In this paper, novel unified equations for predicting the residual flexural tensile strength of normal-weight, lightweight, and ultra-lightweight steel fiber-reinforced concrete (SFRC) are proposed. The unified equations were obtained by conducting multiple nonlinear regression analysis on the test results from 60 notched prism tests conducted according to EN 14651. The proposed unified equations account for fiber geometry, fiber content, concrete compressive strength, and concrete density. Unlike existing prediction equations, which can only predict the flexural tensile strength of normal-weight SFRC, the proposed equations are applicable for SFRC with varying densities. Test results from the literature verified the accuracy of the proposed equations to within 10% of observed values, on average. Compared to the existing equations, the proposed unified equations were better at predicting residual flexural tensile strength of both normal-weight and lightweight steel fiber reinforced concrete.

中文翻译：

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预测轻钢纤维混凝土残余抗拉强度的统一方程

在本文中，提出了预测正常重量、轻量级和超轻量级钢纤维混凝土 (SFRC) 残余弯曲抗拉强度的新统一方程。统一方程是通过对根据 EN 14651 进行的 60 次缺口棱柱测试的测试结果进行多元非线性回归分析获得的。建议的统一方程考虑了纤维几何形状、纤维含量、混凝土抗压强度和混凝土密度。与现有的预测方程只能预测正常重量 SFRC 的弯曲拉伸强度不同，所提出的方程适用于具有不同密度的 SFRC。文献中的测试结果验证了所提出的方程的准确度平均在观察值的 10% 以内。与现有方程相比，