Report

Teaser, summary, work performed and final results

Periodic Reporting for period 1 - ReSHEALience (Rethinking coastal defence and Green-Energy Service infrastructures through enHancEd-durAbiLIty high-performance fiber reinforced cement-based materials.)

Teaser

The main goal of the project ReSHEALience is to develop an Ultra High Durability Concrete (UHDC) and a Durability Assessment-based Design (DAD) methodology for structures, to improve durability and predict their long-term performance under Extremely Aggressive Exposures (EAE:...

Summary

The main goal of the project ReSHEALience is to develop an Ultra High Durability Concrete (UHDC) and a Durability Assessment-based Design (DAD) methodology for structures, to improve durability and predict their long-term performance under Extremely Aggressive Exposures (EAE: XS-chloride induced corrosion, XA-chemical attack). The improvement will be supported upgrading Ultra High Performance Fiber Reinforced Concrete with new functionalities. Focus will be on marine structures and infrastructures for geothermal/biomass energy plants, whose severe conditions challenge the performance, lead to quick deterioration and shorten the lifespan, resulting in billions Euro spent each year in repairs.
This goal will be achieved through the following specific objectives (variations compared to current high performance reinforced concrete):
- Tailoring UHDC to target a 100% enhancement in material durability and upgrading experimental methods to measure its durability in service conditions (cracked state) and validate an enhancement of at least a 30%.
- Proposing new design concepts DAD, for the use of UHDC and assessing the structures durability and Life Cycle Analysis with a 95% confidence level, to achieve an increase service life of 30%, and a long-term reduction of maintenance costs by at least 50%. This will be validated also through long-term monitoring in six full-scale proofs-of concept that UHDC in real conditions.
- Developing a theoretical model to evaluate ageing and degradation of UHDC structures in EAE with a 75% accuracy, extending the modelling to predict the lifespan, validating the predictions against the monitoring of the pilots.
- Developing a Business Plan per each industrial partner analysing the market sectors where the developments will be exploited.
- Informing a high number and variety of stakeholders through several tailored communication and dissemination activities.
The competence garnered by all the partners will put them in the forefront of the civil engineering field in order to provide sustainable solutions for the most challenging needs of our society.

Work performed

The project has now just concluded its first M18 reporting period (01-01-2018/30-06-2019). The main results achieved are, with reference to the SOs:
- Analysis of current design practice for r/c structures in EAEs and identification of where the implementation of innovative material and structural design concept could bring substantial advantages to the design, construction and management of the structure portfolio of beneficiaries;
- definition of the main target indicators for both fresh- and hardened-state properties of UHDCs to be employed in the prototypes as well as for direct and indirect durability indicators for the verification of the KPIs;
- adaption of the production techniques of functionalizing nano-constituents to UHDC production, including scalability to large volumes and verification of their compatibility and performance into EAE;
- definition of the composition and identification of the tensile constitutive relationships of the UHDC mixes (including TRC based ones) to be employed in the design and construction of the pilots, including their adaption to different application technologies and preliminary assessment of the experimental scattering in industrial level production and its effects on the values of material partial safety factors;
- experimental testing the durability of the selected UHDC in the un-cracked state and verification of the achieved target 100% enhancement and definition of methods and preliminary assessment of long-term durability performance UHDCs in the cracked state, also focusing on the self-healing capacity of the materials to maintain the “design-wise” anticipated level of performance in the intended structural service scenarios;
- definition of the DAD methodology framework, to quantify the service life from the evolution curve of the performance against the intended limit state as the time when a certain pre-defined safety margin against the design actions is no longer guaranteed. The comparison between curves built for conventional HPC as well as for the UHDC solutions developed in ReSHEALience will allow to quantify the achieved at least 30% increase in service life;
- implementation of a self-healing modelling approach based on internal variable concept into a discrete modelling framework for cementitious composites and validation of the approach against experimental results for ordinary concrete;
- design of the six pilots, including their monitoring plan, and completion of authorization procedure for their construction in the intended locations
- definition of a common framework for LCA/LCC/SLCA for the analysis of the six pilots;
- organization of 2 one-day industry oriented events, achievement of 344 subscribers to the newsletter, participation and paper presentation into 5 international thematic conferences and publication of related papers (2 scopus indexed, 2 open access); participation with a dedicated booth corner into 5 fairs and communication of the project initiatives and contents into 50 different other events, including 8 technical training courses for professional engineers; starting 8 PhD theses and completion of 5 MSc theses.

Final results

The inter-disciplinary concept of the project moves from stakeholder needs to solve problems of non-efficient use of resources in the structural design and construction of selected applications. The project concept moves from a prescription-based to a performance-based material and structural durability concept. The use of UHDC is meant as a driver to shape this conceptual approach through the following advances with respect to the current SoA:
• A breakthrough durability-based material concept and design in which durability is not a bonus but becomes the governing objective, transforming cement-based construction materials from “durability passive” spectators, with structural functions, into active players able to govern aging and degradation processes also through the use of “tailored” value-added synergy-acting functionalities;
• A robust design-oriented durability evaluation and modelling activity in real service conditions, scaling up the modelling to real scenarios, including probabilistic and fuzzy-based incorporation into DAD approach of self-healing concepts, through the concept of “healable crack width”, as a function of material compositions and exposure scenario;
• A holistic design approach, which moves from the material to the structural durability level, able quantify the increase in the service life of structures made of UHDC, and the related outcomes in terms of LCC and SLCA. The proposed holistic approach for the design and assessment of UHDC structures has to be intened as a KET for large scale marked diffusion of UHDCs and increase innovation uptake of construction industry, dismantling the concept of advanced cement based materials as luxury products.
The demonstation provided by ReSHEALience through the six different pilots, which will be designed, built and monitored, even after the project end, under real site conditions, will provide a clear demonstration of the true performance of materials, products and structures aiming at overall resilience of engineering applications, which encompasses material robustness, structural and material redundancy and resourcefulness and rapidity, through synergy between material functionalities and tailored design.

Website & more info

More info: http://www.uhdc.eu.