Refereed Journals

Globally, governments and policymakers are pursuing net-zero carbon targets by 2050 through sustainable energy transitions and innovative financial instruments. One such underutilised tool is energy-efficient mortgages (EEMs), despite their potential to support green building development and retrofit activities. This paper examines the barriers hindering the adoption of EEMs and proposes strategies to improve their uptake. The study employs a systematic literature review (SLR) guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol. Thirty articles were retrieved from Scopus, Web of Science and Google Scholar and analysed using qualitative thematic analysis. The review identifies five interrelated categories of barriers: knowledge and awareness, financial, market, methodological and standardisation, and policy and regulatory barriers. A key novel insight is that knowledge and awareness constitute the foundational barrier, influencing the severity and persistence of other constraints. The study further identifies policy and regulatory factors as a central leverage point due to their role in shaping market conditions and enabling coordinated interventions. In addition, EEMs are positioned as a financial and economic tool for advancing net-zero energy buildings (NZEBs) by incentivising investment in energy-efficient housing. The findings indicate that EEM adoption can be strengthened through coordinated interventions, including clear policy frameworks and standards, targeted financial incentives and capacity-building initiatives. These measures enable the integration of energy efficiency into mortgage underwriting and valuation, improve affordability and reduce perceived risks. Higher uptake of EEMs can enhance residential energy efficiency and support progress toward SDG 11, SDG 13 and wider decarbonisation objectives under the Paris Agreement.

Laterite and lateritic soils are products of weathering under tropical conditions that is rich in the oxides of iron and aluminium. In-situ, the presence of these oxides leads to the creation of a structure which control most of the engineering properties. When compacted, however, a new compaction-induced structure is formed. In tropical environments, road and railway construction usually involve deep cuts in lateritic soils that is reworked and compacted into embankments. The analysis and modelling of stability and performance of these cuts and embankments require a good understanding of the mechanical behaviour of intact and of compacted lateritic soils. A laboratory experimental study was conducted to determine the differences in the effects of structure on behaviour of intact and of compacted samples. Samples of an intact lateritic soil were obtained and recompacted samples were prepared at the same insitu dry density and water content of 1.654Mg/m3 and 16.5% respectively. The intact and re-compacted samples were subjected to one dimensional consolidation in the oedometer test and also to the consolidated undrained triaxial tests at stress levels of stress ranging from 20kPa to 400kPa. The consolidation and shear strength behaviour are discussed in terms of the differences between the intact and compacted samples. The material parameters for modelling the behaviour are obtained and discussed.

The study determines the effect and suitability of snail shell powder (SSP) as partial cement replacement. Blended cements with snail shell powder ranging from 0 to 15% mixes were produced. The compressive strength test was used to determine the mechanical properties while Sorptivity tests were adopted to determine the water absorption properties. The Fourier Transform Infrared Spectroscopy (FTIR) and X-ray diffraction (XRD) analysis were used to determine the hydration behavior of the cement system. Compressive strength results showed that the maximum SSP replacement level with respect to strength was 5% at all curing periods. The 15% SSP mixture achieved a 2-day compressive strength of 31.2 MPa, exceeding that of the reference mortar, its 28-day strength was only comparable to the control and lower than that of the 5% SSP mixture. Infrared spectrometry and XRD analysis showed the presence of cement hydrated minerals including ettringite, monosulphonate, portlandite and other unhydrated cement minerals in the blended cement samples. Bands associated with CaCO₃ were observed in the blended mortar mixtures, reflecting the calcium carbonate nature of the SSP. The 15% snail shell blended cement mortar presented the lowest initial sorptivity coefficient of 8.0 × 10^− 9 mm·s^−1/2, resulting in an 84% reduction compared to the control. Corroborating the strength performance and the sorptivity results, the 15% replacement was the best-performing within the investigated range under the studied conditions. With consideration on substantial cement or clinker reduction, 15% snail shell replacement is recommended for the production of 32.5R CEM 11 A-L grade of cement.

The closure of the South and North Heap Leach Facilities at Gold Fields Ghana Limited created an opportunity to evaluate the reuse potential of heap leach residues as sustainable construction materials rather than adopting conventional reclamation approaches. This study presents a comprehensive assessment of heap leach materials sampled from multiple pad locations within the Tarkwa Mine. Laboratory investigations included X-ray fluorescence (XRF), compressive strength testing, sodium sulphate soundness, and alkali-silica reactivity analyses to determine the engineering and environmental suitability of the materials for construction applications. Results showed that the combined SiO2 + Al2O3 + Fe2O3 contents of all samples exceeded the ASTM C618 minimum requirement for natural pozzolans, indicating potential suitability as supplementary cementitious materials. Residual cyanide concentrations ranged from 0.14 to 0.30 mg/kg, significantly below internationally accepted limits, while heavy metal concentrations, including arsenic, chromium, and lead, remained within permissible environmental thresholds. Concrete specimens produced using the heap leach materials as aggregates achieved compressive strengths corresponding to concrete classes C7.5–C30 after 28 days of curing, with cement additions equivalent to 50–100% of the cement content required for conventional 1:2:4 concrete mixes. The findings demonstrate the feasibility of repurposing heap leach residues as alternative construction aggregates and supplementary cementitious materials, providing a sustainable mine closure strategy that supports waste valorization, resource efficiency, and circular economy practices in the construction and mining sectors