The construction industry, known for its low productivity, is increasingly utilising software and mobile apps to enhance efficiency. However, more comprehensive research is needed to understand the effectiveness of th...The construction industry, known for its low productivity, is increasingly utilising software and mobile apps to enhance efficiency. However, more comprehensive research is needed to understand the effectiveness of these technology applications. The PRISMA principles utilised a scoping review methodology to ascertain pertinent studies and extract significant findings. From 2013 onwards, articles containing data on mobile applications or software designed to enhance productivity in the construction sector were obtained from multiple databases, including Emerald Insight, Science Direct, IEEE Xplore, and Google Scholar. After evaluating 2604 articles, 30 were determined to be pertinent to the study and were subsequently analysed for the review. The review identified five key themes: effectiveness, benefits, successful implementation examples, obstacles and limitations, and a comprehensive list of software and mobile apps. In addition, 71 software and mobile apps have shown potentially how these technologies can improve communication, collaboration, project management, real-time collaboration, document management, and on-the-go project information and estimating processes in the construction industry, increasing efficiency and productivity. The findings highlight the potential of these technologies such as Automation, Radio-Frequency Identification (RFID), Building Information Modeling (BIM), Augmented Reality (AR), Virtual Reality (VR), and Internet of Things (IoT) to improve efficiency and communication in the construction industry. Despite challenges such as cost, lack of awareness, resistance to change, compatibility concerns, human resources, technological and security concerns and licensing issues, the study identifies specific mobile applications and software with the potential to enhance efficiency significantly, improve productivity and streamline workflows. The broader societal impacts of construction software and mobile app development include increased efficiency, job creation, and sustainability.展开更多
Amidst the recent development in the usage of curtain walls for office buildings, high utilization of energy and poor thermal comfort issues have become paramount. This paper assesses thermal comfort in multi storey (...Amidst the recent development in the usage of curtain walls for office buildings, high utilization of energy and poor thermal comfort issues have become paramount. This paper assesses thermal comfort in multi storey (naturally and mechanically ventilated) office buildings in Accra, the Capital city of Ghana using Fanger’s Predicted Mean Votes (PMV) and Predicted Percentage of Dissatisfied persons (PPD) model. The model relates to the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) Standard 55 (which gives an acceptable temperature range of 23℃ - 26℃) and the International Standards Organization (ISO) 7730. Indoor environmental parameters (temperature and relative humidity) of 4 multi storey office buildings were recorded over a 10 month period. The environmental parameters were analyzed using PMVcalc_v2 software which resulted in the generation of PMV-PPD values. The findings reveal high PMV-PPD values in the Naturally Ventilated Building (NVB) whiles the Mechanically Ventilated Buildings (MVB) fall within the comfort zone. Meanwhile, the Actual Mean Votes (AMV) by the occupants suggest all four buildings are relatively comfortable with the mechanically ventilated offices being more comfortable. Additionally, it is recommended that buildings are orientated with their longer sides facing north-south, with enough shading in order to improve the thermal comfort conditions of work spaces.展开更多
The act of unauthorized siting of buildings has persisted in most developing countries. Despite numerous efforts at local levels to address this problem, its existence and effects keep on rising in various metropolise...The act of unauthorized siting of buildings has persisted in most developing countries. Despite numerous efforts at local levels to address this problem, its existence and effects keep on rising in various metropolises in Ghana. This research explores the causes of unauthorized siting of buildings in Asakae, a suburb of the Sekondi-Takoradi Metropolis, and suggests measures to curb them. In view of this, a sample size of 182 house-owners was chosen for the study. Accordingly, the sample size was determined using Fisher et al. formula and questionnaire survey approach was adopted for the study. More so, data generated from the survey were further analyzed, using Relative Importance Index. The findings of the survey indicated that ignorance on planning and building regulations, inadequate housing schemes, unrealistic zonings and the location of land are critical variables which influence unauthorized siting of buildings. It is recommended that the populace should be given regular public education on land-use planning and the building regulations of Ghana. More so, the Assemblies should automate their systems, with respect to monitoring and detection of buildings under construction;so that buildings that were being located at unapproved places could be quickly detected, and appropriate measures could be taken before their completion.展开更多
BIM (building information modeling) is a technological innovation, not only during the design process, but also during the planning and preparation stages of a construction project, as it also supports making invest...BIM (building information modeling) is a technological innovation, not only during the design process, but also during the planning and preparation stages of a construction project, as it also supports making investment decisions. An innovation which is comparable, if only slightly less significant, was the transition from using 2D systems to the 3D structural model design. The article outlines the advantages of using BIM in the preparatory stages of a construction project. It also presents benefits which relate to the employment of the BIM system in cost estimation process. The article describes the Zuzia BIM system which uses the BIM model, as this system has just been created in Poland for the purpose of construction cost estimation. The preparation of the bill of quantities is automated in this system and this has been achieved on the basis of data directly obtained from virtual models of buildings, which were carried out thanks to the collaboration of various design sectors. The article authors, using their own experience, present difficulties which can be encountered by cost estimators in Poland when calculating the value of a building with the help of the BIM concept. The article shows the design errors that prevent or hinder takeoff automatic calculation based on BIM model. Design errors shown in the article are for example reinforcement bars have been defined by a designer as elements hollow in the middle or as one element for the whole building, one type of elements assigned as few different or incorrect defining of elements in relation to the type of works.展开更多
