The mixture of aggregate, filler, and binder produces Cold Bituminous Emulsion Mixtures (CBEM). CBEM has many several environmental and cost-effective benefits. However, it offers poor early life properties besides achieving maximum strength it required a long curing period. In this experimental study, waste rice husk ash and ordinary Portland cement are used as substitutes for mineral filler with 0%, 1%, 2%, and 3%. The main objective of this study is to improve performance CBEM by combining Waste Rice Husk Ash (WRHA) and Ordinary Portland Cement (OPC). To evaluate enhancement in performance of CBEM, Retained Stability test, Tensile Strength Test, and Marshall Stability Test were conducted. The experimental results show that the tensile strength and Marshall stability of CBEM increased drastically by replacing mineral filler with waste rice husk ash and ordinary Portland cement. The moisture-induced damages are reduced due to the WRHA and OPC is added in the CBEM. As the tensile strength values and stability values of WRHA modified CBEM are more optimistic than OPC modified CBEM.
In every construction project, cost estimation is one of the most crucial aspects that is critical to the project's success. To achieve a proper estimate, price accuracy is fundamental. Building Information Modeling (BIM) is a distinguishing result of the growth of modern information technology in the building industry. Because of its direct quantity extraction features, using BIM in quantity takeoff leads to highly accurate quantities and cost estimation. Meanwhile, there may be few hindrances that lead to errors in price accuracy of BIM-based quantity takeoff. Thus, this study intends to ascertain to which extent the BIM base quantity takeoff is being satisfied with the accuracy of cost estimation by evaluating the impact of BIM-based takeoff advantages and drawbacks for the accuracy of cos estimation and recommending suitable measures to improve the accuracy. To attain the aim, an extensive literature synthesis was piloted to develop a questionnaire survey was carried out upon the key findings of the literature. This paper presents a comprehensive literature review to get an overview of the cost estimation and BIM-based and CAD-based quantity takeoff while identifying the factors affecting accuracy with their advantages and drawbacks. Then the study concludes factors that facilitate increasing the price accuracy with the use of BIM. Later on, twelve possible measures to improve estimating accuracy through BIM-based takeoff were tested in the questionnaire survey. The most significant method was revealed to be equipped estimators with the required software information to prepare more accurate cost estimates using BIM-based quantity takeoff.
Previous repetitive scheduling models were focused on one issue in optimizing project duration or total costs, such as: Interruption, buffer inserting, or acceleration. The main objective of this research is to develop an optimization model which identifies the optimum solution that minimizes total project cost under a group of constraints considering different scenarios for incorporating Interruption, buffer time, and schedule acceleration. Thus, the model user can choose the scenario which best fits his desire. The main contributions of the developed, optimized model are: 1) Scheduling and interruption module capable of optimizing schedules for least total project cost, 2) Scheduling and buffering module of optimizing schedules for least total project cost, 3) A buffering approach that provides a structured tool for building buffers to protect the project schedule from expected delays, 4) A schedule acceleration module that comprises unit-based acceleration algorithm capable of finding least cost of acceleration plans through accelerating units instead of activities, and 5) Queuing criteria for schedule acceleration that allows considering cost slope and contractor's judgment while prioritizing units for acceleration. The developed model is automated using the c # programming language. Thus, the current model is flexible for the user to choose some essential features such as interruption percentage, overtime factor, relative weights allocated to cost slope , and contractor's judgment in acceleration, resulting in saving the user's time suiting large- size projects.
Cost overruns have provided a significant challenge in the construction industries of both developed and developing countries. The purpose of this study was to investigate the influence Subcontractor Oversight on Construction Cost Overruns of real estate projects in Nairobi and Kisumu Counties. The study was guided by objective, to establish the extent to which subcontractor oversight influence real estate construction projects cost overruns. The research adopted descriptive survey and correlational research designs. The study targeted a population of 4000 project professionals that constituted 7 professionals from active real estates in Nairobi and Kisumu Counties and 10 key informants from the real estate industry. Using the Krejcie and Morgan table of sample size determination, the sample size for this study was 351. The study then adopted stratified, simple random and purposive sampling methods to select appropriate sample sizes from the study population strata. Structured questionnaire was the main instrument for data collection, supported by interview guide. Hypothesis was tested at α=0.05 level of significance and the results were: H0: There is no significant relationship between subcontractor oversight and real estate construction projects cost overruns was rejected since P=0.000<0.05. Considering the study findings and conclusions, the following recommendations were made: Project professionals and other relevant real estate project stakeholders should encourage comprehensive subcontractor oversight as critical concerns in assembling pertinent information and creating avenues that could be utilized to reduce real estate construction projects cost overruns.
