I-15 north of Salt Lake City, Utah, is a busy eight-lane highway that handles approximately 140,000 vehicles per day. It’s also a highway that recently underwent repairs on a 5.11-mile section between Centerville and Farmington. Since I-15 is the primary route into and out of Salt Lake City on the north side of town, UDOT placed significant restrictions on the work window for the project. Construction had to be completed within 90 calendar days, with a lane closure length limit of 2.5 miles and a working time window of seven hours each night. Lanes had to be open to traffic by 5 a.m., except on Saturday and Sunday.
The general contractor, Greene’s Inc. of Utah, had many phases of this project to complete and because of the short work window, several of them had to be taken on simultaneously. The project consisted of partial-depth repair with a flexible patch material; full-depth precast panel replacement; surface grinding; joint clean and reseal; mill and repave the inside and shoulder lanes with hot-mix asphalt; and guardrail upgrades. One of the characteristics that made this project different was that UDOT requested that all repairs be made prior to the grinding, which would be the final step. This technique has not been very successful in the past for patching, but Greene’s Inc. had used Crafco materials on projects before and selected Roadsaver 211 for the joint repairs and TechCrete as the patching material.
Crafco’s technical department created and tested several models pertaining to the installation of the TechCrete. An optimum formulation was accepted by UDOT consisting of an initial lift of TechCrete; then after some cooling a second lift of TechCrete that had been stone blended into the mix for added structure was placed. A surface cover stone of 1/2 in. uniformly graded rock was ironed into the surface in order to create a durable, flexible and smooth-riding concrete patching material that will perform after surface grinding.
Greene’s Inc. used four Crafco Patcher II machines to install the TechCrete material, and before the project was complete over 300,000 lb of TechCrete was installed in the 90-day timeframe. The TechCrete withstood the 1/4- to 3/8-in. grinding that took place after it was installed and is performing as expected.