Severity of Causative Factors to Construction Waste Generation: Iraq Construction Industry

Objectives: Construction and Demolition (C and D) wastes affect negatively to environment and economic of Iraq. This paper presents the severity of 78 identified factors contributing to C and D waste generation in Iraqi construction industries. Methods/Statistical Analysis: The structured questionnaire survey amongst contractors, consultants and clients was conducted and a total of 208 valid response data was collected for the analysis purpose. Descriptive analysis employing average score index was used for collected data. Findings: The results indicate severity of each factor toward the C and D waste generation and also the severity ranking. It was found that poor site management, lack of experience, rework, design errors and lack of environmental awareness are ranked as five most sever factors to C and D waste generation in Iraqi construction industry. Application/Improvements: Benefit from this study will be shared amongst researchers and also construction community to ensure the minimization of the (C and D) waste generation in Iraq. *Author for correspondence


Introduction
Construction industries play a significant part for improving socio-economic condition of any country. The impact on economic, the advantages of investment and assistances to employment are extremely tremendous in construction industries. The construction industries predict the overall direction of an economy and by this mean, it often designated as a prominent economic sector 1,2 . Construction industry has a dynamic capacity in most developing countries and for this reason; it is among the most prosperous sectors in the globe and remains so with the continuation of the development of any country 3

Construction Waste Causative Factors Group
The rapid growth in construction activities during the last few decades has brought huge amount of waste generation world widely. Most of such waste is not recycled nor reused but subsequently transferred to landfills 2,26 , consequently exerts massive pressure on the landfill depletion and harms adversely our surroundings and the environment. Improper and illegal CW dumping depends on many factors during the construction activities.
In 27 categorized such factors into four groups: design; procurement; handling of materials; and operation. In 28 stated that CW generation is not just a technical problem, but a behavioristic one also. In 29,30 also supported this statement and there are many factors for contributing the Construction Waste. As 27 categorized these factors under four categories like "design", "procurement", "handling of materials" and "operation". While the fifth major factor "workers" added by 29,30 . In 31 supported the researchers' findings on the sources of waste generation, and added "site condition" and "external factors" as two more categories. While others 32,33 increase the sources of waste to 10 as shows in Table 3, proposed groups of factors by previous researchers. Table 3 presents several groups effects of Construction Waste generation found by previous research which carried out in different countries.  develop the significant CW management system at project sites on expeditious basis and moreover to analyze the influencing factors that contribute to cause the CW. Thus, to overcome this problem, proper steps must be taken and introducing the effective waste management practices 46 . In 46 concluded that effective waste management implementation will guarantee the construction material flow in a closed loop so as to minimize the CW generation, decrease the need for landfills demanded and more than that will preserve natural resources but prior to those, the causes of waste generation are compulsory to find. Iraq is a developing country and currently facing problem with the CW which has brought many illegal dumping sites 6,48 but at the same time, many organizations are working to finding out the source causes of CW and the effective practices for relieving from such problems 48 . Table 2 illustrates the volume of (C and D) waste and total waste for Iraqi governorates for the last three years. Table 3 indicates that Iraq construction industry also producing huge amounts of (C and D) waste generation. Figure 1 shows the percentage of the resulting of (C and D) waste generation to total (C and D) waste generation for Iraqi cities except Anbar and Ninawa 50 . Figure 4 illustrates the percentage of C and D waste compared to total waste of each city in Iraq for 2015, 2016 and 2017, respectively.

Data Collection
This study was carried out in three phases: In the first phase, identified 78 important factors affecting Construction Waste generation through literature review and designed questionnaire survey. In the second phase, a pilot study was carried out to identify the factors effecting Construction Waste generation. The third phase, actual study was carried to calculate the mean score and the ranking of factors by importance. Also analyses the current views of the participants in the construction  industry in Iraq on the generation of Construction Waste. The structured questionnaire contains mainly two parts: The demographic data sample of the participated respondents and identifies the 61 factors that mainly contributed to the C and D waste generation. All such factors had been categorized into 7 groups. The study involved 38 experts selected from contractors, consultants and clients who are experienced in handling construction projects in Iraq. The participants were invited to give correct rating as per the Likert scale: 1-5 points (from the lowest to highest level) for each factor to check the relative importance for considering in CW generation.

Respondents Demography
Actual survey involved bigger samples to give better representation of construction practitioners in deciding the outcome of this survey. The actual survey was accomplishing to define the ranking based on mean score value of the causative and effective factors. In the meantime, the survey was conducted using the developed questionnaire based on the findings from pilot survey. Questionnaire sets were distributed among construction practitioner randomly selected in Iraq.
Two hundred twenty (220) sets of questionnaire were circulated for the collection of data, a total 208 completed questionnaire sets were received back within a time period of 3 months with respond rate of 95%. The respond rate is acceptable as it is around 20-30% response rate is considered as normal in construction research 51,52 . Table 4 shows the summary of statistics for collected samples.
In Table 5, it can be seen that most of the questionnaires were collected through in person/site visit. The percentage of questionnaires received from the respondents through in person/site visit is 140 out of the 140 questionnaires received with percentage 100%.

