Objective. In this paper, we give an overview about a new LCA method for infrastructure development. The objective of the method is to introduce the idea of LCA to decision-making systems of infrastructure development. By applying LCA in each decision-making procedure, environmental loads are thought to be reduced efficiently and wholly.
Results and Discussion. The method and the inventory database have the following characteristics:（1）covering all the related activities,（2）based on material quantities,（3）having clear evidence,（4）categorizing emission coefficients from perspective of those concerned with infrastructure development,（5）able to reflect site oriented data, and（6）updated annually. Several estimations of CO2 emissions for construction technologies showed that the developed method calculates almost all of the CO2 emissions using the appropriate emissions coefficients. Applying the developed method, we find significant and efficient way to reduce environment loads.
Conclusions. The developed method has good applicability except the following cases:（1）taking into account the environmental loads in using phase of infrastructure,（2）reflecting site conditions unexpected at decision-making moment. We must take care with emissions factors of steel and cement. The emissions factor of steel can change if we adopt “multi-step-recycling-scenario”. The CO2 emissions of cement can change if we consider the effect of CO2 uptake by cement hydrate.
The construction industry is essentially an industry with a high degree of locality. Socioeconomic infrastructure realized through construction activities has generally been developed by local people using local materials. Globalization has promoted internationalization in the construction industry as elsewhere, however the basics of the construction system have remained unchanged. What makes this possible is the existence of concrete as a construction material. Its primary component materials are aggregate, cement and water, with aggregate constituting approximately seventy percent of the total volume. Concrete is thus made from the most abundant substances on Earth, and this is one of the main reasons why its production has been able to expand to respond to growing construction demand. Concrete is nowadays the second most consumed substance on Earth after water. To state the case in extreme terms, we might say that contemporary society could not exist without concrete, and it is no exaggeration to say that the development of a nation has been directly proportional to the consumption of concrete. There are two problems concerning concrete and steel, which are necessary for the development of socioeconomic infrastructure. One is that, despite an abundant availability of their material resources, the volume of consumption is enormous. Another is that the production of cement and steel generates a large amount of carbon dioxide, known to be a greenhouse gas. However, there are no alternatives to concrete and steel as basic materials for the development of socioeconomic infrastructure. Mankind thus has no choice but to continue utilizing concrete and steel, while a significant increase in material consumption as well as the resulting carbon dioxide emissions due to growing population and socioeconomic expansion will most likely become a strong factor in hampering sustainable global development. As the concrete and construction sectors are expected to have such a great impact, they are required to precisely understand the degree of their involvement, and strive for reduction of their environmental load. In fact relevant research and study activities have intensified in recent years. The authors take pride in leading such activities both in Japan and overseas. Specifically, in the Japan Concrete Institution（JCI）, we have been engaged in researches conducted by the technical research committees on concrete related to the environment, and are presently focused on researches with the sustainability committee. In the Japan Society of Civil Engineers（JSCE）and the Architectural Institute of Japan（AIJ）, we have published guidelines regarding the environment and construction in concrete respectively. Internationally, the authors take a leading role in the Commission 3 of the International Federation for Structural Concrete（fib）, Concrete Sustainability Forum of the American Concrete Institute（ACI）, Sustainability Forum of the Asian Concrete Federation（ACF）, and TC71/SC8（Environmental management for concrete and concrete structures）of the ISO. In this article, the authors give an outline concerning environmental assessment tools, activities of international associations, and the present state of development of environmental standards, in relation to efforts concerning global environmental issues with respect to concrete, an enormous amount of which is used for the development of socioeconomic infrastructure.
Objective. Provision of social capital may bring large-scale change in a socio–economic system. Therefore, the system boundary of LCA for infrastructure should be larger than that for general products. “Extended Life Cycle Environmental Load (ELCEL)” is a concept for evaluating changes in comprehensive environmental impacts of infrastructure projects. However, uncertainty of the results increases when the boundary of evaluation is extended because it contains some uncertaint data given by forecast models. In this study, a framework for setting the system boundary and analyzing the uncertainty of the LCA results for a transport infrastructure project is proposed. Results and Discussion. The system boundary is set step-wise, as follows, 1) “System Life Cycle Environmental Load (SyLCEL)” that includes infrastructure’s lifecycle and the activities using it, 2) “ELCEL-1” that includes SyLCEL and another competitive traffic mode, and 3) “ELCEL-2” that includes ELCEL-1 and alternative route. Life Cycle Inventory (LCI) shows the difference between the results of SyLCEL and ELCEL. In a case study for Light Rail Transit (LRT), changes in car traffic conditions and route choices after LRT provision are considered by ELCEL. A sensitivity analysis shows a demand shift from vehicle to LRT in the LCI result. However, this data contains uncertainty caused by the forecast. Uncertainty analysis shows that the result may change if these data have a wide range of errors. Conclusions. The result of LCI for infrastructure depends on the system boundary setting. It is also important to conduct an uncertainty analysis to improve the reliability of the LCA result. If the uncertainty of LCI results is very large and is caused by the errors of input data, two countermeasures can be employed. One is conducting additional research to decrease the uncertainty of input data. However, in cases where additional research is not possible or effective, it is necessary to determine whether the inclusion of uncertaint data in the analysis must be avoided to ensure high reliability of the result.