There is a growing concern of the integration of bamboo as a material into the building construction industry even though its potential is underscored. Certain factors serve as barriers to the use of bamboo in buildin...There is a growing concern of the integration of bamboo as a material into the building construction industry even though its potential is underscored. Certain factors serve as barriers to the use of bamboo in building construction. This study employed a questionnaire survey which sought to investigate the perceptions of 84 Architects and 100 Senior Managers of small and medium scale Building construction firms on the factors that influence the use of bamboo in building construction. Relative Importance Index and Chi-squared tests were performed to identify the significant factors that influence the use of bamboo in building construction. The results showed that the building contractors considered nonspecification of bamboo for building projects by Architects, inadequate bamboo processing companies in Ghana and insufficient cooperation from government to be the key factors which influence the use of bamboo for building construction. The results further showed that the Architects considered lack of knowledge in bamboo detailing, limited knowledge of bamboo and lack of expertise to use it, and inadequate bamboo processing companies to be the key influential factors inhibiting the use of bamboo in building construction. The results are of value to the construction industry as it identifies significant factors which influence the usage of bamboo in building construction. Promotion of bamboo usage in building construction should be given the needed publicity to create the awareness of its potential as a building material.展开更多
This paper mainly discusses the problems existing in the traditional design process of the refrigeration station and tries to solve them with BIM technology. Considering the characteristics of BIM technology, BIM desi...This paper mainly discusses the problems existing in the traditional design process of the refrigeration station and tries to solve them with BIM technology. Considering the characteristics of BIM technology, BIM design process is presented based on the traditional design process to achieve the goal of improving design quality and efficiency.展开更多
This study aims to determine the key and underlying Leadership and Top Management (LTM) factors that have a significant impact on sustaining the implementation of Total Quality Management (TQM) within the construction...This study aims to determine the key and underlying Leadership and Top Management (LTM) factors that have a significant impact on sustaining the implementation of Total Quality Management (TQM) within the construction industry in Ghana. The research methodology employed in this study was a quantitative technique. Questionnaires were distributed to 641 participants within construction industry in Ghana. Questionnaires retrieved for the analysis were 536. Three steps approached were used for the data analysis. These include Exploratory Factor Analysis (EFA), Confirmatory Factor Analysis (CFA), and Structural Equation Modeling (SEM) analysis. After conducting the EFA and CFA, SEM was also used to analyze the construct validity. The SEM analysis helps to determine four key indicator variables for the leadership and top management construct. These include Leadership/Top Management approach to employees’ management, Leadership/Top Management understanding of TQM, Leadership/Top Management empowerment of employees to resolve quality issues, and Leadership/Top Management endorsement of TQM. All the four indicator variables were found to be good of fit and closely associated with the dependent variable. The study adds to the body of knowledge by using EFA, CFA and SEM techniques to establish key leadership and top management factors affecting TQM implementation in Ghana’s construction industry. The findings in general suggested that leadership and top Management factors identified have a direct positive impact on sustaining TQM implementation in the Ghanaian construction industry. Consequently, the leadership and top management factors identified in this study can help improve TQM in the Ghanaian construction industry.展开更多
Coping strategies adopted to deal with psychological health issues could have influences on the general health, productivity and task performance of the employee. This study sought to investigate the coping strategies...Coping strategies adopted to deal with psychological health issues could have influences on the general health, productivity and task performance of the employee. This study sought to investigate the coping strategies adopted by construction employees to deal with the causes and effects of occupational psychological disorders such as burnout and workaholism. To achieve this aim, the methods of focus group discussions were first employed. A total of 16 semi-structured focus group discussions were held in Ghana, with 90 construction employees. The focus group study revealed 25 coping strategies adopted as efforts to mitigate the causes and 22 coping strategies adopted as responses to moderate the effects of occupational psychological disorders. A quantitative study involving 150 construction professionals and 150 construction trade workers were also conducted in Ghana to investigate the coping strategies that were highly adopted by the two construction working groups. The findings from the study revealed that the construction professionals adopted delegating complicated tasks and seeking medical attention as the most common coping strategies to manage the causes and effects respectively. The construction trade workers were also revealed to adopt withdrawing from work duties or changing jobs and taking in more caffeinated drinks as the most common coping strategies to manage the causes and effects respectively. Exploratory factor analysis was employed, and the findings were put into the main constructs. The causes focused coping strategies were categorized under avoidance, alteration, adaptation, and acceptance. The effects focused coping strategies were also categorized under healthy and unhealthy coping strategies. This study recommends appropriate coping strategies and interventions in the construction industry such as education of construction personnel on the consequences of various coping strategies.展开更多
Personal factors could act as intervening variables between the causes and effects of psychological health conditions of employees. This study focused on six personal intervening factors that were associated with the ...Personal factors could act as intervening variables between the causes and effects of psychological health conditions of employees. This study focused on six personal intervening factors that were associated with the risks of occupational psychological disorders namely: low self-esteem, negative personality trait, unproductive core beliefs, poor self-concept evaluation on performance, poor relationship with others and poor time management skills. An investigation on the level of severity of these personal intervening factors was conducted involving 150 construction professionals and 150 construction trade workers, who were purposively selected in Ghana. The personal factors that were found to be prevalent among the construction employees were low self-esteem and poor time management skills. Correlation analysis and regression analysis were used to determine the relationships between the personal intervening factors and demographic factors such as the age, educational levels and marital status of the research participants. The results of the study indicated that the age and marital status of the respondents had no significant relationship with any of the personal intervening factors. Personal factors such as personality trait and relationship with others also had no relation with any of the demographic factors analyzed. The educational level of the respondents, however, had a significant relationship with the factors of self-esteem, productive core beliefs, self-evaluation on performance and time management skills. An independent two-sample T-test was used to compare the means of the factors with significant relations. This study revealed that construction employees who were highly educated had better self-esteem and time management skills than those who were less educated. The findings from this study broaden the view of moderators on influential sources of psychological health conditions of employees.展开更多
