scholarly journals Influence of Steel Slag-Superfine Blast Furnace Slag Composite Mineral Admixture on the Properties of Mortar and Concrete

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Zhenguo Liu ◽  
Zongxian Huang
Keyword(s):  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Steel Slag ◽  
Autogenous Shrinkage ◽  
Mineral Admixture ◽  
Strength Development ◽  
Adiabatic Temperature Rise ◽  
Solid Ratio ◽  
Composite Mixture ◽  
Furnace Slag

A composite mineral admixture was prepared by steel slag and superfine blast furnace slag. The influence of superfine blast furnace slag content of the composite mixture on the mortar and concrete was investigated. The results show that the composite mineral admixture may decrease the strength of concrete at the early age but improve the strength development over time. Increasing the content of superfine blast furnace slag can reduce the degradation of the early strength. The reduction of the autogenous shrinkage and adiabatic temperature rise is significant when the composite mineral admixture is added. The reduction is more obvious when the water-to-solid ratio (w/s) is low. The results show that with steel slag and superfine blast furnace slag playing as complementary parts in the composite mineral admixture, it can be used as an effective substitute of cement.

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.

Early Age Cracking Characteristic of Concrete with Compound Admixtures

2013 ◽  
Vol 325-326 ◽  
pp. 71-74
Author(s):  
Yun Feng Li ◽  
Dong Sheng Zhang ◽  
Li Xu
Keyword(s):  
Blast Furnace ◽  
Fly Ash ◽  
Blast Furnace Slag ◽  
High Performance ◽  
High Performance Concrete ◽  
Steel Slag ◽  
Test Method ◽  
Mineral Admixture ◽  
Early Age ◽  
Furnace Slag

The shrinkage cracking of concrete plays an important role to the accelerated deterioration and shortening the service life of concrete structures. The mineral admixture will be a perfect component of high performance concrete and its utilization will be a valuable resource for recycling. Early age cracking characteristics of concrete with compound admixtures, such as steel slag, blast furnace slag, fly ash, are studied in this paper using plate test method. The better anti-cracking performance of concrete will be realized when blast furnace slag replacing cement at 30%, steel slag and fly ash as the equal mixture components replacing cement at 30%, three kinds of admixtures replacing cement at 30% under the proper proportion.

scholarly journals Cement Kiln By-Pass Dust: An Effective Alkaline Activator for Pozzolanic Materials

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1770 ◽  
Author(s):  
Lukáš Kalina ◽  
Vlastimil Bílek ◽  
Tomáš Kiripolský ◽  
Radoslav Novotný ◽  
Jiří Másilko
Keyword(s):  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Autogenous Shrinkage ◽  
Cement Industry ◽  
Strength Development ◽  
Cement Kiln ◽  
Binder Phase ◽  
Fine Grained ◽  
Furnace Slag ◽  
Alkali Activated

Cement kiln by-pass dust (CKD) is a fine-grained by-product of Portland clinker manufacturing. Its chemical composition is not suitable for returning back into feedstock and, therefore, it has to be discharged. Such an increasing waste production contributes to the high environmental impact of the cement industry. A possible solution for the ecological processing of CKD is its incorporation into alkali-activated blast furnace slag binders. Thanks to high alkaline content, CKD serves as an effective accelerator for latent hydraulic substances which positively affect their mechanical properties. It was found out that CKD in combination with sodium carbonate creates sodium hydroxide in situ which together with sodium water glass content increases the dissolution of blast furnace slag particles and subsequently binder phase formation resulting in better flexural and compressive strength development compared to the sample without it. At the same time, the addition of CKD compensates the autogenous shrinkage of alkali-activated materials reducing the risk of material cracking. On the other hand, this type of inorganic admixture accelerates the hydration process causing rapid loss of workability.

scholarly journals Property Comparison of Alkali-Activated Carbon Steel Slag (CSS) and Stainless Steel Slag (SSS) and Role of Blast Furnace Slag (BFS) Chemical Composition

Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3307 ◽  
Author(s):  
Jinyan Liu ◽  
Cheng Yi ◽  
Hongguang Zhu ◽  
Hongqiang Ma
Keyword(s):  
Stainless Steel ◽  
Blast Furnace ◽  
Activated Carbon ◽  
Carbon Steel ◽  
Blast Furnace Slag ◽  
Steel Slag ◽  
Stainless Steel Slag ◽  
Solid Ratio ◽  
Furnace Slag ◽  
Alkali Activated

