Activity: Membership › Membership of research network or expert group
Even though reinforced concrete (RC) is one of the most used manmade materials in the world, and adequate models exist for the prediction and design of the ultimate capacity of RC structures, the prediction of service life behaviour is still not mature enough for actual design purposes. This may lead to immediate repair needs, inadequate service life behaviour even when regulatory prescriptions for design are strictly followed, or at other times to unnecessary overdesign of reinforcement, which has negative consequences on both sustainability and economic aspects. This is amplified by development of new more sustainable cements and supplementary materials since the range of material properties needed for SLS-design is considerably wider than for ULS design. The problem stems to a more fundamental set of mutually influencing factors that clearly require further development and integration: (i) lack of proper understanding of the fundamental mechanisms involved in the processes of hydration-induced temperature, shrinkage, creep and herewith caused cracking; (ii) lack of integrative developments combining material scientists and structural engineers for the relevant concerns in research; (iii) lack of definitions/recommendations for collaborative developments of field-involved stakeholders towards better behaviour (material technologists, structural designers, contractors, material suppliers); (iv) lack of integration of experimental developments for restrained behaviour in complex reinforced systems with predictive/simulation methodologies; (v) lack of benchmarking and integration of existing methodologies for simulation/prediction of stresses and crack widths during service life, including simplified code-based approaches and advanced simulations (e.g. backed by FE method), which are able to cope with the combined effects of applied load (sustained) and restrained deformation at both early ages and in the longer term.
The TC intends to contribute to the body of knowledge regarding the above-mentioned research/industry gaps, both on material and structural level, towards a better design for serviceability of RC structures, which in turn shall contribute for an overall improved service life. The TC will join binomials of experts: (i) from material science and structural design; (ii) focused mostly in early age behavior and those focused mostly in long term performance (iii) those focused in experimental approaches and those focused in simulation, and also; (iv) from academia/research and industry.
The topic of cracking in RC structures for serviceability has been addressed in the past, but never with the integrative perspective aimed with this TC, which is expected to bring about a significant number of new insights of important benefits for researchers and practitioners.
The TC excludes extreme loading situations related to fire, cryogenic temperatures, earthquake, fatigue and blasting, for example. Cracking due to swelling reactions (e.g. alkali silica reaction, delayed ettringite formation), other deterioration mechanisms, reinforcement corrosion and any type of volume change occurring in concrete before setting is also excluded.