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Abstract This paper aimed to investigate the durability of ambient-cured fly ash-phosphogypsum blended geopolymer mortar (GPM) when exposed to a water and sulfate environment at different durations. Water absorption, porosity, and sulfate resistance tests were conducted to determine the durability. The GPM was prepared at 0 wt%, 30 wt%, and 40 wt% PG replacement of fly ash content in the mixture. The mix proportions were determined experimentally at 10 M sodium hydroxide, alkaline liquid/precursor of 0.4, sodium silicate/sodium hydroxide of 1.5, and binder/aggregate of 1.0. The samples were immersed in potable water and magnesium sulfate solution. The changes in weight, length, and compressive strength were monitored. Scanning electron microscopy-energy dispersive X-ray spectroscopy was used to analyze the structure and composition. The findings showed that GPM with 30 wt% phosphogypsum added had lower water absorption, porosity, and sulfate attack than GPM with 0 wt% phosphogypsum attributed to the formation of hydrated gels leading to a dense microstructure and improved strength. The changes in weight, length, and strength variations trend for GPM were within optimal performance standards. This has implications for the practical application of GPM in construction where it can be used as an alternative to Portland cement mortar in sulfate-rich environments.

Abstract The nonlinearity and heterogeneity of geopolymer mix design have urged the research community to supplement the existing experimental design approach with machine learning and empirical regression models to improve the practical strength performance of geopolymers. This systematic review aims to elaborate and consolidate the fundamental machine learning algorithms and statistical models applied in the strength prediction of geopolymers. This review specifically delves into the statistical linear/nonlinear optimization algorithms, supervised machine learning algorithms, and model performance statistical metrics. The PRISMA and Scopus databases were used for bibliometric data extraction. The search strings devised to carry out the review were “geopolymer” OR “alkali-activated materials” AND “machine learning” OR “statistical modeling”. This review observed that neural networks, random forest, support vector machines, and Gaussian process regression give better strength prediction performances with R2 values > 0.9 and RMSE values

Amidst the global discourse on the provision of low-income housing, there has been a growth in studies to assess the governance issues related to the sustainability of housing delivery. Despite housing policy and legislative frameworks existing in developing countries, several governance issues have limited the sustainability of housing delivery mechanisms. Therefore, this study aims to unpack housing delivery approaches through the lens of governance. Adopting an exploratory approach, this study seeks to understand strategic and operational approaches used by government institutions to promote collaborative strategies in the planning and delivery of housing projects. Empirical data is used to understand mechanisms, processes and systems involved in the planning and delivery of low-income housing projects, using the Gauteng City Region as an area of study. The findings reveal there is that there is a limited understanding of the concept of governance within public sector institutions. Additionally, the institutional arrangements of the three spheres of government (national, provincial and local) have an impact in the delivery processes of low-income housing projects. A shift is important in the understanding and application of governance principles in housing policy and programme implementation to realise the value of governance. This study concludes with implications for policy and academics highlighting the role of stakeholder participation, transparency, and accountability.

The sustainability of small and medium-sized contractors (SMCs) is vital, considering the critical role they play in socio-economic development globally. SMCs in Namibia have been consistently grappling with high failure rates over the years, largely due to a dearth of robust policy frameworks to guide SMC development and sustainability in the country. This study investigates the critical success factors (CSFs) for SMCs’ sustainability in Namibia. Using a qualitative approach, data were collected from 60 purposively selected construction industry participants, comprising owner-managers of contracting firms, policymakers, and construction professional consultants. Interviews were conducted with the participants, using a semi-structured interview tool. Data were then analysed using reflexive thematic analysis. The findings revealed six CSFs, including public and private institutions’ collaborative support, skills training, an enabling construction business environment, access to adequate and affordable finance, consistent work opportunities, and firm owner’s entrepreneurial skills. The identified CSFs culminated in the development of a framework for guiding the development of SMCs in Namibia. By incorporating the six CSFs in the framework, SMCs could be effectively developed and sustained. The framework may assist policymakers in making fundamental policy reforms and developing appropriate and context-specific interventions to sustain SMCs in Namibia and similar contexts.

South Africa is endowed with a wealth of coal-fired power stations that can produce extremely high volumes of fly ash per year exceeding 34 million tonnes. The use of high-volume fly ash (HVFA) binders in the construction sector has the capacity to significantly reduce greenhouse gas emissions associated with traditional cement production and offset the carbon footprint of Eskom. The excessive production of fly ash by Eskom warrants the need for developing ultra-high-volume fly ash binders (UHVFA, fly ash/binder > 60 wt%). Nonetheless, fly ash (FA) replacement of cement is still largely limited to 35% regardless of more ambitious research indicating the potential to surpass 60%. In view of the urgent need for South Africa to offset and reduce its carbon footprint, this work reviews and summarises the literature on the performance of HVFA binders with a focus on two specific areas: (i) strength and (ii) durability. On HVFA binder strength, the focus is drawn on work that analysed the compressive strength, flexural strength, and split tensile strength. This review focuses on the extant literature analysing the durability of HVFA binders using various tests, including sorptivity, resistivity, permeability, tortuosity, rapid chloride penetration tests, resistance to sulphate attack, and microstructural analysis. As the FA content increases towards optima, i.e., 50–80%, the most indicative composite characteristics of the strength and durability properties are UCS (30–90 MPa) and permeability (low). This review reveals the leading methodologies, instrumentation, findings, challenges, and contradictions.

