The California Department of Transportation (Caltrans) uses Rapid Strength Concrete (also known as High Early Strength Concrete) to repair or rehabilitate concrete pavements. Failed concrete slabs are removed and replaced with Rapid Strength Concrete (RSC) that is often volumetrically proportioned in the field. Both Type III Portland cement concrete and specialty cements are used to prepare RSC.
The performance of slab replacement strategy using RSC has been questionable based on past experience. A study was conducted to evaluate and compare the performance of RSC made with the two different cement types. Due to relatively short performance data and variability of the influencing performance factors, no definite conclusions were derived from this study.
One consideration in potential short service life of slabs constructed with RSC is the limitation of proper concrete curing. Internal Curing (IC) with light weight aggregate is employed to compensate for the lack of external/surface curing of the concrete. A pilot slab replacement project on I-680 in Bay Area was identified and slabs were placed side by side with and without light weight aggregate to monitor and compare the performance of the RSC using Internal Curing. The steps that are taken to initiate, design and construct this pilot project is discussed in this paper. The Department plans to monitor, test and report the expected improvement in the performance of RSC with Internal Curing in the future.