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Though research on FRP reinforcement has led to the development of several design recommendations over the past 25 years, recent efforts have focused on the development of unified design procedures and models that can account for the effect of both conventional steel and advanced FRP reinforcement. Examples of such efforts are testament to the level of maturity reached by this novel reinforcing solution and will facilitate a more widespread adoption of FRP reinforcement. The relatively lower modulus of elasticity of FRP materials compared to steel reinforcement may lead to large strains, crack widths and deflections, and as a consequence the design FRP reinforced concrete structures is often governed by serviceability requirements. This paper outlines the principles underlying the recommendations for the serviceability limit state design of FRP reinforced concrete structures included in the next generation of Model Code, discussing merits and limitations as well as comparing to other relevant proposals., Support provided by Spanish Ministry of Science and Innovation (MCIN/ AEI) and by European Funds for Regional Development through projects PID2020‐119015GB‐C22, RTI2018–097314-B-C21 and PID2021-123701OB-C21 is acknowledged., Postprint (published version)

There is a need to develop innovative repair materials which can overcome the challenges of cement-based repair mortars being relatively prone to shrinkage effects. In practice, free shrinkage of repair mortar is often considered as an indicator for potential cracking and delamination of applied repair mortars due to restrained shrinkage effects. As it is hard to measure restrained shrinkage directly, a restraint factor (R) can be used to correlate both. This study investigates the shrinkage characteristics of strain-hardening cementitious composites (SHCC), making use of polyvinyl-alcohol (PVA), high-density poly-ethylene (HDPE), or short glass fibres, for the repair and strengthening of existing concrete structures. Along with drying shrinkage and autogenous shrinkage, restrained shrinkage has been characterized with respect to the concrete substrate. Furthermore, pull-off tests were performed to assess the bond properties of these repair mortars. The results show around 65% higher autogenous shrinkage in high strength SHCC mixes while there was a decrease in drying shrinkage compared to the reference mix. In contradiction to what was initially expected, an increase in fibre content from 1.5 to 2.0 vol% resulted in a significant increase in autogenous shrinkage, especially in the high strength SHCC mixes. The restraint factor for all repair mortars was determined and was found to be in the range of 0.82–0.94. The pull-off tests showed an overall excellent bond behaviour of all studied mortars., Concrete Structures