A practical mix design and performance metrics for fly ash-phosphogypsum blended geopolymer paste and mortar is lacking. This study focused on investigating the physico-chemo-mechanical performance and mix design of ambient-cured fly ash-phosphogypsum geopolymer paste (FPGP) and mortar (FPGM). The geopolymer was formed by reacting binary powder precursor (fly ash+phosphogypsum) and alkaline activator (NaOH+Na2SiO3). The fly ash was substituted with varying weight proportions of phosphogypsum (i.e., 10 %, 20 %, 30 %, 40 %, 50 %). Experimental testing and analysis were done based on ASTM standards, XRF, XRD, SEM-EDS, ANOVA, and Python. The workability, setting time, flexural strength, compressive strength, morphology, and mineralogy were studied. The multivariate regression approach was used to model the relationship between compressive strength and alkaline liquid/precursor. The optimum mixture conditions for FPGP and FPGM were 30 wt% phosphogypsum, alkaline liquid/precursor of 0.4, 10 M NaOH, Na2SiO3/NaOH of 1.5, and binder/aggregate of 1.0. The results showed that the workability of FPGP ranged from 185 mm to 112 mm while that of FPGM ranged from 145 mm to 100 mm. The FPGP and FPGM had considerably lower initial and final setting times of (18 – 37 min, 81 – 155 min) and (14 – 29 min, 67 – 142 min), respectively. The compressive strength of FPGP ranged from 7.3 MPa to 27.24 MPa while that of FPGM ranged from 9.5 MPa to 43.27 MPa. There was a strong connection between compressive and flexural strength giving R2 values > 0.8. Based on the adjusted R2 values and ANOVA, the proposed mix design models were statistically significant since the p-value (0.000) was less than the 0.05 significance level and the value of F (197.953) was greater than the critical value of 1. At high curing duration, the concentration of NaOH and alkaline liquid/precursor facilitated the dissolution of Ca2+ in phosphogypsum and Si4+and Al3+ in fly ash forming a C-(N)-A-S-H matrix crucial to the strength development of geopolymers. The statistical metrics implied a good performance accuracy and reliability of the proposed model equations and can find practical applications in construction materials design. For optimal results, it is recommended to use the prediction models within the specific input parameters employed in this study.

Public transport is a fundamental aspect of urban life and its quality of service can significantly impact the daily life of passengers. Research on quality of service in public transport is vital to creating efficient and inclusive public transport systems. This study which is both timely and imperative, provides a systematic literature review and bibliometric analysis of quality of service in public transport with special focus on gender and machine learning. The study employed a systematic search in Web of Science using relevant keywords. Based on 270 published articles on the Web of Science, we evaluate the state of knowledge through keyword analysis, co-occurrences, and co-citations. It appears that key themes in quality of service in public transportation have shifted from efficiency to user satisfaction and perceptions. However, there is limited literature on public transport service quality in the global south, particularly in Africa, compared to the global north. In particular, the study revealed that the total publications focusing on gender in Africa is two. Moreover, much of the literature on the African continent emanates from authors and countries outside the continent. It often does not reflect the lived realities of the state of public transport in Africa. Similarly, emerging issues pertaining to machine learning and gender in public transport also require consideration. This paper paves the way for policy, practice, and further research. The review will be useful reference for evolutions of quality of service in public transport research.

While governments remain accountable for the delivery of infrastructure services, given the paucity of public resources, studies have recommended the use of private sector finance (PSF) as an alternative approach to delivering sustainable infrastructure both in developed and developing economies. Despite the recommendation, there has been very little use of PSF in delivering public projects, particularly in sub-Saharan Africa. Therefore, this study explores the constraining factors for the use of PSF in the delivery of public infrastructure in Tanzania and proposes recommendations. A total of 10 semi-structured interviews were conducted with different stakeholders delivering public infrastructure services. Interviewees were purposefully selected. Data were analyzed through conceptual content analysis. The findings reveal that the top five constraining factors were inadequate knowledge and skills, lack of policy to support or suffice PSF, bureaucracy or delays of approvals, lack of proper models for PSF, and lack of skilled people or existence of a big national skill gap. Thus, the identified constraints provided useful insights and were used as a road map for suggesting appropriate solutions to enhance the use of PSF. Furthermore, this is the first study to empirically explore the constraining factors for PSF in delivering infrastructure projects in the Tanzanian context.

