Early Age Cracking Control in Semimassive Walls of RC Tanks by Internal Cooling

Semimassive tanks must satisfy the requirement of watertightness, so all attempts to reduce early-age imposed strains lead to considerable financial savings. The impact of a cooling pipe system (CPS) on a reinforced concrete (RC) tank wall where early-age cracks developed during construction has been analyzed. It has been proven that for RC tanks, the factor that contributes most to tensile stresses in the semimassive walls is the mean temperature of the maturing concrete. The second most influential factor is derived from self-stresses, and the least influential factor is the stress gradient. The calculations of self-stresses indicate that the use of a CPS leads to the formation of favorable compressive rather than tensile stresses in the central part of the wall. Most importantly, a CPS in RC tank walls significantly reduces the width of cracks that result from the cumulative effect of early-age and long-term imposed strains. The performed analysis provides a basis for the effective design of a CPS in RC tank semimassive walls. © 2021 American Society of Civil Engineers.