The design, construction and heavy vehicle simulator testing results on roller compacted concrete test sections at the CSIR innovation site and on a full-scale test road at Rayton

Abstract

Paper presented at the 33rd Annual Southern African Transport Conference 7-10 July 2014 "Leading Transport into the Future", CSIR International Convention Centre, Pretoria, South Africa.Although the use of Roller Compacted Concrete (RCC) is not new in South Africa, the use of it to construct roads is not that well known or studied. The Gauteng Provincial Department of Roads and Transport (GPDRT) in conjunction with the CSIR Built Environment and Cosal Consultants CC started a research programme in the use of RCC technology for roads. Whereas RCC is normally constructed with a relatively low labour component using heavy mechanical equipment, one of the aims of this investigation is to evaluate the structural performance of RCC constructed with a relatively high labour component using hand-operated equipment. The evaluation was done using the Heavy Vehicle Simulator (HVS) of the GPDRT. This paper briefly details two investigations, one conducted at the CSIR innovation site and the other test on a full-scale test road close to Rayton, Gauteng. The second investigation started in July 2013, and this paper deals mainly with the construction and initial test results of this test. Through HVS testing it has been shown that this type of pavement performed well in the dry state, even when constructed on a substandard support system. Test results indicate that this type of pavement exceeded its predicted performance. The use of hand labour for layer compaction is discouraged as this can lead to layer densities of lower than acceptable standards which result in poor performance. The importance of proper RCC mix design to mitigate the negative effects of shrinking and crack forming is highlighted in this study.