Refereed Journals

In Sub-Saharan Africa (SSA) the rapid and market-driven spread of the motorcycle taxi in the last two or three decades has made it the dominant means of (intermediate) transport in most urban (and rural) settings. Using primary data collected in five SSA countries, as part of a VREF study, this paper investigates the various MCT business models that have emerged and their implications for the overwhelmingly male operators, opportunities for introducing female operators and for the role of policy-makers to regulate, modernize, formalize and support the sector. Opportunities for key stakeholders and policy makers to learn from each other – both ‘best practice’ and what does not work – remain limited at national level, let alone at regional level. This study shows that there are – despite some differences – many similarities between the MCT sector’s operational model and their challenges, so there should be ample opportunity to learn from each other to improve the quality of this now essential mobility service

The most valuable natural resource on Earth is groundwater, which serves more than
two billion populaces as a drinking water source worldwide. Despite its vital importance,
groundwater has faced significant challenges, particularly in terms of its quality. Therefore, a
thorough understanding of groundwater hydrogeochemistry is essential to assess the water
needs for domestic use and irrigation use. This research evaluates groundwater quality in
granitoid aquifers in the Kassena Nankana, Bawku West, and Garu Tempane districts of Ghana.
An integrated approach was used, incorporating The World Health Organization (WHO), the
Water Quality Index (WQI), and irrigation indices to offer recommended values for domestic and
irrigation purposes.  

Evaluating road surface conditions is a crucial aspect of the operation and maintenance of road infrastructure. This issue is particularly pronounced for unpaved roads, which lack protective hard surfaces like concrete or asphalt. New methods are emerging for identifying and extracting road surface condition parameters from remotely sensed imagery. Accordingly, this study demonstrates an approach to identify and extract road surface condition parameters from remotely sensed images obtained from unpaved roads with distinctive environmental characteristics. An Unmanned Aerial Vehicle (UAV) was employed to capture images of unpaved roads, which were then pre-processed and analysed by constructing a digital elevation model (DEM) and orthomosaic. The processed imagery was validated against conventional field measurements of road defects. The number of defects identified and their severity was comparable for both methods. The defect counts were similar in all cases except for one, which varied between the two approaches. The predictions of defect severity, expressed as percent count, were accurate -vegetation encroachment had the highest rate at 100 %, while depression had the lowest at 25 %. These findings highlight thepotential of using remotely sensed imagery from UAVS to identify, extract, and measure road surface condition parameters for unpaved roads. The results can assist road agencies in the country in promoting low-cost and effective road maintenance operations.

The growing interest in sustainable alternatives to traditional steel fiber reinforcement has led to increased exploration of plant fibers for concrete applications due to their low carbon footprint and renewability. This study investigates coconut coir fibers (CF) as a single reinforcement material in concrete, alongside synthetic polypropylene fibers (SF) and a hybrid combination (SF50CF50) for comparative analysis. The mechanical properties evaluated include compressive and flexural strength, while durability aspects focused on water absorption, porosity, chloride penetration, and drying shrinkage. Results showed that SF exhibited the highest compressive strength, whereas CF underperformed at all curing ages. However, all fiber-reinforced concretes (FRC) demonstrated improved flexural strength compared to plain concrete. In terms of durability, both water absorption and porosity decreased with fiber incorporation, indicating reduced void content. However, CF exhibited better resistance to chloride penetration than SF and hybrid FRC.

 Using conventional methods of concrete production to achieve expected results is challenging, hence the use of chemical admixtures which is also little researched in Ghana. The study conducted a concrete mix design for project construction, following significant challenges encountered in attaining the desired strength of 30MPa at a slump of S3 (100-150mm). To address the challenge, a concrete mix design was produced according to EN 206 standard mix design at the laboratory of the Council for Scientific and Industrial Research (CSIR)-Building and Road Research Institute (BRRI)-Ghana. A chemical admixture consisting of high-range water-lowering sulfonated naphthalene formaldehyde (SNF) was used in the design. Once the laboratory mix design was completed, the concrete mix proportions were adopted for field application. When employing 385kg/m3 of Portland cement, a water-to-cement ratio of 0.49, a water content of roughly 189kg/m3, and an admixture content of 3.28kg/m3, the laboratory mix design yielded a 28-day compressive strength of 37 MPa (5366 psi). After 28 days of curing, both the laboratory (37MPa) and field-prepared (31MPa) concretes met the minimum strength of 30MPa with the laboratory-controlled concrete exhibiting compressive strength results that were approximately 16% greater than those of the field-prepared concretes. The report revealed that the use of SNF resulted in 18% savings in cement thereby reducing carbon emissions and 5% savings in cost, urging a case for the use of chemical admixtures for structural and non-structural concrete components of the project for the sake of durability, sustainability and cost.