In order to compare the properties of alkali-activated carbon steel slag (CSS) and stainless steel slag (SSS), the effects of sodium hydroxide/sodium silicate solution mass ratio (NH/NS), liquid/solid ratio and blast furnace slag (BFS) dosage on the compressive strength, hydration products and hydration degree of CSS and SSS were studied. Furthermore, a combination of X-ray diffraction (XRD), thermo-gravimetric analysis coupled with differential thermal analysis (TGA-DTA), Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscope-energy dispersive spectrometer (SEM-EDS) were used to characterize the morphology and structure of alkali-activated CSS-BFS and SSS-BFS cementitious materials. As the results revealed, the primary hydrate of alkali-activated CSS and SSS is C-(A)-S-H with Q2 [SiO4] units, which has a low Ca/Si ratio and includes inert phases like a CaO-FeO-MnO-MgO solid solution (RO) in CSS while cuspidine, magnesiochromite etc. in SSS. More active C3S and β-C2S promote the alkali activation of CSS, whereas the less active γ-C2S hinders the depolymerization of SSS. The incorporation of BFS does not change the hydrate, whose seed effect is helpful for accelerating the depolymerization and polycondensation of CSS and SSS, especially for SSS, and makes the hydrate increase significantly. Owing to the high SiO2 and Al2O3 contents of SSS, the C-(A)-S-H chain length is increased, thus facilitating the polycondensation effect. In this study, the optimal NH/NS of CSS and SSS is NH/NS= 1:2, and the optimal liquid/solid ratio is 0.29. Compared to CSS–BFS, the C-(A)-S-H gel produced by SSS–BFS has lower Ca/Si and Al/Si ratios. Unlike CSS, pure SSS is inappropriate as an alkali-activated precursor and needs to be co-activated with BFS.

scholarly journals Control of the setting reaction and strength development of slag-blended volcanic ash-based phosphate geopolymer with the addition of boric acid

2021 ◽  
Author(s):  
Jean Noël Yankwa Djobo ◽  
Dietmar Stephan
Keyword(s):  
Blast Furnace ◽  
Boric Acid ◽  
Blast Furnace Slag ◽  
Volcanic Ash ◽  
Strength Development ◽  
Main Process ◽  
Reaction Products ◽  
Setting Times ◽  
Granulated Blast Furnace Slag ◽  
Furnace Slag

AbstractThis work aimed to evaluate the role of the addition of blast furnace slag for the formation of reaction products and the strength development of volcanic ash-based phosphate geopolymer. Volcanic ash was replaced by 4 and 6 wt% of ground granulated blast furnace slag to accelerate the reaction kinetics. Then, the influence of boric acid for controlling the setting and kinetics reactions was also evaluated. The results demonstrated that the competition between the dissolution of boric acid and volcanic ash-slag particles is the main process controlling the setting and kinetics reaction. The addition of slag has significantly accelerated the initial and final setting times, whereas the addition of boric acid was beneficial for delaying the setting times. Consequently, it also enhanced the flowability of the paste. The compressive strength increased significantly with the addition of slag, and the optimum replaced rate was 4 wt% which resulted in 28 d strength of 27 MPa. Beyond that percentage, the strength was reduced because of the flash setting of the binder which does not allow a subsequent dissolution of the particles and their precipitation. The binders formed with the addition of slag and/or boric acid are beneficial for the improvement of the water stability of the volcanic ash-based phosphate geopolymer.

Effects of Fly Ash and Granular Blast-Furnace Slag on Development Rate of Strength of Concrete

2014 ◽  
Vol 629-630 ◽  
pp. 371-375
Author(s):  
Ji Wei Cai ◽  
Si Jia Yan ◽  
Gong Lei Wei ◽  
Lu Wang ◽  
Jin Jin Zhou
Keyword(s):  
Blast Furnace ◽  
Fly Ash ◽  
Blast Furnace Slag ◽  
Development Rate ◽  
Mineral Admixture ◽  
Mineral Admixtures ◽  
Conventional Concrete ◽  
Enhancing Effect ◽  
Substitution Content ◽  
Furnace Slag

Fly ash (FA) and granular blast-furnace slag (GBFS) are usual mineral admixtures to conventional concrete, and their contents substituted for Portland cement definitely affect development rate of strength of concrete. C30 and C60 concrete samples with FA and/or GBFS were prepared to study the influence of substitution content of the mineral admixtures on 3 d, 7 d and 28 d strength. The results reveal that the development rate of strength in period from 3 d to 7 d gets slow with increasing content of mineral admixtures except for concrete with only GBFS less than 20%. In the case of substituting FA as the only mineral admixture for part of cement, the development rate of strength of C30 concrete in period from 7 d to 28 d keeps roughly constant even that of C60 concrete increases. When substituting mineral admixtures in the presence of GBFS for cement within experimental range, the development rate of strength in period from 7 d to 28 d gets fast with increasing substitution content. The enhancing effect of combining FA and GBFS occurs in period from 7 d to 28 d for both C30 and C60 concretes (FA+GBFS≤40%), even occurs in period from 3 d to 7 d for C60 concrete. Based on 7 d strength and the development rate, 28 d strength of concrete can be predicted accurately.

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.

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