Determination of concrete strength based on the double-hole shear in situ test

摘要

The determination of concrete strength in situ plays a critical role in the quality of structural engineering analysis and acceptance. The strength is usually determined through pure tension tests, like the common pull off test. However, in most applications, the shear strength is more interested. A novel approach, that is instrumented double-hole shear test, was presented for determining the strength of concrete. Drill two holes at two sides of measured concrete area, and the indentor is loaded from one hole in giving shear failure. Then, determine the strength of concrete according to the maximum shear stress when it's destroyed. Conduct the double-hole shear test and the cubic compresion strength test on the different strength of concrete specimens and establish the correlations between the two strength values. The results show that the ratio of the two strength values is in the range from 0.085 to 0.351, which depends on the concrete strength. And the two strength values have a good linear relationship so it can provide a new method which can easily and reliably determine the concrete strength in situ.