Exploring the Influence of Sample Geometry on the Tensile Strength of Rock and Concrete: An Integrated Experimental and Numerical Analysis

This study investigates the impact of size and shape on tensile strength (TS) in brittle materials, examining rock and concrete samples through direct tensile (DTS), Brazilian tensile (BDS), and three-point bending (TPBT) tests, complemented by numerical modeling. Findings reveal a notable decrease in TS for rock samples as the sample size increases, while the variation in TS for concrete samples remains insignificant. The TPBT test consistently produces higher TS values, averaging approximately 2.2 times that of the Brazilian and direct tensile tests, which exhibit comparable strengths. In numerical modeling, the assumption of material uniformity and homogeneity introduces a discrepancy between numerical and experimental results. However, this discrepancy diminishes as the sample size increases. The study underscores the influence of sample heterogeneity on variations in tensile strength.