Better Concrete Mixes for Rapid Repair in Wisconsin

Project Details









Steven M. Cramer, Le T. Pham, Mark B. Snyder


Wisconsin Department of Transportation


Calcium chloride, Concrete, high early strength, Life cycle analysis, Mix design, Portland cement, rapid repair, Rigid pavement



Project description

With the increasing demands on the highway system and increasing costs of user delay, the use and development of rapid-repair techniques are expected to grow rapidly. High early strength (HES) portland cement concrete can help reduce the duration of traffic closures while being cost-competitive with other solutions such as concrete using proprietary cements and precast concrete. This research investigated the performance of HES portland cement concrete used for pavement repairs through multiple approaches. Thirteen mixtures were made and tested in the laboratory for strength, drying shrinkage, and scaling resistance. A field review of 12 recent rapid-repair pavement projects in Wisconsin was conducted to evaluate field performance of the pavements. An informal survey of Wisconsin concrete suppliers was conducted to obtain information on mix design, challenges, and approaches to rapid repair of pavement. Life-cycle cost analysis was conducted for pavement repairs using cost data assumed to be representative of the lab tested mixtures and precast concrete. The field review showed no significant durability issues except for one project where severe scaling occurred. Concrete using portland cement with calcium chloride accelerator can surpass WisDOT compressive strength requirements of 3000 psi in 8 hours and have satisfactory scaling resistance. Concrete using a nonchloride accelerator had excellent scaling resistance, slightly higher shrinkage than non-accelerator concrete, and may be a good alternative to calcium chloride when the strength requirement of 3000 psi can be extended to within 10 hours. Overall it appears that durability issues that occurred in rapid-repair pavements are more likely due to difficulties associated with construction or mix procedures than the WisDOT specifications. To ease these difficulties, the use of dry calcium chloride may be considered if it can be mixed uniformly with the concrete. An upper slump limit specifically for rapid-repair concrete would provide flexibility and may be higher than that for conventional concrete.