ACI Concrete Strength Testing Technician Practice Test

What is the minimum amount of cylinders that need to be measured if they come from a lot of molds with consistent size?

1. One for each five specimens

2. One for each ten specimens

3. Two per day

4. Three per lot

The correct answer is: One for each ten specimens

To determine the appropriate answer, it is essential to understand the guidelines for measuring concrete specimens in a testing scenario. When handling a lot of concrete cylinders made from molds of consistent size, the industry standard typically recommends measuring one cylinder for every ten specimens. This approach ensures that there is a sufficient sample size to assess the overall strength and consistency of the concrete without overburdening the testing process. Therefore, measuring one for every ten specimens provides a balance between accuracy in assessing the concrete's quality and efficiency in testing procedures. The guidelines suggest that this sampling ratio helps in not only maintaining an effective use of resources but also in capturing variations that might occur due to the batching process, mixture consistency, or other factors affecting concrete strength. Thus, measuring cylinders at this rate supports reliable and valid results, propagating confidence in the quality control processes.