The construction industry (CI) continues to be the cause of injuries and illnesses to many workers worldwide. Collaboration between the construction health and safety agent (CHSA) and other built environment professionals may improve the impact of the CHSA on health and safety (H&S) performance. However, no study has identified the factors that determine CHSA collaboration on construction sites. A three rounds Delphi study was conducted to identify the factors that determine CHSA collaboration. A panel of 14 experts serving the CI were selected from four continents and were asked to identify additional factors and validate the factors identified from literature. Microsoft Excel 2016 was used to analyse the data; group medians were calculated to reach consensus, and open question responses were summarised qualitatively. The experts confirmed the existence of the factors identified in the literature. The factors that determine CHSA collaboration on construction projects include mutuality, trust, enabling environment, personal characteristics, common purpose, institutional support, and project context. Drawing from the findings, the study suggests that these seven factors can influence CHSA collaboration. The study is limited to 14 experts and more experts could have provided more information. The factors that determine CHSA collaboration identified in this study may not be exhaustive and another study may provide different factors. Further research could adopt other research methods such as the quantitative method, in order to determine the impact of these factors on CHSA collaboration. Factors that determine CHSA collaboration on construction projects should be identified, implemented, and monitored, in order to increase the influence of CHSA on H&S performance.

AbstractHealth and safety issues have always been a major problem and concern in the construction industry. Although substantial improvements in construction safety have achieved in the past decades, the industry lags other industries on safety. Therefore, this research is to explore the worker’s behaviour about safety performance, mainly focusing on worker’s competence mediated by safety orientation on safety performance. A questionnaire survey was used for this study validated by the experts. In all, 600 respondents were randomly selected from government and private construction industries and yielded a response rate of 430 (71.6%). Additionally, correlational analysis and structural equation modeling (SEM) were used to examine the research hypotheses. The finding showed that worker’s competence has a significant impact on safety performance. Indeed, safety orientation mediated the relationship between worker competence and safety performance. Thus, this study carries values to the Sustainable Development Goals (SDG) such as goal 3 (SDG 3) that tries to enhance the good health & well-being of the societies and workplace through the investigation of the effective factors on the safety performance of the construction industry. Ultimately, the findings of this study contribute to the achievement of Sustainable Development Goal 8 (SDG 8) through encouraging the entrepreneurship as are effective measures to eradicate or decrease forced labour, slavery, and incompetent worker at the workplace (focusing on behavioural aspects). In this regard, the goal is to achieve full and productive employment and decent work, for all women and men by 2030.

The outbreak of COVID-19 has adversely affected university students’ learning process, especially in developing countries like Nigeria. Consequently, many institutions have adopted social media for the learning process because of the COVID-19 lockdown. Hence, the current study aimed at assessing the influences of social media learning environments on the learning process among university Architecture, Engineering, and Construction (AEC) students during the COVID-19 Pandemic lockdown. Data was collected from the students of AEC-related courses using a structured questionnaire. Warp 7.0 PLS-SEM was used for the analysis of the collated data and model development. The study results indicated that the AEC students’ psychological capital (PsyCap) moderates the relationships between social media learning environments and the learning process among AEC university students in Nigeria. The results also showed significant influence change between the social media learning environments and the learning process among the AEC students in Nigeria. The study is limited to students in the AEC-related courses in Nigerian universities. Moreover, the results of this study could be helpful to other developing countries having issues with the use of social media learning environments. The study further recommends the training of AEC students on the use of resources in the social media learning environments for the positive developmental state of the student’s self-efficacy, hope, optimism, and resilience.

Environment protection legislation is often inadequate and poorly implemented in Africa even though literature shows that it is important for environmental protection. Furthermore, there is a paucity of studies which examine the catalytic role of legislation in the building infrastructure sustainability agenda. Therefore, to bridge that knowledge gap, this study examined the adequacy of environment protection legislation for building infrastructure projects in Zambia and their associated challenges and solutions. The study used an exploratory qualitative approach using semi-structured interviews with key stakeholders on environment protection. The study theorises that environment protection legislation in Zambia is fairly adequate but with inadequacies in its implementation, some with omitted content, and poor understanding of the importance of environment protection. Solutions include increasing the level of implementation of the legislation and championing awareness of the importance of protecting the environment. The findings have implications for sustainability transitioning in Africa.

Despite drones being successfully utilized for monitoring and detecting hazards in mines, there is limited research on their application for open-pit stockpile volumetric computation compared to traditional methods. Furthermore, time, cost, and safety have challenged the use of the traditional approach. Present study aims to fill the gaps by conducting a comparative analysis of stockpile volumetric computation utilizing a drone and traditional approach. A mapping framework is proposed to guide mine personnel on how to conduct open-pit stockpile volumetric computations. The methodology comprises using a drone and traditional survey approach to measure the volume of a known quarry stockpile. Drone-captured images are processed in Pix4D mapper software and geometric techniques are applied to the traditional survey approach. Findings show that the smaller the error of the checkpoints the more accurate the generated model making the measurements reliable. The generated Pix4D quality report showed a root mean square error of 0.019. The drone percentage error to the actual volume is 2.6% while the traditional approach is 1.3%. Both estimations are less than the maximum allowable percentage error of ± 3%. Therefore, compared to the traditional approach drone technology provides an accurate, cost-effective, fast, and safe working distance suitable for stockpile volumetric computations in open pit quarries.

