Investigation into early deterioration of surface dressings in Ghana

Thumbnail Image
Journal Title
Journal ISSN
Volume Title
The success of bituminous surface dressing depends primarily on the adhesion of the chippings to the road surface. Premature failure of surface dressing in the country has become prevalent to the extent that some constructions begin to deteriorate soon after being in service. The overall aim of this research was to identify the possible causes of early deterioration of surface dressings in Ghana. The methods adopted for the study were: (i) examination of the existing local specifications for bituminous surface dressing, (ii) data collection through the use of a well-structured questionnaire to assemble empirical knowledge on surface dressing practices in Ghana, and (iii) visit to surface dressing construction site to assess construction practices. The study revealed that designers of the seal do not take into consideration the road surface temperature when specifying the binder viscosity. Also, not all the recommended tests are performed on the chippings by some of the contractors to ascertain aggregate conformity to the specifications. The study also established that rolling requirements were often ignored during construction and where rolling was carried out, sometimes the equipment used did not conform to specification. Because most of the contractors were not using electronic bitumen distributors and chipping spreaders, the possibility of inaccurate binder and aggregate application exist.
A thesis submitted to the Department of Civil Engineering, College of Engineering, in partial fulfillment of the requirements for the degree of Master of Science Road and Transportation Engineering,