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Cracking, deformation and rutting are the most prevalent types of pavement distress, and these deformations and flow characteristics greatly distress the pavement features while also limiting its use. In India, on the other hand, more than 300 million scrap tyres are generated each year, and their disposal has become a severe environmental issue. Furthermore, the scrap generated by the used tyre must be disposed of properly. Hence, this study presents the experimental investigations of bitumen incorporating with Crumb rubber as main additive along with SBS polymer, to enhance the engineering property.

Crumb rubber (CR) was used as an additive along with styrene–butadiene–styrene (SBS) polymer to enrich the engineering qualities of the bitumen to reduce the disposal problem of scrap tyres and reduce the risk of environmental pollution. Because SBS polymer is expensive, response surface methodology modelling's central composite design (CCD) was used to optimise the number of tests. CCD modelling's input factors (process variables) were the inclusion rates of SBS and CR, which ranged from 2% to 5% and 4% to 10%, respectively, by total weight. Furthermore, the influence of SBS polymer and CR on the characteristics of modified bitumen was prioritised.

The addition of SBS and CR enhanced the bitumen's penetration resistance at service temperatures. Furthermore, increasing the SBS and CR concentration affected the flow characteristics of the modified bitumen and enhanced its viscosity. The addition of SBS and CR as bitumen modifiers increased penetration resistance by 24.06%. The Dynamic Shear Rheometer test demonstrated that the complex modulus of virgin bitumen increases with increasing SBS and CR content, which is consistent with the shifting softening point trend. The dosing rate of up to 3.5% SBS and 11% CR considerably contributed to the creation of polymer link networks, which increased the complex modulus of the bitumen by 16.5%. The CCD model's analysis of variance and Pareto bar chart demonstrated that the dose of CR is significant in improving the engineering features of the virgin bitumen rather than the SBS.

The utilisation of CR as a bitumen modifier may solve the problem of waste tyre disposal while also lowering the risk of environmental damage. Furthermore, because the presence of CR increased the engineering properties, particularly the complex modulus of virgin bitumen, the use of CR in combination with SBS polymer can be an efficient and cost-effective strategy to improving bitumen qualities.

This paper aims to explore the intellectual structure shaping the circular economy (CE) discourse within the built environment in Africa.

The study adopted a bibliometric analysis approach to explore the intellectual structure of CE in the built environment in Africa. The authors collected 31 papers published between 2005 and 2021 from the Scopus database and used VOSviewer for data analysis.

The findings show that there are six clusters shaping the intellectual structure: demolition, material recovery and reuse; waste as a resource; cellulose and agro-based materials; resilience and low-carbon footprint; recycling materials; and the fourth industrial revolution. The two most cited scholars had three publications each, while the top journal was Resources, Conservation and Recycling. The dominant concepts included CE, sustainability, alternative materials, waste management, lifecycle, demolition and climate change. The study concludes that there is low CE research output in Africa, which implies that the concept is either novel or facing resistance.

The data were drawn from one database, Scopus; hence, adoption of alternative databases such as Web of Science, Google Scholar and Dimensions could potentially have yielded a higher number of articles for analysis which potentially would result in different conclusions on the subject understudy.

This study made a significant contribution by articulating the CE intellectual structure in the built environment, identified prominent scholars and academic platforms responsible for promoting circularity in Africa.

This paper aims to present the responses of students to various aspects of a cluster of discrete modules delivered using a studio-based learning pedagogy.

A variation of a case study approach was used that included observations and a survey of student opinions on six constructs or themes after a period of eight weeks into the semester about their experience of studio-based learning in a three-module cluster. This paper only reports on the findings of the analysis of the self-administered survey of the views of students.

The student responses were analysed using SPSS (version 22). It is evident that the distinguishing features of the studio-based learning form of instructional delivery were reflected in their views despite the instructional space being far from ideal. However, given that this was their first experience they were apprehensive about the benefits of the approach to them personally especially in terms of whether their acquired knowledge base was broad enough for them to be confident about their future careers. The mapping of the learning outcomes of the modules against the project phases demonstrated that only the mode of transmission had in fact changed. Students were reticent about taking responsibility for their own learning possibly because they perceived that as being too risky.

The research is limited because the findings are based on a single case and a sample of students who had experienced eight weeks of studio-based learning of a cluster of three discrete modules in a revitalised construction program.

The findings of this study have implications for the way construction programs are delivered at institutions of higher education.

The purpose of this paper is to investigate the perception of high school students on the factors impacting their career decisions and whether gender and grade have an influence on the decision‐making process.

Literature review was used to identify relevant factors which were incorporated into the design of the survey instrument. The questionnaire was administered via a postal survey and information collected from 599 male and 491 female high school students in the Western Cape Province. Survey response data were subjected to descriptive statistics and subsequently parametric tests.

Salary, working conditions, opportunities for promotion and lifelong learning were reported by both male and female students as the most important factors, whereas family tradition and peers were the least important factors according to the male and female high school students, respectively. Grade had a significant impact on the process with students in Grade 11 scoring higher on salary, working conditions and lifelong learning opportunities whereas Grades 12 and 10 scored higher on skills shortage and family tradition, respectively.

