Investigation of mechanical properties, high-temperature resistance and microstructural properties of diatomite-containing geopolymer mortars

İLKENTAPAR S., Ozsoy A.

ARABIAN JOURNAL OF GEOSCIENCES, cilt.15, sa.6, 2022 (SCI-Expanded) identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 15 Sayı: 6
  • Basım Tarihi: 2022
  • Doi Numarası: 10.1007/s12517-022-09824-7
  • Dergi Adı: ARABIAN JOURNAL OF GEOSCIENCES
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Agricultural & Environmental Science Database, Aquatic Science & Fisheries Abstracts (ASFA), Geobase, INSPEC
  • Anahtar Kelimeler: Geopolymer, Fly ash, Diatomite, Strength, Microstructure, ACTIVATED SLAG MORTARS, F FLY-ASH, STRENGTH, METAKAOLIN, CONCRETE, PASTE, WORKABILITY, COMPOSITE, CEMENT
  • Erciyes Üniversitesi Adresli: Evet

Özet

Diatomite is a porous natural pozzolana that contains lots of silica minerals. The usage of diatomite as a natural pozzolana in geopolymer binder systems was examined in the study due to its high percentage of silica mineral. Fly ash-based geopolymer mortars containing 1%, 2%, 3%, 4%, and 5% diatomite in mass basis were produced with alkali activator at 3 different (8%, 10%, and 12%) Na ratios. The produced geopolymer mortars were heat cured at 2 different curing temperatures (60 degrees C, 90 degrees C) for 3 different curing times (24, 48, 72 h). Based on the test results obtained, it was observed that the diatomite substitution increased the flexural strength (in the order of 30%), the compressive strength (in the order of 35%), and increased the abrasion resistance of geopolymer mortars at the optimum alkaline ratio with curing conditions in comparison to reference mortar. Two percent diatomite substitution positively affected the compressive strength of geopolymer mortars cured at 60 degrees C after exposing the samples to 300 degrees C and 600 degrees C elevated temperatures. FESEM images revealed gains and losses in mechanical strength before and after exposure to elevated temperatures (300, 600, and 900 degrees C). Therefore, it was concluded that diatomite as a natural pozzolana can be utilized in a geopolymer mixture.