Provisional results from accelerated pavement testing of roller-compacted concrete in South Africa

Abstract

In conjunction with the Gauteng Department of Roads and Transport and Cosal Consultants CC in South Africa, the CSIR Built-Environment is evaluating the applicability of Roller Compacted Concrete (RCC) as an option for the upgrading and rehabilitation of low-volume residential and provincial roads. The ultimate aim of the study is to build confidence in the use of RCC, with cognizance being taken of the pavement structure, support conditions, construction, climate, and traffic. Whereas RCC is normally constructed with a relatively low labor component and with heavy mechanical equipment, the goal of this investigation was to evaluate the structural performance of RCC constructed with a relatively high labor component using handoperated equipment. This is in line with the South African Government’s drive towards sustainable job creation, together with the pressing need for the upgrading and maintenance of the low-volume road infrastructure. Fullscale Heavy Vehicle Simulator (HVS) tests were conducted to determine the structural capacity of the RCC. This paper summarizes the provisional results from the first Accelerated Pavement Test (APT) on the control section, constructed using conventional methods and equipment. Through APT testing it was shown that this type of pavement performed exceptionally well in the dry state, even though it was constructed on a substandard support system. Initial indications are that actual performance exceeded predicted performance. Sensitivity to water is an important factor that will be investigated in subsequent testing. Testing of the labor-intensive constructed sections will be documented in a separate paper.