Qualification of concrete mixtures for fast track construction applications

Abstract

Fast track construction is a special type of construction where construction methods and activities are planned to minimize the construction duration. Since the duration of the hardening period of concrete is largely undefined at the time of placement, it becomes difficult to schedule the time necessary for the curing of concrete in fast track intersection constructions. In order to plan and organize a construction, the construction schedule needs to be established prior to the beginning of the actual construction. Therefore, a good estimation of the duration of the curing of concrete activity needs to be made by the scheduler. In this research, a method that can be used to predict the time of curing and strength development for a concrete application is proposed. By using this method, concrete strength can be predicted non-destructively by measuring the maturity of concrete and utilizing a strength-maturity relationship. A series of laboratory tests was carried out and the results of these tests were statistically analyzed to develop a strength-maturity relationship. A temperature independent model was developed to be able to utilize it at different curing conditions. This model can be used in the field to validate the strength of concrete by measuring the maturity of concrete. Field work was carried out to evaluate the applicability of the method in the field. Finally, a concrete temperature simulation program was used to predict the opening time of a concrete slab under prevailing site conditions.