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Waste management on construction sites

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Waste Management on Construction Sites study

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Waste management on construction sites

  1. 1. WASTE MANAGEMENT ON CONSTRUCTION SITES A Thesis Submitted to the Department of Building and Construction Engineering at the University of Technology in Partial Fulfillment of the Requirements for the degree of Master of Science in Building and Construction Engineering (Project Management) By Ali Hasan Hadi Al-Ayem supervised by Dr. Zeyad S. M. Khaled Dr. Basil S. Al-Shathr Asst. Prof. Asst. Prof. 3/12/2014
  2. 2. INTRODUCTION Construction waste is a major challenge because of its tremendous environmental and economic bad effects (Shen, 2004)..  Environmentally: construction waste produces an average of (32%) of the total annual waste that is disposed to landfills.  Economically: It comprises (10-20%) of the total annual construction materials used. hence (4-10%) of the project total cost is wasted.
  3. 3. DEFINITIONS  Material Waste: is defined as any losses produced by activities that generate direct or indirect costs but do not add any value to the product (Lauri, 199). It is also defined as the surplus materials that are generated from construction, renovation and demolition activities (Formoso, 1999).  Construction Waste Management: is the process of developing and implementing a strategy or a plan to reduce the generated waste to the minimum extent possible by three approaches: Reducing, Reusing, and Recycling.
  4. 4. RESEARCH OBJECTIVES  Finding out waste percentages of ten major construction materials on local scale.  Employing the waste percentages as early warning indicators that point out any access in waste percentages at early stages.  Developing a computerized system to be used as a tool for managing construction waste in the local construction industry.
  5. 5. RESEARCH JUSTIFICATION  Construction waste in the local construction industry do not receive enough care. There is a serious need to understand the impact of construction waste on the environment and the economic benefits gained through reducing the construction cost.  A successful construction waste management reserves the environment by utilizing the use of natural resources in addition to the economic benefits. For many developed countries the construction waste management is no longer an option but became a necessity.
  6. 6. RESEARCH METHODOLOGY 1. Literature Review 1.1 To explore the issue of construction waste including its generation, causes, types, management, and treatments. 1.2 To study the facilities of Statistical Package for Social Sciences (SPSS) and Microsoft Project (MS-Project) programs.
  7. 7. RESEARCH METHODOLOGY 2. Data Acquisition To determine the average waste percentages of construction materials at the local construction industry in Karbala: 2.1 Past records of thirty construction projects concerning ten major types of construction materials are studied carefully and analyzed. Table (1) shows number of project related to each Client visited. (Continued)
  8. 8. Table 1: Allocation of Finished Projects Covered No. of studied projects Client 10Directorate of Education in Karbala . 9General Secretariat of the Husseiniya Shrine. 5Directorate of Municipality in Karbala . 3 Local Branch of the General Directorate for Roads and Bridges. 2 Directorate of Electric Power Distribution in Karbala . 1General Secretariat of the Abasia Shrine. 30Total
  9. 9. Ceram.MarbleTilesGyps.StoneBrickSteelCementGravelSandProject ---18.0712.07-5.075.6910.1811.12Almujtaba Library. 8.398.19-17.88-15.244.595.4110.2511.32Second Municipal. 10.628.28-18.17-15.314.615.5810.3312.00Sixth Municipal. 11.547.89-18.68-15.434.694.8410.4212.07Gardens Dept. ---17.8511.43-4.734.7610.5312.66Alwaeli Hospital. --11.7017.94-15.674.845.1811.0311.70Alsomood school. --11.8018.33-15.784.815.0711.3211.80Alhindia school. --12.9117.59-15.964.945.0311.4112.91Almojtaba school. --12.9818.95-16.15.135.0811.2812.98Alshimokh school. --13.3317.37-16.285.275.2110.7813.33Altaka school. --11.813.91-16.385.395.3310.6211.80Omalhawa school. --13.6419.21-16.415.475.4110.8613.64Alrafidain school. --14.0017.20-16.55.565.4810.9114.00Aldobat school. --14.1214.64-16.645.645.1811.5914.12Alitarat school. Table 3: Waste Percentages Determined From Past Records
