Comparative Life Cycle and Cost Analysis of Asphalt Production

This report presents a comprehensive life cycle assessment (LCA) and cost analysis of asphalt production, a crucial component in the construction industry. The study investigates the environmental impacts of asphalt pavements, addressing concerns about particulate emissions and climate change. ...Read More

ENGINEERING RESEARCH PROJECT PLANNING
By Name
Course
Instructor
Institution
Location
Date

Introduction
Asphalt pavement has remained to be a single fundamental component within the construction
industry besides providing excellent basic utility to the human race. Nevertheless, due to
economic as well as social development, a large volume of non-exhaust particulate emission
release to the atmosphere resulting in climate change all over the world. To effectively lower
such emissions, there has to be in place a strategy for the involved agencies as well as
government to measure besides assessing the released emissions (Akbarian et al., 2019). Life
cycle assessment, LCA, tends to be one of the most commonly used tools in the quantification
and assessment of the environmental effects of the maintenance and construction of pavement.
Life cycle assessment provides an elaborate and includes technique for assessment of the total
environmental effect of product that aids in ensuring the technique does not lead to unplanned
effects with regard to net increase or decrease in the effect.
In as much as International Organization for Standardization has come up with an avalanche of
standards for carrying out Life cycle assessment on product as demonstrated in ISO 14040,
conducting a life cycle assessment on a pavement could be more sophisticated in comparison
with the general consumer products (Anastasiou, Liapis and Papayianni, 2015). The life cycle for
the case of a pavement is inclusive of material production, use, construction, maintenance as well
as end of life phases. The life cycle of a general pavement is as demonstrated in the figure below.
Pavement life cycle assessment tends to be a cradle to grave tool that is used for the assessment
as well as quantification of the environmental effects from maintenance as well as construction
of pavement. Cradle to grave begins from acquisition of raw materials from the natural
environment to production of a product as well as finishing through sending back to nature the
product. Pavement life cycle assessment is able to quantify the cumulative environmental effects

that take place from all the various phases in the life cycle of the pavement. Incomplete source of
data being included for instance acquisition of raw materials, delivery of material as well as
extreme disposal of product tend to hinder the process. Hence in a bid to include the effects
during the pavement life cycle, pavement life cycle assessment furnish presents a holistic
perception of the environment parts of the product related.
Aims/Objectives
The principal objective of the study is to carry out life cycle assessment and cost analysis of
production of asphalt in the capacity of a pavement material that is used in the constriction of
highway
Figure 1: Components & phases of pavement life cycles
The figure above is a demonstration of the phases as well as components of the pavement life
cycles. Construction and maintenance of pavement is made up of five major phases among them
raw materials and production, construction, maintenance, usage and end of life. Each phase of
the pavement maintenance and construction is composed of various components with each

component illustrating the correlation between the surrounding and pavement. Such components
demonstrate the environmental effects of pavement directly. In as much as the indirect processes
are not shown the supporting processes for such processes will be included (Babashamsi et al.,
2016).
Literature Review
Pavement life cycle assessment began being used in the quantification and assessment of the
environmental effects of construction and maintenance of highways in the 1990s even though
previous researches established the application of life cycle assessment in the maintenance and
construction of pavement assessment tends to be a significantly new idea. In most cases, the
model of pavement life cycle assessment is composed of material, usage, construction,
maintenance as well as end of life even though most of the works involving construction and
maintenance of pavement does not include the main segments.
Going by Yu et al. (2012) two major components in pavement life cycle assessment models
being usage alongside traffic congestion output from maintenance and construction of pavement
are often assumed that result from large competition (Butt, Toller and Birgisson, 2015). It was
stated by Huang et al. (2009) that the delay of traffic during the maintenance and construction of
pavement may result in relatively higher consumptions of fuel as well as emisions of particulate
matter released into the atmosphere. The gaps in usage and traffic congestion phases as studied
by Zhang et al. (2010) of the life cycle of pavement require significant improvement. Such gaps
are often data sources outdate, not compete usage phase as well as end of life phase that are just
taken as end point pavement life cycle even though most high mix asphalt tends to be recycled
and old Portland cement is broken down and used again as base course aggregates

