Pavement repair has been an issue in many areas throughout the United States. North Carolina’s efforts to improve roadways and alleviate traffic congestion in the Triangle resulted in the I-40 "Fortify" rebuild project, which was part of a 10-year improvement plan. The repairs included work along the southern stretch of I-40 in Raleigh, where pavement replacement was needed. Investigation of the roadways showed that the 30-year-old pavements were cracking and crumbling because of a chemical reaction—alkali-silica reactivity (ASR)—beneath the road.
As the road deteriorated, the safety of the motorists who frequented this busy highway was jeopardized, so replacing the pavement was deemed essential. The roadway has more than 120,000 vehicles travel on the highway every day.
The North Carolina Department of Transportation (NCDOT), District 9, oversaw the full-depth panel replacement on this section of I-40. Lane Construction and Heartland Concrete were brought in to perform these repairs for NCDOT. Heartland Concrete chose to use a highly durable material that is highly resistant to ASR, gains strength quickly, and has low shrinkage: Rapid Set® Cement.
The process involved mixing the bulk Rapid Set® Cement in a volumetric mixer, and then finishing using a roller screed and float.
The specifications for these repairs called for the concrete to meet a 400-psi flexural strength in four hours. Rapid Set® Cement not only met the strength but beat the requirements and reached 400-psi flexural strength in two hours—half the time. By achieving the flexural strength in half of the required time, it allowed for more hours of production each day.
During the three months of the repairs on this section of the highway, 3,070 cubic yards of Rapid Set® concrete was placed.