What is a key reason for testing compressive strength of concrete cylinders?

Testing the compressive strength of concrete cylinders is primarily done to determine if the concrete has reached a sufficient strength to be opened to traffic. This is essential in construction and infrastructure projects, as it ensures that the concrete can withstand the loads and stresses it will encounter once the surface is used.

Concrete typically goes through a curing process, and the strength gains are monitored to ensure that the material meets the required specifications before it is subjected to traffic. If the compressive strength is insufficient at the time of testing, it indicates that the concrete is not yet ready for use, helping prevent potential failures or damage to the structure.

While improving mix design, evaluating aggregate quality, and assessing worker performance are important aspects of concrete production and quality assurance, the immediate concern after pouring concrete is to confirm its strength for safe usage. Thus, testing for compressive strength is a critical step in determining readiness for traffic.