。最后，提出了配有箍筋的钢筋SFRELC梁的抗剪开裂力、剪裂缝宽度和抗剪承载力的预测公式。