The present paper introduces the concepts of exergy and treats it applications to analysis of the gain in exergy efficiency between one-step and multi-step thermal processes. The analysis, which is carried out with th...The present paper introduces the concepts of exergy and treats it applications to analysis of the gain in exergy efficiency between one-step and multi-step thermal processes. The analysis, which is carried out with the Excel-based SEPE program, is exemplified with the comparison between single-step and two-steps heat pump setup for providing heat to a floor heating system and for domestic hot water. The paper discusses the use of the concept of exergy efficiency as a measure of success for design of a heat pump application and how the use of information on exergy destruction and temperature levels in different parts of the system add a new perspective to the analysis and the evaluation of the system performance. The paper shows how this information can be used to improve the system configuration and also the operation of the system for given boundary conditions. This is especially useful when the energy from the low temperature sources can be utilized at different temperature or quality levels such as for space heating and domestic hot water.展开更多
This paper presents the effect of fly ash grain-size fractions on Portland-fly ash cement hydration and its properties. Siliceous fly ashes of size fraction of 0 - 16 and 16 - 32 μm, separated from initial fly ash sa...This paper presents the effect of fly ash grain-size fractions on Portland-fly ash cement hydration and its properties. Siliceous fly ashes of size fraction of 0 - 16 and 16 - 32 μm, separated from initial fly ash samples from 1st, 2nd and 3rd hopper in ESP system, were analysed. Cement hydration was investigated by determination of hydration heat and content of Ca(OH)2 and C3S in cement samples. Water to cement ratio and initial setting time of cement pastes as well as compressive strength and microstructure of cement mortars were also analyzed. Results showed that the same amount of the same size ash fraction can give cement of lower or higher early strength and its lower or higher increase with time. Incorporation of 20 wt% of ash fraction of 0 - 16 μm can produce Portland-fly ash cement CEM II/A-V of strength class 42.5R (from 2nd hopper) or 52.5N (from 3rd hopper). Cement containing 40 wt% of ash fraction of 0 - 16 μm from 2nd and 3rd hopper can be classified as pozzolanic cements CEM IV/A-V of strength class 42.5 and normal or rapid early strength, respectively. Different development of strength of cement with addition of the same size ash fraction separated from the initial ash sample from the next hopper in ESP system is connected with higher depolymerization degree of SiO4 units in ash glass, resulting from the greater amount of AlO4 units replacing SiO4 units. Ash fraction of 16 - 32 μm shows lower depolymerisation of glass network and as a consequence lower hydration degree of C3S to portlandite and calcium silicate hydrates (C-S-H).展开更多
Academia and industry research enables researchers to conduct research projects that are more relevant to current business practices and context. Although, several construction research works have been done by the aca...Academia and industry research enables researchers to conduct research projects that are more relevant to current business practices and context. Although, several construction research works have been done by the academics in the tertiary institutions in Ghana, it is sad to know that, a large number of these research works have not moved from the pure stage to the applied stage. This study seeks to establish the imperative of academia and industry collaboration in building research in Ghana. A total of 116 construction practising professionals consisting of Ghana Institute of Construction (GIOC) corporate members (QS, Architects, Engineers and so on) from the industry, and academics from tertiary academic institutions (That’s, Lecturers from KNUST and UEW) that run postgraduate construction programmes in Ghana as at February 2016 constituted the respondents for this study. Census and systematic sampling techniques were used for the sampled population. Descriptive statistics was employed in the data analysis for the mean and standard deviation (SD) score values of variables. The most imperatives for academia and industry collaboration were found to be: ensuring research findings solve socio-economic and development problems, the intermittent collapse of buildings, support for the local industries to produce quality materials locally to feed the construction industry, proper contract documentations and administration. This research would bring to light the urgent issues in the construction industry that calls for greater collaboration between the academia and industry in Ghana. It reveals a deeper understanding on the need for collaborative research in the Ghanaian construction industry, by providing the most imperatives to academia-industry collaborative research in Ghana.展开更多
The concept of construction productivity and the needs for incentive schemes towards improving the performance of Artisan has long been established. The choice of particular scheme either financial or non financial an...The concept of construction productivity and the needs for incentive schemes towards improving the performance of Artisan has long been established. The choice of particular scheme either financial or non financial and to what level it contributes to the productivity of employees remain at stake. Therefore, this study set to evaluate the level of awareness, impact and contribution of the schemes with more emphasis to the non financial incentive schemes. A questionnaire survey involving management and artisans of the three tiers of NCl (Nigerian Construction Industry): large, medium and small within Kaduna and Abuja Nigeria was conducted. Three hundred (300) responses from the management and artisans were used for analysis, inferences and conclusions. The survey result revealed that non-financial incentive schemes are mostly employed in the large and medium scale construction firms. Though, preference by medium and small scale firms was based on those that do not require fund to implement and maintain. It was concluded that, construction firms operating in Nigeria ought to strive more towards implementing non-financial incentive in their organization since artisans are willing to improve their output.展开更多
