Tensile Strength Evaluation by Brazilian and Direct Tensile Tests: Experimental Insights and Influencing Factors

Abstract This empirical analysis focuses on evaluating the relationship between the results obtained from the Direct Tensile Test (DTT) and the Brazilian Test (BT). Through both a review of existing literature and original laboratory experiments, the study explores how factors such as uniaxial compressive strength (UCS) and rock weathering are related with the correlation between the tensile strength values derived from these two testing methods. A series of laboratory tests has been proposed to analyze how the direct tensile strength (DTS) and Brazilian tensile strength (BTS) ratio varies in two initially homogeneous materials, one with low and the other with high UCS, that are progressively degraded through microwave exposure in the laboratory. Based on the results obtained, knowing the UCS and the condition of the rock makes it possible to determine whether the results from the DTT and BT are comparable. Since in many projects only BTs are conducted, this knowledge is crucial to avoid overestimating the tensile strength of the rock and to ensure the safety and stability of structures.