Suchergebnisse

The following are available online at http://www.mdpi.com/2071-1050/12/24/10278/s1: Excel file with input data for the parametric numerical study ; Recycled aggregate concrete (RAC), i.e., concrete produced with recycled concrete aggregate (RCA) has been heavily investigated recently, and the structural design of RAC is entering into design codes. Nonetheless, the service load deflection behavior of RAC remains a challenge due to its larger shrinkage and creep, and lower modulus of elasticity. A novel solution to this challenge is the use of layered concrete, i.e., casting of horizontal layers of different concretes. To investigate the potential benefits and limits of layered concrete, this study contains a numerical parametric assessment of the time-dependent sustained service load deflections and environmental impacts of homogeneous and layered NAC and RAC one-way slabs. Four types of reinforced concrete slabs were considered: homogeneous slabs with 0%, 50% and 100% of coarse RCA (NAC, RAC50 and RAC100, respectively) and layered L-RAC100 slabs with the bottom and top halves consisting of RAC100 and NAC, respectively. In the deflection study, different statical systems, concrete strength classes and relative humidity conditions were investigated. The results showed that the layered L-RAC100 slabs performed as well as, or even better than, the NAC slabs due to the differential shrinkage between the layers. In terms of environmental performance, evaluated using a "cradle-to-gate" Life Cycle Assessment approach, the L-RAC100 slabs also performed as well as, or slightly better than, the NAC slabs. Therefore, layered NAC and RAC slabs can be a potentially advantageous solution from both structural and environmental perspectives. ; This study has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement no. 836270 and from the United States Department of State through the Fulbright Visiting Scholar Grant "Optimization of Stratified Recycled Concrete Structures Based on Numerical Analyses and Life Cycle Assessment." Any opinions, findings, conclusions, and/or recommendations in the paper are those of the authors and do not necessarily represent the views of the funding organizations. ; Peer Reviewed ; Postprint (published version)