Hydration Process and Compressive Strength of Slag-CFBC Fly Ash Materials without Portland Cement

作者：Nguyen Tien Dung^*; Chang Ta Peng; Chen Chun Tao

来源：Journal of Materials in Civil Engineering, 2015, 27(7): 04014213.

DOI：10.1061/(ASCE)MT.1943-5533.0001177

• Hydration
• Slag
• Fly ash
• Microstructure
• Compressive strength

This study mixed ground granulated blast-furnace slag (S) and circulating fluidized bed combustion (CFBC) fly ash (CA) without any portland cement or alkaline activator to produce an eco-binder, abbreviated as SCA binder. The hydration process, microstructure, and compressive strength of hydrated SCA materials were investigated. Although both the slag and CA had poor hydration with water, the SCA binder produced satisfactory hydration products with sufficient cementitious properties. These hydration products detected by Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) were ettringite (AFt), calcium silicate hydrate (C-S-H), and calcium aluminosilicate hydrate (C-A-S-H). The scanning electron microscope (SEM) micrograph showed these hydration products formed dense microstructure for SCA pastes. As a result, the SCA materials had sufficient compressive strength for practical applications in building materials and civil engineering structures. The compressive strengths of the SCA paste and mortar reached 75MPa at 28days. Moreover, the SCA concretes met the requirements for structural concrete. An equation to predict the compressive strengths of the SCA concrete was proposed and agreed well with the experimental results.

• 出版日期2015-7