The process of decision making and risk analysis are essential tasks along the construction project cycle. Over the years, construction practitioners and researchers have used various methods, tools and techniques to ...The process of decision making and risk analysis are essential tasks along the construction project cycle. Over the years, construction practitioners and researchers have used various methods, tools and techniques to evaluate risk and assist in making more concise decisions. Most practitioners, however, rely on their expert judgment, past experience, intuition, acquired and accumulated knowledge and gut feelings to make decisions. Aleatory (natural, heterogeneity and stochasticity) and epistemic (subjective, ignorance) are the two major types of uncertainties observed in natural sciences. Practitioners traditionally deal with aleatory uncertainty through probabilistic analysis based on historical data (frequentist approach); and epistemic uncertainty, on the other hand, handled through the Bayesian approach which has limitations since it requires a priori assumption. This paper reports the application of the DST (Dempster Shafer Theory) of evidence to determine the most critical risk factors affecting project cost contingencies using their epistemic probabilities of occurrence. The paper further discuses how these factors can be managed to enhance successful delivery of infrastructural projects. It uses the mixed methodology, with data gathered through structured questionnaires distributed to construction clients, contractors, professionals and experts in the built environment. The research revealed that design risk, financial risk and economic risk were most important cost risk categorizations. In particular, scope changes, incomplete scope definition, incomplete design, changes in specification, micro and macroeconomic indicators and delayed payment problems were identified as the most important risk factors to be considered during the cost contingency estimation process, hence successful delivery of infrastructural projects. The paper concludes by recommending modalities for managing the contingency evolution process of risk estimation to enhance successful delivery and management of infrastructural projects.展开更多
This paper explored the antecedents and the role of local artisans in Spatial Planning (SP) activities in Ghana. The paper was based on the results of an inspection of 5896 already built houses at Mepe in the Volta Re...This paper explored the antecedents and the role of local artisans in Spatial Planning (SP) activities in Ghana. The paper was based on the results of an inspection of 5896 already built houses at Mepe in the Volta Region of Ghana. A mixed method research approach was used to gather the data through snowball non-probability sampling technique. It enabled the researchers to identify 100 local artisans. Survey questionnaires were used, which was followed by structured interviews with five (5) elders who lived in the town for over 65 years. The results showed that the early houses were built on community lands with mud and thatch clustered with narrow and unnamed alleys. Property owners heavily depended on local artisans for professional guidance, although some artisans were ill-trained and unaware of existing government SP regulations. The study was limited to artisans who practiced at the local community level. The findings showed that many local artisans were poorly trained, resulting in poor workmanship and non-compliance with local planning regulations. The paper recommends the integration of SP into the artisanal curricula at both local and national levels to improve their skills.展开更多
The construction industry in most developing economies is dominated heavily by small and medium scale enterprises. These construction enterprises need to thrive in an extremely competitive business environment. Conver...The construction industry in most developing economies is dominated heavily by small and medium scale enterprises. These construction enterprises need to thrive in an extremely competitive business environment. Conversely, most of these small and medium scale construction enterprises (SMSCE) are fraught with a plethora of barriers that inhibit and threaten their growth and survival. This research sought to evaluate the critical barriers that affect the growth of SMSCEs in the Ghanaian Construction Industry. The quantitative research method was adopted using a structured questionnaire with variables that were identified through a comprehensive literature review. The survey questionnaire was administered to 400 respondents comprising 250 SMSCEs, 100 Local Authority Engineers, and 50 Consultants to elicit data based on the identified variables. The major findings established by the study as barriers to the growth of SMSCEs in Ghana are largely structured as financial/fiscal barriers, business development barriers, technical/technological barriers, corruption barriers, knowledge management barriers, project acquisition barriers. A guiding framework should be developed based on the barriers identified to aid the growth and survival of SMSCEs in Ghana.展开更多
There is a perpetual problem of partial or complete roof collapse within the Tamale Metropolis and other parts of Ghana.This has become an issue of grave public concern since this menace affects both public buildings ...There is a perpetual problem of partial or complete roof collapse within the Tamale Metropolis and other parts of Ghana.This has become an issue of grave public concern since this menace affects both public buildings of all kinds(schools,offices,churches,mosque etc.)as well as domestic buildings.This research sets out to conduct comprehensive investigations into the nature of roof failures,causes,and effects and then propose remedial actions towards stemming the tide.The study employed the use of roof construction affirmation surveys,questionnaires,interviews and focus group discussions.Relevant information synthesized indicates that the roof type,construction materials,building type and environmental conditions are crucial causative factors.Major consequences of roof failures include damage to personal belongings and exposure to inclement weather conditions,the psychological trauma victims are subjected and pressure on incomes and living conditions as a result of the cost of repair or replacement of the roofs.It is recommended that expert advice be sought in checking maintenance requirements of existing roofs in the study area and also during the design and construction of new roofs.Tree planting programmes for this heavily deforested region should be encouraged.The use of green timber for roof construction must be replaced with well-seasoned ones.Proper construction detailing and placement openings buildings should be done so that wind flow during a windstorm is optimized.展开更多
This study aims at developing a Knowledge Management Implementation Framework for adoption by firms in the Ghanaian construction industry. Recent developments in the field of Knowledge management in the construction s...This study aims at developing a Knowledge Management Implementation Framework for adoption by firms in the Ghanaian construction industry. Recent developments in the field of Knowledge management in the construction sector have led to a renewed competition in driving organizational performance. However, the construction industry in Ghana lacks a knowledge management implementation framework that addresses the needs of the Ghanaian construction supply chain while a comprehensive approach to managing knowledge remains nebulous. The study adopted an extensive literature review of existing knowledge management models to provide the basis for the development of the proposed framework for Ghana. The proposed knowledge management implementation framework was subjected to testing and validation by project managers drawn from nineteen indigenous construction firms in Ghana. The technology acceptance model (TAM) was used as the criteria to validate the proposed knowledge management implementation framework. The proposed Guribie & Tengan knowledge management implementation framework was perceived to be useful, and easy to use and the intention to adopt and use was high among indigenous Ghanaian construction firms. The study recommends further validation using wider population to enhance the efficacy of the framework for wider industry acceptance to enhance organizational competitiveness and performance delivery.展开更多
