01739562

Component

https://doi.org/10.1177/0361198120915892

This paper presents the mechanical properties of alkali activated concrete (AAC) cured at 70°C for 24?h. The AAC mixtures were synthesized using five class C fly ashes (FAs) having different chemical and physical properties. Sodium hydroxide (SS) and sodium silicate (SH) were used as the alkali activators in this study. A conventional concrete (CC) mixture, having a compressive strength of 34.5?MPa, was synthesized using ordinary Portland cement (OPC) mixture for comparison purposes. The slump, as well as the compressive, tensile splitting, and flexural strengths were investigated at different concrete ages up to 28?days. The results revealed that with increasing the calcium content in an FA used to synthesized AAC mixture, the slump value and the mechanical properties decreased. All AAC mixtures reached approximately 92% of their 28-day compressive strength after 1 day compared with only 29% in the case of CC. Therefore, AAC can be used in applications where rapid strength gain is required, such as urgent repair, precast industry, and so forth. The measured data was also used to develop a set of equations to accurately predict the splitting tensile and flexural strengths.

© National Academy of Sciences: Transportation Research Board 2020.

English

pp 430-443

2020-5

Transportation Research Record: Journal of the Transportation Research Board

Web

References (42)

Activation (Chemistry); Alkali; Calcium; Compressive strength; Concrete; Flexural strength; Fly ash; High early strength cement; Mechanical properties; Slump test; Sodium hydroxide; Sodium silicate; Tensile strength

Highways; Materials; Pavements

TRIS, TRB, ATRI

May 13 2020 3:06PM