Construction-related Factors Research Articles

Assessing and Monitoring of Building Performance by Diverse Methods

Buildings are one of the largest contributors to energy consumption and greenhouse gas emissions (GHG) in the world. There is an increased interest in building performance evaluation as an essential practice to design a sustainable building. Building performance is influenced by various terms, for example, designs, construction-related factors such as building envelope and airtightness, and energy technologies with or without micro-generations. How well a building performs thermally is key to determining the level of energy demand and GHG emissions. Building standards and regulations, in combination with assessments (e.g., energy modeling tools) and certifications, provide sets of supports, guidelines and instructions for designers and building engineers to ensure users’ health and well-being, consistency in construction practices and environmental protection. This paper reviews, evaluates and suggests a sequence of building performance methods from the UK perspective. It shows the relationships between such methods, their evolutions and related tools, and further highlights the importance of post-occupancy analysis and how crucial such assessments could be for efficient buildings.

Gauging the impacts of urbanization on CO2 emissions from the construction industry: Evidence from China

The construction industry has aided rapid urbanization in China, significantly contributing to CO2 emissions. However, few studies have investigated the impacts of urbanization on CO2 emissions from the construction industry and the regional heterogeneity or considered the construction-related factors for urban construction scale to represent urbanization. To compensate for these limitations, this study aimed to explore the impacts of urbanization on CO2 emissions from the construction industry. Herein, the urban construction scale was used to represent urbanization, along with population size, economic growth, and technology level. An augmented Stochastic Impacts by Regression on Population, Affluence, and Technology model was used to estimate the cross-province panel data from three regions in China during 2008–2017. The heterogeneity due to regional differences in urbanization levels was addressed by classifying China into three regions— urbanized, urbanizing, and under-urbanized. The findings suggest that population size, economic growth, construction of residential buildings, and technology level were the primary factors impacting CO2 emissions, and the impact presented a declining trend from the urbanized to the urbanizing and under-urbanized regions. Specifically, an inverted U-shaped relationship existed between CO2 emissions and urban economic growth, and the urbanized region indicated a higher inflection point than other regions. The urbanization ratio was negatively correlated with CO2 emissions, while the energy intensity, per capita floor space of urban residential buildings, and per capita length of drainpipes were positively correlated with the CO2 emissions in all three regions. Further, the technology level was conducive to CO2 emissions reduction, however, it requires further improvement. The per capita area of paved roads exerted significantly negative effects in the urbanized region and insignificant in the urbanizing and under-urbanized regions. Overall, these results can help formulate policies to mitigate the construction industry's carbon emissions.

Protecting the Environment with Geosynthetics: 53rd Karl Terzaghi Lecture

AbstractDesign- and construction-related factors that affect leakage through geomembranes, used either alone or in a composite liner, are examined. The development, detection, and number of holes t...

Understanding off-site readiness in Indian construction organisations

PurposeThis paper presents a bespoke model for understanding off-site construction (OSC) readiness among Indian construction organisations. This model presents 17 variables for discussion, the results from which help support OSC strategic decision-making.Design/methodology/approachFactor analysis was used to investigate the relationship between variables to group them into factors. After identifying 26 different variables, these were reduced to 17 using factor analysis and categorised into four groups. Descriptive statistical analysis and factor analysis using SPSS was used to develop a hierarchy of factors that affect OSC readiness in India. These findings were reinforced by five domain experts to support the results.FindingsMinimising on-site duration, ensuring cost and time certainty and transportation issues were identified as the three most important factors, whereas lack of guidance and scepticism were among the lowest factors affecting the Indian OSC sector.Research limitations/implicationsThis research is specifically focused on OSC within the Indian construction sector. As such, data collection, propagation and analysis should be constrained to the population context regarding inference, generalisability and repeatability.Practical implicationsThe proffered OSC readiness model offers OSC practitioners an ability to assess the OSC readiness of construction organisations in India. This includes the evaluation and benchmarking of processes in both strategic and operational phases, including highlighting areas of concern and scope for further development (to achieve optimal advantage of OSC methods).Originality/valueOriginality rests with the use of factor analysis and descriptive statistical analysis to study the influence of different construction-related factors and variables on the OSC sector in India. This impact readiness model is context-specific to the Indian OSC sector – providing a unique insight into the causal factors and dependencies that can affect the adoption and uptake of modern methods of construction in India.