Concretes on the basis of the alumosilicate polymer can be prepared by alkali activation (NaOH, sodium water glass) of waste brown coal fly ash. The preparation is possible: (1) by using a short-term heating of t...Concretes on the basis of the alumosilicate polymer can be prepared by alkali activation (NaOH, sodium water glass) of waste brown coal fly ash. The preparation is possible: (1) by using a short-term heating of the concrete mix (to 80 ℃); or (2) by allowing the mix to harden spontaneously at a temperature of 20 ℃. The concretes prepared by short-time heating attain high strength values after their preparation; the values are comparable to those characterizing concretes obtained on the basis of Portland cement. The strength development of concretes hardening at 20 ℃ is substantially less steep but, nevertheless, the strength attained after about 60 days is practically identical with that of the concretes exposed to a short-time heating. The shrinkage of concretes prepared by short-time heating is very small as compared with the concretes allowed to harden spontaneously; the shrinkage of latter concretes is larger than that of the concretes on the basis of Portland cement. The concretes on the basis of alumosilicate polymer exhibit much better resistance to the corrosive action of the environment as compared with those prepared on the basis of Portland cement.展开更多
文摘The construction industry, known for its low productivity, is increasingly utilising software and mobile apps to enhance efficiency. However, more comprehensive research is needed to understand the effectiveness of these technology applications. The PRISMA principles utilised a scoping review methodology to ascertain pertinent studies and extract significant findings. From 2013 onwards, articles containing data on mobile applications or software designed to enhance productivity in the construction sector were obtained from multiple databases, including Emerald Insight, Science Direct, IEEE Xplore, and Google Scholar. After evaluating 2604 articles, 30 were determined to be pertinent to the study and were subsequently analysed for the review. The review identified five key themes: effectiveness, benefits, successful implementation examples, obstacles and limitations, and a comprehensive list of software and mobile apps. In addition, 71 software and mobile apps have shown potentially how these technologies can improve communication, collaboration, project management, real-time collaboration, document management, and on-the-go project information and estimating processes in the construction industry, increasing efficiency and productivity. The findings highlight the potential of these technologies such as Automation, Radio-Frequency Identification (RFID), Building Information Modeling (BIM), Augmented Reality (AR), Virtual Reality (VR), and Internet of Things (IoT) to improve efficiency and communication in the construction industry. Despite challenges such as cost, lack of awareness, resistance to change, compatibility concerns, human resources, technological and security concerns and licensing issues, the study identifies specific mobile applications and software with the potential to enhance efficiency significantly, improve productivity and streamline workflows. The broader societal impacts of construction software and mobile app development include increased efficiency, job creation, and sustainability.
文摘Amidst the recent development in the usage of curtain walls for office buildings, high utilization of energy and poor thermal comfort issues have become paramount. This paper assesses thermal comfort in multi storey (naturally and mechanically ventilated) office buildings in Accra, the Capital city of Ghana using Fanger’s Predicted Mean Votes (PMV) and Predicted Percentage of Dissatisfied persons (PPD) model. The model relates to the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) Standard 55 (which gives an acceptable temperature range of 23℃ - 26℃) and the International Standards Organization (ISO) 7730. Indoor environmental parameters (temperature and relative humidity) of 4 multi storey office buildings were recorded over a 10 month period. The environmental parameters were analyzed using PMVcalc_v2 software which resulted in the generation of PMV-PPD values. The findings reveal high PMV-PPD values in the Naturally Ventilated Building (NVB) whiles the Mechanically Ventilated Buildings (MVB) fall within the comfort zone. Meanwhile, the Actual Mean Votes (AMV) by the occupants suggest all four buildings are relatively comfortable with the mechanically ventilated offices being more comfortable. Additionally, it is recommended that buildings are orientated with their longer sides facing north-south, with enough shading in order to improve the thermal comfort conditions of work spaces.
文摘The act of unauthorized siting of buildings has persisted in most developing countries. Despite numerous efforts at local levels to address this problem, its existence and effects keep on rising in various metropolises in Ghana. This research explores the causes of unauthorized siting of buildings in Asakae, a suburb of the Sekondi-Takoradi Metropolis, and suggests measures to curb them. In view of this, a sample size of 182 house-owners was chosen for the study. Accordingly, the sample size was determined using Fisher et al. formula and questionnaire survey approach was adopted for the study. More so, data generated from the survey were further analyzed, using Relative Importance Index. The findings of the survey indicated that ignorance on planning and building regulations, inadequate housing schemes, unrealistic zonings and the location of land are critical variables which influence unauthorized siting of buildings. It is recommended that the populace should be given regular public education on land-use planning and the building regulations of Ghana. More so, the Assemblies should automate their systems, with respect to monitoring and detection of buildings under construction;so that buildings that were being located at unapproved places could be quickly detected, and appropriate measures could be taken before their completion.
文摘BIM (building information modeling) is a technological innovation, not only during the design process, but also during the planning and preparation stages of a construction project, as it also supports making investment decisions. An innovation which is comparable, if only slightly less significant, was the transition from using 2D systems to the 3D structural model design. The article outlines the advantages of using BIM in the preparatory stages of a construction project. It also presents benefits which relate to the employment of the BIM system in cost estimation process. The article describes the Zuzia BIM system which uses the BIM model, as this system has just been created in Poland for the purpose of construction cost estimation. The preparation of the bill of quantities is automated in this system and this has been achieved on the basis of data directly obtained from virtual models of buildings, which were carried out thanks to the collaboration of various design sectors. The article authors, using their own experience, present difficulties which can be encountered by cost estimators in Poland when calculating the value of a building with the help of the BIM concept. The article shows the design errors that prevent or hinder takeoff automatic calculation based on BIM model. Design errors shown in the article are for example reinforcement bars have been defined by a designer as elements hollow in the middle or as one element for the whole building, one type of elements assigned as few different or incorrect defining of elements in relation to the type of works.