The construction sector has made a significant contribution to global environmental problems, both directly and indirectly, while forging an inextricable bond with society and country's economy. Nevertheless, as the industry's demands for climate change mitigation and resource efficiency expand, sustainable procurement has emerged as a corporate concern. Building construction is intrinsically prone to changes in the construction industry because it is a key sector of the construction industry. By incorporating sustainable components into the procurement process, building constructions are becoming more sustainable, and sustainable procurement has become a major turning point in the building industry's evolution. Nonetheless, the efficacy of sustainable procurement is dependent on the positive and demonstrable control of challenges, which limits the sustainable procurement of buildings. The paper includes a detailed literature review highlighting the importance of sustainable procurement, as well as its benefits, drivers, barriers, and measures. For the successful fulfillment of targeted objectives, a quantitative research approach has been used. A questionnaire survey was conducted, focusing on 30 professionals with some practical experience with sustainable procurement. The questionnaire survey's results were then analyzed using descriptive statistics and the relative relevance index (RII). The analysis showed that sustainable procurement is challenged by aspects such as difficulty in tender evaluation by considering the cost of the entire product/service life cycle, lack of support from the senior management on the implementation of the concept, and lack of sustainable procurement policies. Furthermore, promoting a positive context for implementing of sustainability practices, establishing measurable sustainable procurement goals. Moreover, conducting procurement post-review to detect overlooked environmental concerns could be the preferable measure to address barriers to sustainable procurement.
Buildings failure in Kampala City has occurred frequently, leading to increase in the spate of building collapse that has claimed the people’s lives. Although different strategies to eliminate structural failure of buildings have been devised by KCCA (Kampala Capital City Authority), the challenge continues to affect different parts of the city, causes of which this study examined. Although the Government of Uganda through the Ministry of Lands, Housing and Urban Development (MLHUD) and KCCA has enacted guidelines for the construction industry, numerous buildings have still continued to succumb to failure, implying that the strategies to eliminate the structural failure of buildings as established by Government exist but are not being followed or enforced. The purpose of the study was to assess the causes of collapse of buildings in Kampala, to establish the impact of building failure to stakeholders, to assess the performance of the strategies designed by KCCA to mitigate the occurrence of structural failure of buildings and to develop a framework for mitigating and eliminating structural failure. The study adopted a case study research design employing the triangulation approach with both quantitative and qualitative approaches. The study population comprised of 200 respondents from the following bodies: UIPE (Uganda In statute of professional Engineers), ERB (Engineers Registration Board), MOWT (Ministry of Works and Transport), MLHUD (Ministry of Lands Housing and Urban Development), LC (Local Council) and KCCA members. The data collected were analyzed quantitatively using SPSS (Statistical Package for Social Scientist) Ver. 16. Qualitative data was further analyzed according to objectives. Findings were presented using frequencies and tables. The findings indicated that buildings without approved drawings was ranked 1st cause of building failure, on the impacts created by failure of structural buildings; failure to pay borrowed resources from financial institutions was ranked 1st by the respondents and findings the existing strategies to eliminate structural building failure revealed that planning ranked 1st. it was concluded that there is need for enhancement of coordination among the MDAs (Ministry Departments and Agencies) charged with planning and development of Kampala city, involvement of taskforces at Division level and increase in the outreach and sensitization of the population to report cases to concerned authorities.
This paper will discuss the impact of individual owner's decisions on projects by presenting different case studies and particular experiences while working for a private family-owned property development company. The discussion of this paper will demonstrate different situations were owners and senior management took discrete resolutions based on personal desire which have impacted projects time, cost or quality. Project managers will find it challenging to perform basic project management procedures and proficiency in providing technical advices to handle the changes in a more professional manner while working for this type of family business where owners and senior management are giving single decisions without executing proper due-diligence from the experts. There aren’t many literature discussing this topic specifically, as most of the researches are discussing family business in general, nonetheless, this paper is focusing on the impact on projects and the difficulty of handling projects while working for private owners who take decisions based on general knowledge or personal appetite. This paper is based on physical instances and situations and case studies.
