Change orders are common and clearly noticeable in Jordanian construction industry. Several studies have identified change orders as significant problem in Jordanian construction projects, and they mainly cause delay ...Change orders are common and clearly noticeable in Jordanian construction industry. Several studies have identified change orders as significant problem in Jordanian construction projects, and they mainly cause delay and cost overrun. This situation spurs the researchers for investigating the significant causes of change orders in construction projects. Thus, this paper aims to determine the main causes of change orders in the Jordanian construction private sector which responsible for significant cost overrun. Both qualitative and quantitative methods, i.e. interview and questionnaire techniques, were used to achieve this aim. Interviews were conducted as the first stage of data collection, and the results formed the basis of the questionnaire, which was distributed across the Jordanian construction sector. Content analysis was used to analyse the interview responses, while factor analysis, correlation and the Severity Index (SI) were used to analyse the questionnaire results. The findings identified three main categories of causes of change orders in private sector, namely engineering causes, causes related to the client, and circumstances of the project, with sub-causes in each category which are related to each other in significant ways and which affect each other.展开更多
As the construction sector is a major energy consumer and thus a significant contributor of CO_2 emissions in China,it is important to consider carbon reduction in this industry.This study analyzed six life-cycle stag...As the construction sector is a major energy consumer and thus a significant contributor of CO_2 emissions in China,it is important to consider carbon reduction in this industry.This study analyzed six life-cycle stages and calculated the life-cycle CO_2 emissions of the construction sector in 30 Chinese provincial jurisdictions to understand the disparity among them.Results show that building materials production was the key stage for carbon reduction in the construction sector,followed by the building operation stage.External variables,e.g.,economic growth,industrial structure,urbanization,price fluctuation,and marketization,were significantly correlated with the emission intensity of the construction sector.Specifically,economic growth exhibited an inverted U-shaped relation with CO_2 emissions per capita and per area during the period examined.Secondary industry and land urbanization were negatively correlated with CO_2 emission intensity indicators from the construction sector,whereas tertiary industry and urbanization were positively correlated.Price indices and marketization had negative effects on CO_2 emission intensity.The policy implications of our findings are that cleaner technologies should be encouraged for cement providers,and green purchasing rules for the construction sector should also be established.Pricing tools(e.g.,resource taxes)could help to adjust the demand for raw materials and energy.展开更多
文摘Change orders are common and clearly noticeable in Jordanian construction industry. Several studies have identified change orders as significant problem in Jordanian construction projects, and they mainly cause delay and cost overrun. This situation spurs the researchers for investigating the significant causes of change orders in construction projects. Thus, this paper aims to determine the main causes of change orders in the Jordanian construction private sector which responsible for significant cost overrun. Both qualitative and quantitative methods, i.e. interview and questionnaire techniques, were used to achieve this aim. Interviews were conducted as the first stage of data collection, and the results formed the basis of the questionnaire, which was distributed across the Jordanian construction sector. Content analysis was used to analyse the interview responses, while factor analysis, correlation and the Severity Index (SI) were used to analyse the questionnaire results. The findings identified three main categories of causes of change orders in private sector, namely engineering causes, causes related to the client, and circumstances of the project, with sub-causes in each category which are related to each other in significant ways and which affect each other.
基金Under the auspices of the National Natural Science Foundation of China(No.41101567)
文摘As the construction sector is a major energy consumer and thus a significant contributor of CO_2 emissions in China,it is important to consider carbon reduction in this industry.This study analyzed six life-cycle stages and calculated the life-cycle CO_2 emissions of the construction sector in 30 Chinese provincial jurisdictions to understand the disparity among them.Results show that building materials production was the key stage for carbon reduction in the construction sector,followed by the building operation stage.External variables,e.g.,economic growth,industrial structure,urbanization,price fluctuation,and marketization,were significantly correlated with the emission intensity of the construction sector.Specifically,economic growth exhibited an inverted U-shaped relation with CO_2 emissions per capita and per area during the period examined.Secondary industry and land urbanization were negatively correlated with CO_2 emission intensity indicators from the construction sector,whereas tertiary industry and urbanization were positively correlated.Price indices and marketization had negative effects on CO_2 emission intensity.The policy implications of our findings are that cleaner technologies should be encouraged for cement providers,and green purchasing rules for the construction sector should also be established.Pricing tools(e.g.,resource taxes)could help to adjust the demand for raw materials and energy.