文摘There is a growing concern of the integration of bamboo as a material into the building construction industry even though its potential is underscored. Certain factors serve as barriers to the use of bamboo in building construction. This study employed a questionnaire survey which sought to investigate the perceptions of 84 Architects and 100 Senior Managers of small and medium scale Building construction firms on the factors that influence the use of bamboo in building construction. Relative Importance Index and Chi-squared tests were performed to identify the significant factors that influence the use of bamboo in building construction. The results showed that the building contractors considered nonspecification of bamboo for building projects by Architects, inadequate bamboo processing companies in Ghana and insufficient cooperation from government to be the key factors which influence the use of bamboo for building construction. The results further showed that the Architects considered lack of knowledge in bamboo detailing, limited knowledge of bamboo and lack of expertise to use it, and inadequate bamboo processing companies to be the key influential factors inhibiting the use of bamboo in building construction. The results are of value to the construction industry as it identifies significant factors which influence the usage of bamboo in building construction. Promotion of bamboo usage in building construction should be given the needed publicity to create the awareness of its potential as a building material.
文摘This paper mainly discusses the problems existing in the traditional design process of the refrigeration station and tries to solve them with BIM technology. Considering the characteristics of BIM technology, BIM design process is presented based on the traditional design process to achieve the goal of improving design quality and efficiency.
文摘This study aims to determine the key and underlying Leadership and Top Management (LTM) factors that have a significant impact on sustaining the implementation of Total Quality Management (TQM) within the construction industry in Ghana. The research methodology employed in this study was a quantitative technique. Questionnaires were distributed to 641 participants within construction industry in Ghana. Questionnaires retrieved for the analysis were 536. Three steps approached were used for the data analysis. These include Exploratory Factor Analysis (EFA), Confirmatory Factor Analysis (CFA), and Structural Equation Modeling (SEM) analysis. After conducting the EFA and CFA, SEM was also used to analyze the construct validity. The SEM analysis helps to determine four key indicator variables for the leadership and top management construct. These include Leadership/Top Management approach to employees’ management, Leadership/Top Management understanding of TQM, Leadership/Top Management empowerment of employees to resolve quality issues, and Leadership/Top Management endorsement of TQM. All the four indicator variables were found to be good of fit and closely associated with the dependent variable. The study adds to the body of knowledge by using EFA, CFA and SEM techniques to establish key leadership and top management factors affecting TQM implementation in Ghana’s construction industry. The findings in general suggested that leadership and top Management factors identified have a direct positive impact on sustaining TQM implementation in the Ghanaian construction industry. Consequently, the leadership and top management factors identified in this study can help improve TQM in the Ghanaian construction industry.
文摘Coping strategies adopted to deal with psychological health issues could have influences on the general health, productivity and task performance of the employee. This study sought to investigate the coping strategies adopted by construction employees to deal with the causes and effects of occupational psychological disorders such as burnout and workaholism. To achieve this aim, the methods of focus group discussions were first employed. A total of 16 semi-structured focus group discussions were held in Ghana, with 90 construction employees. The focus group study revealed 25 coping strategies adopted as efforts to mitigate the causes and 22 coping strategies adopted as responses to moderate the effects of occupational psychological disorders. A quantitative study involving 150 construction professionals and 150 construction trade workers were also conducted in Ghana to investigate the coping strategies that were highly adopted by the two construction working groups. The findings from the study revealed that the construction professionals adopted delegating complicated tasks and seeking medical attention as the most common coping strategies to manage the causes and effects respectively. The construction trade workers were also revealed to adopt withdrawing from work duties or changing jobs and taking in more caffeinated drinks as the most common coping strategies to manage the causes and effects respectively. Exploratory factor analysis was employed, and the findings were put into the main constructs. The causes focused coping strategies were categorized under avoidance, alteration, adaptation, and acceptance. The effects focused coping strategies were also categorized under healthy and unhealthy coping strategies. This study recommends appropriate coping strategies and interventions in the construction industry such as education of construction personnel on the consequences of various coping strategies.
文摘Personal factors could act as intervening variables between the causes and effects of psychological health conditions of employees. This study focused on six personal intervening factors that were associated with the risks of occupational psychological disorders namely: low self-esteem, negative personality trait, unproductive core beliefs, poor self-concept evaluation on performance, poor relationship with others and poor time management skills. An investigation on the level of severity of these personal intervening factors was conducted involving 150 construction professionals and 150 construction trade workers, who were purposively selected in Ghana. The personal factors that were found to be prevalent among the construction employees were low self-esteem and poor time management skills. Correlation analysis and regression analysis were used to determine the relationships between the personal intervening factors and demographic factors such as the age, educational levels and marital status of the research participants. The results of the study indicated that the age and marital status of the respondents had no significant relationship with any of the personal intervening factors. Personal factors such as personality trait and relationship with others also had no relation with any of the demographic factors analyzed. The educational level of the respondents, however, had a significant relationship with the factors of self-esteem, productive core beliefs, self-evaluation on performance and time management skills. An independent two-sample T-test was used to compare the means of the factors with significant relations. This study revealed that construction employees who were highly educated had better self-esteem and time management skills than those who were less educated. The findings from this study broaden the view of moderators on influential sources of psychological health conditions of employees.
