Which of the following methods can be used for in-place concrete strength testing?

The Schmidt Hammer Test is a widely used method for in-place concrete strength testing. This non-destructive testing technique measures the rebound hardness of concrete surfaces. By impacting the surface with a spring-loaded hammer, the amount of rebound provides an indirect measure of the concrete's compressive strength. This method is particularly useful when it is necessary to evaluate the strength of existing structures without damaging them, allowing for quick assessments across large areas.

In contrast, the other methods listed have different applications or limitations. The compression test and the flexural test typically involve extracting samples of concrete and testing them in a laboratory setting to determine their strength, making them destructive and not suitable for in-situ assessments. The coring test, while it can provide valuable information about the strength of the concrete, also requires the removal of a sample from the structure, which means it does not fit the criteria for in-place testing as it compromises the integrity of the original structure.