Improving Labour Productivity in Ghanaian Building Construction Projects

Abstract Labour productivity is key to the success of every construction project. The paper seeks to determine the factors that affect labour productivity and proffer possible ways to improve it in building construction projects. The study was preceded by a literature review. Data used were primary data collected through the use of questionnaires. The total number of respondents was 175. Snowball sampling technique was used in sampling respondents. Factor analysis was performed on the data collected and mean scores were also generated. The findings of the study showed that the use of wrong equipment, misuse of time schedule, lack of training sessions, poor site organisation, lack of motivation for workers, delays in the supply of materials and rework were the critical factors affecting labour productivity in building projects of Ghana. However, the major ways of improving labour productivity in building construction projects, according to the study, were to correct bad behaviour that negatively influenced productivity, proper layout of site, to improve health and safety, to use proper materials handling systems and to set targets for employees. Management must put structures in place to restrict human, material and construction related factors. This is because giving concessions in these areas can take a toll on productivity.

A meta-network-based risk evaluation and control method for industrialized building construction projects

Construction methods in developing countries such as China are gradually industrializing due to rising labor costs, new techniques, tools, procedures and management methods. This makes it essential to develop new risk evaluation and control methods. Previous research seems to ignore the risk management of the application of new construction technologies and procedures. The identification of risk mechanisms is unclear, leading to a lack of clear guidance for risk avoidance and control. This paper describes a network model based on meta-network analysis of project objectives, risk events, risk factors and stakeholders in the construction process of building industrialization. According to ISO 31000, the main processes of risk management in the model has three parts: risk identification, risk analysis and evaluation, and risk treatment and control. Risk factors are identified from previous literature and site investigation, and the indirect impact on project objectives is analyzed and calculated with the networks in the meta-network. The order of importance is evaluated and used as the foundation of risk treatment and control. The analysis of the crucial risk factors makes it possible to identify the stakeholders who influence them, leading to suggestions for relevant control strategies. A residential building construction project in South China that uses the building industrialization construction system serves as a case study to verify the feasibility and applicability of the risk management system. Results show that critical risk factors are construction-related factors and design-related factors. The water and electricity engineers, the project manager, the project secretary, the field engineer, the project supervisor and the main contractor engineer have a significant influence on the risk factors. A stakeholder supervision system with targeted risk control strategies is proposed.

Perceptions on construction-related factors that affect concrete quality, costs and production

Structured and unstructured factors affect concrete product. Structured factors are related to concrete production and unstructured factors are related to the construction process. This study focuses on examining the perceived importance of unstructured factors (i.e., construction-related factors) on concrete compressive strength, concrete costs and production rates on the jobsite and understanding the influence of construction experts"™ characteristics, such as profession, on their perceptions. A comprehensive literature review was performed to identify unstructured factors. A survey was then designed and deployed to 297 experts from the construction industry and academia to examine the importance of the identified factors through the relative importance index (RII) method and to further identify additional unstructured factors. Likert aggregation and tests for equality of odds were used to compare and analyze responses of two groups of participants, namely architects and engineers. Curing humidity, crew experience and compaction method are the top three factors perceived to affect concrete compressive strength, whereas crew experience, mixing time and compaction method are the factors perceived to affect concrete costs and production rates the most. Crew experience, compaction method and mixing time dominate the global ranking of perceived affecting factors for concrete compressive strength, costs and production rates. Architects were found to be more likely to perceive high or very high impacts of these factors on concrete. The present study increases our understanding of construction-related factors to facilitate project management and preserve concrete characteristics.