Collaboration is key to the success of construction project delivery. Several researchers have realised the importance of collaboration for health and safety (H&S) performance. The construction industry (CI) is affected by poor H&S performance exacerbated by lack of collaboration. The purpose of the article is to conduct a systematic literature review to identify factors of collaboration that will improve H&S performance in CI. A literature review method was adopted; identification test method was used to identify collaboration factors. Using Scopus and Google Scholar, a total of 758 papers were identified. 57 papers were found to be relevant for review through content analysis and were analysed in terms of source and year of publication, research method, country of origin, and research focus. The review identified 11 critical success factors of collaboration: trust, culture, commitment, communication, clear roles and responsibilities, resource/information sharing, mutual goals, conflict resolution, early involvement of key participants, competence, and continual improvement. These factors can influence H&S performance in construction projects. Focusing on these factors can facilitate collaboration, thus improving H&S performance. The limitation of this article is that the literature review covered a period between 2010 to 2019. Searches in other search engines might have provided additional information on collaboration. The findings of this study make way for future research into the impact of collaboration on H&S performance and provide an understanding that H&S performance can be improved by adopting collaboration. The review concludes that CI should adopt collaboration to influence H&S performance.

Increasing demand for infrastructure amidst the surge in the urbanization of cities and newly emerging commercial nerves has spurred the need to reinvent and rethink traditional approaches for delivering infrastructure. This has been identified as even more critical given the global drive and discourse on the sustainability of the construction sector and its health and safety performance. Given the potential gains of adopting construction automation and AI in infrastructure delivery, stakeholders’ convincing appreciation of its benefit is vital to its widespread adoption in the AEC sector. This explored and evaluated the critical benefits of integrating automation in construction processes in the architectural, engineering, and construction sector and the use of artificial intelligence (AI) in driving its systems and workflows. The study adopts an interpretive structural modeling approach based on interviews of construction stakeholders in diverse countries to develop a hierarchical model of the interrelationships of the benefits. Furthermore, the Matrice d’Impacts croises-multiplication applique a classement analysis (MICMAC) was used to categorize the benefits. Highlighted perceived benefits such as improved project quality, simplification of construction tasks, workflow improvements, and safety performance, amongst others, were fractionalized into levels. The study’s findings are critical in satisfying a cost-benefit index of adopting automation and AI in the AEC sector. The results provide recommendations on effective approaches pivotal to driving automation and AI for practice and research. This is of further importance to construction stakeholders, policymakers, and local authorities in building strategies and roadmaps for proper integration of these systems and widespread adoption.

The innovation of technology, particularly Artificial Intelligence (AI), has rapidly changed the world. It is currently at a nascent stage worldwide in the construction industry throughout the lifecycle of projects. However, construction organisations of developing countries such as South Africa are still lagging in recognising the need to adopt emerging digital innovations such as AI to improve the built sector’s performance. This study aims to identify organisational factors imperative to driving the adoption of AI in construction organisations. The study uses a quantitative survey approach to collect data through snowball sampling of industry experts on factors associated with AI adoption. With data from 169 respondents, exploratory factor analysis was adopted to identify critical organisational factors to ease AI adoption in the industry. Furthermore, confirmatory factor analysis was employed to demonstrate the relationship among the constructs. The study proposes 17 factors to drive organisational AI, categorised into four components; innovative organisational culture, competence-based development, collaborative decision-making, and strategic analysis. However, previous studies have identified organisational factors of AI in the construction and allied industries. This study presented the organisational factors of AI in the construction industry using EFA and CFA, a method not used in articles presented in the SLR identified. The use of CFA improves the measurement of the constructs. It thus enhances understanding of the underlying components of a construct and its relationship with AI in the construction industry.

Fatalities, injuries, and illnesses continue to occur in the construction industry (CI), despite efforts made by clients, designers, and contractors. The lack of collaboration between these project actors and construction health and safety agents (CHSA) remains a challenge for both construction professionals and academics. Given the urgent need for CHSA to collaborate with other construction project members, this study proposes a model for improving CHSA collaboration and its influence on health and safety (H&S) performance. The exploratory sequential mixed method, which included a Delphi study and a questionnaire survey, was adopted. H&S experts were purposively sampled. A three-round Delphi study was conducted to identify the factors, and these factors were categorized into 9 main factors developed from a review of the literature and the input of 15 H&S experts, 14 of whom completed all 3 iterations. Stratified sampling was used to gather quantitative data. A total of 257 questionnaires were returned, of which 213 responses were usable for analysis. Exploratory factor analysis (EFA) using Statistical Package for the Social Sciences (SPSS) version 26 was conducted and resulted in 6 main factors. A confirmatory factor analysis (CFA) of structural equation modeling (SEM) was used to establish the validity and reliability of constructs, and finally, path analysis in EQS version 6.4 was used to analyze the results of the questionnaire survey and evaluate the goodness of model fit. The findings were that mutuality, trust, institutional support, project context, and common purpose contribute to CHSA collaboration. Additionally, the influence of project context, common purpose, and CHSA collaboration on H&S performance were found to be statistically significant. The study’s implication is that in order to improve H&S performance, clients, designers, and contractors may not limit the participation of CHSA on the project. The implication for the CI is that by promoting CHSA collaboration, the likelihood of CHSA influence could increase and H&S performance could improve on construction projects. The study revealed that collaboration should be considered for improving H&S performance. The study is limited to respondents who met the selection criteria to participate in the Delphi study and questionnaire survey. Any registered persons who did not receive regular communication and announcements would have not participated. Despite the requirements of the South Africa Construction Regulations 2014 that CHSA should be part of the construction project team, more studies should be conducted to investigate the CHSA level of involvement on the project.

