scholarly journals Synergistic Excitation Mechanism of CaO-SiO2-Al2O3-SO3 Quaternary Active Cementitious System

2021 ◽  
Vol 8 ◽  
Author(s):  
Fusheng Niu ◽  
Yukun An ◽  
Jinxia Zhang ◽  
Wen Chen ◽  
Shengtao He
Keyword(s):  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Steel Slag ◽  
Cementitious Materials ◽  
Test Block ◽  
Hydration Reaction ◽  
Alkaline Environment ◽  
Granulated Blast Furnace Slag ◽  
Cementitious System ◽  
Furnace Slag

In this study, the influence of steel slag (SS) content on the strength of the cementitious materials was investigated. The quaternary active cementitious material (CaO-SiO2-Al2O3-SO3) was prepared using various proportions of steel slag (SS), granulated blast furnace slag (BFS), and desulfurized gypsum (DG). The mechanism of synergistic excitation hydration of the cementitious materials was examined using various techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectrometry (FTIR). The strength of the mortar test block was initially increased and decreased later with the increase of the SS content. Mortar test block with 20% steel slag, 65% granulated blast furnace slag, and 15% desulfurized gypsum with 0.35 water-binder ratio showed the highest compressive strength of 57.3 MPa on 28 days. The free calcium oxide (f-CaO) in the SS reacted with water and produced calcium hydroxide (Ca(OH)2) which created an alkaline environment. Under the alkaline environment, the alkali-activated reaction occurred with BFS. In the early stage of hydration reaction, calcium silicate hydrate (C-S-H) gel and fibrous hydration product ettringite (AFt) crystals were formed, which provided early strength to the cementitious materials. As the hydration reaction progressed, the interlocked growth of C-S-H gel and AFt crystals continued and promoted the increase of the strength of the cementitious system.

scholarly journals Characterization of Supplementary Cementitious Materials and Fibers to Be Implemented in High Temperature Concretes for Thermal Energy Storage (TES) Application

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 5190
Author(s):  
Laura Boquera ◽  
David Pons ◽  
Ana Inés Fernández ◽  
Luisa F. Cabeza
Keyword(s):  
Tensile Strength ◽  
Blast Furnace ◽  
High Temperature ◽  
Blast Furnace Slag ◽  
Steel Slag ◽  
Cementitious Materials ◽  
Iron Silicate ◽  
Supplementary Cementitious Materials ◽  
Granulated Blast Furnace Slag ◽  
Furnace Slag

Six supplementary cementitious materials (SCMs) were identified to be incorporated in concrete exposed to high-temperature cycling conditions within the thermal energy storage literature. The selected SCMs are bauxite, chamotte, ground granulated blast furnace slag, iron silicate, silica fume, and steel slag. A microstructural characterization was carried out through an optical microscope, X-ray diffraction analysis, and FT-IR. Also, a pozzolanic test was performed to study the reaction of SCMs silico-aluminous components. The formation of calcium silica hydrate was observed in all SCMs pozzolanic test. Steel slag, iron silicate, and ground granulated blast furnace slag required further milling to enhance cement reaction. Moreover, the tensile strength of three fibers (polypropylene, steel, and glass fibers) was tested after exposure to an alkalinity environment at ambient temperature during one and three months. Results show an alkaline environment entails a tensile strength decrease in polypropylene and steel fibers, leading to corrosion in the later ones.

Study on Sulfate Resistance of Concrete with Compound Mineral Admixture

2011 ◽  
Vol 99-100 ◽  
pp. 420-425 ◽  
Author(s):  
Qian Rong Yang ◽  
Xiao Qian Wang ◽  
Hui Ji
Keyword(s):  
Blast Furnace ◽  
Fly Ash ◽  
Blast Furnace Slag ◽  
Steel Slag ◽  
Sulfate Attack ◽  
Mineral Admixture ◽  
Sulfate Resistance ◽  
Chemical Attack ◽  
Granulated Blast Furnace Slag ◽  
Furnace Slag

The strength, expansion and amount of scaling of concrete with compound mineral admixture (CMA) from steel slag, granulated blast furnace slag and fly ash were studied. The result shows that damage by crystallization press from sulfate attack when concrete was exposed to sulfate environments under wetting–drying alternation is much larger than that from sulfate chemical attack. Adding CMA to concrete could reduce the damage from expansion of concrete caused by sulfate chemical attack, but the resistance of concrete to damage by crystallization press from sulfate attack was remarkably reduced.

Sign in / Sign up

Export Citation Format

Share Document