Pavement life cycle assessment is able to measure and assess every pavement life cycle phase as
well as component to greater depth. Unluckily due to time, knowledge as well as data
constraints, pavement life cycle assessment tends to be quite a challenge. Each of the
environmental assessment had to make this scope simple as well as limit the extent of their study
on the process and phases which can rationally be accomplished. Nevertheless, numerous studies
continue with the theory as well as guidelines of life cycle assessment to the greatest possible
extents in attaining at least partial pavement life cycle assessment. Documents that may be used
as the basis of research on life cycle assessment of pavement are as recommended by Santero
and Horvath (2009)
Table 1: Method, region and scope of asphalt life cycle assessment
Numerous studies reviewed in this report are inclusive of only life cycle inventories as opposed
to the life cycle impact assessment in the pavement. In as much as life cycle inventories to be
taken into consideration as differentiated research via the same guidelines of the ISO 14040
which conduct full life cycle assessment research. Five studies reviewed in this investigation
give a presentation of the published pavement LCA as well as life cycle inventories works as of
the year 2010. In particular, this review is not inclusive of the work which concentrate only on

recycle pavement materials and will concentrate on the main components of every research as a
significant assessment of the techniques features or quality (Cao et al., 2017).
Some of the common perceptions of the methods as well as scope which are included in the
pavement life cycle assessment of the reviewed literature are shown in table 1. The study shows
a summary of the pavement structures as well as pavement life cycle assessment technique which
is adopted in the analysis. Nearly all the studies conducted comparison between asphalt and
concrete pavement and linked with asphalt concrete as well as jointed plain concrete pavements
study which turned out to be most general. Such comparisons offer a description into the
commonest chosen materials that are used for construction and maintenance works of pavement.
All the studies have involved a process based life cycle assessment method which will require
detail sources of data for each single process in pavement life cycle. The reviewed pavement life
cycle assessment is obviously focusing on various kinds of pavements having different
methodologies as well as geographical scope that entail huge implications to their system
boundaries as well as doubt in their outcomes (Chen and Wang, 2018). The following segment of
the review would be investigative of the combination as well as discrepancies found in these
researches with regard to strengths, requirements as well as weaknesses of the existing body
toward decision making in pavement life cycle assessment.
The review is as well inclusive of the ability of the pavement life cycle assessment to make a
choice on the materials for construction and maintenance of the pavement that are most cost
effective. The pavement life cycle assessment reviewed is inclusive of adequate as well as
elaborate samples to approve the life cycle assessment as well as achieve early pavement life
cycle assessment results and sources of data which often accommodate persistent impacts

towards the same system of product (Farina et al., 2017). Nevertheless, the original pavement life
cycle assessment information is often a challenge to determine.
The chronicle of pavement life cycle assessment tends to be fulfilling with demonstrations of
early pavement life cycle assessment results with information as well as determination as
highlighted in the reviewed studies. Hence the main objective of this review is to delve into the
pavement life cycle assessment as well as offer recommendation in advance to see the
functioning of pavement life cycle assessment enhanced in the quantification and assessment of
environmental impacts.
The pavement life cycle assessment literature is examined through four major kinds of
methodologies that include functional unit equality, data quality, and equality of system
boundary as well as doubt related and surrounding metrics. Such types are of importance in
equality and assessment of the results from various researchers as well as in making certain
decision regarding environmental impacts of different life cycle phase, components as well as
types of pavement from significant part of pavement life cycle assessment.
Functional Unit Equity
A major interference of the general current pavement life cycle assessment revolves around the
deficiency of agreement regarding the functional unit in assessing the pavements which equated
and referred in pavement life cycle assessment that has been reviewed (Galatioto et al., 2015).
The parameters of the functional unit that are used in the pavement life cycle assessment for the
researches that are reviewed are as shown in the table below. Such features are composed of
general identifier for each of the functional units adopted in the literature. There are as well

