2. Development of LCCA and LCA

#### 2.1 Development of life cycle cost analysis

The concept of life cycle cost analysis (LCCA) has been introduced into the road engineering since the 1960s, when it was proposed by the US military and applied to the procurement of military equipment, aiming to solve the problem of deterioration of pavement performance and increase of maintenance costs at that time. The AASHTO pavement design guide of 1986, 1993, and 2002 all required the use of LCCA for the comparison and selection of the scheme, and the design specifications prepared by the National Highway Network in 1995 clearly stipulated that a complete LCCA report must be made for government investment projects exceeding \$25 million [1].

Walls and Smith [31], issued a technical bulletin on LCCA, introducing a detailed method for calculating user costs in the operating area and introducing

#### Integrated Life Cycle Economic and Environmental Impact Assessment for Transportation… DOI: http://dx.doi.org/10.5772/intechopen.86854

probabilistic methods to discuss the uncertainty of LCCA. The announcement first discusses the basic principles widely followed by LCCA and then gives the application case of traditional LCCA pavement design. Secondly, the uncertainty of input parameters is discussed, and the acceptable range of time and discount rate is provided. Thirdly, the sensitivity analysis of traditional LCCA method is discussed. Finally, it proposes the specific contents of user cost including delay cost, vehicle operation cost, and accident cost and presents the specific calculation method [2].

Delwar and Papagiannakis evaluated government and user costs of roads under a variety of road and traffic conditions, based on data from the Department of Transport in Washington. The evaluation results show that the user cost may be significantly higher than the government cost, so the user cost cannot be ignored in the life cycle cost analysis [3].

Chan et al. studied and analyzed the accuracy of LCCA decision-making and the accuracy of life cycle costs based on data and case studies from the Michigan Department of Transportation. The results show that LCCA can correctly predict and select the lower cost pavement scheme, but the actual cost is usually lower than the estimated value of LCCA. This result may be due to the inadequate consideration of specific pavement characteristics in cost estimation, so improving the process of pavement construction and maintenance cost estimation can help to realize the potential of LCCA pavement scheme selection [4].

To sum up, after 10 years of development, the analysis method of LCCA is relatively mature at present, but there is still a lack of data needed for evaluation. Since its inception, LCCA has been widely used in the road industry and has become a necessary component of road program evaluation in the United States. So far, the classification and calculation methods of owner cost and user cost of LCCA have been relatively mature, and the corresponding calculation tools have been widely used in many states of the United States [5].

### 2.2 Development of life cycle assessment

In the 1970s, the oil crisis caused widespread global interest in energy, and then the world began to see a boom in building energy consumption research. The energy consumption survey of buildings first emerged in the United States and the United Kingdom. They mainly inspect the energy consumption of existing buildings, tap their energy saving potential, and carry out energy saving transformation, which is called energy auditing [6]. Initially, researchers abroad concentrated on civil buildings and then gradually extend to all aspects of infrastructure construction. Research on road energy consumption has also appeared relatively early, and a lot of research achievements have been made and applied in practice.

Häkkinen and Mäke lä studied the life cycle of pavement in Finland based on the life cycle assessment theory. Through the analysis and comparison of common concrete pavement and stone matrix asphalt (SMA) pavement, the author thinks that in terms of energy consumption, if feedstock energy (refers to the combustion energy contained in raw materials of road construction, which can no longer be used as energy) is taken into consideration, asphalt pavement consumes twice as much energy as cement concrete pavement. If feedstock energy is not included, the energy consumption of these two pavements is equal. In terms of carbon dioxide emissions, common concrete pavement discharges 40–60% more than asphalt pavement, and the difference varies depending on the specific maintenance scheme [7].

Horvath and Hendrickson evaluated hot-mixed asphalt concrete pavement and continuously reinforced concrete pavement (CRCP) in the United States. After analysis and comparison, the author came to the conclusion that during the

that LCA method is composed of four parts: definition of goals and scope, inventory analysis, impact assessment, and result interpretation. It studies and analyzes the stages of raw material acquisition, construction, use, maintenance, and end of life, which is of great significance for promoting the ecological development of road construction. However, existing analysis isolates economic costs and environmental impacts from each other and fails to fully explore the overall impact of the product. This chapter will summarize the international research development of LCCA and LCA applied on transportation infrastructure and puts forward the idea of evaluating the whole life cycle by combining the two life cycle methods; the calculation models involved in the integrated method will also be introduced, so as to provide reference for the decision of multi-scheme comparison in road engineering

The concept of life cycle cost analysis (LCCA) has been introduced into the road engineering since the 1960s, when it was proposed by the US military and applied to the procurement of military equipment, aiming to solve the problem of deterioration of pavement performance and increase of maintenance costs at that time. The AASHTO pavement design guide of 1986, 1993, and 2002 all required the use of LCCA for the comparison and selection of the scheme, and the design specifications prepared by the National Highway Network in 1995 clearly stipulated that a complete LCCA report must be made for government investment projects exceeding \$25

Walls and Smith [31], issued a technical bulletin on LCCA, introducing a detailed method for calculating user costs in the operating area and introducing

and the popularization and application of the life cycle methods.

2. Development of LCCA and LCA

Transportation Systems Analysis and Assessment

million [1].

90

Figure 1. Product life cycle.

2.1 Development of life cycle cost analysis

production stage of materials, the energy consumption of asphalt concrete pavement is about 40% more than that of CRCP, but most of the environmental indicators of asphalt concrete pavement are better than that of CRCP [8].

3. Application of life cycle assessment in China

DOI: http://dx.doi.org/10.5772/intechopen.86854

and social benefits of cement-stabilized base [18].

that of the asphalt one [16].

pavement [20].

