Dynamic characterization of full-scale structures made with recycled coarse aggregates

Abstract

The incorporation of recycled aggregates produced from concrete waste is an option that could reduce the consumption of natural resources and landfill disposal, with significant environmental gains. Several investigations have been conducted to study the viability of this use of concrete waste, with a focus on the material, mechanical and durability related behaviour of recycled aggregates concrete. The structural behaviour has not been properly studied to date, despite some investigations already performed on two-dimensional scaled-down frame structures and on concrete elements, like beams and column–beam joints. To encourage the use of recycled aggregates concrete, the authors conducted experiments on four full-scale recycled aggregates concrete structures with various recycled aggregates incorporation ratios. Here, the dynamic characterization tests made on the structures are described and analysed. The concrete Young's modulus of finite elements models of the test-structures was calibrated with data from the tests, namely the natural frequencies associated with each modal shape. It was proven that the pattern of response of the different structures was the same and that the aggregates used had a relatively small influence on the Young's modulus. One of the concrete mixes included a superplasticizer and the use of this admixture resulted in a concrete structure with higher stiffness than all the other mixes, including a reference mix with no recycled aggregates. To the authors' best knowledge, this is the first study regarding the dynamic behaviour of full-scale recycled aggregates concrete structures and the dynamic properties of recycled aggregates concrete.