parameters that are used in the determination of the functional unit that include climate,
guideline as well as relevant specification.
Table 2: Parameters of functional unit in pavement LCA
The different functional units adopted in asphalt life cycle assessment literature was the major
challenge in coming up with pavements that are most environmental friendly. The decision of the
outcomes is only applicable to the situations which were assessed in the related research. It is a
bit of a challenge making decision on the results in case various countries are involved. Three
various nations were demonstrated in table 1 (Giani et al., 2015). The research location
variability will offer discrepancy in the outcomes due to the different electricity mixes, axle load,
programs of maintenance, production practices as well as components that are specific to a
location. Hence, the outcomes of the studies from various countries are not comparable in a
manner that is straightaway.
The challenge of different functional units is due to the complexity in the nature of pavements as
opposed to deficiency in the coordination of the pavement life cycle assessment that pavements
are not easy when it comes to determination using one or more of the functional units. This is as
result of the pavement structure for instance type, thickness as well as material features of the
pavement which are strongly affected by the environmental condition, traffic features, and design
life among other project specific inputs (Liu, Wang and An, 2018). The variability of such

components creates a condition that two pavements having the same length may have different
basic characteristics.
Still, functional unit in pavement life cycle assessment having pavement structural features is not
sufficient as an input. In as much as loading transportation may be precisely discovered using
tonne-kilometers or generation of electricity using kilowatt-hour, it is not possible to put
pavement in the same functional unit (Mehany and Guggemos, 2016). Hence the wide
characteristics of pavement quite a challenge to set up one functional unit that is usage in
pavement life cycle assessment. Separate pavement life cycle assessment would need to be
establishing a sole functional unit depending on the aim as well as area of research. Thus, the
fundamental of offering description to the functional unit ought to refer to a standard set of
features which precisely describe the structure of the pavement as well as the material attributes,
the appropriate variables alongside the standard of pavement performance.
Still, adding dynamism to the functional unit for a big range of pavements to be determined
using a dynamic, uniform as well as platform of research institution. Pavement life cycle
assessment users ought to be informed of the outcomes from each research would not be
appropriate for every other research due to the different functional unit adopted. Extensive
investigation may aid in acknowledging the validity of the findings, modification of the
functional unit as well as definition of the appropriate set of activities which results are best
applicable (Moretti et al., 2017).
Comparability of System Boundary
The main objective of any life cycle methodology revolves around assessing a product or the
service life cycle life cycle through the incorporation of direct as well as indirect environmental

effects. Modelling and investigation of each phase of the pavement life cycle is limited but little
understanding of the system in research and challenge in development of appropriate sources of
data. Finally, the challenges in reviewed pavement life cycle assessment literature obtained short
sighted of pavement life cycle often investigating just for manufacturing, extraction, placement
as well as transportation of pavement material (Pasetto et al., 2017). Components as well as
phases of pavement which offer a complete pavement cycle indicating the environmental effect
really had effects by more sources than those demonstrated in the figure 1 above.
Some pavement life cycle assessment has elaborated their area of research to include traffic
delay, carbonation as well as lighting. Unluckily, there is still not enough comprehension to the
life cycle. Furthermore, pavement equality using appropriate sources of data resulted in lowering
environmental effects. Besides, previous research established the normally excluded phases as
well as elements are strongly affected to the entire environmental effects of pavement
construction as well as maintenance works (Wang et al., 2016).
For example, rolling resistance as well as traffic delay may result in more environmental effects
in comparison with the construction material and equipment and still, inadequate research taking
into consideration such elements in early stage as opposed to the final pavement life cycle
assessment stage (Rodríguez-Alloza et al., 2015). The components of life cycle in pavement life
cycle assessment are shown in table 3 in the manner they are reviewed in pavement life cycle
assessment literature. Production as well as extraction of material tends to be the only elements
defined by each of the selected research. Still, there is inadequate research conducted on
including traffic delay element in the pavement life cycle assessment. Just two researches or
studies incorporate such an element with most of the other researcher being inclusive of the
component of site equipment adopted in construction but left out the component of traffic delay.

