Ordinary concrete beams (shear span–depth ( a / d ) ratio > 2) often used in mega and small structures, while deep beams ( a / d ratio < 2) are designed for some architectural purposes. Limited researches on the behavior of fiber-reinforced concrete (FRC) using only steel fibers are available to assess the effect of a / d ratio. This study investigates the flexural capacity and load–displacement behavior of polyvinyl alcohol FRC (PVA-FRC) ordinary and deep beams by varying a / d ratio. In 02 mix types, plain and containing metakaolin as 10% cement replacement, up to 3% volume fraction of PVA fibers added by volume of concrete. Using each mix, 03 beams of each of the size as 100 × 200 × 1500 mm, 100 × 200 × 700 mm, and 100 × 200 × 500 mm cast and tested to failure under third-point loading using a / d ratio as 3.5, 1.5, and 1.0, respectively. The test results showed a significant effect of a / d ratio on the flexural capacity; however, the deflection-hardening response is independent. Besides, an analytical expression to predict the flexural strength based on a / d ratio proposed, which is validated through finite element analysis (FEA). The experimental flexural strengths confirmed the results obtained from the analytical model and FEA, whereas the FEA results also endorsed load–displacement behaviors of PVA-FRC.

中文翻译：

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基于实验和有限元分析的高强度 PVA-FRC 梁 a/d 比的弯曲研究

普通混凝土梁（剪跨-深度（a / d ）比> 2）常用于大型和小型结构，而深梁（a / d 比< 2）是为某些建筑目的而设计的。对仅使用钢纤维的纤维增强混凝土 (FRC) 行为的有限研究可用于评估 a / d 比的影响。本研究通过改变 a / d 比来研究聚乙烯醇 FRC (PVA-FRC) 普通梁和深梁的抗弯能力和荷载位移行为。在 02 混合类型中，普通和含有偏高岭土作为 10% 的水泥替代品，按混凝土体积添加高达 3% 的 PVA 纤维体积分数。使用每种混合料，03 根梁的尺寸分别为 100 × 200 × 1500 mm、100 × 200 × 700 mm 和 100 × 200 × 500 mm，并使用 a / d 比为 3.5 在第三点加载下进行破坏测试、 1.5 和 1.0 分别。试验结果表明a/d比对抗弯承载力影响显着；然而，偏转硬化响应是独立的。此外，提出了一种基于 a / d 比率预测弯曲强度的解析表达式，该表达式通过有限元分析 (FEA) 进行了验证。实验弯曲强度证实了从分析模型和 FEA 获得的结果，而 FEA 结果也支持 PVA-FRC 的载荷-位移行为。