Flexural Behavior of Reinforced Concrete Beams Made with Recycled Concrete Aggregates

The reuse of Construction and Demolition Waste (CDW) to produce new materials is an effective method for reducing the negative impacts from the inadequate waste disposition, in addition to bringing economic and environmental benefits to the industry. The use of Recycled Concrete Aggregate (RCA) in concrete is a technique widely disseminated, however, using this material for structural applications is a target of distrust among professionals in the construction sector. Therefore, the purpose of this study is to analyze the influence of using RCA to replace 100% of course natural coarse aggregates with size fraction 9.5–19 mm in the flexural behavior of reinforced normal-strength concrete beams (35 MPa). In addition to a reference mixture produced with only natural aggregates, a Recycled Aggregate Concrete (RAC) mixture was designed, according to the well-known Compressible Packing Model (CPM), using RCA from demolition waste. The mechanical behavior of the concrete mixtures was characterized by compressive and splitting tensile tests. A pair of flexural critical beams of each concrete mixture was tested under a supported four-point loading condition at the age of 28 days. All tested beams had 240 cm length and rectangular cross section of 20 × 30 cm2. The experimental cracking, yielding and ultimate load of the beams were measured. Besides that, the load-strain behavior for concrete was obtained, as well as the load-deflection behavior. The results showed that the flexural behavior of RAC beams was not negatively affected by the presence of RCAs.