93

In China, research on road energy consumption is mainly carried out from a single aspect, such as production of raw materials or construction technics, but few

From the perspective of economy and energy consumption, Fusen Fang studied

Gu found that the less smooth the pavement, the higher the fuel consumption of the car. By studying the relationship between road surface smoothness and automobile fuel consumption, the author mainly discussed how to improve the pavement smoothness as a way to save energy and gain economic benefits [17].

Ye studied the fatigue and energy consumption optimization design of cementstabilized base. The multilayer elastic system theory is used to directly calculate the stress and strain of pavement structure to obtain its mechanical and fatigue characteristics. Based on this, the paper performs thickness optimization and simple energy consumption analysis and calculation and discusses the technical, economic,

Zhang started with the application effect of the old asphalt regenerator researched and produced in Guizhou province and collected relevant work efficiency quota data in the regenerated asphalt pavement project in Anshun, Duyun, and Zunyi. After comprehensive analysis and comparison, it is found that

Han made an economic comparison between cement pavement and asphalt pavement in terms of construction cost and fuel consumption, mainly comparing the price of raw materials and the cost of maintenance, and thought that cement pavement has great advantages over asphalt pavement in economy. Moreover, from the perspective of pavement operation, the author analyzed that the fuel consumption of asphalt pavement is about 10% more than cement pavement due to the phenomenon of "deflection basin" of flexible structure of asphalt

Yi et al. compiled the energy consumption calculation and environmental assessment methods for the warm mix asphalt (WMA) and half-warm mix asphalt mixture. The analysis shows that the heating of coarse aggregate and the evaporation of water consume nearly 70% energy in the process of mixing. The production temperature has a great influence on the energy loss in the process of asphalt mixture mixing. The higher the production temperature, the more the energy loss. The energy loss during the mixing process of half-warm mixed asphalt mixture is

Shang et al. used the LCA theory and method to divide the life cycle of highways into four stages: material production, construction, maintenance, and dismantling, so as to study the energy consumption and atmospheric emissions within the life cycle of highways. According to the research, the proportion of energy consumption in the production stage of building materials is about 55.7% of the total energy consumption, followed by the maintenance and repair stage 40.5%, the construction stage 5.6%, and the dismantling stage 4%. The results show that most of the highway life cycle energy consumption is the direct and indirect energy consump-

the energy consumption is different due to different seasons [19].

nearly 50% less than that of hot mix asphalt mixture [21].

tion in the material production process [22].

research focus on the energy consumption during the lifetime of pavement.

Integrated Life Cycle Economic and Environmental Impact Assessment for Transportation…

and analyzed the cement pavement and asphalt pavement with a life span of 30 years in 1984. The author believes that when the discount rate is no more than 12%, the present value cost of cement concrete pavement is always less than asphalt

concrete pavement. However, when the energy contained in asphalt itself is ignored, the energy consumption of cement concrete pavement is 8–17% more than

Roudebush compared and analyzed the cement concrete pavement and asphalt concrete pavement in the United States. The author concluded that the value of the asphalt pavement is approximately one time more than that of the cement pavement, about 90.8%. In the stage of material production and pavement maintenance, the energy value of asphalt concrete is approximately two times that of cement concrete [9]. Berthiaume and Bouchard applied exergy, an energy derivative, to study the energy consumption and environmental impact of asphalt and cement concrete pavement structure in Canada. Exergy describes the energy differences of thermodynamic equilibrium between products, which is a tool for measuring product energy and explaining energy quality differences [10].

Mroueh et al. got rid of the traditional comparison between asphalt and concrete and focused on the evaluation and analysis of the application of industrial byproducts in pavement structure. The report analyzed the environmental impact of seven pavement structures with fly ash, crushed concrete waste, and blast furnace slag as the substitutes of original materials [11].

Stripple made a comparatively comprehensive study and comparison between cement concrete pavement and cold mix and hot mix asphalt concrete pavement, including accessory facilities of highway such as vegetation, fence, sign, and so on. According to the report, the energy consumption of cement concrete pavement is higher than that of asphalt concrete pavement. For the asphalt mixtures, they both produce the same amount of energy in the stage of production, but the cold mix one increases the energy consumption due to the addition of emulsifier [12].

Nisbet et al. listed life cycle inventory (LCI) of urban roads and highways in the United States and analyzed the energy consumption of cement concrete pavement and asphalt concrete pavement, respectively. For asphalt concrete pavement, the impact of transportation factors is not obvious. When the feedstock energy of asphalt is included, cement concrete pavement requires less materials, has lower energy resources, and has less exhaust emissions, no matter for urban roads or highways [13].

Park et al. based on the method of composite life cycle assessment, combined with the Korean economy and national energy balance sheet, applied the input– output model to assess energy consumption and gas emissions from roads in material selection and production stages [14].

Zapata and Gambatese [15] found that the results of Horvath and Hendrickson [8] were contrary to those of Stripple [12]. Therefore, by using the same preset conditions as Horvath and Hendrickson, the energy consumption of asphalt concrete pavement and continuous reinforced concrete pavement (CRCP) during the material production and construction stage is analyzed to make a relatively fair comparison. The results show that CRCP consumes more energy in the material production and construction stage, of which the energy consumption of cement production is the main factor, while the drying energy consumption of mixed aggregates is the significant factor affecting the energy consumption of asphalt pavement [15].

The framework of life cycle environmental assessment is relatively complete after years of research, but there are still a lot of deficiencies in the detailed model, and the data collection is also in the initial stage. The framework and theory of LCA have been accurately described in ISO 14040/ISO 14044 series standards, but there are still many different opinions and methods in its application on road.

Integrated Life Cycle Economic and Environmental Impact Assessment for Transportation… DOI: http://dx.doi.org/10.5772/intechopen.86854