Analysis of construction-related factors affecting the efficiency of construction labour

Irrespective of significant relevance of construction industry to economic growth of developed and developing nations, labour efficiency in the construction industry remains relatively low and thus affects construction project delivery and client's satisfaction. This paper aims at exploring adverse construction related factors contributing to the shortfall of construction labour efficiency in the South African construction industry. The study adopts mixed methodological approach,administering closed ended questionnaires to construction professionals on Western Cape and Gauteng construction sites, while experienced construction site supervisors were interviewed to validate quantitative data obtained. Statistical Package for Social Sciences (Version 22) and content analysis were used respectively to analyse data obtained. Communication ability of site managers, construction skills of site supervisors and effective site planning ability of contractors were found as the predominant construction related factors affecting the efficiency of construction labour. This study is restricted to contractors, site supervisors and site managers' related factors affecting the efficiency of construction labour. Adequate application of findings presented in this study will significantly reduce the current prevalent construction time and cost overruns through an improved construction workforce performance. Enhanced construction productivity is a product of construction labour efficiency that ensures achievement of construction project objectives and heightens contribution to South African economic development.

Effects of construction-related factors on chip seal performance

Chip seal is an economical type of asphalt pavement that is widely used in countries such as Turkey, Australia, South Africa and New Zealand. However, unlike hot mix asphalt pavements, the performance of this type of pavement can be affected by many different parameters. Although these parameters have been identified in the literature, the extent to which each of these parameters affects the performance of chip seal has not yet been determined. The leading parameters affecting chip seal performance are those related to construction, including the adhesion capability of the aggregate used in construction, natural dust amount of the aggregate, ambient temperature during construction, bitumen temperature in the bitumen distributor tanks, time between bitumen spraying and aggregate spreading, time between aggregate spreading and rolling, time between construction stages, surface temperature during construction, aggregate and bitumen designs, in situ plate test values and per cent embedment of the aggregates. To determine the effect of these construction parameters on pavement performance, they were observed and measured on five test roads. The chip-sealed test roads were monitored for 1year with nondestructive tests and observations to determine which construction-related parameters affect the performance of the pavement. The study results indicated that macrotexture loss is the most important deterioration factor in chip-sealed pavements; initial texture depth is also important with respect to the long-term performance of chip-sealed pavements. Rolling operations is another important factor for the performance of chip seal. If rolling operations are performed at high ambient temperatures, the per cent embedment of the aggregate will increase, causing the chip seal to deteriorate more rapidly. Consequently, the ambient temperature during the construction of chip seal is important; thus, chip seal should not be constructed at ambient temperatures lower than 30°C or higher than 43.5°C.

Factors Affecting Strength of Road Base Stabilized with Cement Slurry or Dry Cement in Conjunction with Full-Depth Reclamation

Full-depth reclamation (FDR) in conjunction with cement stabilization is an established practice for the rehabilitation of flexible pavements. Conventionally, the FDR process involves applying dry cement powder with a pneumatic spreader, but this process can create undesirable fugitive cement dust. To solve this problem, cement slurry has been proposed because it can allow cement stabilization to be used in urban areas. This research sought to (a) identify construction-related factors that influence the strength of road base treated with cement slurry in conjunction with FDR and quantify the effects of those factors and (b) compare the strength of road base treated with cement slurry with that of road base treated with dry cement. Full-factorial laboratory experimentation on a road base sampled from an FDR project was conducted. The 7-day unconfined compressive strength was measured as the dependent variable. The independent variables included cement content; slurry water batching temperature; presence of a set-retarding, water-reducing admixture; cement slurry aging temperature; cement slurry aging time; cement–aggregate mixing time; and form of cement. The results suggested that the slurry water batching temperature, the haul time, the environmental temperature, and the presence of a set-retarding, water-reducing admixture would not significantly affect the strength of a cement-treated base (CTB) within the ranges of the factors investigated in this research. However, cement content and cement–aggregate mixing time were found to be positively correlated with CTB strength, regardless of the cement form. Additionally, the use of cement slurry was found to result in slightly lower strength values than the use of dry cement.