It was revealed by Santero & Horvath (2009) that omission of use phase may result in a big error
in the assessment of pavement life cycle assessment. It is able to generate potential impact to
environmental effect of construction and maintenance works of pavement. Previous studies had
established the importance of including traffic delay in the framework of pavement life cycle
assessment. In the reviewed publication on pavement life cycle assessment, just two research
including traffic delay component in the initial stages of the construction work of pavement as
well as just one for maintenance phase.
The maintenance phase enjoys the effectives of being a significant provider to the entire
environmental effects (Santos et al., 2018). Still, there have not been attempts to make it feature
more widely or even to establish the accuracy of the option of maintenance schedules results.
Previous studies offered insights into a better instance of data input that a maintenance schedule
may be incorporated in as much as it recognized to discard the smaller as well as routine works
of maintenance for instance diamond grinding and crack sealing.
A study carried out by Santera et al. (2011) was inclusive of the use phase in pavement life cycle
assessment. The pavement life cycle assessment researches that were exclusive of use phase
turned out to be the most significant gap from the perspective of a system boundary. Going by
Zhang et al. (2010) pavement life cycle use phase was inclusive of the impacts of roughness of
pavement on the fuel economy of vehicle. The resulting correlation is not reflective of any
mechanistic segment of pavement vehicle interaction and due to the dependence on the tested
heavy trucks at non-freeway speeds; it was not best suited for modelling of freeway passenger
vehicles as well as traffic light.

Hence through the addition of just a specific phases as well as elements of pavement LCA, the
usefulness of the outcomes can be identified. None of the studies include all complete pavement
life cycle phase and the components that are omitted often offer to a great extent to the results of
the pavement life cycle assessment in such an effective manner that is transformative of the
outcomes of the research (Santos et al., 2015). There are normally limitations including access to
data as well as project scope to include each element of pavement life cycle assessment thus the
aim to get a view on the effectiveness of non-sealed parameters via assessment of accuracy. The
omitted components should be fully subjected to the public where the weaknesses are precisely
defined.
Conclusion
In as much as energy consumption is the major environmental parameter taken into consideration
in this review, there is yet to be an agreement on the elementary explanation of the
methodologies adopted. Such for instance hydrocarbon and bitumen bear an exact quantity of
feedback energy included in the energy consumption. The feedback energy should be
incorporated in each energy assessment. Most of the reviews do not offer description of the
environmental impact as a general assessment. The aim to study and examine the effectives of
environmental effects may be derived from ISO 14040. The goal is conducted through categorise
emissions as well as other environmental contributor into effect group.

A good number of the reviewed pavements life cycle assessment are best grouped as pavement
life cycle inventories as a result of some or whole omission of effect assessment process. The
pavement life cycle inventories provide relevant sources of data even though still not sufficient
for making decisions. The impacts of emissions for instance SO2, CO as well as NOx is quite
challenging to assessing prior to their classification in more specific groups for example human
toxicity, photochemical smog or formation. In spite of appropriate assessment for such impact
groups set, that requires space to separate the data for definition of pollution emission sources.
This type of data input requires relevant figures of data while discovery or need for wide
hypothesis is a challenge.

