Strength and abrasion performance of recycled aggregate based geopolymer concrete

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Lakew A. M., Al-Mashhadanı M. O. M., Canpolat O.

SIGMA JOURNAL OF ENGINEERING AND NATURAL SCIENCES, vol.40, no.1, pp.1-7, 2022 (ESCI) identifier

  • Publication Type: Article / Article
  • Volume: 40 Issue: 1
  • Publication Date: 2022
  • Doi Number: 10.14744/sigma.2021.00021
  • Journal Indexes: Emerging Sources Citation Index (ESCI), Academic Search Premier, Directory of Open Access Journals
  • Page Numbers: pp.1-7
  • Keywords: Compressive strength, splitting tensile strength, Fexural strength, Abrasion resistance, Geopolymer concrete, Recycled aggregate
  • Yıldız Technical University Affiliated: Yes


This experimental work evaluated geopolymer concrete containing fly ash and slag by partial replacement of natural coarse aggregate (NCA) with recycled coarse aggregate (RCA) to manufacture environmental-friendly concrete. The proportion of recycled aggregates considered consists of 10%, 20%, 30%, and 40% of the total coarse aggregate amount. Also, a steel fiber ratio of 0.3% was utilized. The mechanical properties and abrasion resistance of fly ash/slag-based geopolymer concrete were then assessed. Majorly, the mechanical strength of the concrete samples decreased by the increase of RCA content. The geopolymer concrete with 40% RCA gave 28.3% lesser compressive strength and 24% lower splitting tensile strength than NCA concrete at one year. Also, the flexural strength of concrete specimens was reduced by 35% (from 5.34MPa to 3.5MPa) with the incorporation of 40% RCA. The incorporation of 30% RCA caused 23% and 22.6% reduction in compressive strength at 56 days and one year, respectively. The flexural and splitting tensile strength of the specimens was not significantly reduced (less than 10%) with the inclusion of a recycled coarse aggregate ratio of up to 30%. Furthermore, the abrasion wear thickness of every concrete sample was less than 1 mm. RCA inclusion of 20% produced either insignificant reduction or better strength results compared to reference mixtures. As a result, it was considered that the combination of 0.3% steel fiber and 20% recycled coarse aggregate in fly ash/slag-based geopolymer concrete leads to an eco-friendly concrete mix with acceptable short and long-term engineering properties that would lead to sustainability in concrete production and utilization sector.