RECYCLED CONCRETE AGGREGATES FROM DIFFERENT SOURCES: CHARACTERIZATION AND USE IN STRUCTURAL CONCRETE

Author(s): Guilherme C. Cordeiro, Gabriela V. Maioli, Amanda P. Vieira, Mônica B. Leite
Book Title: III Progress of Recycling in the Built Environment
Editor: I. Martins, C. Ulsen and S. C. Angulo
e-ISBN: 978-2-35158-158-2
Publisher: RILEM Publications SARL
Publication year: 2015
Pages: 147-156
Total Pages: 10
Language: English

Abstract: The use of recycled aggregates has been adopted as an environmentally responsible practice to mitigate the impact caused by the waste generation in Civil Construction and the great amount of natural resources used to produce aggregates. The present study proposes to compare the characteristics of two recycled concrete coarse aggregates with a natural coarse aggregate aiming the use in structural concrete. The first recycled aggregate was produced in laboratory using one-year-old specimens of concrete. The second recycled aggregate was produced from the demolition waste of a soccer stadium concrete structure, which was built in 1954 in the state of Rio de Janeiro, Brazil. After the collection, both materials were crushed and classified for a maximum size of 12.5 mm. A known quality natural aggregate originated from a granitic rock was used as the reference. All aggregates were characterized by particle size distribution, Micro-Deval abrasion, water absorption, density and packing density tests. After that, five different concrete mixtures were produced: one of reference with 100% of granite as coarse aggregate, two concrete mixtures with 50% of granite and 50% of each recycled aggregate, and two concrete mixtures using 20% of rice husk ash, by volume, as cement replacement material, and using the same RCA and granite contents as the two prior mixtures. The concrete characterization was carried out by slump, compressive strength at 7 and 14 days tests. The results showed that both RCAs presented adequate density, gradation and particle shape to applications in concrete. Moreover, the RCAs had Micro-Deval higher than the usual limit stablished for using in structural concretes. However, blending RCAs with the natural aggregate resulted in abrasion loss values within the range of the structural concrete aggregates.

Online publication: 2015
Publication Type: full_text
Public price (Euros): 0.00