Council for Scientific and Industrial Research, Building and Road Research Institute, Kumasi, Ghana, India

Laboratory classification, compaction and bearing test results indicate that the natural materials are unsuitable by standard gravel acceptance specifications for road base construction. However, the bearing properties can be improved to meet base-material specifications through treatment with about 5% cement. Results of construction control studies also revealed that the laboratory compaction properties of both the raw and cement-stabilised gravels are easily reproduced in the field using fairly light, smooth-wheel rollers. This means that the complaints by contractors of difficulty in achieving design specifications using similar plants during construction is not justified.

Notwithstanding the results of the studies reported herein, it is not possible at the moment to suggest any construction control specifications for these gravels until more data on their in-service performance in the roadway has been collected and analysed over a number of years.