Utilising emerging innovative technologies and systems to improve construction processes in an effort towards digitalisation has been earmarked as critical to delivering resilience and responsive infrastructure. However, successful implementation is hindered by several challenges. Hence, this study evaluates the challenges facing the adoption of unmanned aerial vehicles towards the digitalisation of the built environment. The study adopted a quantitative survey of built environment stakeholders in developed and developing economies. A total of 161 completely filled forms were received after the survey, and the data were analysed using descriptive analysis and inferential statistics. The study’s findings show that there are different barriers experienced between developed and developing countries in the adoption of drones towards digitalising construction processes in the built environment. Moreover, economic/cost-related factors were identified as the most critical barriers to the adoption of drones, followed by technical/regulatory factors and education/organisation-related factors. The findings can assist the built environment in reducing the impact of these barriers and could serve as a policy instrument and helpful guidelines for governmental organisations, stakeholders, and others.

Globally, transformation is etched in all sectors of the economy. In the South African context, transformation is viewed as the catalyst to address the country’s socio-economic problems and their associated impact on different sectors and the economy at large. However, progress on transformation within the built environment has been slow in comparison with other sectors of the economy. As a result, this has led to a need to examine the transformation processes in the country. This article aims to analyse transformation strategies as conceptualised and implemented by various sectors. The article is based on a multi-case study of identified sectors and organisations that have developed and implemented transformation strategies. The materials used to conduct the study include sector transformation strategies, charters, journal articles, articles published in reputable South African newspapers, organisation reports, information publicly available on the internet, and interviews conducted with sector representatives. The findings show that, for all sectors, transformation strategies are driven through skills development of human resources, with a view to redressing historical imbalances and providing equal opportunities. The process of strategy development involves sectorwide participation and having a champion for the strategy. In order to ensure that strategies are implemented, specific structured training and education programmes from the grassroots to professional level, as well as monitoring of progress are emphasised. Recommendations are made in line with the findings in order to guide the Council for the Built Environment in the development of a strategy for the built environment.

Amidst the global discourse on the identification of strategic land, there has been a growth in planning support systems aimed at assisting policymakers in unlocking the value of strategic land. Despite planning support systems’ immense benefit of aiding planning, there are limited planning support tools to aid communities in marginalised areas to unlock the value of land. Therefore, this study adopts a GIS-based approach to develop a planning support system to identify, quantify and visualise an index for urban agricultural land in a marginalised area. The proposed solution utilised Greater Orange farm, a marginalised area in the City of Johannesburg, as a case study to inform spatial planning for emerging economies. Using the Charrette visioning process, indigenous knowledge systems were incorporated in formulating the criteria, weights, and rulesets. The results reveal spatial sites ranked through an index where sustainable investment in urban agriculture infrastructure should be targeted. The developed index identifies suitable locations for urban agriculture infrastructure and supporting programs. Furthermore, the solution builds from the existing reservoir of PSS in Southern Africa by demonstrating the potential for planning support systems as sustainable data-based decision-making tools to inform spatial planning. Lessons emerging from this study are that there is an inseparable existential connection between indigenous knowledge systems and contemporary sustainability planning, which is critical for ensuring sustainable development.

The geopolymer concept has gained wide international attention during the last two decades and is now seen as a potential alternative to ordinary Portland cement; however, before full implementation in the national and international standards, the geopolymer concept requires clarity on the commonly used definitions and mix design methodologies. The lack of a common definition and methodology has led to inconsistency and confusion across disciplines. This review aims to clarify the most existing geopolymer definitions and the diverse procedures on geopolymer methodologies to attain a good understanding of both the unary and binary geopolymer systems. This review puts into perspective the most crucial facets to facilitate the sustainable development and adoption of geopolymer design standards. A systematic review protocol was developed based on the Preferred Reporting of Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist and applied to the Scopus database to retrieve articles. Geopolymer is a product of a polycondensation reaction that yields a three-dimensional tecto-aluminosilicate matrix. Compared to unary geopolymer systems, binary geopolymer systems contain complex hydrated gel structures and polymerized networks that influence workability, strength, and durability. The optimum utilization of high calcium industrial by-products such as ground granulated blast furnace slag, Class-C fly ash, and phosphogypsum in unary or binary geopolymer systems give C-S-H or C-A-S-H gels with dense polymerized networks that enhance strength gains and setting times. As there is no geopolymer mix design standard, most geopolymer mix designs apply the trial-and-error approach, and a few apply the Taguchi approach, particle packing fraction method, and response surface methodology. The adopted mix designs require the optimization of certain mixture variables whilst keeping constant other nominal material factors. The production of NaOH gives less CO2 emission compared to Na2SiO3, which requires higher calcination temperatures for Na2CO3 and SiO2. However, their usage is considered unsustainable due to their caustic nature, high energy demand, and cost. Besides the blending of fly ash with other industrial by-products, phosphogypsum also has the potential for use as an ingredient in blended geopolymer systems. The parameters identified in this review can help foster the robust adoption of geopolymer as a potential “go-to” alternative to ordinary Portland cement for construction. Furthermore, the proposed future research areas will help address the various innovation gaps observed in current literature with a view of the environment and society.

