Waste management on construction sites

WASTE MANAGEMENT ON CONSTRUCTION SITES

A ThesisSubmitted 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

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.

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.

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.

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.

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.

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)

Table 1: Allocation of Finished Projects Covered

No. of studied projects Client

10 Directorate of Education in Karbala .

9 General Secretariat of the Husseiniya Shrine.

5 Directorate of Municipality in Karbala .

3 Local Branch of the General Directorate for Roads and Bridges.

2 Directorate of Electric Power Distribution in Karbala .

1 General Secretariat of the Abasia Shrine.

30 Total

Ceram. Marble Tiles Gyps. Stone Brick Steel Cement Gravel Sand Project

- - - 18.07 12.07 - 5.07 5.69 10.18 11.12 Almujtaba Library.

8.39 8.19 - 17.88 - 15.24 4.59 5.41 10.25 11.32 Second Municipal.

10.62 8.28 - 18.17 - 15.31 4.61 5.58 10.33 12.00 Sixth Municipal.

11.54 7.89 - 18.68 - 15.43 4.69 4.84 10.42 12.07 Gardens Dept.

- - - 17.85 11.43 - 4.73 4.76 10.53 12.66 Alwaeli Hospital.

- - 11.70 17.94 - 15.67 4.84 5.18 11.03 11.70 Alsomood school.

- - 11.80 18.33 - 15.78 4.81 5.07 11.32 11.80 Alhindia school.

- - 12.91 17.59 - 15.96 4.94 5.03 11.41 12.91 Almojtaba school.

- - 12.98 18.95 - 16.1 5.13 5.08 11.28 12.98 Alshimokh school.

- - 13.33 17.37 - 16.28 5.27 5.21 10.78 13.33 Altaka school.

- - 11.8 13.91 - 16.38 5.39 5.33 10.62 11.80 Omalhawa school.

- - 13.64 19.21 - 16.41 5.47 5.41 10.86 13.64 Alrafidain school.

- - 14.00 17.20 - 16.5 5.56 5.48 10.91 14.00 Aldobat school.

- - 14.12 14.64 - 16.64 5.64 5.18 11.59 14.12 Alitarat school.

Table 3: Waste Percentages Determined From Past Records


9.75 - 10.64 17.68 13.51 14.23 6.03 5.72 8.92 10.64 Alkawther Mall.

6.81 - 12.07 14.94 13.79 - 6.21 5.91 8.75 12.07 Almustafa Mall.

- 7.27 - 17.58 13.97 - 6.46 6.22 8.61 12.04 Zain Hospital.

- 7.38 - 17.47 17.02 - 6.90 6.43 8.83 12.13 Alkafel Hospital.

- - - 15.43 - 13.91 4.54 4.98 9.47 10.63 Alataba Plantation.

9.88 6.54 - 20.31 - 13.64 4.48 4.83 9.56 12.50 Medinat Al-Zairin1.



8.83 9.81 - 17.18 - - 4.01 4.53 12.19 12.66 Mukhaim Toilets1.

7.25 10.09 - 16.97 - 12.00 2.98 4.48 12.96 14.56 Mukhaim Toilets2.

- - - - - - 3.29 4.23 12.43 13.00 Aldariba Bridge.

- - - - - 16.91 3.48 4.08 12.69 13.30 Towayrige Bridge.

- - - - - - 3.54 3.89 11.73 13.34 Algaire Bridge.

13.39 - 13.34 16.28 - 17.46 3.72 3.71 11.84 14.45 Friha E. Station.

10.56 - 13.66 16.17 - 17.91 3.96 3.46 10.18 13.66 Alkhairat E. Station.

Table 3: Waste Percentages Determined From Past Records(Continued)

Table 2: Allocation of Under Construction Projects Visited

No. of studied projects Client

2 Directorate of Education in Karbala.

2 General Secretariat of the Husseiniya Shrine.

1 Karbala Investment Commission.

1 Directorate of Health in Karbala.

6 Total

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)

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

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

FIGURE 2: CONSTRUCTION MATERIALS FLOW CHART

Hauling

Residual materials

Non-reusableReusable

Off-site Recycling, Reclamation or Landfill

Pre-

cons

truc

tion

phas

eStorage

Processing

Supply

Ordering

Con

stru

ctio

n ph

ase

Estimating

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)

Table 4: Observed Waste Percentages


9.67 - 10.17 17.84 11.62 14.50 4.81 5.38 10.33 12.00 Durrat Housing.

- - - - - 15.32 4.34 5.03 10.72 11.92 Khatem Hospital.

- - - - - - 4.64 5.29 11.01 13.01 Orphans School.

10.75 8.93 - - - 15 5.27 4.72 11.44 12.04 Turkish Hospital.

8.81 - - 17.41 - 15.11 4.61 4.90 10.09 12.66 Alsalam school.

9.08 - - 16.71 - 14.66 5.19 5.11 10.23 11.91 Almilad school.

10.27 9.19 9.45 17.25 12.77 15.23 4.81 5.03 10.76 12.47 Norm rates *

* Normal rates are average waste percentages determined from past record.

SOME VISITED CONSTRUCTION SITES

PAST DATA ANALYSIS

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).

Figure 3:MATERIALS WASTE PAST DATA DISTRIBUTIONS

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

Table 5: Results of the test of goodness of fit for past records

*Degree of Freedom. ** Two tailed test.

Asymp. Sig.** Df * Chi-Square Materials

0.045 26 17.103 Sand0.153 28 13.651 Gravel0.194 26 2.406 Cement

0.081 29 2.087 Reinforcement Steel Bars

0.09 29 3.12 Bricks0.163 28 10.71 Thermo-stone0.294 29 4.333 Gypsum0.067 28 26.059 Terrazzo Tiles0.509 28 3.933 Marble0.019 29 8.083 Ceramics

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).

Table 6: Results of the test of hypotheses for observed data

Conf. Interval ***MeanDif. Sig.** Df * t Waste

%

Material

Upper Lower

1.1208 -0.795 0.5206 0.023 29 2.391 12

Sand

1.2008 0.0005 0.6006 0.01 29 2.759 11.920.1208 -1.079 -0.4793 0.036 29 -2.202 13.011.0808 -0.1195 0.4806 0.035 29 2.208 12.040.4608 -0.7395 -0.1393 0.527 29 -0.64 12.661.2108 0.0105 0.6167 0.009 29 2.805 11.911.0968 -0.1815 0.4576 0.058 29 19.74 10.33

Gravel

0.7068 -0.5715 0.0676 0.773 29 0.292 10.720.4168 -0.8615 -0.2223 0.346 29 -0.959 11.01-0.013 -1.2915 -0.6523 0.009 29 -2.813 11.441.3368 0.0585 0.6976 0.005 29 3.009 10.091.1968 -0.815 0.5576 0.023 29 2.405 10.23

Material Waste % t Df * Sig.** Mean Dif.Conf. Interval ***Lower Upper

Cement

5.38 -2.778 29 0.009 -0.3573 -0.7118 -0.0035.03 -0.057 29 0.955 -0. 007 -0.3618 0.34725.29 -2.079 29 0.047 -0.2673 -0.6218 0.08724.72 2.353 29 0.026 0.3026 -0.0518 0.65724.9 0.954 29 0.348 0.1226 -0.2318 0.47725.11 -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 0.49234.34 2.759 29 0.01 0.4813 0.0004 0.96234.64 1.039 29 0. 307 0.1813 -0.2996 0.66235.27 0.571 29 0.016 -0.4467 -0.9296 0.03234.61 1.211 29 0.236 0.2113 -0.2696 0.69235.19 2.113 29 0.043 -0.3687 -0.8496 0.1123

Bricks

14.5 2.903 29 0.007 0.801 0.0404 1.561615.32 0.069 29 0.946 -0.019 -0.7796 0.741614.93 1.345 29 0.189 0.371 -0.3896 1.1316

15 1.091 29 0.284 0.301 -0.4596 1.061615.11 0.692 29 0.494 0.191 -0.5696 0.951614.66 2.323 29 0.027 0.641 -0.1196 1.4016

Table 6: Results of the test of hypotheses for observed data (Continued)

Material Waste % t Df * Sig.** Mean Dif.Conf. Interval ***Lower Upper

Thermo-stone

11.62 2. 937 29 0.006 1.1636 0.0715 2.255912.84 0.766 29 0.45 0.3036 -0.7885 1.395913.77 -2.489 29 0.019 -0.9863 -2.0785 0.105913.59 -2.035 29 0.051 -0.8063 -1.8985 0.285912.56 0.564 29 0.577 0.2236 -0.8685 1.315912.07 1.801 29 0.082 0.7136 -0.3785 1.8059

Gypsum

17.84 -2.159 29 0.039 -0.5777 -1.3153 0.159917.31 -0.178 29 0.86 -0.0477 -0.7853 0.689916.96 1.1301 29 0.268 0.3023 -0.4353 1.039918.01 -2.794 29 0.009 -0.74767 -1.4853 -0.01017.41 -0.552 29 0.585 -0.14767 -0.8853 0.589916.71 2.064 29 0.048 0.55233 -0.1853 1.2899

Terrazzo Tiles

10.17 -2.545 29 0.016 -0.73733 -1.5358 0.06119 1.494 29 0.146 0.43267 -0.3658 1.2311

9.81 -1.303 29 0.203 -0.37733 -1.1758 0.42118.63 2.771 29 0.01 0. 80267 0.0042 1.60119.38 0.182 29 0.857 0.05267 -0.7458 0.8511

10.31 -3.029 29 0.005 -0.87733 -1.6758 -0.079


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


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.

STATISTICAL ANALYSIS RESULTS

Table 7: Statistics of ten construction materials waste percentages

MOHC Range Variance St. Dev. Median Mean Material

10 4.55 1.219 1.104 12.315 12.477 Sand9 4.58 1.378 1.174 10.75 10.76 Gravel4 2.97 0.42 0.648 5.05 5.03 Cement

6 3.92 0.775 0.88 4.77 4.81 Reinf. Steel

15 5.91 1.926 1.387 15.275 15.23 Bricks15 8.81 4.044 2.01 12.7 12.77 Thermo-stone18 6.4 1.785 1.328 17.4 17.25 Gypsum10 6.25 2.151 1.466 9.265 9.45 Terrazzo tiles7 5.48 1.859 1.363 9.015 9.19 Marble7 8.26 4.034 2.008 9.965 10.27 Ceramics

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).

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)

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)

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

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

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

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:

Main Interface

SYSTEM INTERFACES (Continued)

New Project Interface


Work Items Interface


Follow-up Interface


Orders due Interface

SYSTEM INTERFACES(Continued)

Daily Report Output


Waste management Interface


List of actions Output


Waste Report Output


Recycling Output


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.

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)

(Ranked Questions)

MeanScore

Obtained frequency System characteristics Q.

Excel. V. G. Good Poor V. P.6.6 5 14 11 - - Installation 1

6.73 11 4 15 - - Data input 28.13 17 13 - - - Output display 36.2 3 14 11 2 - User interaction 4

5.26 - 8 18 4 - Accuracy of results 5

8 16 12 2 - - MS-project Integration 6

6.73 7 12 11 - - Storage management 77 5 19 6 - - Waste early warning 8

7.06 7 17 6 - - Reducing the waste 95.4 - 10 16 4 - Applicability 10

TABLE 8: EVALUATION OF SYSTEM CHARACTERISTICS

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)

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.

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.

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.

THANK YOU

Waste management on construction sites

Engineering

Transcript of Waste management on construction sites