Roller-compacted concrete (RCC) is a durable, economical paving ma-terial for heavy-duty traffic. In the past, most RCC pavements havebeen built for low-speed traffic because of the difficulty of producing asmooth surface. A composite pavement system consisting of an RCCpavement structure and a hot-mix asphalt (HMA) riding surface is pro-posed. Simplified design tables, based on mechanistic analysis, are pre-sented. Only fatigue cracking was considered, because performancestudies of RCC have shown very little tendency for joint or crack fault-ing. Use of the design procedure is illustrated through an example.Results are compared with several other design procedures. Guidancefor materials selection for the HMA surface layer and the subbase layeris provided, and construction considerations are reviewed. Cost datashow that the initial cost of RCC pavements may be as low as 62% of thecost of conventional paving alternatives (not counting the HMA surfacecourse). Suggested areas for further research into RCC composite pave-ments are discussed. The advances in RCC technology over the past twodecades have made RCC a durable, economical alternative for indus-trial and multimodal pavements. Further use of RCC as part of a com-posite pavement system for highways offers considerable potential. Oneobstacle to use of RCC for highways has been the absence of a suitabledesign procedure. That need has been addressed in this research.

Over the past three decades, more than 100 roller-compacted con-crete (RCC) pavement projects have been constructed in NorthAmerica. RCC is a reliable, economical, durable material for low-speed, heavy-duty pavements. The U.S. Army Corps of Engineers(USACE) has used RCC extensively for tank roads and equipmenthardstands. Other successful projects documented by the PortlandCement Association (PCA) include ports and intermodal terminals,storage areas, and roads (1, 2).

RCC pavements have been used for

• Highway weigh stations,• Airport aprons,• Docks and container ports,• Multimodal facilities, and• Heavy industrial facilities such as logging and automobile

manufacturing.

One obstacle to the use of RCC for high-speed highway pave-ments has been the roughness of the surface. However, a thin hot-mixasphalt (HMA) overlay may be combined with an RCC pavementstructure to produce a composite pavement structure, as illustrated in

Figure 1. The HMA provides the necessary smooth riding surface forhigh-speed traffic.

Recently the South Carolina Department of Transportation(SCDOT) placed an 8-in. (200-mm) thick 1,000 ft (305 m) RCC testsection near Aiken, South Carolina. This pavement has no asphaltoverlay, and the performance has been good so far. SCDOT hasdeveloped a specification for RCC pavement (2, 3). The agency antic-ipates using RCC with a 4-in. (100-mm) overlay as an economical,durable pavement and is considering a larger test section.

The PCA has developed a computer program, RCCPave, for thedesign of RCC industrial pavements, which also may be used forhighway pavements (4). However, this procedure makes no provi-sion for an HMA overlay. Furthermore, the loading conditionsassumed by RCCPave are not realistic for highway traffic becauseonly interior and edge loadings are considered.

A simplified design procedure is presented for RCC compositehighway pavements. First, materials for RCC composite pavementlayers are discussed. Next, the background of the design procedureis presented, along with an illustrative example. Finally, construc-tion of the RCC composite pavement is considered. Durability andeconomy are also addressed.

MATERIALS CONSIDERATIONS

As shown in Figure 1, the RCC composite pavement system con-sists of several layers. The top layer is the HMA riding surface,which will have very low flexural stresses and strains. The secondlayer from the top is the RCC, which will carry the traffic loading.Because the RCC must be well compacted, usually it is necessary toplace a subbase course over the subgrade unless the subgrade pro-vides adequate stiffness and support for the compaction process.The thicknesses and material properties of the layers used to developthis design procedure are shown in Table 1.

HMA Riding Surface

The main reason for the HMA overlay on the RCC is to provide asmooth, high-speed riding surface for the RCC pavement. Typicalfailure modes for HMA pavement layers include cracking, rutting,and material deterioration (5, 6). In the system considered, the HMAlayer is assumed to be 1 in. (25 mm) thick, although it could be madethicker. The HMA was assumed to be fully bonded to the RCCpavement.

Cracking in HMA pavements is caused by flexural fatigue due totraffic and by low temperature strains and increases in stiffness ofthe asphalt. Due to the strong support provided by the RCC, HMAflexural stresses and strains in a composite pavement will be very

Simplified Design of Roller-CompactedConcrete Composite Pavement

Norbert Delatte

Transportation Research Record: Journal of the Transportation Research Board,No. 1896, TRB, National Research Council, Washington, D.C., 2004, pp. 57–65.

Department of Civil and Environmental Engineering, Cleveland State University,Cleveland, OH 44115.

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