  10. 10. Ceram.MarbleTilesGyps.StoneBrickSteelCementGravelSandProject 9.75-10.6417.6813.5114.236.035.728.9210.64Alkawther Mall. 6.81-12.0714.9413.79-6.215.918.7512.07Almustafa Mall. -7.27-17.5813.97-6.466.228.6112.04Zain Hospital. -7.38-17.4717.02-6.906.438.8312.13Alkafel Hospital. ---15.43-13.914.544.989.4710.63Alataba Plantation. 9.886.54-20.31-13.644.484.839.5612.50Medinat Al-Zairin1. 12.659.47-17.39-13.004.314.7613.1911.24Medinat Al-Zairin2. 7.819.67-15.77-12.744.184.6211.7314.55Medinat Al-Zairin3. 8.839.81-17.18--4.014.5312.1912.66Mukhaim Toilets1. 7.2510.09-16.97-12.002.984.4812.9614.56Mukhaim Toilets2. ------3.294.2312.4313.00Aldariba Bridge. -----16.913.484.0812.6913.30Towayrige Bridge. ------3.543.8911.7313.34Algaire Bridge. 13.39-13.3416.28-17.463.723.7111.8414.45Friha E. Station. 10.56-13.6616.17-17.913.963.4610.1813.66Alkhairat E. Station. Table 3: Waste Percentages Determined From Past Records(Continued)
  11. 11. Table 2: Allocation of Under Construction Projects Visited No. of studied projects Client 2Directorate of Education in Karbala. 2General Secretariat of the Husseiniya Shrine. 1Karbala Investment Commission. 1Directorate of Health in Karbala. 6Total 2.2 Field investigation included live observations of materials flow and waste generation in six under construction projects. Table (2) shows number of project related to each client visited . RESEARCH METHODOLOGY(Continued)
  12. 12. Retrospective study is conducted to extract data from materials ordering sheets of thirty finished projects shown in Table (3). Then net quantities are estimated from related drawings. Waste percentages are calculated using equation (1). W% = ........... (1) PAST DATA DETERMINED
  13. 13. Observational method is employed to measure the required data in six under construction projects by the aid of the worksheet shown in Fig. (1). Materials movement stream line once it is delivered to the work site until being used and built in its final position is intensively tracked and measured. Several factors that usually cause construction materials waste in local construction industry are studied in order to discover their influences. The construction materials streamline flowchart is illustrated in Fig. (2). FIELD MEASUREMENTS
  14. 14. FIGURE 2: CONSTRUCTION MATERIALS FLOW CHART Hauling Residual materials Non-reusableReusable Off-site Recycling, Reclamation or Landfill Pre-construction phase Storage Processing Supply Ordering Constructionphase Estimating
  15. 15. Waste percentages are measured in various activities, of different architectural design, at several elevations, for various work gangs. Nevertheless, all of them are carried out at the same storage conditions, with the same way of unloading and handling, and at the same work conditions using the same specifications and equipment available at the local industry. Records of related quantities for thirty finished projects are collected and analyzed as shown in Table (4). FIELD MEASUREMENTS (Continued)
  16. 16. Table 4: Observed Waste Percentages Ceram.MarbleTilesGyps.StoneBrickSteelCementGravelSandProject 9.67-10.1717.8411.6214.504.815.3810.3312.00Durrat Housing. -----15.324.345.0310.7211.92Khatem Hospital. ------4.645.2911.0113.01Orphans School. 10.758.93---155.274.7211.4412.04Turkish Hospital. 8.81--17.41-15.114.614.9010.0912.66Alsalam school. 9.08--16.71-14.665.195.1110.2311.91Almilad school. 10.279.199.4517.2512.7715.234.815.0310.7612.47Norm rates * * Normal rates are average waste percentages determined from past record.
  17. 17. SOME VISITED CONSTRUCTION SITES
  18. 18. PAST DATAANALYSIS  The past data obtained are tested against statistical measures. Normal distribution curves are fitted to verify the credibility ​​of the determined statistical society of past records for each material using the Statistical Package for Social Sciences (SPSS) as shown in Fig (3).