Objective. In Japan, we built a large amount of infrastructures at the high economic growth period. Currently, they’re up for renewal time, therefore it’s anticipated that the costs of those maintenance management and renewal increase rapidly. There are threats of functional decline and serious accident in these dilapidated infrastructures. Moreover, when building construction work, it’s necessary to consider some social influence such as noise, vibration, and construction delay. National Institute for Land and Infrastructure Management advances development of “Strategic Stock Management Method”. Then, in gas utility, Ministry of Economy, Trade and Industry introduced risk management method in the guideline for aging pipes. They presented that setting priorities is indispensable for measures. So, the needs of efficient and appropriate infrastructure stock management rises. The purpose of this study is to propose the measuring method for maintenance management and renewal of infrastructures. Results and Discussion. First, we account the initial construction cost, the maintenance management cost and the risk cost for combined sewerage pipes. At that time, the costs are separated into two pieces (internal costs and external costs), and accounted during the life cycle with area characteristic in mind. Internal costs are actually-occurred, and external costs are negative impacts of surroundings in construction. Then, these costs per year are added up, and to clarify minimized years. Therefore, we estimate appropriated renewal time considering breakage risk and social costs (internal costs plus external costs). As the result, the renewal time has been extended when consider social costs, compared to only internal costs. Thus, the appropriate renewal time is different considering not only internal costs but also social costs and risk. Conclusions. Taking into account the social costs of construction in every region, that the results were compared to extended periods of evaluation and update only the internal cost. The major areas are shown quantitatively that the risk needs to be updated quickly than other areas. From the above, as well as internal cost of construction was found that the difference comes into play when considering the best term update the social costs and risks.
Objective. When we excavate a road for burying gas pipes, excavated soil is generated. City gas companies make efforts 3Rs（Reduce, Reuse and Recycle）for excavated soil aimed to establishment of a sound material-cycle society. In this paper, I introduce the case study of life cycle environment impact assessment of gas pipe burying works based on LIME2.
Results and Discussion. The following results were obtained
1） Environmental load of trenchless method is the smallest in all 3Rs construction methods which were evaluated in this study.
2） Although use of recycled materials（recycled base course materials, recycled asphalt and improved soil）have a large impact in terms of CO2 emissions compared with virgin materials（pit sand etc）, damage cost（integration result）of use of recycled materials are smaller than that of use of virgin materials.
3） A combined 3Rs methods for gas pipeline works is effective to reduce environment impact. Damage cost of combined methods is as low as that of trenchless method.
Conclusions. These results showed that promotion of 3Rs in gas pipe burying works contributes to the prevention of global warming and the conservation of biodiversity. Furthermore, improvement in the assessment of biodiversity, for example, impacts of excavated soil dumping on the ecosystem is expected.
As environmental consciousness has been expanding on a global scale, the railway has drawn attention as the environmentally-friendly transportation system. However, it has been generally discussed only in terms of the operating stage. It is necessary to evaluate the environmental impacts through their whole life cycle. This paper aims to construct a methodology for evaluating the total environmental load of railway systems from the construction to disposal by the application of the life cycle assessment（LCA）. It also considers extended life cycle environmental load（ELCEL）, which includes the effects of the environmental load reduction by decreasing alternatives to railway lines such as car traffic. This method is available for the environmental evaluation of new railway projects in the planning phase.
Following the disaster in Northeast Japan, it is important to obtain an estimation of the scale of lost buildings and infrastructures’ material stock. Therefore the amount of materials necessary for future reconstruction as well as the subsequent waste flow generation could be estimated and, more importantly, proper policies could be proposed for the recovery of stricken areas. In this study, from detailed residential maps, we built a material stock database throughout Japan. And, by extracting material stock with the area affected by the tsunami, we built a lost material stock database. The amount of material stock in the area hit by the tsunami was calculated to be about 29 million tons. Superstructure of buildings is about 10 million tons, and the foundation of buildings is about 19 million tons. The problem lies in the amount of debris, and also the amount of materials in the ground. In this paper, lost material stock of each municipality, and the distribution of lost material stock in Ishinomaki and Higashimatsushima are described.
Objective. This study estimates the carbon footprint（CFP）of conventional rice（variety: Koshihikari produced in Toso area, Chiba Prefecture）. This estimation compares CFP calculation results of Toso area, Chiba Prefecture, with those of specially-cultivated rice in Shiga Prefecture, which have already been reported, and discusses the cause of the difference between them. In addition, the effects of decreasing the number of times the rice is cooked and the heat retention time of the cooked rice on CFP are considered from the viewpoint of environmental conscious behavior.
Method. The functional unit is adopted to express CFP per emission per kilogram of white rice. The lifecycle of rice is classified into five stages, each of which is further divided into seven processes, and CFP is calculated as the total amount of CO2eq emitted from each process.
Results and Discussion. The estimated result of conventional rice CFP was 1,985.7g-CO2eq/kg. Followings are the CFP results obtained for the five lifecycle stages: the raw materials procurement stage: 1467.8 g-CO2eq（component ratio: 73.9%）, the production stage: 43.4g-CO2eq（2.2%）, the distribution and selling stage: 229.8 g-CO2eq（11.6%）, the operation and maintenance stage: 232.7 g-CO2eq（11.7%）, and the disposal and recycling stage: 12.0 g-CO2eq（0.6%）. Most of the CO2 is emitted from the rice farming process of the raw materials procurement stage, especially from the nitrogen chemical fertilizer usage and the methane from paddy fields, which accounts for about one-third of the total conventional rice CFP.
Conclusions. Comparing the CFP of conventional rice in Toso area to that of specially cultivated rice in Shiga prefecture, both the varieties have almost the same values except for CO2 emission from the raw materials procurement stage（CFP of Toso rice is slightly higher than that of Shiga rice）. Therefore, it is important to adopt an environmental conscious cultivation procedure in Toso area, as followed in Shiga area, to reduce CO2 emission. In addition, it is clear that the total CFP slightly declines by decreasing the number of times the rice is cooked and the heat retention time of the cooked rice.