The flexural strength test evaluates which property of concrete?

The flexural strength test is primarily designed to evaluate the modulus of rupture of concrete. The modulus of rupture is a measure of a material's ability to resist bending or flexural stress. This property is critical in applications where concrete members will experience lateral loads, such as beams and slabs.

During the flexural strength test, a beam specimen is subjected to bending until failure, allowing engineers to ascertain how much stress concrete can withstand before cracking or breaking. The test results provide essential information for the design and analysis of concrete structures by ensuring that they can safely carry the expected loads without experiencing significant deflection or failure.

The other aspects mentioned, such as ultimate tensile strength and yield strength, relate to the tensile properties of materials, which are less relevant to concrete, a material that is much stronger in compression than in tension. The modulus of elasticity, while important for assessing stiffness, does not directly give insight into how concrete behaves under flexural loading. Therefore, the modulus of rupture obtained from the flexural strength test is the most relevant and significant outcome for understanding concrete's performance in bending scenarios.