The effects of different production parameters (NaOH concentration, curing regime and replacement ratio of recycled aggregate) on fresh, hardened and elevated temperature performance of geopolymer mortar samples

Küçük Resim Yok

Tarih

2023

Dergi Başlığı

Dergi ISSN

Cilt Başlığı

Yayıncı

Elsevier

Erişim Hakkı

info:eu-repo/semantics/closedAccess

Özet

This paper presents the findings of objective to examine the effects of construction and demoli-tion wastes (CDW) as fine aggregate on the performance of geopolymer mortar (GPM) specimens. In order to examine the effect of NaOH concentration on the performance of GPM samples, NaOH solutions with 3 different concentrations (8, 10 and 12 M) were prepared. GPM samples, in which the fine aggregate part was formed by replace of natural aggregate (NA) and CDW at three differ-ent ratios (0%, 50% and 100%), were cured in water and ambient conditions for 7 and 28 days. The alkali liquid/binder ratio was not determined as a variable and was kept constant at 0.6 for all GPM samples. Subsequently, compressive strength, workability, water absorption, unit weight and high temperature performance on GPM specimens were investigated in detail. All of these ex-perimental parameters were also supported by microstructural analysis (scanning electron mi-croscopy (SEM), X-ray diffraction (XRD), and Fourier Transform Infrared Spectroscopy (FTIR)). The results showed that the compressive strength values of granulated blast furnace slag (GBFS) based GPM samples can be increased up to 105% in case of choosing of water curing instead of curing in ambient conditions. It was determined that the increase in NaOH concentration de-creased the compressive strength values of GPM samples. Furthermore, experimental findings re-vealed that although CDW had a negative impact on the performance of GPM samples, it could still find potential usage area in the geopolymer production. On the other hand, the increases in NaOH concentration and CDW usage ratio led to decreased workability of GPM samples. Finally, it was underlined that the mechanical and physical characteristics of GPM samples decreased sharply with the increasing elevated temperature values (especially at 750 & DEG;C).

Açıklama

Anahtar Kelimeler

Geopolymer, Elevated temperature, Compressive strength, Recycled aggregate, Water absorption

Kaynak

Journal of Building Engineering

WoS Q Değeri

Q1

Scopus Q Değeri

Q1

Cilt

76

Sayı

Künye