Geopolymers vs. alkali-activated materials (AAMs): A comparative study on durability, microstructure, and resistance to elevated temperatures of lightweight mortars

Ameri, F ; Sharif University of Technology | 2019

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  1. Type of Document: Article
  2. DOI: 10.1016/j.conbuildmat.2019.06.079
  3. Publisher: Elsevier Ltd , 2019
  4. Abstract:
  5. This paper studied the durability, microstructure, and fire behavior of lightweight mortars based on cement, metakaolin (MK), ultrafine ground granulated blast furnace slag (UGGBFS), ceramic waste powder (CWP), and clay brick waste powder (CBWP). Two sets of mixes were prepared with two types of lightweight aggregate including lightweight expanded clay aggregate (LECA) and pumice aggregate. Regarding the durability assessment, the electrical resistivity and water absorption of the mortars were measured. The UGGBFS-based alkali-activated mortar with pumice aggregate exhibited the highest electrical resistivity and lowest water absorption, while CBWP-based geopolymer mortar with LECA showed the lowest electrical resistivity, and the water absorption of this mortar was 62% higher than that of the equivalent cement mortar. In addition, scanning electron microscopy (SEM) images showed that UGGBFS-based mortar developed a dense matrix with few pores; whereas, incomplete geopolymerization and voids were detected in CWP- and CBWP-based mortars. Furthermore, the effect of elevated temperatures ranging from 23 to 800 °C on the compressive strength of specimens was investigated. According to the results, CWP- and CBWP-based mortars showed the best performance and retained about 54% and 49% of their original strength at 800 °C, respectively. Furthermore, a statistical study was carried out on the fire test results to quantify the contribution of different parameters using analysis of variance (ANOVA) method. It was shown that temperature was the most influential parameter. © 2019 Elsevier Ltd
  6. Keywords:
  7. Alkali-activated mortar ; Ceramic waste powder ; Clay brick waste powder ; Elevated temperatures ; Geopolymer mortar ; Lightweight mortar ; Metakaolin ; Microstructure ; Water absorption ; Aggregates ; Analysis of variance (ANOVA) ; Blast furnaces ; Brick ; Cement manufacture ; Cements ; Ceramic materials ; Compressive strength ; Durability ; Electric conductivity ; Geopolymers ; Inorganic polymers ; Mortar ; Scanning electron microscopy ; Slags ; Alkali-activated mortars ; Ceramic waste ; Clay-brick wastes ; Elevated temperature ; Geopolymer mortars ; Lightweight mortars ; Metakaolins
  8. Source: Construction and Building Materials ; Volume 222 , 2019 , Pages 49-63 ; 09500618 (ISSN)
  9. URL: https://www.sciencedirect.com/science/article/abs/pii/S0950061819315089