Hartman then discussed the successful project with Henry County Highway Supervisor Joe Wiley, who contacted Chad Hayes of Buster's Cement Products. Wiley was facing an unprecedented 76% mid-year price increase that would have essentially destroyed his budget. Henry County and Buster's partnered to provide RCC on a street project.
In another situation, Builder's Concrete had been in discussions with Calumet Civil Contractors on partnering on a few municipal and county contracts. Calumet is in a unique position because it does not own asphalt plants. It buys asphalt from competitors who own the manufacturing plant.
Calumet was feeling the full impact of the rising asphalt prices. It had several projects on the books that were bid in the 2007 lettings that were not yet built. Like most contractors, Calumet had included what it thought would be the typical increase in material costs. No one anticipated asphalt prices nearly doubling and Calumet was looking at added material costs in excess of six figures on some projects.
The city reviewed an information packet compiled by IRMCA and allowed Calumet to provide the City of Indianapolis with an alternate design on a particular project. Calumet chose a reconstruction project on the city's southeast side, which included installing new sanitary sewers down the middle of several residential streets.
Crews had to remove the existing asphalt streets to perform the work. Calumet and Builder's Concrete asked IRMCA to conduct an analysis of the existing asphalt section, as well as what would be required to substitute RCC for the asphalt base and binder. The stone was already in place and the decision was made to substitute RCC on an inch-for-inch basis.Building a base
As a result, 5 inches of RCC was substituted for the 3-inch base and 2 inches of binder. Given that that concrete is stronger than asphalt on an inch-for-inch basis, the city allowed the substitution. The 1 ½ inches of asphalt surface was retained as a non-structural wearing surface.
Scott Hall, Builder's QC manager, prepared a mix design for the city's review. Hall utilized a dense graded aggregate material with 100% passing the 1-inch sieve. He utilized aggregate gradation analysis techniques that had been used in Builder's industrial floor work.
They also performed strength verification utilizing the hammer drill techniques outlined in ASTM C 1435. Once the mixture was finalized, the mixture's optimal moisture content and maximum density were determined per ASTM D 1557.
Workers installed the project in several phases over a couple of weeks. The first phase was manufactured by Builder's at its dry-batch facility. Calumet had requested 100 yards per hour. Eight ready-mix trucks were dedicated for placement. To properly mix such a dry concrete, Builder's batched 5 yards in each truck.