Open AccessMaterial characterization of geopolymer mortar for its beneficial use in composite construction
Author(s) -
Joachim Juhart,
Christopher Gößler,
Cyrill Grengg,
Florian Mittermayr,
Ognjen Rudić,
Andrew McIntosh,
Bernhard Freytag
Publication year - 2021
Publication title -
rilem technical letters
Language(s) - English
Resource type - Journals
ISSN - 2518-0231
DOI - 10.21809/rilemtechlett.2020.125
Subject(s) - shrinkage , metakaolin , materials science , geopolymer , portland cement , composite material , mortar , ultimate tensile strength , compressive strength , composite number , hardening (computing) , thermal expansion , cement , layer (electronics)
This paper investigates material properties of metakaolin/slag-based geopolymer mortar (GPM), relevant for composite action with conventional Portland cement-based concrete (PCC). GPM formulations with different workability (soft and stiff-plastic consistencies) were developed and characterized with regard to their compressive and tensile strength development over time, their shrinkage behaviour during hardening under different ambient conditions, as well as their thermal expansion. With the experimental data obtained, a coefficient of thermal expansion and equations for predicting the strength development were calculated. The GPMs exhibited significant autogenous shrinkage and drying shrinkage. Additionally, high very early shrinkage, tested by a new image correlation method, occurred immediately after setting under dry conditions. Thereby, the observed extent of early shrinkage strongly depended on the specimens’ thicknesses. Furthermore, the basic characteristics of autogenous and drying shrinkage of GPM were enlightened and compared to PCC.