Over a period of 22 « hours, West Palm Beach-based CSR Rinker Materials Corp. placed 10,327 cubic yards of value-added concrete for the Santa Maria condominiums. The project's foundation mat--believed to be the largest residential mat in Florida history--measures 125x290 feet, is 10 feet thick, and reinforced with 3,300 tons of steel rebar. To complete the pour, Rinker used 100 trucks, based out of five of the company's batching facilities, and made 1,147 deliveries throughout the day. The crews averaged 500 cubic yards per hour throughout the day. The concrete used in the project has a slump range of 8 to 10 inches, a maximum freefall of 15 feet, a maximum lift thickness of 7 feet, and a design strength of 5000 psi after 56 days. The addition of 40% fly ash effectively controlled the heat of hydration, lessening the chance that cracks would appear in the mat in the future.