The cross‐sectional data made it difficult to generalise the findings.

The findings are of particular importance to high school teachers and guidance counsellors who influence career choices amongst high school students. It is likely that teachers and counsellors themselves have been negatively influenced by the poor image of the construction industry. The identification of factors enables the development of viable strategies and balances the social dynamics of the male dominated environment.

There are few studies which try to investigate the career decision‐making process of high school students in an African environment. These results challenge the factors impacting career decision making among South African high school students and provide information rarely examined. Conclusively, the paper finds that control variables such as grade and gender are significant in the career decision‐making process of high school students. This paper contributes to bridging that gap.

The purpose of this paper is to investigate the perceived age differences in job satisfaction of construction workers in South Africa, and how these differences affect job overall satisfaction of young and old workers on construction sites in South Africa.

The empirical study involved construction workers at operational levels comprising younger (age<40 years) and older (age>40 years) in the Western Cape province. A total of 300 questionnaires were sent to potential respondents chosen from construction workers within the Western Cape province. A total of 65 useable questionnaires were returned giving a response rate of 22 per cent.

Results of this paper indicate that job satisfaction differential does not exist between younger and older construction workers in South Africa. Overall the findings suggest that although both younger and older workers rank the relationship with workmates as being poor, age does not have an influence on the effects of the aspects of work, however, the differences are significant for one of the job satisfaction effects with younger workers reporting higher scores on “indifference”, whereas the younger workers rank poor recognition of abilities as the most effect in comparison to the older workers who reported suffering from a “lack of alertness” as the most ranked effect.

The relatively small sample means that the findings presented are not generalisable to the wider population of workers in the South African construction industry.

The paper offers practical suggestions to the construction industry and management in general on how to minimise the negative job effects arising from lack of job satisfaction. Contributes to the theory building efforts in the discipline of organisation behaviour.

The paper examines job satisfaction related issues in a developing economy and under‐researched area. The Herzberg's two factor theory of motivation which has hitherto been based on white‐collar and its applicability to blue‐collar workers such as construction bricklayers, general workers and site based personnel remains to be tested, more so with the African context.

The purpose of this paper is to identify, explore, rank the relative importance and determine the prevalent allocation response trends of the major construction risk factors considered by general contractors operating in the State of Qatar.

A structured questionnaire survey comprising 37 potential risk factors was distributed to a statistically representative sample of contractors. The influence ranks of the factors explored were determined using the “Relative Importance Index (RII)” technique, whereas the prevalent trend of contractors’ attitudes toward risk allocation of each factor investigated was quantified and expressed as a percentage, based on the number of respondents who selected a specific option, in relation to the total number of respondents.

The results obtained indicate that risks related to the “client” group are perceived as most critical, followed by the “consultant”, “contractor” and “exogenous” group-related factors, respectively. The outcomes further show that the “transfer” option is the contractors’ prevalent response to “client” and “consultant”-related risks, while the “retention” decision is the principal pattern linked to “contractor” and “exogenous” group-related risk factors.

The dominant respondents’ perception that the crucial construction risks are related to clients and consultants suggests that these two parties have an essential role in controlling the negative ramifications of the associated factors.

The findings suggest that increasing designers’ awareness of the significant effect of applying the constructability concept can considerably help reducing the risks concomitant of the construction operation. Policy makers may contribute, moreover, in alleviating the risk of incompetent technical staff and operatives’ employment by controlling the migration of inexperienced and unskilled construction workforce into the State.

Given the knowledge gap for the major construction risk factors considered by general contractors in Qatar, the results reported in this study can provide clients, industry practitioners and policy makers with guidance to effectively manage the significant risks determined, which can further assist in achieving a reasonable level of competitiveness and cost-effective operation.

This paper aims to report on the development of a model to improve process health and safety within the context of a petrochemical environment to achieve a generative health and safety culture within that sector.

A quantitative research methodology and deductive research approach were used in the study. A survey was conducted in a major petrochemical enterprise in the KwaZulu-Natal province of South Africa with 259 returned and duly completed questionnaires. The data was statistically analysed using statistical packages for social science version 25.

This study found that the key process health and safety critical drivers needed to grow a generative process health and safety culture were leadership commitment, chemical exposure management, health and safety risk assessment, process hazard analysis and permit to work.

This study was conducted in the KwaZulu-Natal Province of South Africa within the petrochemical industry. Because of self-reported methods of data collection, there is a probability of bias existing in the results of the study.

The contribution of this research is to understand, based on theoretical assumptions, how health and safety improvement could be institutionalised in an organisation. The developed model can be used as a practical tool.

This paper is part of the larger discussion of increasing importance in health and safety policy-making. This study aims at contributing to the literature in the field of health and safety by incorporating the drivers towards a generative process health and safety culture.

This study provides a model to assist senior management to reduce exposure to process health and safety hazards in the petrochemical industry and improve overall performance.