Geopolymer is an inorganic material formed through the chemical reaction of an aluminosilicate precursor and an alkaline or acidic activating solution. It is seen as a green new alternative binder to ordinary Portland cement (OPC) for sustainable infrastructure development. The strength of the unary or blended geopolymer product is dependent on the composition and properties of the polymeric gel influenced by the ratios of Al2O3/SiO2, CaO/SiO2, CaO/(SiO2 + Al2O3), Na2SiO3/NaOH, SiO2/Na2O, and liquid/binder (L/B). Essential scientific inquiry has been progressively addressed by utilizing expert assessment and research metrics. The network visualization of bibliometric co-occurrence and co-citations is of particular significance. The present study aims to highlight the trends and progress of the most influential publication sources, keywords, authors, articles, and countries in geopolymer research in the last 10 years. Bibliometric data were retrieved through Scopus and visualized in VOSviewer to create bibliometric networks. The yearly distribution and growth trends (April 2011–2022) of geopolymer, geopolymer mortar, and geopolymer concrete before (after) applying inclusion criteria were from 754 to 9887 (5186), 47 to 1374 (866), and 145 to 3721 (2253), respectively, attributed to the discoveries in more precursor materials such as laterite and the growing interest in fire and heat-resistant structures, water and wastewater treatment, cement and concrete, and brick manufacturing. The top three journals in terms of prestige for geopolymer publications were the Journal of Hazardous Materials with an impact factor equal to 14.224 and h-index equal to 307, Cement and Concrete Research with an impact factor equal to 11.958 and h-index equal to 239, and the Journal of Cleaner Production with an impact factor equal to 11.072 and h-index equal to 232. The top three journals in terms of average citation per document were Cement and Concrete Research (135.75), Materials and Design (75), and Cement and Concrete Composites (68.35). Keywords such as “geopolymers”, “inorganic polymer”, “geopolymer”, “compressive strength”, “fly ash”, and “geopolymer concrete” had the highest occurrences in publications. John Provis—University of Sheffield, Prinya Chindaprasirt—Khon Kaen University, and Jay Sanjayan—Swinburne University of Technology had the highest total citations of 6377, 5626, and 4311, respectively. The highest number of publications were from China, India, Australia, the United States of America, and Malaysia. The bibliometric findings from this study can act as a tool for academicians and policymakers to exchange research expertise, collaborate on novel geopolymer research, and create innovative joint ventures.

Reality Capture (RC) is a state-of-the-art technology for digital data gathering and visualization of the actual environment through virtual means. In recent years, RC has contributed significantly to the digitalization of the construction industry globally. However, there are no systematic critical analyses of the benefits and challenges of RC technologies in construction project management (CPM) to drive its adoption. This research provides a detailed overview of the potential benefits and constraints of RC to tackle CPM concerns successfully and efficiently. This study uses the PRISMA procedure to conduct a systematic literature review. Based on the inclusion and exclusion criteria set for the study, 96 articles were considered relevant for review. The articles were analyzed using content analysis techniques to synthesize identify emerging themes. A four-step procedure was used to classify the articles into pre-construction planning, designing and construction. The review show that (a) RC is useful during the planning and designing stage, as the success of a construction project depends on accurate data to reduce the risk of cost and time overruns; (b) the benefits of RC adoption are accurate data, reduced time spent on project monitoring, progress tracking, and quality assessment; (c) RC on a construction site aids in the resolution of the industry’s fragmented nature through collaboration; quick and prompt decision making through remote monitoring and control of projects. RC is used as a visualization tool and for digital documentation of as-built models, construction verification, and flaw discovery, thereby improving work processes to achieve project success; (d) the most challenging aspect of incorporating RC on a construction site is the high investment cost. In the digital revolution era, this study could aid in the knowledge and optimal use of Reality Capture in numerous areas of CPM.

