Experimental investigation of mix design for high-strength alkali-activated slag concrete

2021 ◽  
Vol 291 ◽  
pp. 123387
Author(s):  
Nilvan T. Araújo Júnior ◽  
Victor M.E. Lima ◽  
Sara M. Torres ◽  
Priscilla E.A. Basto ◽  
Antônio A. Melo Neto
Materials ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2072 ◽  
Author(s):  
Sung Choi ◽  
Kwang-Myong Lee

The performance of alkali-activated slag (AAS) paste using activators of strong alkali components is affected by the type, composition, and dosage of the alkaline activators. Promoting the reaction of ground granulated blast furnace slag (GGBFS) by alkaline activators can produce high-strength AAS concrete, but the workability might be drastically reduced. This study is aimed to experimentally investigate the heat release, workability, and setting time of AAS pastes and the compressive strength of AAS mortars considering the Na2O content and the ratio of Na2O to SiO2 (Ms) of binary alkaline activators blended with sodium hydroxide and sodium silicate. The test results indicated that the AAS mortars exhibited a high strength of 25 MPa at 24 h, even at ambient temperature, even though the pastes with an Na2O content of ≥6% and an Ms of ≥1.0 exhibited an abrupt decrease in flowability and rapid setting.


2018 ◽  
Vol 761 ◽  
pp. 7-10 ◽  
Author(s):  
Barbara Kucharczyková ◽  
Vlastimil Bílek Jr. ◽  
Dalibor Kocáb ◽  
Ondřej Karel

The paper deals with the experimental determination of shrinkage development of the composites based on the alkali-activated slag (AAS). The main aim of the experimental investigation was to verify the effect of the addition of shrinkage-reducing admixture (SRA) on the overall process of shrinkage properties during AAS composites ageing.


2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Fulin Wang ◽  
Guoliang Chen ◽  
Lu Ji ◽  
Zhengping Yuan

Backfilling disposal based on cement solidification is one of the ways to solve the environmental and safe problems of uranium tailing surface stacking. Alkali-activated slag, especially sodium silicate activated geopolymer, has become the preferred cementing material for the uranium tailing backfilling system because of its advantages of corrosion resistance and high strength. In this paper, uranium tailings and slag are taken as research objects, and the unconfined compressive strength (UCS) is taken as the main quality index. The preparation method of the cemented uranium tailing backfill based on alkali-activated slag was studied, hereinafter referred to as CUTB. The effects of additive amount, activator amount and activator modulus on the strength of CUTB were investigated. The results show that alkali-activated slag is an effective cementing material for the backfilling system of uranium tailing aggregate. The maximum UCS of 28 d age in the test groups is 16.45 MPa. Quicklime is an important additive for preparing CUTB. When the amount of quicklime is 0%, the early and late strengths of the filling body cannot be measured or at a very low level. At the age of 7 d, the order of each factor is additive amount > activator modulus > activator amount, but at the age of 28 d, the order of each factor is additive amount > activator amount > activator modulus. The test results can provide a basis for choosing cementitious materials for backfilling disposal of uranium tailings.


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