Report on Roller-Compacted Concrete Pavements (ACI 325.10R-95)

Description

This state-of-the-art report contains information on appli-cations, material properties, mix proportioning, design, con-struction, and quality control procedures for roller com-pacted concrete pavements (RCCP). Roller compacted con-crete (RCC) use for pavements is relatively recent and the technology is still evolving. Over the last ten years several major pavement projects have been constructed in North America using RCC and the performance of these pavements has generally been favorable. Roller compacted concrete pavements are also gaining acceptance in several Europeancountries and Australia.

The advantages of using RCC include cost savings as a re-sult of the construction method and the increased placement speed of the pavement. RCC pavements do not use dowels, steel reinforcement, or forms. This also results in significant savings when compared to the cost of conventionally con-structed concrete pavements .Roller compacted concrete is used in two general areas of engineered construction: dams and pavements. In this docu-ment, RCC will be discussed only in the context of its use inpavements. RCC for mass concrete is discussed in ACI207.5R.Roller compacted concrete for pavements can be de-scribed as follows: A relatively stiff mixture of aggregate [maximumsize usually not larger than 3/4 in. (19 mm)], cementi-tious materials and water, that is compacted by vibra-tory rollers and hardened into concrete. When RCC is used as a surface course, a minimum compressive strength of 4000 psi (27.6 MPa) is generally specified.

The materials for RCC are blended in a mixing plant intoa heterogeneous mass which has a consistency similar todamp gravel or zero slump concrete. It is placed in layersusually not greater than 10 in. (254 mm) compacted thick-ness, usually by an asphalt concrete paving machine. Thelayers are compacted with steel wheel vibratory rollers, withfinal compaction sometimes provided by rubber tire rollers.The pavement is cured with water or other means to providea hard, durable surface. RCC pavements are usually de-signed to carry traffic directly on the finished surface. Awearing course is not normally used, although a hot mix as-phalt overlay has been added, in some cases, for smoothnessor rehabilitation. Transverse and longitudinal contractionjoints for crack control are not usually constructed in RCC pavements.