Treatment of Uncertainties in the Semi-Probabilistic Design of Precast Concrete Structures with Reclaimed Elements

The construction industry contributes to a significant proportion of the global annual car-bon emissions. To aid in mitigating the negative carbon implications and extend the lifetime usability of concrete components through circular design, the ReCreate project aims to investigate the deconstruction of precast concrete buildings and the reuse of reclaimed structural elements in new designs. In conventional concrete design and code specifications such as EN1990:2002, full and semi-probabilistic methods are available to estimate the reliability of structures. In the case of reuse, however, materials have aged, developed, and plateaued over decades of service, altering the constitutive assumptions underlying many design methods. Essential resistance model considerations include the mechanical properties of the concrete and reinforcement steel, reinforcement layout, geometrical properties, degradation mechanisms, serviceability damage, and bond integrity. Varying levels of information from the original design will be available, including undocumented alterations performed during construction or renovation stages. Several variables, such as element geometry and material resistances, can be determined more precisely through post-deconstruction testing and inspections. To understand the implications of material variability in reclaimed precast concrete elements, this paper first provides an overview of existing probabilistic theory and material safety factors for conventional designs, with particular reference to Eurocode 2. An inventory of the relevant variables affecting the reliability of reused elements is presented and discussed. Finally, the reliability of non-destructive testing on reclaimed and in-service rein-forced concrete elements is discussed.