Objectives: The nutrition of construction workers is related to their health and safety (H&S) at work. Research on the factors influencing construction workers’ food choices and overall nutrition is limited, in South Africa and indeed Africa as a whole. The present paper aims to develop and validate a questionnaire on factors influencing construction workers’ food choices. Design: The study adopted a quantitative approach; 42 items, divided into six constructs, were used to develop a field-survey questionnaire after a detailed literature review. Setting: The study was conducted on eight construction sites (consisting of five building construction and three road construction sites), chosen through heterogeneity sampling, in Midrand, Centurion, Johannesburg and Samrand. Subjects: Participants included construction workers actively involved in site activities. Outcome measures: Principal components analysis (PCA) was conducted to examine the structures and validity of the constructs. Cronbach’s alpha test and mean inter-item correlations were used to examine internal consistency reliability. Results: After repeated factor analysis, the questionnaire on food-choice factors revealed seven different factors: food context, biological factors, nutritional knowledge, personal ideas and systems, economic factors, resources and cultural background. These factors explained 60.09% variance. Cronbach’s alpha coefficients ranged from 0.62 to 0.85, signifying good internal consistency reliability. Conclusion: The determinants of construction workers’ food choices are vital considerations when designing and implementing nutrition interventions in the South African construction industry. Future research can adopt the instrument and developed model when conducting psychometric evaluations of construction workers’ food-choice determinants.

Though studies in construction robotics and human–robot teams research have explored varying themes, an in-depth study of the state-of-the-art of methodological paradigms appropriate for construction robotics research is hitherto lacking, taking into consideration that several studies have highlighted conflicting methodological components such as research design, methods, data sources, data types and analytical techniques. To better understand this underexplored area, this study uses a four-stage review approach utilising a scientometric and systematic analysis method based on 112 articles. Using statistical analysis to evaluate the relationship between research components, the study reveals strong associations between components of research methods, data sources and analytical techniques. Researchers are also increasingly looking to mixed paradigms in data sources and designs, highlighting a methodological plurality in construction robotics research. Implications on what this means for the future of construction robotics, policy and stakeholders are discussed in the study.

The paper reports on an assessment of the mediation effect of a firm’s business partnership on procurement planning factors influencing the quality performance of primary healthcare building facilities. A quantitative data collection approach was adopted in the study using structured questionnaires circulated to 520 respondents comprising project managers in the Nigerian construction industry. A stratified proportionate random sampling method was used for the selection of respondents which yielded 370 responses and 357 were used for analysis. Findings were that procurement planning factors influenced the quality performance of primary healthcare building facilities, and the firm’s business partnerships mediate the relationship between procurement factors and quality performance of primary healthcare building facilities. This study serves as awareness to governments and other stakeholders in the construction industry on the provision of quality primary healthcare building facilities by leveraging a firm’s business partnership as a mediating factor. Findings show that the relationship would enhance the rapid provision of quality healthcare building facilities for the growing population of Nigeria and other developing countries facing similar shortages of quality healthcare building facilities.

With the emergence of Building Information Modelling (BIM) as central to construction design, planning, execution and maintenance, integration into the entire infrastructure sustainability process is imperative for achieving sustainable development. Despite its immense benefit of aiding compliance to sustainable construction, potential barriers continue to widen the gap in implementation. Therefore, this study adopts the “interpretive structural modelling approach” to advance a ranked structure of the interrelatedness of the barriers to integrating BIM in buildings sustainability assessment. The “Matrice d’Impacts croises-multipication applique a classement analysis (MICMAC)” was utilised to categorise the identified adoption barriers in the model. The identified barriers and relationship with themselves are valuable in discussing the challenges to BIM-based LCA and developing policies and design decisions to drive the process further. Further, it adds to the emerging discussion of BIM from the life cycle sustainability assessment perspective for infrastructure. The findings are critical for policy, stakeholders and extending the body of knowledge.

The health and safety (H&S) of site workers in the construction industry has been overwhelmingly studied for decades. However, there is scant literature which analyses underlying structures of safety performance measures especially as related to their unhealthy and unsafe eating behavior. The paper presents findings on an exploratory factor analysis of H&S performance measures. A 10-item questionnaire which was developed after an extensive literature review was used to collect empirical data on SP of construction workers in the Gauteng Province of South Africa. Findings revealed that safety performance of site workers could be reasonably measured by two constructs. The two constructs were clearly defined as trailing and prevailing. The emerged trailing measures were named lagging indicators while the prevailing ones were designated as leading indicators. The results support extant literature which advocates the use of both leading and lagging safety performance indicators for effectively assessing construction workers’ safety performance. The study provides evidence which could be beneficial in psychometric evaluation of construction workers’ safety performance and behaviours on construction sites. Keywords: construction workers, factor analysis, Gauteng, safety performance

Communication management is viewed as an imperative factor associated with performance improvement in construction projects. In Eswatini, it is established that projects experience poor project delivery associated with poor communication management practices. This study seeks to elucidate communication management practices informed by local culture and relate it to project outcome. A questionnaire survey of practitioners registered with Eswatini construction industry council was adopted for the study. Data was collected from 66 respondents. Principal axis factoring established nine practices namely; information technology, communication technology, communication skills and competence, communication management plan, teamwork, clear channels within organisation’s structure, project brief requirement management, project brief risk requirement management and context of environment as being key factors to project positive outcome. Spearman’s rho established that a relationship exists between project outcome and three practices namely; information technology, communication management plan and clear channels within organisation’s structure. The findings present key empirical evidence of the communication management practices that relate to project outcome in Eswatini. The study contributes on communication management practices in Eswatini and its relation on project outcome. Limitation of the study conclude that results and analysis cannot be generalised. However, the findings from the research provides opportunities for extensive further research recommendations to assess, refine and understand the effect of the variable’s communication management practice to project outcome.

