Influence of recycled aggregate concrete on resistance of compression members.

The volume of waste is rising worldwide at an alarming rate. The large part of it (approximately 30%) is generated by construction industry. Recycling construction and demolition waste (CDW) have many environmental benefits – we can avoid vast landfilling of usable materials and furthermore we can reduce the extraction of the raw resources. The CDW consists of heterogeneous mix of materials in which the largest portion (approximately 70%) is concrete which is also the main subject of our study. In this article we present main aspects that need to be considered while designing elements from the recycled concrete. We summarize changes in properties of this type of concrete and look at the state of art in this area. Numerous studies have been performed to investigate various characteristic of recycled aggregate concrete (RAC). In the general RAC exhibit lesser performance compared to concrete manufactured with natural aggregate (NA). The focus of most studies is aimed on mechanical and durability properties of the RAC and the major portion of tests is concentrating on small scale samples. We want to contribute to understanding of the RAC with our experimental program. We plan to make full scale columns using RAC. Cross section of proposed columns will be 150 mm x 240 mm and planned height is at 3.8 m. It will be reinforced with 4 reinforcement bars with a diameter of 14 mm and stirrups 6 mm at a mutual distance of 150 mm. Load will act on eccentricity of 40 mm from the center line considering smaller dimension of the cross section of column. There will be various replacement levels tested – 30, 60, 100%. This will be compared with columns made using concrete entirely with NA. [ABSTRACT FROM AUTHOR]