Associate professor, School of Engineering, Purdue University, West Lafayette, IN
The standard superficial Rockwell 15Y hardness test has been adapted for use on concrete. Hardness measurements were made on the mortar regions between the coarse aggregate pieces. A correlation between this hardness and the concrete's compressive strength was developed. For 7.5- by 15-cm (3- by 6-in.) cylinders, it is Rockwell 15Y hardness = 73.5 (log compressive strength in psi) — 187 or 73.5 (log compressive strength in MPa) — 28.0. Various effects of specimen preparation and size are discussed, as are the statistics of the test.
Paper ID: CCA10366J