Transportation infrastructure contributes to the development of an economy. However, the performance of such infrastructure is hampered if sustainability elements are not considered at the initiation/conception and operation stages of the projects. The study aimed to validate a structure of transportation project sustainability measures to evaluate projects and ensure continual delivery of intended benefits in the long run. Empirical data were collected using a field questionnaire survey developed from the literature review and a preliminary qualitative inquiry. A total of 132 built environment professionals were included based on purposeful and snowball sampling techniques. A model-generating confirmatory factor analysis was undertaken to validate underlying structures of sustainability measures established from a preliminary common factor analysis. The findings validated that a four-factor structure, with eleven variables, could adequately measure transportation infrastructure project sustainability (PS). The CFA structure achieved construct, convergent and discriminant validity, with fewer variables than were theorised and subsequently established in the common factor analysis. The validated four-factor structure is envisaged to be useful to transportation infrastructure project stakeholders in better decision-making on project selection being cognizant of these factors, which are indicative of the worthwhileness of projects. In addition, monitoring of the projects during the operational stage, based on the identified indicators, could be done with the aim of delivering long-term benefits to generations of users.

The increased emphasis on health and safety (H&S) in the construction industry in recent years necessitates continuous research on strategies to improve H&S performance in the sector. However, the motives behind the implementation of H&S practices in the construction industry has been explored to a limited extent. The aim of the current study is to classify the drivers behind H&S implementation in the South African construction industry. A field survey was undertaken. Participants, selected through judgemental and snowball sampling techniques, included site engineers, site agents, contracts managers, construction managers and project managers. Mean item score and standard deviation were determined using EXCEL. The need to manage hazards; organisations regard H&S as important; and compliance with the legislation emerged as the most important drivers. The study provides evidence for construction organisations to develop effective strategies to mitigate the occurrence of fatalities and deaths in the construction industry. More robust data analysis techniques could be employed in further studies.

Nutritional knowledge as well as economic, social, biological, and cultural factors have been known to determine an individual’s food choices. Despite the existence of research on the factors which influence nutrition globally, there is little known about the extent to which these factors influence the food choices of construction workers, which in turn influence their health and safety during construction activities. The present article investigates the extent to which construction workers’ nutrition is influenced by nutritional knowledge, as well as economic, environmental, social, psychological, and physiological factors. A field questionnaire survey was conducted on site construction workers in the Gauteng Province of South Africa. Principal components analysis and multiple regression analysis were used to analyze the data. Findings revealed that consumption of foods termed alternative foods including dairy products, eggs, nuts, fish, and cereals, was influenced by nutritional knowledge and resources. Foods termed traditional core foods were influenced by cultural background; foods termed secondary core foods comprising fruits and vegetables were influenced by economic factors, resources, and cultural background; while foods termed core foods were mostly influenced by nutritional knowledge. By providing evidence of the factors which most influence selection and consumption of certain foods by construction workers, relevant nutrition interventions will be designed and implemented, taking cognizance of these factors.

This article presents findings from an investigation conducted in Botswana and South Africa on how construction clients could influence health and safety (H&S) performance on construction projects. The continued poor state of construction H&S and the inability of designers and contractors to influence an industry-wide H&S culture change motivated the article. It was also recognised that one of the reasons the construction industry continued to lag in H&S performance was the way in which H&S implementation and management was organised. The article proposes a client-centred model for H&S performance improvement. The conceptual model and its factors were developed from both literature and a Delphi survey. Structural equation modelling was applied to data collected from a questionnaire survey to design a best fit model. The key finding was that, generally, client H&S culture impacted on project H&S performance. The influence of clients was found to be statistically significant when commitment, communication and H&S procedures were evident. This finding was encouraging as it specifically shows how clients could influence performance. However, it remains to be seen whether these results could be replicated in other datasets. If indeed that is the case, then this article contributes significantly to the body of knowledge.

The purpose of this article is to present findings of a preliminary survey on contractors’ perceptions of clients’ attitude relative to health and safety (H&S) implementation in the construction industry of Botswana and Southern Africa. A questionnaire survey was conducted on construction projects to establish clients’ attitude towards H&S. Interviews were also held with contractors’ representatives on selected construction sites in and around Gaborone, Botswana. Findings from the survey include: clients do not perceive H&S to be very important on construction projects; the majority of clients do not address H&S adequately in contract documentation, and H&S is rarely a major item on the agenda of progress meetings. Findings also included that clients are not fully committed to H&S implementation. The client sets the tone for H&S culture. Client attitude is therefore very important for H&S performance improvement as all stakeholders are compelled to act in line with the client’s values. Various researchers have recognised the importance of the client to H&S performance improvement. The extent to which clients are involved in H&S implementation has, however, not been researched extensively, especially in Southern Africa. This article therefore provides an insight into the clients’ attitude towards H&S and explains the reason for the current state of H&S in Botswana’s construction industry.