  19. 19. Figure 3:MATERIALS WASTE PAST DATA DISTRIBUTIONS
  20. 20. The distribution of each statistical society of past records is submitted to the test of "Goodness of fit" to verify its characteristic under (99%) level of confidence. The results of this test for all materials wastes are summarized in Table (5) which reveals that the statistical society of all materials wastes conform to the normal distribution. PAST DATA VERIFICATION
  21. 21. Table 5: Results of the test of goodness of fit for past records *Degree of Freedom. ** Two tailed test. Asymp. Sig.**Df *Chi-SquareMaterials 0.0452617.103Sand 0.1532813.651Gravel 0.194262.406Cement 0.081292.087 Reinforcement Steel Bars 0.09293.12Bricks 0.1632810.71Thermo-stone 0.294294.333Gypsum 0.0672826.059Terrazzo Tiles 0.509283.933Marble 0.019298.083Ceramics
  22. 22. OBSERVED DATA VERIFICATION Reliability of the method adopted to determine the waste percentages of materials are verified against the data measured from field investigation of six under construction projects. "t- Test" for six different iterations of each material at (99%) level of confidence is conducted as shown in Table (6).
  23. 23. Table 6: Results of the test of hypotheses for observed data Conf. Interval *** MeanDif.Sig.**Df *t Waste % Material UpperLower 1.1208-0.7950.52060.023292.39112 Sand 1.20080.00050.60060.01292.75911.92 0.1208-1.079-0.47930.03629-2.20213.01 1.0808-0.11950.48060.035292.20812.04 0.4608-0.7395-0.13930.52729-0.6412.66 1.21080.01050.61670.009292.80511.91 1.0968-0.18150.45760.0582919.7410.33 Gravel 0.7068-0.57150.06760.773290.29210.72 0.4168-0.8615-0.22230.34629-0.95911.01 -0.013-1.2915-0.65230.00929-2.81311.44 1.33680.05850.69760.005293.00910.09 1.1968-0.8150.55760.023292.40510.23
  24. 24. Material Waste % t Df * Sig.** Mean Dif. Conf. Interval *** Lower Upper Cement 5.38 -2.778 29 0.009 -0.3573 -0.7118 -0.003 5.03 -0.057 29 0.955 -0. 007 -0.3618 0.3472 5.29 -2.079 29 0.047 -0.2673 -0.6218 0.0872 4.72 2.353 29 0.026 0.3026 -0.0518 0.6572 4.9 0.954 29 0.348 0.1226 -0.2318 0.4772 5.11 -0.679 29 0.502 -0.0873 -0.4418 0.2672 Reinfor- cement Steel Bars 4.81 0.065 29 0.949 0.0113 -0.4696 0.4923 4.34 2.759 29 0.01 0.4813 0.0004 0.9623 4.64 1.039 29 0. 307 0.1813 -0.2996 0.6623 5.27 0.571 29 0.016 -0.4467 -0.9296 0.0323 4.61 1.211 29 0.236 0.2113 -0.2696 0.6923 5.19 2.113 29 0.043 -0.3687 -0.8496 0.1123 Bricks 14.5 2.903 29 0.007 0.801 0.0404 1.5616 15.32 0.069 29 0.946 -0.019 -0.7796 0.7416 14.93 1.345 29 0.189 0.371 -0.3896 1.1316 15 1.091 29 0.284 0.301 -0.4596 1.0616 15.11 0.692 29 0.494 0.191 -0.5696 0.9516 14.66 2.323 29 0.027 0.641 -0.1196 1.4016 Table 6: Results of the test of hypotheses for observed data (Continued)
  25. 25. Material Waste % t Df * Sig.** Mean Dif. Conf. Interval *** Lower Upper Thermo-stone 11.62 2. 937 29 0.006 1.1636 0.0715 2.2559 12.84 0.766 29 0.45 0.3036 -0.7885 1.3959 13.77 -2.489 29 0.019 -0.9863 -2.0785 0.1059 13.59 -2.035 29 0.051 -0.8063 -1.8985 0.2859 12.56 0.564 29 0.577 0.2236 -0.8685 1.3159 12.07 1.801 29 0.082 0.7136 -0.3785 1.8059 Gypsum 17.84 -2.159 29 0.039 -0.5777 -1.3153 0.1599 17.31 -0.178 29 0.86 -0.0477 -0.7853 0.6899 16.96 1.1301 29 0.268 0.3023 -0.4353 1.0399 18.01 -2.794 29 0.009 -0.74767 -1.4853 -0.010 17.41 -0.552 29 0.585 -0.14767 -0.8853 0.5899 16.71 2.064 29 0.048 0.55233 -0.1853 1.2899 Terrazzo Tiles 10.17 -2.545 29 0.016 -0.73733 -1.5358 0.0611 9 1.494 29 0.146 0.43267 -0.3658 1.2311 9.81 -1.303 29 0.203 -0.37733 -1.1758 0.4211 8.63 2.771 29 0.01 0. 80267 0.0042 1.6011 9.38 0.182 29 0.857 0.05267 -0.7458 0.8511 10.31 -3.029 29 0.005 -0.87733 -1.6758 -0.079 Table 6: Results of the test of hypotheses for observed data (Continued)
