**3.1 Approaches based on the phases of the concrete material life-cycle**

The methodology to assess the environmental impact of a material, includes the calculation of the related emissions generated and energy required in the different phases of the material life-cycle, i.e. from the extraction of raw materials to the end of the first life. Therefore, the use of the life-cycle phases of the concrete material results especially useful to analyse different contributions to more sustainable alternatives of this massive use material.

Evaluating the energy consumption and generated emissions of material alternatives allows to quantify sustainable benefits at different stages of the lifecycle. For instance, in the material production stage, alternatives can be generated to reduce the amount of cement and natural aggregates used in the concrete mix. And in the product manufacture stage, benefits can be achieved by implementing optimised design and construction procedures that reduce the amount of concrete or alternatives with less demanding maintenance interventions, or with better thermal insulation and then less demanding of heating energy. Furthermore, more durable concrete can be produced in such a way that at the end of the first life the material can be reused.

In the present section some of those different approaches are introduced (**Figure 1**).
