Statistical Determination of Cracking Probability for Mass Concrete

This study addresses the use of a stress-to-strength ratio as a failure criterion for thermal cracking. Restrained cracking frame specimens and accompanying match-cured concrete cylinders were tested to determine the ratio of stress-to-splitting tensile strength at cracking. A stress-to-splitting tensile strength ratio of 0.57 was found to give a 50% probability of cracking and lognormal standard deviation of 0.16 when splitting tensile cylinders sized 100 x 200 mm (4 x 8 in:) and 150 x 150 mm (6 x 6 in:) rigid cracking frame specimens were used to determine the stress at cracking. Lognormal fits of the cracking stress from 64 cracking frame tests and the tensile strength calculated from the measured compressive strength using three commonly used equations based on compressive strength were developed. (C) 2014 American Society of Civil Engineers.