Alternative Surfacing for Steep Hill Sections in Ghana – Phase 2

English

The Council for Scientific and Industrial Research (CSIR) in South Africa, in partnership with the Building and Road Research Institute (BRRI) of Ghana, was appointed by the Africa Community Access Partnership (AfCAP), being managed by Cardno Emerging Markets (UK) Ltd on behalf of the UK Department for International Development (DFID), to undertake the second phase of a study on alternative surfacing for steep slopes on low-volume (feeder) roads in Ghana. This followed the first phase study to scope for and select suitable surfacing options for the current project. The principal project partner is Ghana Ministry of Roads and Highways represented by the Department of Feeder Roads (DFR). The contract that was awarded on 24 January 2017, has a start date of 13 February 2017 and is scheduled for completion on 3 February 2020. The objective of the current study is to identify, define and demonstrate appropriate surfacing options as alternatives to the current gravel wearing courses on the steep hill sections of feeder roads in Ghana, and to offer sustainable solutions to address drainage and erosion problems experienced by those steep sections. Demonstration sections will be designed and a nominated contractor will construct the pavements using costeffective machinery and labour-based methods. The sections will be monitored, and data will be collected for development of guidelines and specifications for steep slopes. It is anticipated that the demonstrated surfacings would be adopted by the DFR as treatment options for steep slopes on feeder roads, and spot improvement to vulnerable steep sections of an otherwise acceptable gravel road on flat and rolling terrains to provide all-season access. The work will be carried out in the Eastern region of Ghana. This region has mountainous terrain (several low-volume roads are located on gradients in excess of 12%) and annual mean rainfall of 1,800 mm. The study will not only develop and introduce innovative ways of constructing the alternative surfacings, but will also build capacity and knowledge transfer amongst Ghanaian practitioners, researchers at the DFR, BRRI and Ghana Highways Authority (GHA). The work done during the inception phase and the project planning for subsequent tasks are summarised in this report. Suitable project site selected for the study, and viable research matrix of surfacing options to demonstrate in the project are presented. The preliminary recommendations made in this report will be discussed further with the DFR to ensure effective implementation of the works.

Anochie-Boateng, J.; Debrah, E.