Sustainable materials selection in industrial construction: A life-cycle based approach to compare the economic and structural performances of glass fibre reinforced polymer (GFRP) and steel

In recent years, Glass Fibre-Reinforced Polymers (GFRPs) have shown positive characteristics in terms of both environmental and structural performance, thus proving to be promising materials that can be used in construction to replace traditional materials, such as steel. Regarding environmental performance, the use of GFRP instead of steel can lead to a significant reduction in energy consumption and CO 2 emissions, thus containing the environmental impact during their life cycle and contributing to the energy transition. From a structural point of view, the high corrosion resistance and durability of GFRP structures minimise maintenance requirements and greatly extend their lifespan, which can even be considered unlimited, even in terms of reusability. This paper jointly evaluates for the first time the structural performance and economic viability of industrial constructions made from GFRP pultruded profiles. These performances are then compared with that of equivalent steel constructions. This is done through a standardised and exportable model based on life cycle cost (LCC) which is developed in four phases: (1) technical-mechanical properties and structural analysis of the buildings; (2) modelling and cost estimation; (3) evaluation of the LCC indicator; (4) performance comparison of design alternatives. The elaborations show that industrial GFRP structures, while having a higher investment cost than equivalent steel constructions, can guarantee lower maintenance costs in the long run. Interesting quantitative results are: (i) the construction cost of the GFRP structure exceeds that of the steel structure by about 15%; (ii) maintenance costs are much higher in the steel structure than in the GFRP structure, due to the greater susceptibility to corrosion of structural steel; (iii) in relation to its very high durability, the residual value of GFRP structures coincides with the construction cost, while the residual value of steel structures decreases significantly; (iv) the composite structure has a Global Cost less than 26% of that of the steel structure, being the most economically advantageous alternative considering the costs related to the whole life cycle, also confirming itself as a fairer and more accessible alternative. The proposed Life Cycle Cost-based model can find multiple applications in the field of civil engineering as a valid support for the selection between alternative structural materials, useful for the transition to a more circular, just, and sustainable construction industry.