scholarly journals Geotechnical and Environmental Assessment of Blast Furnace Slag for Engineering Applications

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6029
Author(s):  
Wojciech Sas ◽  
Justyna Dzięcioł ◽  
Algirdas Radzevičius ◽  
Maja Radziemska ◽  
Midona Dapkienė ◽  
...  

The increasing demand for building materials in the road industry creates interest for a new source of high-quality aggregates. In order to conserve natural resources, more attention is focused on anthropogenic soils and industrial solid wastes. For the successful application of these types of soil, a series of geotechnical and environmental tests have to be conducted. A potential hazard in the reuse of wastes from thermal degradation in the construction industry, particularly in reinforced concrete (RC) construction, is the migration of heavy metals into the groundwater environment. In this article, a geotechnical assessment of blast furnace slag (BFS) properties is presented. We conducted a series of CBR, and oedometric tests to evaluate the feasibility of BFS application in earth construction. The oedometric test results show acceptable compression characteristics which are in the range of natural aggregates. The CBR shows that this material may be used as a pavement subbase. We also noticed the preconsolidation pressure phenomenon in both Proctor and vibro-compacted soil during the oedometric test. The compression index and recompression index value show that the compression characteristics are close to those of dense sand. Based on the results described in the article, blast furnace slag is a candidate for technological application and can become one of the elements of sustainable development by contributing to a reduction in the negative environmental impact of production and use of building materials.

2014 ◽  
Vol 1052 ◽  
pp. 392-395 ◽  
Author(s):  
Li Xia He

High Ti-bearing blast furnace (BF) slag is the smelting waste of vanadium titano-magnetite. It has great production but low utilization. The high Ti-bearing BF slag is used in building materials industry, which recycles waste material, saves resources and energy, benefiting environmental protection and achieving sustainable development of resources. Study on the recycling of high Ti-bearing BF slag will be an important subject of our researches in future.


2010 ◽  
Vol 168-170 ◽  
pp. 709-715
Author(s):  
Dongsik Oh ◽  
Doheom Song ◽  
Seongseok Go

Hwangtoh (loess) has pozzolanic properties that mean it can be used as a cement admixture when activated at high temperatures, and that it can be used in combination with building materials such as fly ash or blast furnace slag. This study aimed to analyze the relationship between the compressive strength and the brick bond strength of various mortars containing hwangtoh, and also to find the optimum mixing conditions for the use of hwangtoh. It was found that the mortars’ strength properties are significantly influenced by the water/cement ratio W/C and the activated hwangtoh substitution ratio. We recommend the following materials and mixing conditions: W/C 60%, a cement substitution ratio of activated hwangtoh of 20 ~ 25%, and the addition of 10% blast furnace slag to improve the compressive strength of such mortars.


Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1134 ◽  
Author(s):  
Ilda Tole ◽  
Magdalena Rajczakowska ◽  
Abeer Humad ◽  
Ankit Kothari ◽  
Andrzej Cwirzen

An efficient solution to increase the sustainability of building materials is to replace Portland cement with alkali-activated materials (AAM). Precursors for those systems are often based on water-cooled ground granulated blast furnace slags (GGBFS). Quenching of blast furnace slag can be done also by air but in that case, the final product is crystalline and with a very low reactivity. The present study aimed to evaluate the cementitious properties of a mechanically activated (MCA) air-cooled blast furnace slag (ACBFS) used as a precursor in sodium silicate alkali-activated systems. The unreactive ACBFS was processed in a planetary ball mill and its cementing performances were compared with an alkali-activated water-cooled GGBFS. Mixes based on mechanically activated ACBFS reached the 7-days compressive strength of 35 MPa and the 28-days compressive strength 45 MPa. The GGBFS-based samples showed generally higher compressive strength values.


2018 ◽  
Vol 931 ◽  
pp. 578-582
Author(s):  
Natalia D. Yatsenko ◽  
N.A. Vil'bitskaya ◽  
A.I. Yatsenko

The article deals with the use of blast furnace slag and mineralising additives as raw materials for the production of building materials. Innovative technologies of brick production from natural raw materials and industrial wastes are developed.


2019 ◽  
Vol 25 (3) ◽  
pp. 340-347
Author(s):  
Ting WANG ◽  
Xiaojian GAO ◽  
Jian WANG

As a byproduct of phosphoric acid industry, phosphogypsum has many environmental problems. In order to recycle phosphogypsum to manufacture lightweight building materials, cementitious additives including fly ash, ground granulate blast-furnace slag and Portland cement were added to improve strength and water-resistance and different volume of foam was added to reduce the bulk density. The results show that hydrated lime can improve mechanical strength and water resistance of PG paste and the optimal dosage of hydrated lime is 6 %. Higher addition of fly ash or ground granulated blast-furnace slag improves the fluidity and delays the setting time of PG paste. The addition of 10 ~ 20 % fly ash results in a little reducing influence and 10 % ground granulated blast-furnace slag leads to an increase of 20.7 % for 28 days compressive strength of hardened PG specimen. The higher addition of Portland cement results in the better mechanical strength and water resistance of PG specimens. The 28day compressive and flexural strength reaches 25.9 MPa and 8.9 MPa respectively for the 25 % Portland cement mixture. PG based lightweight building materials can prepared by the addition of 60 % volume of air foam, with compressive strength of 1.7 MPa, bulk density of 521.7 kg/m3 and thermal conductivity of 0.0724 W/(m·K). DOI: http://dx.doi.org/10.5755/j01.ms.25.3.19910


Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2052
Author(s):  
Xilin Li ◽  
Kexin Li ◽  
Qi Sun ◽  
Ling Liu ◽  
Jianlin Yang ◽  
...  

A new environmentally friendly cemented oil shale residue–steel slag–ground granulated blast furnace slag backfill (COSGB) was prepared using oil shale residue (OSR), steel slag (SS) and ground granulated blast furnace slag (GGBS) as constituent materials. Based on univariate analysis and the Box–Behnken design (BBD) response surface method, the three responses of the 28 days unconfined compressive strength (UCS), slump and cost were used to optimize the mix ratio. Using a combination of scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and mercury intrusion porosimetry (MIP), the reaction products, microscopic morphology and pore structure of the specimens with the optimal mix ratio at different curing ages were analyzed. The influence of heavy metal ions from the raw materials and the COSGB mixtures on the groundwater environment was studied by leaching tests. The research demonstrates that the optimal mix ratio is GGBS mixing amount 4.85%, mass ratio of SS to OSR 0.82, and solid mass concentration 67.69%. At shorter curing age, the hydration products are mainly calcium alumino silicate hydrate (C-A-S-H) and calcium silicate hydrate (C-S-H) gels. With the increase of curing age, ettringite (AFt) and C-S-H gels become the main source of the UCS. Meanwhile, the porosity of the filler decreases continuously. The leaching concentration of heavy metal ions from the COSGB mixtures is all lower than the leaching concentration of raw materials and meet the requirements of the Chinese groundwater quality standard (GB/T 14848-2017). Therefore, this new COSGB cannot pollute the groundwater environment and meets backfill requirements. The proposed technology is a reliable and environmentally friendly alternative for recycling OSR and SS while simultaneously supporting cemented paste backfill (CPB).


2021 ◽  
Author(s):  
Pengwei Li ◽  
S.H. Luo ◽  
Qing Wang ◽  
Pudong Zhang ