Development of a Recycling System Policy for Construction and
Demolition Waste Materials with Applications in Libya towards
Sustainable Development
Itad Shiboub Gabriel J. Assaf
Ecole de technologie supérieure | Université du Professer Ecole de technologie supérieure | Université du Québec
Québec 1100, rue Notre-Dame Ouest, Office: A-1491
1100, rue Notre-Dame Ouest, bureau A-1568-46 Montréal (Québec) H3C 1K3
Montréal (Québec) H3C 1K3 Téléphone: (514) 396- 8924
Telephone: (514) 396-8800- 7809 or 5144023512 Email: gabriel.assaf@ etsmtl.ca
Email: an73300@ ens.etsmtl.ca or
i.s73300@ yahoo.com
Keywords:
Recycling; Construction and demolition Waste Material; System dynamics; Modelling; Cement
consumption; Cement production; Road construction; Environmental, Sustainability; Libya.
Abstract
Construction and Demolition Waste (CDW) materials are presently put in landfills (henceforth, Landfill-
Designated Waste). At the same time, many developing countries, particularly in Africa, suffer from a
lack of proper management of suitable materials for road construction, mainly old concrete, brick, asphalt,
gravel, and angular sand. CDW is significant because it may be fully or at least partially reused in new
construction projects, saving valuable and non-renewable resources. In addition to the depletion of natural
resources, the disposal of CDW causes clogging of disposal sites. Due to the absence of a recycling and
reusing policy, there are no alternatives to these disposal sites where CDW piles up. The three challenges
to recycling are: 1) landfill space which is cheap or free; 2) social norms and education surrounding
recycling; and 3) waste is perceived as garbage, and therefore of lesser quality. By quantifying how
landfilling CDW represents an increase in environmental liability and a problem for the future, this
research discusses the waste of the potential value of the material and how existing and scarce resources
might be protected. Thus, CDW is a liability that can be turned into a valuable resource by using System
Dynamics (SD) concepts. In addition, SD presents a convenient framework to monetize the value of the
recycled waste. This framework is based by characterizing CDW and then on reusing it. The results of the
model provide an innovative needs-based recycling policy to manage CDW. The scope of the study is at
the national level, focused on Libya but generalizable to developing countries with comparable climatic,
social and cultural features. Validation in this study relies on three things: 1) verifying that the units that
are input into the model are correct; 2) comparing the results with successful previous studies; 3) using
one specific and very common building design. This needs-based approach regarding required
construction materials relies on estimates of future material needs, from either new or recycled sources,
for both new and rehabilitation projects. This assessment is based on infrastructure needs, population
growth rates, GDP, and cement production and consumption
Specific Issues
The construction of new projects, renovation, and demolition wastes from infrastructure development can
have a great impact on the environment, and on energy and material consumption if they are not regulated
(Marzouk & Azab, 2014)
The general unwillingness to accept second-hand or recycled materials creates a lower demand for
recovered or recycled materials on the market. Nonetheless, the end goal of the project is to develop a
sustainable model of waste management that is appropriate to the social and physical environment as well
as to the economy of a country such as Libya. The recycling of materials helps to reduce landfill
pressures.
During the design stage of construction projects, sustainability principles for holistically integrating
material selection must be incorporated. There is a lot of research in this area but there are still many
obstacles to incorporating sustainability concerns in material selection in order to make the appropriate
decision.
Objectives to Establishing a inable Framework Research
The main goal of this study is to devise a framework and methodology for a developing nation to
establish a recycling policy for construction materials from a socially, economically and environmentally
sustainable perspective.
The specific objectives of this research are:
1) Identify and characterize existing CDW at the national and city levels in a developing country
such as Libya; these must comply with relevant and generally accepted guidelines and standards in
order to establish a reliable and dependable accounting of potential material assets for different
reuse needs.
2) Propose an adapted recycling policy framework for Libya and similar developing countries.
(Nazirah Zainul Abidin (2010) defines sustainable construction as an approach towards the future in
which the needs of development are balanced with a duty to protect the natural environment, public
health, and economic security; i.e., the goal is to develop places that are prosperous for public and
environmental health, and work.
Methodology
The application of SD in this study relies on the VENSIM PLE software. This program has a graphical
user interface (GUI) that is useful to help the user design and test a system dynamics model.
The model aims to reproduce the Reference Behaviour Patterns (RBP) of the roadwork construction
sector as it pertains to buildings that will be reused, recovered, and recycled into base and sub-base
materials for road construction. Once these are properly defined, it will be possible to consider how
policies and community behaviour affect the goal of using recycling to move towards zero landfill waste.
