Efflorescence and subflorescence induced microstructural and mechanical evolution in fly ash-based geopolymers

By Zuhua Zhang, J. Provis, Xue Ma, A. Reid, Hao Wang. Cement & Concrete Composites, 2018

221 citations recorded by the source corpus.

This paper reports the effects of efflorescence on the microstructural and mechanical properties of fly ash-based geopolymers. Geopolymer pastes manufactured by sodium hydroxide and sodium silicate activation of three Class F fly ashes exhibit varying efflorescence behaviour. The geopolymer derived from sodium silicate activation of fine fly ash, which has a compact microstructure, shows a relatively slow efflorescence rate and low efflorescence potential. The efflorescence occurring on the surface of the geopolymer specimens does not change their mineralogical characteristics. However, the compressive strength development and compressive modulus of geopolymers can be affected through processes related to the loss of alkalis, and also to subflorescence. The phenomenon of subflorescence can be regarded as an extended efflorescence taking place under the surface of the material, leading to crystallisation pressure, which may exceed the tensile strength of hardened binders and generate structural damage.

Subfields: Building and Construction, Civil and Structural Engineering, Earth-Surface Processes

View Paper: https://www.semanticscholar.org/paper/0606af608815e6ba3cd87f8cf8eaa291d82a84bd

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Building and Construction

1. Zuhua Zhang
2. Brant Walkley
3. E. Rodríguez

In Civil and Structural Engineering

1. E. Rodríguez
2. A. Kirchheim
3. M. Longhi
4. Brant Walkley
5. Zuhua Zhang
6. Liang Shi
7. Li Yan
8. Y. Zheng

In Earth-Surface Processes

1. A. Kirchheim
2. Zuhua Zhang
3. Brant Walkley
4. E. Rodríguez

Citations in the corpus

• Metakaolin-based geopolymers: Relation between formulation, physicochemical properties and efflorescence formation (2020, background): “According to previous works [22,33] the amount of sodium carbonate phase formation is controlled by the crystallization pressure and humidity within the pore network, while the extent of carbonation and pore size controls the deterioration of the geopolymers cement.”
• The Durability of Alkali-Activated Materials in Comparison with Ordinary Portland Cements and Concretes: A Review (2020, background): “The efflorescence reaction is similar to the carbonation reaction of calcium-free/low-calcium AAMs (the corrosion process only consumes free alkali and the substrate will not cause damage) [119,120].”