●Research Trends and Results

Toward environmentally sustainable infrastructuredevelopment using an LCA tool
SONE Shinri, HeadKIMURA Keiko, Researcher
KANDA Taro, Researcher
SUGABAYASHI Keita, Associate Researcher
Road Environment Division , Environment Department(Key words) Sustainability, LCA, environmental load coefficient, carbon dioxide emissions, final disposal of wastes,
natural resources consumption
1. Introduction
We developed an LCA method for infrastructure(Infra-LCA). This paper introduces efforts now being
made to put this calculation method into practical use.
2. Publication of the LCA manual and the databaseof environmental loads coefficients table
The Infra-LCA manual and the database ofenvironmental loads coefficient tables are available
from “http://www.nilim.go.jp/lab/dcg/index.htm”. The
following are special features of the infra-LCA
method.
・ The environmental loads coefficients tables areclassified into three groups. Each group is used at adifferent level of decision making. The first groupis used to compare environmental loads according
to structure types at the planning level, the second
group is used to compare environmental loads
according to work type at the design level, and thelast group is used to compare environmental loads
according to material and construction machinetypes at the construction level (see Fig 1).
・ Categories of the coefficients correspond to theelement of cost estimation.
Flow of grouping
environmentalloads coefficients

Project flow

Material
Construction
selection

DesignPlanning

Total Life

Construction

MaintenanceTraffics

Embankment

BridgeTunnelCoefficient bystructure

Pavement

Excavation

CulvertSummary ofworks

Surface layer

Base course

Ditch

Coefficient bywork type

As mixture

Recycledaggregate

Road roller

Straight As

Coarse sandFiller

Estimate
standard
Coefficient ofmaterials,construction
machine, …

Figure 1. Group of environmental loads coefficients・ The environmental loads of new technologies canbe calculated under the completely same
conditions as the ordinary environmental loads.
The environmental loads coefficients cover carbon
dioxide emissions, final disposal of wastes, andconsumption of natural resources.
3. Confirming the usefulness of the calculation
method for infra-LCA
Validation of infra-LCA is being conducted by aworking group established by the Japan Society of
Civil Engineers. The working group consists ofscholars specialized in LCA and members ofconstruction consultant companies and construction
companies. The working group pointed out that theenvironment loads of miscellaneous expenses, which
are estimated by multiplying a certain ratio to cost oflabor, material or something, should not be ignored
although it is difficult to determine this using thepresent calculation method. We will closely examine
the miscellaneous expenses, and set a method ofcalculating the environmental loads if necessary.
4. Finding low-environmental loads technologies
The working group has been conducting many casestudies to find how we can reduce the environmentalloads in design and construction technologies and how
much cost will be needed to achieve the reduction
targets. Past studies show that the construction field
has many more technologies to reduce cost as well as
environmental loads than other fields.
5. Introduction of infra-LCA into practical use
Introduction of infra-LCA is undertaken in somespecific usages. One usage is the standard to designate
proposal items as environmentally recommended
items under the Act on Promotion of Procurement ofEco-friendly Goods and Services by the State andOther Entities. Besides this, the application of carbon
dioxide emissions coefficients in a technical guidelineof pavement published by Japan Road Association isplanned.