Organization
Respondents involved in the survey were engaged in different types of organization. The results of respondents based on the type of organization are presented in Figure  2.
From the Figure 2, it is obvious to see that the majority of respondents are working as a contractor: 133 experts with 63.94%, followed by consultants as 61 experts with 29.28% and clients/developer were 14 experts with 6.73%. Since majority of the respondents are from the contractor side, then the input from them are meaningful for this survey as they are the one that spend most of the time at the construction site.

Knowledge and Experience
Respondents involved in the survey have immense practice in managing several kinds of projects in Iraq. The details of projects handled by the respondents are summarizing in Figure 3.
According to Figure 3, 208 of respondents have experience more than 10 years in managing infrastructure projects. Most of the respondents have experience more

Qualification
For expert's academic background, most of them have the qualification of university degree; some even have master and PHD degree as presented in Figure 4.  Respondents' knowledge was measured based on their academic qualification and working experience in the construction industry. Academic qualification and working experience are an essential point and plays important role in understanding any problems at sites. The respondents' knowledge is considered in this questionnaire as to ensure that they have the ability to understand and answer the questionnaire swiftly.

Ranking of Causative Factors
The overall data gathered from 208 respondents for significance level of 61 factors causing Construction  Waste were analyzed statistically using frequency analysis and average index obtained through SPSS V 24 software package. Reliability analysis was used to check the consistency of the collected data. The indicator used for checking the consistency is Cronbach's alpha value. The Cronbach's alpha value consistency degree is varying from 0 and 1 and on the basis that the higher values represent a higher degree of internal consistency of the data 53 . As per 54 , the reliability is considered low if Cronbach alpha value is less than 0.3 and the data cannot be accepted, whereas, consistency of data will be high if the Cronbach alpha value is more than 0.7 and such will be acceptable. A total of 208 valid collected data from the actual survey were analyzed for its consistency using SPSS software to get the Cronbach's alpha values for each group of factor and the overall factors. All the generated value of Cronbach alpha is reorganized as in Table 5.   38 . Thus, the collected data is considered reliable to carry out further analysis. The factors ranked based on average index value. The results of frequency for level of significance, average index and rank of severity for each causative factor of design categories are shown in Table 6a. Table 6a, shows there are 11 factors in design group arranged based on the average index score of severity of each factor contribute to Construction Waste generation. Result from this table indicates that three severest factors are design errors, lack of design information and frequent design changes. This finding concur with the study conducted by 45 where the most sever factors are design errors, lack of design information and frequent design changes.

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Item names  49 found that majority of respondents participating in survey agreed that poor site management is the major factor of Construction Waste generation. In a study related to Construction Waste generation in India highlighted that poor site management factor is major reason of waste generated 55 . Result of the handling group factors are shown in Table 6c. Based on the ranking results, 2 factors have importance level for C and D waste generation. These factors are "Wrong material storage and Poor material handling". This finding is concurrent with the findings from other study by 28 , found that majority of participating agreed that wrong material storage is the main factor of Construction Waste generation. The result of site condition for each factor is as presented in table 6d.
From Table 6d, it was found that "waste resulting from packaging" is the main contribute factor 56 . In another study 57 pointed out the waste resulting from packaging significant factor that contribute C and D waste generation. Table 6e shows the highest severity score in this phase is "mistakes on quantity surveys", subsequently "Ordering errors" this result similar study conducted by 28 , found that majority of the respondents participating that agreed that mistakes on quantity surveys is the major factor of C and D waste generation. According to 34 Table 6f. Table 6f illustrates the highest mean score in the workers group is "lack of awareness among the workers", thence, "Too much overtime for workers", this finding similar to study that conducted by 33 . The result of ranking for external group is shown in Table  6g.
In the external group, most of these factors are difficult control. From Table 6g, it was found that "Lack of legislative enforcement" then "Effect of weather" as the main contributes factors for C and D waste generation 56 and found that majority reason of the huge waste generation was lack of legislative enforcement and effect of weather. In 58 claimed that lack of legislative enforcement, as one of the causative factors to C and D waste generation.

Conclusions
From this investigation, a superior comprehension of the sources and reasons for CWs and the existing waste control practices on construction sites in Iraq was accomplished. The quantity of CW and the generation of waste material at construction projects rely upon different factors. "A poor site management", "Rework", "Poor supervision", "Poor planning" and "Lack of environmental awareness" are the major factors for contributing waste generation as witnessed through the value of degree of importance severity waste index. However, "lack of regulations, enforcement and guidelines" observed in some Iraq construction industry are also aspects that contributed to the generation of CW and could be considered as influencing factors. It is concluded on the basis of results achieved in this research would provide attentiveness to all Iraq construction industries to adopt and follow sustainable CW standards in line with standards originated by numerous international agencies. However; in continuation to this research work, further investigations will be conducted for documentation of the better practices for controlling and minimizing the CW waste and along with minimizing the barriers for that on construction sites in Iraq.