Collier, Zachary; Raghavendra, Amar; Rupnow, Tyson
Louisiana Transportation Research Center; Louisiana Department of Transportation and Development
Concrete pavements; High early strength cement; Patching; Pavement maintenance; Rehabilitation
The requirements for opening concrete pavement repairs to traffic vary greatly around the country. The reasons states and their transportation departments specify these different requirements includes traffic opening requirements, environmental conditions, and locally available materials, among other things. This project reviewed the practices and requirements for early-opening-to-traffic concrete used by other state DOTs. Knowing the best approach to take can lead to dependable concrete, increased use of travel lanes, and a reduced cost of the materials and construction methods. A comprehensive literature review of state specifications and rehabilitation policy was completed. Current and former research on the use of high early strength concrete in pavement rehabilitation was reviewed as well as various material and equipment requirements specified by states in pavement rehabilitation. This report also reviewed responses from a recent National Concrete Consortium state survey which compiled responses on opening and rehabilitation criteria from states across the country. The current Louisiana opening specification for full-depth corner patching, full-depth jointed concrete patching, partial-depth patches of jointed concrete pavement, and continuously reinforced concrete pavement is an opening strength of 3000 psi. The state of Louisiana also allows the use of the maturity method to determine concrete strength on a project by project basis, with the approval of the Chief Construction Engineer. The current specifications are based solely on compressive strength and are not necessarily based on the mechanics of materials. The authors recommend changing the 3000 psi requirement for early opening to traffic to the SHRP-206 findings of 2000 psi. To gain the maximum benefit of early opening, the authors also recommend full adoption of the maturity method for estimating in-place strength.