# Life Cycle Assessment of Concrete Pavement Rehabilitation: A Romanian Case Study
## 1 Introduction  
The life cycle analysis of a product or service is a process with high applicability, making it possible to assess the flows of the materials, energy, and waste of a product over the entire life cycle of the product or service, and its impact on the environment. The analysis covers the complete life cycle of a product, process, or activity, including the production of raw materials, manufacturing, transport and distribution, use, reuse, maintenance, recycling of materials, and final disposal or destruction. According to the standard SR EN ISO 14040: 2007 [1], life cycle means \"consecutive and interrelated stages of a product system, from the acquisition of raw materials or the generation of natural resources to post-use\". The life cycle analysis for construction evaluates the impact of a structure over its lifetime. Once the lifespan has been exhausted, the environmental impact is determined by abandoning or removing the pavement structure. Therefore, the environmental impact assessment has become a key factor in the design and the construction of infrastructure works [2; 3; 4]. After disposal, the materials may be reused whole or in part, if appropriate disposal techniques are applied. This procedure is one of the keys to sustainability. The special features of the construction sector are the large volumes of materials used, the long life of the finished products; the need to consider construction as a whole, rather than to compare alternative materials; and the significant effect of longevity and the need for constructions to repair the environmental loads. A road is different from many other products in that production methods, material consumption, etc., vary significantlyboth between construction projects and within them [5; 6; 7]. A significant example may be geotechnical conditions, which may vary depending on the geographical location of the road. Due to various conditions, it was not possible to use a static life cycle assessment model. Cumulative environmental action along with traffic action during the life of the road proved to be high compared to the loads caused by the construction and the maintenance of the pavement itself [8]. On the other hand, traffic loads and road construction are weighted in different ways, so a direct comparison is not completely unequivocal. If the effect of the pavement structure on environmental and traffic actions could be estimated, it could be significant in terms of energy consumption and atmospheric emissions [9]. However, based on current knowledge, the effect of alternative constructions is extremely difficult to estimate. In the past, consideration of the environmental impact and transport sustainability issues has generally been minimal. Recently, the aggravation of environmental burdens has required an urgent reconsideration of the main environmental aspects in the design and construction of roads. According to European Commission [10] estimates, transport accounts for 32% of Europe's energy consumption and 28% of the total CO\({}_{2}\) emissions. To limit climate change and the resulting global temperature increase by below 2 \({}^{\circ}\)C, a reduction of at least 60% in greenhouse gas emissions compared to 1990 in the transport sector is needed. The most well-known and used evaluation system to determine the life cycle of the road sector is the life cycle assessment method [11]. Figure 1 shows the stages of a road, from construction to the end of the service life. Life cycle assessment is an assessment method used to analyse and quantify the impact of pavement structures on the environment throughout the life cycle. This potential impact concerns the use of non-renewable resources, population health, and environmental consequences, useful in decision-making processes for both infrastructure and traffic planning [11; 12; 13; 14; 15]. The result contains information on energy consumption and greenhouse gas emissions.