In the real world of the construction industry, disputes are inevitable despite the best endeavors of the contracting parties to avoid them. Matters are not helped by the ill-suited nature of the orthodox legal system toward the resolution of construction industry disputes. It is, thus, imperative that effective dispute resolution mechanisms are in place for the proper functioning of the construction industry. This has added impetus to growing interest in Alternative Dispute Resolution (ADR). While contemporary literature from other jurisdictions suggested that ADR is most suited to the nature of construction disputes, the effectiveness of ADR in the construction industry in Uganda lacked lucidity in literature. This birthed the need for a research study of this nature. To distinguish facts from anecdotes, this study empirically assessed the real-world effectiveness of ADR in the construction industry in Uganda through a cross-sectional research design, using the quantitative research approach. A questionnaire survey was conducted among 202 respondents drawn from professionally registered construction firms, architectural firms, quantity surveying firms, consulting engineering firms, and reputable client organizations in Uganda. To preclude subjectivity and imprecision, this study measured the effectiveness of ADR against multiple indicators, speed, cost, fairness, preservation of business relations, flexibility, and confidentiality. The study concluded that ADR is an effective mechanism for resolving disputes in the construction industry in Uganda. Specifically, negotiation was ranked as the most effective ADR technique (d=0.48), followed by mediation (d=0.21) and arbitration (d=0.16). Of significance, this study found that informal ADR is considered more effective than formal ADR. The study recommends the consistent import of ADR provisions into construction contracts, a review of the institutional framework guiding the practice of arbitration in Uganda, and that disputing parties should always explore negotiation options before escalating their disputes.
Rural roads form the largest part of the road network and the main form of access to the rural communities. The poor state of rural road networks not only affects transport of goods and services but also the economic growth. This study sought to assess rural road network management as a driver of economic development using Kabarole District as a case study. A mixed design method was used where qualitative and quantitative data was collected by use of interviews and questionnaire. The population composed political and technical staff involved in rural road management which was represented by a sample size of 95 people. Findings established that the roads in the study area are passable although they quickly deteriorate due to lack of maintenance and heavy rains. The report indicates that high construction costs (µ=4.22), delayed releases (µ=3.91), insufficient funding (µ=3.79), bad weather (µ=4.0) and inadequate equipment (µ=3.56) are the major factors affecting effective rural road management. A methodology was developed considering roads as capital investment where maintenance will be valued above new construction. The study recommends an effective maintenance culture, introduction of public private partnerships in the road maintenance works and encouragement of public participation in the provision of basic facilities through various community self-help developments to reduce dependence on central government. If equal attention was paid to the development and maintenance of the rural roads in Uganda there would be sufficient, safe and reliable physical access to social services; reduced travel time that would be used for wealth creation.
This article addresses the problem of selecting an investment and construction project on a variety of criteria in the face of uncertainty. The complex nature of decision-making when justifying significant indicators of investment and construction project requires decision-makers at the stage of choosing an investment and construction project to increase the level of reliability of organizational and technological decisions by taking into account the stochasticity of processes, variability of the external environment and risks. Also, this article presents an approach to pre-selection of investment and construction projects based on the theory of fuzzy sets, the peculiarity of which is to express multiple unclear information linguistically, which allows to evaluate qualitative and quantitative criteria. The most significant criteria affecting the reliability of the investor’s selection of investment and construction project are given.
Project overruns are still the most common problem in the world, despite the availability of project monitoring tools like Earned Value Management which is proved to the effective monitoring tool which combines three aspects like scope, time and cost at once. Construction project included high risk activity in which must be managed well in all stages, in order to evade project overruns. The study aimed at assessing the use of Earned Value Management in time and cost management for construction projects in Tanzania. However, there are few of researches that discussed Earned Value Management practices in Tanzanian construction industry. Therefore, it was found that there was inadequacy of documented Earned Value Management implementation in Tanzanian construction projects. The feedback from construction experts was obtained through questionnaires. About 161 questionnaires survey were distributed to the contractor’s organizations (Class I and Class II). Out of the 161 distributed questionnaires, only 102 were returned. The data were analysed by using SPSS 20, Microsoft Excel and then ranked conferring to (M.S) mean score for contractor. The general response from respondents were analysed, high scored factors were discussed. All work scope was planned for the project to completion applied in construction projects, all work scope was broken into finite pieces and assigned to either individual or organisation to control, Issuance of Payment is based on work performed and Actual cost incurred were used in measuring work value accomplished; were identified as the most parts of Earned Value Management applied in Tanzanian construction projects, due to having a mean score above 4.00. The study recognised that key players in Tanzania construction industry applied some parts of Earned Value Management concepts during construction projects.