文摘The present paper introduces the concepts of exergy and treats it applications to analysis of the gain in exergy efficiency between one-step and multi-step thermal processes. The analysis, which is carried out with the Excel-based SEPE program, is exemplified with the comparison between single-step and two-steps heat pump setup for providing heat to a floor heating system and for domestic hot water. The paper discusses the use of the concept of exergy efficiency as a measure of success for design of a heat pump application and how the use of information on exergy destruction and temperature levels in different parts of the system add a new perspective to the analysis and the evaluation of the system performance. The paper shows how this information can be used to improve the system configuration and also the operation of the system for given boundary conditions. This is especially useful when the energy from the low temperature sources can be utilized at different temperature or quality levels such as for space heating and domestic hot water.
基金The paper is financed by the Polish State Committee for Scientific Research,project No.N N506 299139.
文摘This paper presents the effect of fly ash grain-size fractions on Portland-fly ash cement hydration and its properties. Siliceous fly ashes of size fraction of 0 - 16 and 16 - 32 μm, separated from initial fly ash samples from 1st, 2nd and 3rd hopper in ESP system, were analysed. Cement hydration was investigated by determination of hydration heat and content of Ca(OH)2 and C3S in cement samples. Water to cement ratio and initial setting time of cement pastes as well as compressive strength and microstructure of cement mortars were also analyzed. Results showed that the same amount of the same size ash fraction can give cement of lower or higher early strength and its lower or higher increase with time. Incorporation of 20 wt% of ash fraction of 0 - 16 μm can produce Portland-fly ash cement CEM II/A-V of strength class 42.5R (from 2nd hopper) or 52.5N (from 3rd hopper). Cement containing 40 wt% of ash fraction of 0 - 16 μm from 2nd and 3rd hopper can be classified as pozzolanic cements CEM IV/A-V of strength class 42.5 and normal or rapid early strength, respectively. Different development of strength of cement with addition of the same size ash fraction separated from the initial ash sample from the next hopper in ESP system is connected with higher depolymerization degree of SiO4 units in ash glass, resulting from the greater amount of AlO4 units replacing SiO4 units. Ash fraction of 16 - 32 μm shows lower depolymerisation of glass network and as a consequence lower hydration degree of C3S to portlandite and calcium silicate hydrates (C-S-H).
文摘Academia and industry research enables researchers to conduct research projects that are more relevant to current business practices and context. Although, several construction research works have been done by the academics in the tertiary institutions in Ghana, it is sad to know that, a large number of these research works have not moved from the pure stage to the applied stage. This study seeks to establish the imperative of academia and industry collaboration in building research in Ghana. A total of 116 construction practising professionals consisting of Ghana Institute of Construction (GIOC) corporate members (QS, Architects, Engineers and so on) from the industry, and academics from tertiary academic institutions (That’s, Lecturers from KNUST and UEW) that run postgraduate construction programmes in Ghana as at February 2016 constituted the respondents for this study. Census and systematic sampling techniques were used for the sampled population. Descriptive statistics was employed in the data analysis for the mean and standard deviation (SD) score values of variables. The most imperatives for academia and industry collaboration were found to be: ensuring research findings solve socio-economic and development problems, the intermittent collapse of buildings, support for the local industries to produce quality materials locally to feed the construction industry, proper contract documentations and administration. This research would bring to light the urgent issues in the construction industry that calls for greater collaboration between the academia and industry in Ghana. It reveals a deeper understanding on the need for collaborative research in the Ghanaian construction industry, by providing the most imperatives to academia-industry collaborative research in Ghana.
文摘The concept of construction productivity and the needs for incentive schemes towards improving the performance of Artisan has long been established. The choice of particular scheme either financial or non financial and to what level it contributes to the productivity of employees remain at stake. Therefore, this study set to evaluate the level of awareness, impact and contribution of the schemes with more emphasis to the non financial incentive schemes. A questionnaire survey involving management and artisans of the three tiers of NCl (Nigerian Construction Industry): large, medium and small within Kaduna and Abuja Nigeria was conducted. Three hundred (300) responses from the management and artisans were used for analysis, inferences and conclusions. The survey result revealed that non-financial incentive schemes are mostly employed in the large and medium scale construction firms. Though, preference by medium and small scale firms was based on those that do not require fund to implement and maintain. It was concluded that, construction firms operating in Nigeria ought to strive more towards implementing non-financial incentive in their organization since artisans are willing to improve their output.
文摘The process of decision making and risk analysis are essential tasks along the construction project cycle. Over the years, construction practitioners and researchers have used various methods, tools and techniques to evaluate risk and assist in making more concise decisions. Most practitioners, however, rely on their expert judgment, past experience, intuition, acquired and accumulated knowledge and gut feelings to make decisions. Aleatory (natural, heterogeneity and stochasticity) and epistemic (subjective, ignorance) are the two major types of uncertainties observed in natural sciences. Practitioners traditionally deal with aleatory uncertainty through probabilistic analysis based on historical data (frequentist approach); and epistemic uncertainty, on the other hand, handled through the Bayesian approach which has limitations since it requires a priori assumption. This paper reports the application of the DST (Dempster Shafer Theory) of evidence to determine the most critical risk factors affecting project cost contingencies using their epistemic probabilities of occurrence. The paper further discuses how these factors can be managed to enhance successful delivery of infrastructural projects. It uses the mixed methodology, with data gathered through structured questionnaires distributed to construction clients, contractors, professionals and experts in the built environment. The research revealed that design risk, financial risk and economic risk were most important cost risk categorizations. In particular, scope changes, incomplete scope definition, incomplete design, changes in specification, micro and macroeconomic indicators and delayed payment problems were identified as the most important risk factors to be considered during the cost contingency estimation process, hence successful delivery of infrastructural projects. The paper concludes by recommending modalities for managing the contingency evolution process of risk estimation to enhance successful delivery and management of infrastructural projects.
