ACI Concrete Strength Testing Technician Practice Test

What compressive strength must sulfur mortars and high-strength gypsum cement cubes demonstrate?

1. 30 MPa (4350 psi)

2. 40 MPa (5800 psi)

3. 35 MPa (5000 psi) or the cylinder strength, whichever is greater

4. 25 MPa (3625 psi)

The correct answer is: 35 MPa (5000 psi) or the cylinder strength, whichever is greater

The requirement for sulfur mortars and high-strength gypsum cement cubes to demonstrate a compressive strength of 35 MPa (5000 psi) or the cylinder strength, whichever is greater, is grounded in ensuring that the materials used in construction can withstand the demands placed on them. This standard is particularly relevant in construction applications where the use of sulfur and gypsum-based materials is common. Using this criterion, specifying a strength of 35 MPa or higher allows for flexibility in quality assurance, as it can adapt to varying cylinder strengths based on the actual mix and testing conditions. If the cylinder strength surpasses 35 MPa, that higher value then becomes the benchmark for minimum acceptable strength. This approach encourages better practices in mixing and curing while also providing a safeguard against subpar performance. Other potential values given in the choices do not align with the rigorous standards set for sulfur mortars and gypsum cement, putting them at a disadvantage in terms of strength reliability and structural integrity.