cubic yards of RCC
pound minimum of cementitious materials per cubic yard of RCC
The new Prichard Intermodal encompasses approximately 100 acre site in Prichard, WV. It is serviced by a Norfolk Southern railroad line. The site is bordered by the Big Sandy River on the west, which is also a state line between West Virginia and Kentucky. The facility offers industrial and warehousing space, a modern and efficient freight container service and improved access to international rail lines. The purpose of the project is to stimulate and support economic development within the region and provide and maintain connections to key regional and national transportation corridors.
Morgan Corp. Contributions
Morgan Corp. was the RCC paving subcontractor working with the prime contractor - Mountaineer Contractors. Morgan Corp. scope of work included mixing, transporting and placing more than 21,000 cubic yards of RCC paving. The entire RCC pavement is 18 inches thick, placed in two 9-inch lifts. Underneath the RCC layers, the pavement section consisted of a bituminous stabilized open graded drainage layer over an aggregate base course on top of the prepared subgrade.
The project specification required a minimum of 500 lbs. of cementitious materials per cubic yard of RCC. The specified compressive strength of molded cylinders was 5,000 psi at 28 days. Morgan Corp. designed the RCC mixture, which was verified by an independent testing laboratory. The RCC was mixed in a RapidMix 600 continuous pugmill mixer. A three bin blending hopper was used to convey the predetermined aggregate proportions to the mixer hopper. In addition to the plant primary cement silo, an auxiliary cement silo was used to augment the cement feed and maximize the RCC production rate in order to feed two paving trains simultaneously. Two Volvo high-density paving machines operating back-to-back placed the two lifts of RCC. The top lift was spread within 30 minutes of placing the bottom lift to ensure bonding at the lift interface. Cores obtained from the test section demonstrated 100% bonding at core locations.
Morgan Corp. optimization of the RCC mix design included several trial mixtures and selection of the best mix meeting (1) the required engineering properties and (2) the required performance during placing and rolling. The optimized gradation of the combined aggregates mixed with 500 lbs. of cement per cubic yard produced a compressive strength consistently exceeding the specified compressive strength by a wide margin.