CONVOCATORIA: 2021 PROYECTOS DE I+D+I PARA LA REALIZACIÓN DE PRUEBAS DE CONCEPTO
Programa Estatal de Generación de Conocimiento y Fortalecimiento Científico y Tecnológico del Sistema de I+D+i y Programa Estatal de I+D+i Orientado a los Retos de la Sociedad
Keywords: metakaolin, coal bottom ash, natural stone filler, fibre reinforced concrete, self compacting concrete, curing conditions, precast element, BIM tool
The durability of a concrete infrastructure is defined by its ability to sustain reliable levels of serviceability and structural integrity in environmental exposure which may be harsh without any major need for repair intervention throughout the design service life. Conventional concrete has relatively low tensile capacity and ductility, and thus is susceptible to cracking. Cracks are considered to be pathways for harming substances, which lead to the early onset of deterioration processes in the concrete or reinforcing steel. In the view of increasing cracking of structures, researchers invented a method named as self-healing to overcome concrete structure deterioration.
Autogenous healing is one of the possible strategies for self-healing. In this technique, the presence of water is vital for proceeding chemical reactions. In HACCURACEM (previous research project) it was seen that the use of internal curing agents, that act as water reservoirs is a good option to promote this healing technique. Other engineered self-healing strategies are the used of admixtures or fibres. The use of admixtures, metakaolin and/or various types of fillers, was analised in HACCURACEM with good results although the combinations with other techniques as the use of fibres was suggested in this previous project. Therefore previous projects (HACCURACEM) was able to design sustainable high performance self-compacting concretes based on low clinker cements with internal curing agents to increase its useful life. This project was developed at the laboratory level and allow the researcher to get the TRL3 level in this field.
Therefore, based on these previous results, this project (PREHEALING) aims to prove the efficiency of using fibres as restraining agents combined with the internal curing aggregates and low clinker cementitious systems in real scale precast concrete elements to define the best curing conditions and promote the use of these sustainable fabrication strategies in the precast industry. All the elements will be implemented in BIM tools. This will lead the technology to a TRL4 level. Considering that there are various companies that have shown interest in the proposal (letters of intesest of Construcciones Lopez Cao, SL; Misturas SA; Extraco, SA, Prefhorvisa Outeiro, SL and K2 Estudio de Ingeniería SL) it is expected to probably get the TRL5.
The main objective of the project is to prove the efficiency of using fibres as restraining agents combined with the internal curing aggregates and low clinker cementitious systems in real scale precast concrete elements to define the best curing conditions and promote the use of these sustainable fabrication strategies in the precast industry
- To prove the efficiency of the different strategies separately and together at the material scale checking the suitable behaviour at fresh state and hardened state (specially shrinkage)
- To prove the efficiency of the healing strategies separately and together at real scale using a concrete element with a high surface to volume ratio (partition wall prototype)
- To prove the efficiency of the healing strategies separately and together at real scale using a concrete element with a low surface to volume ratio (beam prototype)
- To employ BIM methodology in the development of the concrete elements and to finally model them as parametric objects that can be used by the engineers in the building design.
- To disseminate the results to the society and to the industry, specially to the precast industry so as to promote the use of the modelled elements.
The tests (material scale and real scale) will be done using two different external curing conditions.
Methodology and implementation plan