Clinkerless ultra-high strength concrete based on alkali-activated slag at high temperatures

With the wide application of high strength concrete in the building construction,the risk making concrete subject to high temperatures during a fire is increasing. Comparison tests on the mechanical properties of high strength concrete (HSC) and normal strength concrete (NSC) after the action of high temperature were made in this article, which were compared from the following aspects: the peak stress, the peak strain, elasticity modulus, and stress-strain curve after high temperature. Results show that the laws of the mechanical properties of HSC and NSC changing with the temperature are the same. With the increase of heating temperature, the peak stress and elasticity modulus decreases, while the peak strain grows rapidly. HSC shows greater brittleness and worse fire-resistant performance than NSC, and destroys suddenly. The research and evaluation on the fire-resistant performance of HSC should be strengthened during the structural design and construction on the HSC buildings.

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Investigation of engineering properties of normal and high strength fly ash based geopolymer and alkali-activated slag concrete compared to ordinary Portland cement concrete

Construction and Building Materials ◽

10.1016/j.conbuildmat.2018.11.083 ◽

2019 ◽

Vol 196 ◽

pp. 26-42 ◽

Cited By ~ 32

Author(s):

Nabeel A. Farhan ◽

M. Neaz Sheikh ◽

Muhammad N.S. Hadi

Keyword(s):

Fly Ash ◽

Portland Cement ◽

Ordinary Portland Cement ◽

High Strength ◽

Engineering Properties ◽

Portland Cement Concrete ◽

Cement Concrete ◽

Alkali Activated Slag ◽

Activated Slag ◽

Alkali Activated

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Influence of Na2O Content and Ms (SiO2/Na2O) of Alkaline Activator on Workability and Setting of Alkali-Activated Slag Paste

Materials ◽

10.3390/ma12132072 ◽

2019 ◽

Vol 12 (13) ◽

pp. 2072 ◽

Cited By ~ 6

Author(s):

Sung Choi ◽

Kwang-Myong Lee

Keyword(s):

Setting Time ◽

High Strength ◽

Abrupt Decrease ◽

Na2o Content ◽

Alkali Activated Slag ◽

Granulated Blast Furnace Slag ◽

Type Composition ◽

Activated Slag ◽

Binary Alkaline ◽

Alkali Activated

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.

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