ACI Concrete Strength Testing Technician Practice Test

What does the term 'modulus of rupture' refer to in concrete testing?

1. The compressive strength of the concrete

2. The tensile strength calculated during fracture

3. The stiffness of the concrete mix

4. The elasticity of the concrete specimen

The correct answer is: The tensile strength calculated during fracture

The term 'modulus of rupture' refers specifically to the tensile strength of concrete when a specimen fractures. This measurement is crucial because concrete is primarily strong in compression but relatively weak in tension. The modulus of rupture is determined through tests that assess how much tensile stress a concrete beam can withstand before failing. Thus, this property effectively captures the material’s performance in real-world applications where tensile forces are present, providing critical insight into the structural integrity of concrete in service. Understanding this property is vital for engineers and technicians, as it informs decisions on mix designs, structural applications, and necessary reinforcements to ensure that concrete elements can resist the types of stresses they will encounter during their lifetime.