Fly-ash-based geopolymer composites incorporating cold-bonded lightweight fly ash aggregates

Öz H. Ö., YÜCEL H. E., Güneş M., Köker T. Ş.

Construction and Building Materials, cilt.272, 2021 (SCI-Expanded) identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 272
  • Basım Tarihi: 2021
  • Doi Numarası: 10.1016/j.conbuildmat.2020.121963
  • Dergi Adı: Construction and Building Materials
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, CAB Abstracts, Communication Abstracts, INSPEC, Metadex, Veterinary Science Database, Civil Engineering Abstracts
  • Anahtar Kelimeler: Geopolymer composite, LWFAs, Microstructural analyses, Physical properties, Strength and Durability
  • Hatay Mustafa Kemal Üniversitesi Adresli: Evet

Özet

In this study, effects of cold-bonded lightweight fine aggregate (LWFA) on the geopolymer composites (GCs) were investigated in terms of fresh, physical, mechanical and durability properties. LWFA and different diameters quartz aggregates were used in the production of fly-ash-based GCs. However, LWFA was only replaced with the quartz aggregate of 1.2–2.5 mm. A mixture of 12 M NaOH and Na2SiO3 solution was prepared as 1/2.5. Unit weight, specific gravity, water absorption, apparent porosity, compressive and flexural strengths, ultrasonic pulse velocity and water sorptivity coefficient of GCs were determined. According to the test results, workability of GCs improved as the usage rate of LWFA increased. Due to the surface characteristics of LWFA, the mechanical properties of GC were enhanced by the geopolymerization reaction conducted between LWFA with alkali activators. Thus, the compressive strength of GC with 25% LWFA was 39.6% higher than that of the control GC at 28th day. This conclusion supported by TGA/DTA and FTIR analysis indicated that N-A-S-H gel of GC incorporating 25% LWFA was higher compared to control mixture. Also, GCs incorporating 40% and higher LWFA showed lower performance than control GC.