Refereed Journals

Portland-limestone cement (PLC) currently has gained widespread use as the most accessible and sustainable blended cement in the market. However, in many African countries, including Ghana, the use of clay pozzolana (CP) in the concrete industry has primarily relied on ordinary portland cement (OPC). In this study, PLC Type II/B-L was partially replaced with CP at levels ranging from 10 to 50% by weight. The investigation included compressive strength testing, nondestructive evaluations using electrical surface resistivity, pulse velocity, and chloride penetration tests, targeting a characteristic strength of 30 MPa (4351.13 psi). Additionally, an environmental impact assessment based on the carbon footprint of both control and CP concretes was conducted. The mixture design followed the EN 206 standard. A total of 72 cubic molds were produced for the strength test. The results showed that CP concretes with between 10 and 20% replacement achieved strength values of 35 and 33 MPa (5076.4 and 4786.32 psi), respectively, higher than the target of 30 MPa (4351.13 psi) strength at 28 days. However, mixtures with 30 to 50% replacement required extended curing periods of 60 to 90 days to reach the desired strength. At extended curing, 10 to 50% CP replacement attained strength between 32 and 41 MPa (4641.28 and 5946.64 psi). Nondestructive test results showed no direct correlation with compressive strength, confirming that different factors govern strength, resistivity, and pulse velocity. The environmental impact assessment revealed a 14 to 51% reduction in carbon strength index (CSi) and a 19 to 36% increase in carbon durability index (CRi) with 10 to 50% CP (for CSi) and 10 to 40% (for CRi). The thermodynamic modeling also revealed that pozzolana contents below 30% primarily promoted pozzolanic reactions, enhancing performance compared to the control mixture. Based on these results, 20 to 30% CP replacement is recommended to ensure reliable performance, while higher levels (>30%) require further durability evaluation for long-term use.

Although motorized two- and three-wheelers are affordable, fast and can travel on poor road conditions, their negative consequences cannot be ignored. This study seeks to investigate the trend and compare the nature of crashes involving motorized two-wheelers and three-wheelers (comprising rickshaws and tricycles). Crash data for the twenty-year period, 2002–2021 and the accumulated number of registered motorcycles were used for the trend analysis. Data for the four-year period, 2018–2021, was used for the comparative analysis of the different types of motorcycles. To determine whether there are differences between the variables, chi-square (χ2) tests were performed on the crash data for the various motorcycle modes to assess statistical significance. From the
analysis, motorcycle is now the riskiest mode of transport in Ghana contributing 31.7% of fatalities in 2021 from a 2.7% share in 2002. Fatalities among motorcyclists increased by over 1800%, the highest of any road user type during the period. The two-wheelers constituted 85% of all the deaths with tricycles and rickshaws representing 13% and 2%, respectively. Fatalities among the different types of motorcycles varied with gender, age, time of day, day of week, collision type, region, type of ridership and number of vehicles involved in collision. A policy framework is required by the National Road Safety Authority (NRSA) to regulate commercial motorcycle operations which have fast become part of the commercial transport system, albeit illegal, in all parts of the country. The police should ensure the strict enforcement of crash helmet wearing among the two-wheelers to reduce fatalities.

Globally, about 1.19 million people died from road traffic injuries in 2021, of which more than 90% occurred in low- and middle-income countries. Every 1% increase in speed results in a 4% likelihood of a fatal crash and a 3% risk of a serious crash. The study aimed to establish the prevalence and predictors of speeding in two Ghanaian cities–Accra and Kumasi–across six rounds of data collection between 2022 and 2024. Microwave radar guns were used to unobtrusively observe vehicle speeds from 15 sites per city. Every site was observed for five daily sessions, for two weekdays and one weekend per data collection round. The prevalence of speeding was comparatively higher in Accra than in Kumasi (54% vs. 31%). Speeding generally decreased over the observation rounds for both cities with significant differences across the rounds (p < 0.001). When adjusted for vehicle, driver and environmental factors, speeding in both cities was more likely among young drivers, male drivers, SUVs, motorcycles, and sedans (p < 0.05). Other speeding predictors included company-owned vehicles and weekends (p < 0.05). Empirical evidence from the study is useful for designing strategies to improve road safety in urban Ghana.

Seatbelt and child restraint use are cost-effective ways of reducing the severity of road traffic injuries among vehicle occupants and children, respectively. The study aimed to determine the prevalence and associated factors of seatbelt and child restraint use in Accra, Ghana, using a multi-round cross-sectional observation design spanning the period 2015 – 2020. Between 6 and 15 sites were randomly selected in areas where traffic slowed down considerably or completely stopped. Nine observational rounds were undertaken during the period with a gap of six months between each round. The overall seatbelt usage was 48.7% (n = 481,585), with a significant difference among drivers’ (78.9%, n = 258,996), front-seat passengers’ (14.4%, n = 206,578) and rear-seat passengers’ use (2.2%, n = 16,011) (p < 0.001). Child seat usage was far lower at 5.9%. The observed driver seatbelt use, passenger seatbelt usage and child seat usage generally declined significantly between August 2015 and November 2020. Both seatbelt and child restraint use were lowest among males, truck vehicles, on weekends and in presence of camera enforcement, among other specific factors. Policy reforms should prohibit young children from occupying front seats and place clear legal responsibility on drivers to secure all passengers.

Sustainable construction practices are crucial to fostering development without depleting critical resources. This study investigates the adoption of rammed earth (RE) by specifically assessing the perceived barriers inhibiting its adoption in the Ghanaian construction industry. Primary data, sourced from literature, was used to develop a structured close-ended questionnaire administered to 114 construction professionals. Descriptive analysis, Krushal-Wallis, and Exploratory Factor Analysis were used to analyze the data. The findings indicate that while professionals possess a general understanding of sustainability, they reported being less conversant with specific sustainable practices such as RE construction. The results suggest that a strong affinity for conventional materials, the absence of dedicated local guidelines, and limited knowledge are viewed by professionals as critical sub-factors hindering widespread adoption of RE. Further analysis revealed four principal categories of barriers hindering RE’s adoption: systemic barriers, technological and financial barriers, socio-cultural and user acceptance barrier, and logistical and socio-economic barriers. The factor analysis confirmed systemic barriers, such as inadequate guidelines and regulation and minimal academic coverage, as the most significant perceived impediments. Based on these perspectives, it is recommended that academic and industrial institutions create forums to promote knowledge of RE and other vernacular techniques among students and professionals respectively. The findings provide a basis for policymakers to develop frameworks to revive interest in vernacular construction. The study, therefore, contributes to the acceleration of sustainable construction practices in Ghana and the sub-Saharan region at large.