ACI Concrete Field Testing Technician - Grade I Practice Exam

When consolidating a flexural strength test specimen by rodding, how many strokes should be used for each 2 in.^2 [14 cm^2] of top surface area?

1. One stroke

2. Two strokes

3. Three strokes

4. Four strokes

The correct answer is: Two strokes

When consolidating a flexural strength test specimen using the rodding method, the recommended practice is to use two strokes for each 2 inches squared of top surface area. This approach ensures adequate compaction of the concrete within the mold, helping to eliminate air pockets and voids that could adversely affect the test results. Proper consolidation is critical in flexural strength testing because it influences the density and homogeneity of the specimen, ultimately impacting the accuracy and reliability of the strength readings. Using two strokes creates a balance that allows for sufficient compaction without overly disturbing the mix, which could lead to segregation of the ingredients. Adhering to this standard practice provides consistency in the testing process, aligning with established industry guidelines that are designed to generate repeatable and valid results.