What distinguishes this research is that it introduces the modelling of cement production and consumption
values pertaining to buildings. (Ali et al., 2016) points out that cement is crucial to making concrete and
that over 97% of Libyan construction employs cement (Ngab, 2007). For this reason, the first step is to
use a Statistical analysis of cement production to make an estimate of concrete in Libyan CDW. In other
words, it can be easily determined how much cement is produced in or imported into the country; it can
also be determined how much of this goes into construction in the country; because this holds true for the
other construction materials, the composition of the CDW can be derived. Such an analysis is possible
because there are good records of data pertaining to cement use, but it is also necessary to use such an
analysis because fieldwork, that might otherwise be conducted, is not possible due to the political
situation in Libya; there is also a general lack of consistent data on the kind and quantity of construction
projects. Another way to qualify the data is by using a per capita comparison with countries that have
similar social and economic characteristics, i.e. ones that derive their primary economic strength from
petroleum exports and that have a similar cultural makeup.
Using Cement Consumption to Estimate Libyan CDW
In the 1970s, Libya was considered the highest per capita consumer of cement, averaging about six
million tons each year (Ngab, 2007). From 1992 through 2006, the consumption of cement went up
markedly from about four million tons per year to about seven million tons per year; this was because of a
large number of government construction projects. Prior to 2011, the government had initiated some
projects to increase domestic cement production, aiming at bringing it up to about 13.5 million tons by
2010 (AUCBM, 2007); Libya was in fact producing about ten million tons annually. Libya does not
produce enough cement to fulfill its own needs and therefore has imported much of this cement from
neighbouring countries, such as Egypt, Tunisia, and Turkey (Ali et al., 2016). There had been plans to
raise the levels of cement production to as much as 15 million tons before 2011; in fact, the Libyan
government had issued permits to several foreign corporations to help make up the shortfall in cement
production.
Table 2: Construction developments that were in process or that were planned up until 2010 (Ali et al.,
2016)
‘Company Project type ‘Type of cement Planned Planned ‘Production
production production started
capacity under | capacity under
study" construction”
Libyan cement Fattaih Factory | Anew production line | White 190 = 2008
Lib itFattaih Factory | A new production line | White - = 2008.
Libyan cement Fattaih Factory | A new production line _| Normal 950 - 2008
‘Libyan cement Hawari Factory ‘A new production line | Normal 1330 = 2008
‘Libyan cement Benghazi Factory | Improving production | Normal 475 = 2008
line
Ablia Cement Factory Zliten A new production line ‘Normal - 900 2008
Ablia Cement Factory Libdeb ‘Anew production line | Normal : 1500 2008
‘Ablia Cement Factory Koms Anew production line | Normal = 1500 2008
‘Orascom Gro ‘New factory ‘Nomal z = 2008
Total (8 projects) 2945 3900
Total of expansions: 6845
“Thousands of tonnes per year
Simulation and Policy
The Average GDP growth Rate and Fraction of GDP Going to Cement Production are critical factors in
waste generation as shown in Figure 3.0. The results are shown in Figure 3.1, expressed as the following
equation:
Fconcret= Pconcret*(1+A GDP) * (1+A Population)
Where:
Fconcret= future production of concrete waste, Pconcret=Present production of concrete waste.
20 million tons
per year
Annual cement
Average GDP production
growth Rate
Fraction of GDP Going
to Cement Production
Average
GDP
Net Change in
Average GDP
Figure 3.0 shows the relationship between Annual Cement Production, Average GDP, and the
Fraction of the GDP that goes to cement production.
Current
Annual cement production
go Mt
=
Average GDP
Fraction of GDP Going to Cement Production
2010 2020 2030
Time (Year)
Figure 3.1 shows the output of the scenarios between Annual Cement Production, Average GDP,
and the Fraction of the G DP that goes to cement production.
_
Effect of the Waste to Roads Demand for
Waste va Recycling
Ratio of Waste
pe to Initial
ees ‘Available ZZ
x
\ ma Waste = Landfill
Available Designated Waste
New Waste Generatio
[Cement in} From Different A
pei verage Time for
New Conticton NE Sante of Waste Going to
of Buildings. | *——_ Buildings d — ‘Landfills
aan Anmeal Avena life of Average Building
emen ~
Fraction of GDP Going Production acai a= /Genemtion
to Cement Production —
Average GDP
growth Rate
Net Change in
Average GDP
Figure 3.2 Shows the Model Benchmark for CDW Management and the Flows and Stocks with the
Important Factors
The data will be aggregated so that the model remains usable. As such, all recyclable materials will be
counted together; the population and degree of urban development will determine the total user base; for
the purposes of the model, this user base is assumed to be as active as possible given the facilities
available. If such aggregation affects the results of the model, it is hoped that it is minimal and that the
trade-off is reasonable, considering the scope of the project.
