Department of Civil Engineering, Erbil Technical Engineering College, Erbil Polytechnic University, Erbil, Iraq.
PLoS One. 2022 Mar 31;17(3):e0265677. doi: 10.1371/journal.pone.0265677. eCollection 2022.
One of the methods to improve the structural design of concrete is by updating the factors given in standard codes, especially when non-conventional materials are used in concrete beams. Accordingly, this study focuses on the colorations between the compressive strength and shear strength of high-strength concrete beams with and without steel fibers. For that purpose, different models are proposed to predict shear strength of high-strength concrete beams, by taking different combinations of the main variables: beam cross-section dimension (width and effective depth), reinforcement index, concrete compressive strength, shear span ratio, and steel fiber properties (volumetric content, fiber aspect ratio, and type of steel fibers). Multi-linear and non-linear regression analyses are used with large database experimental results found in the literature. The predicted results from the proposed equations are composed with different available models from codes, standards, and literatures. The calculated results showed better correlations and were close enough to the experimental data. Based on the data given in the standard codes, the shear strength is proportional to compressive strength ([Formula: see text]) of the power 0.5. However, this value may not be adequate for modern cement and concrete containing steel fibers. Therefore, the mentioned power value must be reduced 5 times to 0.1.
提高混凝土结构设计的方法之一是更新标准规范中给出的因素，特别是在非常规材料用于混凝土梁时。因此，本研究重点关注高强混凝土梁有无钢纤维时抗压强度与抗剪强度之间的关系。为此，提出了不同的模型来预测高强混凝土梁的抗剪强度，考虑了主要变量的不同组合：梁截面尺寸（宽度和有效深度）、配筋指数、混凝土抗压强度、剪跨比和钢纤维特性（体积含量、纤维长径比和钢纤维类型）。使用来自文献中的大型数据库实验结果进行多元线性和非线性回归分析。从建议的方程中得到的预测结果与规范、标准和文献中的不同可用模型组合在一起。计算结果显示出更好的相关性，并且与实验数据足够接近。根据标准规范中给出的数据，抗剪强度与抗压强度([Formula: see text])的 0.5 次方成正比。然而，对于现代含有钢纤维的水泥和混凝土，这个值可能不够。因此，必须将所述幂值减少 5 倍至 0.1。