References
Akbarian, M., Ulm, F.J., Xu, X., Kirchain, R., Gregory, J., Louhghalam, A. and Mack, J., 2019.
Overview of Pavement Life Cycle Assessment Use Phase Research at the MIT Concrete
Sustainability Hub. In Airfield and Highway Pavements 2019: Innovation and Sustainability in
Highway and Airfield Pavement Technology (pp. 193-206). Reston, VA: American Society of
Civil Engineers
Anastasiou, E.K., Liapis, A. and Papayianni, I., 2015. Comparative life cycle assessment of
concrete road pavements using industrial by-products as alternative materials. Resources,
Conservation and Recycling, 101, pp.1-8
Babashamsi, P., Yusoff, N.I.M., Ceylan, H., Nor, N.G.M. and Jenatabadi, H.S., 2016. Evaluation
of pavement life cycle cost analysis: Review and analysis. International Journal of Pavement
Research and Technology, 9(4), pp.241-254
Butt, A.A., Toller, S. and Birgisson, B., 2015. Life cycle assessment for the green procurement
of roads: a way forward. Journal of Cleaner Production, 90, pp.163-170
Cao, R., Leng, Z., Hsu, M.S.C., Yu, H. and Wang, Y., 2017. Integrated sustainability assessment
of asphalt rubber pavement based on life cycle analysis. In Pavement Life-Cycle Assessment (pp.
209-220). CRC Press
Chen, X. and Wang, H., 2018. Life cycle assessment of asphalt pavement recycling for
greenhouse gas emission with temporal aspect. Journal of Cleaner Production, 187, pp.148-157

Farina, A., Zanetti, M.C., Santagata, E. and Blengini, G.A., 2017. Life cycle assessment applied
to bituminous mixtures containing recycled materials: Crumb rubber and reclaimed asphalt
pavement. Resources, Conservation and Recycling, 117, pp.204-212
Galatioto, F., Huang, Y., Parry, T., Bird, R. and Bell, M., 2015. Traffic modelling in system
boundary expansion of road pavement life cycle assessment. Transportation Research Part D:
Transport and Environment, 36, pp.65-75
Giani, M.I., Dotelli, G., Brandini, N. and Zampori, L., 2015. Comparative life cycle assessment
of asphalt pavements using reclaimed asphalt, warm mix technology and cold in-place
recycling. Resources, Conservation and Recycling, 104, pp.224-238
Liu, Y., Wang, Y. and An, D., 2018. Life-cycle CO2 emissions and influential factors for asphalt
highway construction and maintenance activities in China. International Journal of Sustainable
Transportation, 12(7), pp.497-509
Mehany, M.S.H.M. and Guggemos, A.A., 2016. Risk-Managed Lifecycle Costing for Asphalt
Road Construction and Maintenance Projects under Performance-Based Contracts. ASCE-ASME
Journal of Risk and Uncertainty in Engineering Systems, Part A: Civil Engineering, 2(4),
p.05016001
Moretti, L., Mandrone, V., D’Andrea, A. and Caro, S., 2017. Comparative “from cradle to gate”
life cycle assessments of Hot Mix Asphalt (HMA) materials. Sustainability, 9(3), p.400
Pasetto, M., Pasquini, E., Giacomello, G. and Baliello, A., 2017. Life-Cycle Assessment of road
pavements containing marginal materials: comparative analysis based on a real case study.
In Pavement Life-Cycle Assessment (pp. 199-208). CRC Press

Rodríguez-Alloza, A.M., Malik, A., Lenzen, M. and Gallego, J., 2015. Hybrid input–output life
cycle assessment of warm mix asphalt mixtures. Journal of Cleaner Production, 90, pp.171-182
Santos, J., Bressi, S., Cerezo, V., Presti, D.L. and Dauvergne, M., 2018. Life cycle assessment of
low temperature asphalt mixtures for road pavement surfaces: A comparative
analysis. Resources, Conservation and Recycling, 138, pp.283-297
Santos, J., Bryce, J., Flintsch, G., Ferreira, A. and Diefenderfer, B., 2015. A life cycle assessment
of in-place recycling and conventional pavement construction and maintenance
practices. Structure and Infrastructure Engineering, 11(9), pp.1199-1217
Wang, H., Thakkar, C., Chen, X. and Murrel, S., 2016. Life-cycle assessment of airport
pavement design alternatives for energy and environmental impacts. Journal of Cleaner
Production, 133, pp.163-171