Temporary Precast Panels and Self-Consolidating Concrete for Accelerated Slab Replacement

Abstract

An innovative method was developed to accelerate replacement of segments of slabs in concrete pavement rehabilitation projects with the goal of increasing production and reducing construction time. The two-component method involved the use temporary and reusable precast panels and self-consolidating concrete (SCC). Laboratory tests were performed to develop the proper SCC mix and precast panel design. Field demonstration was conducted in a dedicated test track to validate the method. The SCC mix incorporated 1” (25 mm) maximum size coarse aggregate, low w/c and as a combination of admixtures to increase and maintain workability, and accelerate early strength development. Two precast panels were prepared to be installed in slab replacement pits. A pavement test track was used to demonstrate validity of the method. Inside the track a slab-replacement testpit was prepared and used to evaluate the installation and removal of the panels, as well as the casting of the replacement slab using the SCC mix. The precast panels and replacement slab were tested under multiple cycles of heavy trucks without experiencing panel failure or cracking. The method was validated for speed of panel installation, as well as rapid SCC mix discharge, workability retention and high early strength.