  26. 26. Marble 9.52 -1.265 29 0.216 -0.34133 -1.0853 0.4027 10 -3.043 29 0.005 -0.82133 -1.5653 -0.077 8.44 2.737 29 0.01 0.73867 -0.053 1.4827 8.93 0.921 29 0.365 0.24867 -0.4953 0.9927 9.71 -1.968 29 0.059 -0.53133 -1.2753 0.2127 9.07 0.403 29 0.69 0.10867 -0.6353 0.8527 Ceramic 9.67 1.724 29 0.095 0.68733 -0.4114 1.7861 9.38 2.452 29 0.02 0.97733 -0.1214 2.0761 10.17 0.47 29 0.642 0.18733 -0.9114 1.2861 10.75 -0.985 29 0.333 -0.39267 -1.4914 0.7061 9.13 3.079 29 0.005 1.22733 0.1286 2.3261 10.08 0.696 29 0.492 0.27733 -0.8214 1.3761 Table 6: Results of the test of hypotheses for observed data (Continued)
  27. 27. The descriptive statistics; mean, median, standard deviation, range, variance, and others of all materials wastes are determined using SPSS. The results are summarized in Table (7) and they confirm that the waste of materials at the local construction industry in Karbala is relatively higher than the limits set by the Iraqi Ministry of Housing and Construction (MOHC) but it is predictable and avoidable which coincides with the research hypothesis. STATISTICALANALYSIS RESULTS
  28. 28. Table 7: Statistics of ten construction materials waste percentages MOHCRangeVarianceSt. Dev.MedianMeanMaterial 104.551.2191.10412.31512.477Sand 94.581.3781.17410.7510.76Gravel 42.970.420.6485.055.03Cement 63.920.7750.884.774.81Reinf. Steel 155.911.9261.38715.27515.23Bricks 158.814.0442.0112.712.77Thermo-stone 186.41.7851.32817.417.25Gypsum 106.252.1511.4669.2659.45Terrazzo tiles 75.481.8591.3639.0159.19Marble 78.264.0342.0089.96510.27Ceramics
  29. 29. CONSTRUCTION WASTE MANAGEMENT SYSTEM Open vs. close systems The construction industry is usually considered as an open loop system that consists of input, processing, and output. An attempt to achieve higher efficiency in materials usage is made by adding a feedback flow of waste materials which convert the open loop system to a close one as shown in Fig. (4) (Poon, 2004).
  30. 30. Figure 4: Open and close loop systems Input Processing Output + WasteInput Output + Waste Open Loop System Waste feedback Close Loop System Processing CONSTRUCTION WASTE MANAGEMENT SYSTEM(Continued)
  31. 31. A system is developed in an attempt to convert the traditional open loop system to a close one. It is developed to serve as a tool to be used by construction engineers during the execution phase. CONSTRUCTION WASTE MANAGEMENT SYSTEM (Continued)
  32. 32.  Easy to install and operate.  Do not need excessive input data.  Capable to comprise all necessary information in its database.  Provides understandable and useful reports.  Flexible and capable to handle wide range of applications.  Compatible with other systems that are used in the same field. PRINCIPLES OF THE SYSTEM
  33. 33.  Reducing waste: The developed system employs the principles of ‘supply chain method’ (SCM) or ‘just-in-time’ delivery concept (JIT) to supply the construction materials to sites.  Reusing waste: The developed system offers possible ways to reuse waste materials in the same project through functioning as an expert system.  Recycling waste: The developed system provides possible options (if any) for recycling construction materials waste that cannot be reused. SCOPE OF THE SYSTEM
  34. 34. 1. Inter basic information of the project. 2. Import the time table of the project from MS-Project program. 3. Determine quantities needed in progress for each material. 4. Optimize the available space of material storage. 5. Determine optimal demand dates. 6. Prepare a daily report about each material with e-mail possibility. 7. Alarm an early warning in case of excessive waste. 8. Offer all possible ways to reuse waste in the coming activities. 9. Offer opportunities of recycling materials that cannot be reused. The framework of the developed system and its programming interlinks are summarized in Fig (5). FUNCTIONS OF THE SYSTEM
  35. 35. SYSTEM INTERFACES Running the system does not need any special training above minimal computer skills for the system is designed to be user- friendly and self-exploratory in which the interfaces enable the user to run the system easily. The followings are the interfaces of system:
  36. 36. Main Interface SYSTEM INTERFACES(Continued)
