Effect of Steel Fiber Content on Punching Shear Performance of Reinforced Concrete Slab
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摘要: 通过对钢纤维体积率为0和0.38%的双向板试件进行冲切试验,得到试件的破坏形态、钢筋和混凝土荷载-应变规律等,进而量化评估钢纤维掺量对钢筋混凝土桥面板冲切性能的影响。结果表明:钢纤维体积率为0与0.38%的试件相比,相同荷载作用下后者的钢筋、混凝土应变较小;首条裂缝的出现时间推迟;试件在冲切破坏时挠度变形较大且板底表面混凝土脱落较少。Abstract: In order to study the influence of steel fiber content on the punching performance of reinforced concrete slabs, we conducted the punching test of two-dimensional plate specimens with steel fiber volume fractions of 0 and 0.38%, and obtained the failure modes, the law of bars strains and concrete strains of the specimens. Then, we quantitatively evaluated the influence of steel fiber content on the punching performance of reinforced concrete slabs. The results show that comparing with the specimens with 0 and 0.38% steel fiber volume, the bars strains and concrete strains of the latter are less under the same load, and the first crack was delayed. The deflection of the specimen during punching failure is larger and less concrete on the bottom surface of the specimen shed.
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Key words:
- Punching strength /
- Steel fiber /
- Reinforced concrete slab /
- Destructive form
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表 1 板试主要参数
Table 1. Main parameters of the test piece
试件名 板边长/mm 支撑长度/mm 加载板边长/mm 板厚/mm 有效高度/mm 保护层厚度/mm 配筋率/% 钢纤维体积率/% 试块抗压强度/MPa 试块抗劈拉强度/MPa 混凝土强度 冲切强度/kN S-1 1500 1300 100 140 115 15 0.64 0 38.7 2.14 C30 308 G-1 1500 1300 100 140 115 15 0.64 0.38 35.62 2.95 C30 313 表 2 混凝土的配合比
Table 2. Concrete mix ratio
名称 水胶比 砂率 用量/kg·m-3 石子 砂 Ⅱ级粉煤灰 P·O 42.5R级水泥 水 泵送剂(聚羧酸) 混凝土 0.45 0.42 1 035 750 90 300 175 7.2 -
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