Akademik Veri Yönetim Sistemi
Environmental Research & Technology, cilt.4, sa.3, ss.244-248, 2021 (Hakemli Dergi)
Recycled aggregates and geopolymer binders are green materials contributing to the sustainability of the planet. We investigated the performance of geopolymer concrete using recycled
aggregates (fly ash (FA) and ground granulated blast furnace slag (GGBS)) related to their
mechanical properties. Geopolymer concrete were prepared by mixing 50% low calcium fly
ash, 50% GGBS, sodium hydroxide and sodium silicate solution, Coarse aggregate (Natural
coarse aggregate, Recycled coarse aggregate), Fine aggregate (Crushed Sand, Riverbed Sand)
and elastoplastic fibers. Recycled aggregate used was obtained locally from Istanbul, Turkey.
To explore the efficiency of recycled aggregate, during the production of geopolymer concrete,
partial replacement of recycled coarse aggregate with natural aggregate was made in 10, 20,
30, and 40%. To compare the results, geopolymer concrete containing 100% natural aggregates
was made. Since concrete gains strength with time after casting, On Day-28 and Day-90, the
compressive strength, split tensile strength, and flexural strength of those geopolymer based
concrete were examined. Results of the test showed that the compressive strength of 28 and
90 days w.r.t. different ratios was 26.8, 25.3, 24.2, 23.1, 23 MPa, and 30.2, 28.1, 27.0, 25.2, 25.0,
23.0 Mpa respectively, while split tensile strength was 1.9, 1.5, 1.5, 1.4, 1.4 MPa and 2.0, 1.9, 1.9,
1.6, 1.5 MPa respectively, and the ultimate flexural strength of tested beams were in the range
of 3.53 to 4.54MPa. Although the general performance of the produced samples was showing
a decrement with the increasing ratio of recycle aggregates, the obtained results indicated that
using recycled aggregate is up to some extent of 30% is beneficial in terms of strength.