01662763

Component

Alkali-activated fly ash (AAFA) is usually cured at elevated temperature, which limits its wide field applications, while several studies have also shown that properties of AAFA cured at ambient temperature can be significantly improved by incorporating different additives. This research investigated the impact of substituting a small portion of fly ash with different cementitious additives including slag, metakaolin, and silica fume on various properties of AAFA mixtures at ambient curing conditions. The workability, geopolymerization heat released, compressive strength, Young’s modulus, electrical resistivity, and chloride permeability were measured. The effects of binder composition on compressive strength gain and stiffness development were monitored at different curing ages. The effects of different chemical compositions and concentrations of alkaline solution on the mechanical properties and permeability characteristics of AAFA with these additives were also investigated. Results showed that all additives decreased the workability. Replacing 10% of fly ash with metakaolin significantly improved the early strength and stiffness, whereas inclusion of slag with fly ash led to achieve electrical resistivity and compressive strength comparable to those of ordinary portland cement.

This paper was sponsored by TRB committee AFN10 Standing Committee on Basic Research and Emerging Technologies Related to Concrete.

18-05132

English

7p

2018

Transportation Research Board 97th Annual Meeting

Digital/other

Figures; References; Tables

Alkali; Cement; Cement additives; Fly ash; Mechanical properties; Permeability

Materials; Transportation (General)

Transportation Research Board Annual Meeting 2018 Paper #18-05132

TRIS, TRB, ATRI

Jan 8 2018 11:17AM