Figure 3.3 Results for Landfill Waste, Annual Cement Production, and Waste to Roads Recycling.
400M _ ton/Year
to
100M_ ton
2 ton/Year
3B ton
0 ton/Year
0 ton
0 ton/Year
0 ton
5 T 20 25
‘Time (Year)
rnnual Cement Production : C ton/Y ear
Available Waste ton
Waste to Roarls Recy ding :C ton/Y ear
Waste in Landfills : C
Awailable Waste
ton
"
ie]
6
g
Landfill Designated Waste
N
too ear
eh
000
RRRE 6 £8
New Waste Generation Prom Different Resources
Waste to Roads Reewcling
OnN-A
o
10 20
Time C¥ear)
Validation and Verification
Validation and verification gets easier as the model develops because these factors build on each other.
These can be summarized into three categories, each of which includes highlights of the validation efforts
that were conducted. Validation in this study relies on three things: 1) verifying that the units that are
input into the model are correct; 2) comparing the results with successful previous studies, for example
(Bala, 2017;Mashayekhi, 1993), 3) Using one specific building, the specifications of which are discussed
below. The present study successfully executed the first two validation steps.
Conclusion
The general trend is that, as the income of a community grows, this leads to the increase in building
projects, and CDW. Around the world, there are a number of different methods of disposal; the most
common are landfilling and open dumping. Landfilling is very common in industrialize countries but
open dumping is the most common in countries like Libya because there is little to no cost associated
with it and it usually does not have any governmental organization. In this case, the outskirts of urban
areas and natural geographic areas such as valleys are used for this. If recycling is ever to be
economically attractive for many small governments, there must be a recovery phase, wherein useful
materials can be extracted, and subsequently used in the base and sub-base for future roadwork
construction.
Figure 3.3 shows the results of the model illustrating how the Landfill-Designated Waste increases
steadily over time. The behaviour of the Annual Cement Production shows the same results; this is an
important indication and implies that there is a significant relationship between Annual Cement
Production and Landfill-Designated Waste. This will help the stakeholders make a suitable strategic plan
for recycling CDW. As shown in figure 3.1, in 2005, the first year shown in the simulation, Libya had an
annual cement production of about two million tons; in the same year, it had an annual GDP of US$100
billion; because the GDP growth is related to population growth, with a population estimate for 2030 of
about 7 million people, the GDP is about. The construction sector in cities is tied to the grown rate of the
GDP; the migration of populations into cities also stimulates construction. The outcome of more
construction is the use of more cement, and the production of more waste. Therefore, more waste
management infrastructure is needed. Without recycling and reusing waste, there are two primary
environmental effects: a scarcity of natural resources; landfill sites being clogged.
There is a growing crisis in Libya with regard to CDW because many cities are affected. This is a
particular problem because there is a lot of CDW that still has not been collected from the 2011
revolution. There has also been a lot of economic growth since then (especially in 2012), and this
inevitably leads to more CDW. This problem is not only a problem for Libya but also for similar
countries, such as Syria and Iraq. The present model can be used to help solve this problem, and includes
aspects such as Life-Cycle Cost Analysis (LCCA).
References
Bala, B. K., Arshad, F. M., & Noh, K. M. (2017). Stock and Flow Diagram. Dans System Dynamics (pp.
53-118). (S.1.) : (s.n.). https://doi.org/10.1007/978-981-10-2045-2 4
Marzouk, M., & Azab, S. (2014). Environmental and economic impact assessment of construction and
demolition waste disposal using system dynamics. Resources, Conservation and Recycling, 82, 41-
49. https://doi.org/10.1016/j.resconrec.2013.10.015
Mashayekhi, A. N. (1993). Transition in the New Y ork State solid waste system: A dynamic analysis.
System Dynamics Review, 9(1), 23-47. https://doi.org/10.1002/sdr.4260090103
Nazirah Zainul Abidin. (2010). Sustainable Construction in Malaysia — Developers ’ Awareness.
Proceedings of World Academy of Science, Engineering and Technology, 5(2), 122-129.
Ngab, A. S. (2007). Libya - the Construction Industry — an Overview (pp. 201-209). Karachi, Pakistan :
CBM-CI International Workshop.