文摘This paper explored the antecedents and the role of local artisans in Spatial Planning (SP) activities in Ghana. The paper was based on the results of an inspection of 5896 already built houses at Mepe in the Volta Region of Ghana. A mixed method research approach was used to gather the data through snowball non-probability sampling technique. It enabled the researchers to identify 100 local artisans. Survey questionnaires were used, which was followed by structured interviews with five (5) elders who lived in the town for over 65 years. The results showed that the early houses were built on community lands with mud and thatch clustered with narrow and unnamed alleys. Property owners heavily depended on local artisans for professional guidance, although some artisans were ill-trained and unaware of existing government SP regulations. The study was limited to artisans who practiced at the local community level. The findings showed that many local artisans were poorly trained, resulting in poor workmanship and non-compliance with local planning regulations. The paper recommends the integration of SP into the artisanal curricula at both local and national levels to improve their skills.
文摘The construction industry in most developing economies is dominated heavily by small and medium scale enterprises. These construction enterprises need to thrive in an extremely competitive business environment. Conversely, most of these small and medium scale construction enterprises (SMSCE) are fraught with a plethora of barriers that inhibit and threaten their growth and survival. This research sought to evaluate the critical barriers that affect the growth of SMSCEs in the Ghanaian Construction Industry. The quantitative research method was adopted using a structured questionnaire with variables that were identified through a comprehensive literature review. The survey questionnaire was administered to 400 respondents comprising 250 SMSCEs, 100 Local Authority Engineers, and 50 Consultants to elicit data based on the identified variables. The major findings established by the study as barriers to the growth of SMSCEs in Ghana are largely structured as financial/fiscal barriers, business development barriers, technical/technological barriers, corruption barriers, knowledge management barriers, project acquisition barriers. A guiding framework should be developed based on the barriers identified to aid the growth and survival of SMSCEs in Ghana.
文摘There is a perpetual problem of partial or complete roof collapse within the Tamale Metropolis and other parts of Ghana.This has become an issue of grave public concern since this menace affects both public buildings of all kinds(schools,offices,churches,mosque etc.)as well as domestic buildings.This research sets out to conduct comprehensive investigations into the nature of roof failures,causes,and effects and then propose remedial actions towards stemming the tide.The study employed the use of roof construction affirmation surveys,questionnaires,interviews and focus group discussions.Relevant information synthesized indicates that the roof type,construction materials,building type and environmental conditions are crucial causative factors.Major consequences of roof failures include damage to personal belongings and exposure to inclement weather conditions,the psychological trauma victims are subjected and pressure on incomes and living conditions as a result of the cost of repair or replacement of the roofs.It is recommended that expert advice be sought in checking maintenance requirements of existing roofs in the study area and also during the design and construction of new roofs.Tree planting programmes for this heavily deforested region should be encouraged.The use of green timber for roof construction must be replaced with well-seasoned ones.Proper construction detailing and placement openings buildings should be done so that wind flow during a windstorm is optimized.
文摘This study aims at developing a Knowledge Management Implementation Framework for adoption by firms in the Ghanaian construction industry. Recent developments in the field of Knowledge management in the construction sector have led to a renewed competition in driving organizational performance. However, the construction industry in Ghana lacks a knowledge management implementation framework that addresses the needs of the Ghanaian construction supply chain while a comprehensive approach to managing knowledge remains nebulous. The study adopted an extensive literature review of existing knowledge management models to provide the basis for the development of the proposed framework for Ghana. The proposed knowledge management implementation framework was subjected to testing and validation by project managers drawn from nineteen indigenous construction firms in Ghana. The technology acceptance model (TAM) was used as the criteria to validate the proposed knowledge management implementation framework. The proposed Guribie & Tengan knowledge management implementation framework was perceived to be useful, and easy to use and the intention to adopt and use was high among indigenous Ghanaian construction firms. The study recommends further validation using wider population to enhance the efficacy of the framework for wider industry acceptance to enhance organizational competitiveness and performance delivery.
基金This study was part of the research project CEZ:MSM 6046137302: "Preparation and research of functional materials and material technologies using micro-and nanoscopic methods" and Czech Science Foundation Grant 103/08/1639 "Microstructure of inorganic alumosilicate polymers".
文摘Concretes on the basis of the alumosilicate polymer can be prepared by alkali activation (NaOH, sodium water glass) of waste brown coal fly ash. The preparation is possible: (1) by using a short-term heating of the concrete mix (to 80 ℃); or (2) by allowing the mix to harden spontaneously at a temperature of 20 ℃. The concretes prepared by short-time heating attain high strength values after their preparation; the values are comparable to those characterizing concretes obtained on the basis of Portland cement. The strength development of concretes hardening at 20 ℃ is substantially less steep but, nevertheless, the strength attained after about 60 days is practically identical with that of the concretes exposed to a short-time heating. The shrinkage of concretes prepared by short-time heating is very small as compared with the concretes allowed to harden spontaneously; the shrinkage of latter concretes is larger than that of the concretes on the basis of Portland cement. The concretes on the basis of alumosilicate polymer exhibit much better resistance to the corrosive action of the environment as compared with those prepared on the basis of Portland cement.