NIGHTTIME CONSTRUCTION ISSUES REVISITED

An investigation into nighttime construction operations at highway maintenance and reconstruction sites is presented in this paper. This investigation, which is part of a research project sponsored by the Illinois Department of Transportation (IDOT), involved two questionnaire surveys. The first survey is concerned with state Departments of Transportation (DOT's), while the other is concerned with IDOT districts. The surveys addressed issues pertaining to the different aspects of nighttime construction work such as the current practice in nighttime operations, construction-related factors, traffic-related factors, and social, economic, and environmental factors. Research results suggest that there is agreement between the two groups on many aspects of nighttime operations, however some other aspects received conflicting opinions. Many important findings were drawn from these surveys and are summarized in this paper. The study recommends the use of a more quantitative approach in dealing with some aspects of nighttime operations. This can easily be achieved on projects with dual shifts so as to exclude the effect of other affecting factors. The study also recommends the use of a separate bidding of nighttime pay items. This may not only prevent contractors from complaining about prices, but also result in more accurate and possibly lower bids. Also, any incentives provided in nighttime contracts should more reflect the expected benefits of nighttime work, particularly the savings in road user costs.

Quality of Pavement Construction in Saudi Arabia

The road network in Saudi Arabia has experienced remarkable development both in length and standards to become one of the longest and most modern highway networks in the Middle East. Quality of performance of some roads, however, was below a satisfactory level. Various parameters directly and indirectly contribute to the pavement quality performance. The contributing factors are design, specifications, environment (traffic, temperature), and construction-related factors; the indirect factors are managerial-related factors. This paper reviews the factors that contribute to the quality of pavement performance in Saudi Arabia. This review was achieved via both a comprehensive literature review and a highway contractor's survey. The significant performance factors were arranged into three groups: (1) managerial-related factors that include qualification of owner's inspection team, contractor experience, and capability; (2) design and specifications-related factors that include consideration of regional condit...

Stability of Ballasted Woody Debris Habitat Structures

An important component of stream restoration in the Pacific Northwest is the reintroduction of large woody debris (LWD) and construction of LWD habitat structures in degraded systems. A significant problem faced by engineers involved in stream restoration is a lack of physically based guidelines for design and construction of ballasted LWD habitat structures. A simple theoretical approach is developed that forms the basis for determining ballast requirements for three types of LWD structures. Field monitoring and assessment were undertaken to test the approach and to compare predicted and observed stability for approximately 90 ballasted LWD structures. The results indicate that the stability of single-LWD and single-LWD with root wad structures can be successfully predicted by the theory. The stability of the multiple-LWD structures proved to be more complex to predict because numerous design and construction-related factors influence stability. A design approach based on factors of safety is recommended.

Technological risk perception and nuclear power costs: The quantification of uncertainty

The cost of nuclear power has escalated significantly in recent years, confounding the optimistic projections of planners and contributing to a serious slowdown in the industry. In this paper we investigate the factors underlying nuclear cost escalation and specify a nonlinear regression technique that identifies costs caused by public and professional uncertainty about future technological performance as opposed to costs based on objective design and construction-related factors. Using multivariate analysis of variance we establish a positive relationship between costs related to uncertainty and such plant specific factors as size, age, and vintage (year of initial operation). Specifically, uncertainty and its associated costs are shown to be greater for larger plants with more advanced technology and to decrease as plants accumulate operating experience. This result suggests that the tendency in the industry toward rapid deployment of large plants with innovative technologies has had a deleterious impact on power generation costs.