Refereed Journals

The link between past and present generations can only be maintained with effective preservation of cultural (Architectural) heritage. Architectural Heritage Preservation (AHP) is under threat in Ghana with an apparent dwindling awareness, unrelenting teardowns and destruction of historic buildings and places for other infrastructure development and spontaneous housing settlements. This paper seeks to review literature to establish the need to conduct further research on the state of architectural heritage preservation in Ghana. This research is underpinned with interpretivism and theoretically assesses the state of AHP in Ghana through review of literature. Literature reviewed revealed low publicity concerning heritage preservation, inadequate human resource responsible for heritage preservation and need to improve Ghana’s Architectural Heritage management. The study therefore recommends further research in heritage studies to ensure effective protection and preservation of Ghana’s rich architectural heritage.

With the increase of construction activities in Ghana, there is an increasing demand in building materials leading to the shortage of the conventional materials. The informal sector is gradually seeing the introduction of quarry dust as a substitute of sand in block production. This paper focuses on a comparative analysis of the quality of sandcrete blocks and quarry dust cement blocks. Block samples were gathered from various suppliers around the Prampram and Dawhenya areas and through various laboratory tests were tested for their dimension tolerance, water absorption and compressive strengths. Aggregate samples were also taken from suppliers for sieve analyses. The study revealed that the quarry dust cement blocks contained relatively higher percentages of coarse grade particles compared to the sandcrete blocks. The total average water absorption of sandcrete blocks was found to be 3.90% while quarry dust showed an improved value of 3.28%. Sandcrete blocks were averagely found to be of a higher compressive strength of 4.31N/mm2, with quarry dust at 3.0N/mm2 . The study suggested the likelihood of a lesser use of cement in the production of quarry dust cement blocks due to the similarities in colour between the quarry dust and cement, hence, negatively affecting its compressive strength.

The use of Unmanned Aerial Vehicles (UAVs) for remote data acquisition has rapidly evolved in recent years. The integration of UAV with Global Positioning System (GPS) and Geographic Information System (GIS) techniques have reduced time and cost in acquiring data for inaccessible land areas. Topographical mapping of water bodies, marshy areas or land areas without land cover using traditional methods of surveying in Ghana is time consuming and challenging. This study considered topographical mapping of muddy Tailings Storage Facility (TSF) sites at a rain forest mining area at Osino in the Eastern Region of Ghana. DJI Phantom 4 Pro consumer UAV was flown at an altitude of 75m in a 3D flight mode. Real Time Kinematic (RTK) GPS was used to coordinate a reflective-marked Ground Control Point (GCP). Georeferencing the orthophoto was done using the GCP. Digital Terrain Model (DTM) was generated from the processed orthophotos after which contours at 5 m interval were generated. Cross sections across the TSF were drawn for further geotechnical and stability analysis for the tailings dam. The accuracy of the topographic map is below 5 cm and confirms the suitability of using consumer grade UAVs for topographical mapping of inaccessible areas in a costeffective manner. Thus, the integration of RTK technology with the UAV and GIS is a feasible and appropriately accurate solution for mapping inaccessible areas.

This study investigated the processes influencing the chemistry of surface and shallow groundwater in tropical coastal environments - south east of greater Accra region of Ghana using GIS models and combination of geological and hydro geochemical techniques for sustainable management of freshwater resources and abundantly available brackish water resources. A total of 37 shallow groundwater and 11 surface water samples were collected and analysed for their physico-chemical constituents. The samples were adjusted to room temperature after which the hydrogen ion concentration (pH), Total Dissolve Solids (TDS) and Electrical Conductivity were measured with a precision of 0.01 for both parameters using a La Motte, USA in unfiltered samples. The analysis of major and minor ions were performed using ion chromatography (DIONEX-ICS-1000 Series). The geographical locations of the samples were recorded with the aid of a handheld Global Position System (GPS). The analysed shallow groundwater indicates minimum salinity values of 70.2 psu/ppm, maximum salinity of 4398.3 psu/ppm with an average of 1571.4 psu/ppm whilst surface water has minimum salinity of 33.8 psu/ppm, maximum of 43574 psu/ppm with an average of 4972.6 psu/ppm therefore highly saline. The total minimum dissolved solid (TDS) concentrations is 87.5 ppm, maximum of 5160 ppm with an average of 1911.96 ppm for shallow groundwater and for surface water minimum of 38.4 ppm, maximum of 27100 ppm and average 3938.12 ppm.

This study investigated pozzolan from the co-firing of clay and rice husk. Rice husk was used to replace clay at 1.0%, 1.5% and 2.0% and calcined at 800°C. Pozzolanic strength activity index (PSAI) was performed on the calcined powder materials in accordance with the ASTM C311 standard. The calcined material that obtained the highest PSAI was selected and used to optimize the calcined pozzolan added to Portland cement. The optimum mixture proportions were used for ²⁹Si and ²⁷Al MAS NMR as well as water sorptivity and shrinkage studies which involved autogeneous and drying shrinkages. The results of the study showed that calcined clay that contained 2.0% rice husk had the optimum PSAI whereas 30 wt.% replacement content was the optimum cement replacement. The ²⁹Si and ²⁷Al MAS NMR showed that the superior strength of the optimum mortar mix to the control was due to a stable monosulphate phase formed at the octahedral environment and the formation of extra calcium aluminosilicate phases in the mortar mix. The initial and secondary sorptivity values of the pozzolan were 0.0055 and 0.0022 mm/sec^1/2 respectively, lower than the values of the control , which were 0.0299 and 0.0083 mm/sec^1/2 respectively. The shrinkage performances of the Portland cement-pozzolan mix were much enhanced than the unblended mortar mix. The inclusion of the co-fired materials reduced the embodied carbon by approximately 29%. The use of the co-fired material could be a sustainable means to dispose of waste rice husk and also reduce embodied carbon.