This research attempts to examine whether motivation factor differences exist across generation X and Y construction professionals in Hong Kong’s registered general building contractors (RGBC). Recent research demonstrated a paucity of studies on motivation factors of construction professionals of different generations. A thorough literature review was conducted to identify the motivation factors of construction professionals. The findings of the literature review form the base for the constitution of a survey questionnaire used to gather attitudes of both generation X and Y RGBC’s construction professionals towards the identified motivation factors. 44 generation X and 65 generation Y RGBC’s construction professionals returned the survey. The motivation factors of both generation X and Y RGBC’s construction professionals are prioritised. By utilising Spearman’s rank correlation, this research found that a weak correlation in the rankings of motivation factors exist across generation X and Y RGBC’s construction professionals ( ). The hypothesis of this research was thus accepted, concluding that generation X and Y RGBC’s construction professionals perceive motivation factors differently.
As the project management knowledge guide (PMBOK®) Guide can guide project team throughout the project management process and save it from critical failure. This study aims to evaluate the level of PMBOK® Guide application and also identified factors affecting the application of this guide in construction projects in Yemen. In order to achieve the objectives of the study, questionnaire was developed as a main instrument of the study to collect the primary data. The questionnaire consisted of three main parts: the first part relates to general information and the second part relates to the extent of Implementation of the PMBOK® Guide. This study targeted the engineers of the Social Fund for Development, and 76 questionnaires were distributed to the study sample, and were then subjected to statistical analysis using the statistical program (SPSS). The results of this study showed that the PMBOK® Guide in construction projects in Yemen applied partially and Closing Process Group and Project Quality Management; are ranked highest from Process Group and Knowledge Areas respectively. Qualification is found to be the most significant variable. The study recommended that, there is need for the constructions’ management and projects managers in Yemen to be exposed to PMBOK® guide and how it could be applied in their construction projects.
Utilizing previous lessons gained from past construction activities shall not be the task limited to project managers alone. Engineers involved in a certain project from the conception to implementation shall be well aware of similar projects performed in the same context. Literature indicates consistent appearance of akin factors causing cost overruns and schedule delays attributed to the complex nature of construction industry even if every project experiences different challenges. The Ethiopian construction industry is just a subset of the broad global engineering projects where stakeholders are required to enhance construction project performance through conceptualized experiential reusable knowledge in a sustainable manner. In the framework of reusable knowledge management, the Ethiopian construction industry is not observed to fully transpire organized lesson learned collection methods and the obtained knowledge sharing approach. Not applying existing knowledge in new or progressing constructions has both time and cost implications. Therefore, systematic way of knowledge flow and experience sharing both at individual and company level has to grow well in order to offer ameliorated guiding principles to manage construction risks without repeating past mistakes. This work by itself will ignite initiation at least towards in-house proper documentation and utilization of prior experiences within construction companies and/or at large to nationwide accessible database (with appropriate security level) of socio-technical interactions among stakeholders.
Building failures result into economic and temporal deviations in construction industry. Despite the efforts to improve the quality of construction works through use of advanced technology, increased labor force for professionals in the construction industry, increased availability of construction equipment, there is still low quality work. The purpose of the study was to develop strategies to mitigate building failures in the construction industry in Uganda. The study adopted a descriptive survey research design which was carried out in the districts of Greater Bushenyi district in Western Uganda. The study population comprised of 210 respondents: Supervising engineers, Site engineers, Site foremen, Clerk of works and Clients. Causes of building failures were categorized as: consultant related; contractor related, client related and external related factors. The data collected were analyzed quantitatively using SPSS Ver.20 and Microsoft excel. Data were further analyzed using correlation and regression analysis. Findings were presented using frequencies, tables, pie charts and graphs. The findings indicated that Inadequate supervision of works (RII= 0.77); Shortage of equipment and materials (RII=0.76); Cash flow problems (RII=0.67) and Inflation in prices (RII=0.70) were the leading causes of building failure in their respective categories. Based on study findings, it was concluded that there is a great influence of consultant related factors on the causes of building failures more particularly related with inadequate supervision of projects. Factors relating to defects in structures can potentially be avoided if qualified construction professionals are appointed to exercise due diligence and if professional teams are given the opportunity to guide contractors during contract execution.