  37. 37. New Project Interface SYSTEM INTERFACES(Continued)
  38. 38. Work Items Interface SYSTEM INTERFACES (Continued)
  39. 39. Follow-up Interface SYSTEM INTERFACES(Continued)
  40. 40. Orders due Interface SYSTEM INTERFACES(Continued)
  41. 41. Daily Report Output SYSTEM INTERFACES (Continued)
  42. 42. Waste management Interface SYSTEM INTERFACES (Continued)
  43. 43. List of actions Output SYSTEM INTERFACES (Continued)
  44. 44. Waste Report Output SYSTEM INTERFACES (Continued)
  45. 45. Recycling Output SYSTEM INTERFACES (Continued)
  46. 46. SYSTEM EVALUATION The developed system is implemented in six under-construction projects in Karbala in order to:  verify its flexibility, accuracy, effectiveness, and suitability for application.  find out application difficulties, and  explore any additional arguments of the users.
  47. 47. Direct interviews are also conducted with each project associated staff including (the representative of the consultant firm, the resident engineer, the site engineer, the quantity surveyor, and the store keeper). Interviews are documented by a Questionnaire Form for specific ranked system characteristics as shown in Table (8). SYSTEM EVALUATION(Continued)
  48. 48. (Ranked Questions) Mean Score Obtained frequencySystem characteristics Q. Excel.V. G.GoodPoorV. P. 6.651411--Installation1 6.7311415--Data input2 8.131713---Output display3 6.2314112-User interaction4 5.26-8184-Accuracy of results5 816122--MS-project Integration6 6.7371211--Storage management7 75196--Waste early warning8 7.067176--Reducing the waste9 5.4-10164-Applicability10 TABLE 8: EVALUATION OF SYSTEM CHARACTERISTICS
  49. 49. It can be noticed from the ranked answers that: 1. Installing the system is easy. 2. Data input is smooth. 3. Output is reliable. 4. Interaction between the user and the system is efficient. 5. Results are accurate. 6. Integration between the system and MS-project is effective. 7. Early warning of waste excess is active. 8. Employing the system in the local construction industry is possible. SYSTEM EVALUATION(Continued)
  50. 50. CONCLUSIONS 1. The actual waste percentages of construction materials exceed the limits set by (MOHC) listed in Table (7). 2. Local contracting companies do not seem to be concerned about material waste. 3. High variation in wastage is found for different construction materials at the same project itself . 4. There is a considerable variance between waste percentages of the same material from site to site. 5. A serious absence of the appropriate knowledge of construction materials waste management is found. 6. Most of the generated waste can be avoided by implementing few preventive measures.
  51. 51. RECOMMENDATIONS 1. The Ministry of Planning is invited to develop the contract conditions in order to compel contractors to apply construction waste control clauses at the construction phase. 2. The Ministry of Construction and Housing is invited to issue instructions to enable construction firms to use feasible approaches for construction waste management. 3. The Ministry of Environment is invited to conduct studies to determine the environmental and economical effect of construction waste. 4. The Iraqi Engineers Syndicate is invited to hold symposiums to raise the awareness of the professional teams concerning construction waste. 5. The Union of Iraqi Contractors is invited to conduct symposiums to raise contractors' awareness concerning construction waste.
  52. 52. FUTURE STUDIES 1. Investigation of alternative waste disposal methods. 2. Develop a Waste Disposal Data System because there is acute demerit in the construction waste data base at local scale. 3. Develop more general waste management system for the Iraqi construction environment as a whole. Finally, it is recommended to use the system developed through this research.
  53. 53. THANK YOU

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