The United Kingdom is currently facing a housing shortage and has been for many years, caused mostly by natural growth in population, immigration and an aging housing stock. The solution to combat this problem is not as simple as constructing many hundreds of thousands of homes across the country, with many setbacks caused by economic, environmental and social concerns. The design and planning of individual residential projects, with fundamentally sustainable schemes could help to mitigate the concerns that are causing setbacks to house building. Building Research Establishment Environmental Assessment Methodology (BREEAM) is the world’s longest established method of assessing, rating and certifying the sustainability of buildings produced by Building Research Establishment (BRE). Implementing BREEAM on construction projects can vastly increase their sustainability compared to those that simply follow regulations. Projects that follow BREEAM specifications covered any additional costs by lower running costs during the building’s life. Providing people in the UK with homes which are built in a highly sustainable manner may allow huge benefits that outweigh the costs for both of the residents and the wider population. The general knowledge and consciences of people is also increasing for a more sustainable world, and as construction can contribute but also take away greatly from the sustainability of society, this approach to building seems obvious and yet is nowhere near mainstream as one may expect. This study looks to investigate the reasons behind a low proportion of BREEAM implementation on residential projects, when at first glance the benefits seem to greatly outweigh the costs. Secondary data gathered through a desk study was used to help determine the costs and benefits of residential projects that have implemented BREEAM. The researcher also attempted to gather primary data in the form of interviews and a questionnaire, gaining an insight into a current construction industry view on the usage of BREEAM.
Cost over-runs of building projects still persist in spite of the considerable research available on the subject. In Uganda, the arbitrary and deterministic contingencies of 0%-10% in building projects are routinely inadequate to contain cost over-runs of up to 52%. The construction industry therefore should not relent on continued research on this challenge. The purpose of this research was to develop a model that predicts cost over-runs of building projects using statutory public procurement requirements of bid time, performance bond, insurance, workload and experience of building contractors. These requirements are set and enforced by public procurement entities hence are relevant, easy to control and measure to high accuracy for predicting cost over-run. The study used change process theory because it forecasts construction changes like cost changes represented in this research by cost over-run. The principle of parsimony in regression modelling was applied to procurement requirements that correlate with cost over-run. Purposive and snow-ball sampling were used in survey of construction professionals, consultants and contractors of building projects with cost over-runs. Correlation and independence of procurement requirements on 37 cost over-run datasets were analysed by Spearman's bivariate correlation co-efficient and variable inflationary factor respectively. The prediction model explains 63% of cost over-runs with 9% margin of error. In the model, bid time, performance bond, workload and experience all reduce cost over-run except insurance amount that increases it marginally. The study demonstrates superiority of probabilistic models over deterministic models in determining cost over-runs. The small regulatory bid times of some procurement methods need to increase to reduce cost over-runs. The main contribution of this paper is the demonstrated potential alternative function of using public procurement requirements for predicting cost over-runs. This approach adds to and departs from the current use of public procurement requirements for only evaluating contractors to undertake building construction contracts.
Concrete is an essential widely used material in the construction industry worldwide. Notable concrete products used in Ghana’s construction industry are precast septic tanks, box and pipe culverts, fence posts, concrete poles, roof tiles, precast beams and columns, pavement blocks and slabs etc. Though the variety is large, there exists significant price disparities for the same materials across markets in Ghana. This study assessed differential pricing of concrete products on the Ghanaian construction market with the objective of ascertaining the determinants and causes of differential pricings, and the effects of these differentials on the construction industry in three major cities (Accra, Kumasi and Sunyani) in Ghana. Price data was collected, collated and analyzed from the three cities and the determinants, causes and effects of differential pricings were assessed and ranked based on existing literature. An overall assessment indicated that the main determinant of differential pricings was material input, whereas cost of production was the highest ranked cause of differential pricing. Uncertainties during project estimation which include taxes was also seen to be the highest ranked effect of differential pricing. It is recommended that drastic steps be taken by Government to reduce the uncertainties such as subsidizing some taxes on the importation of raw materials and the use of other inputs in producing concrete products.
Organizational change is inevitable and occurs for many reasons. This study reveals, through in-depth interview, change driving forces, change management process, and effective change management critical factors in contractors. Increased competition, New laws and regulations, Organizational growth, and Unexpected economic crises are the most significant drivers for contractor organizational changes. When a change is introduced, contractors follow a systematic process in managing the change but with poor planning and implementation. Top management support and a prior clear definition of a change are the most critical factors for successful change management. The research also provides recommendations such as recruiting change management professionals and considering positive and productive changes management critical factors in their change process to help improving their change management.
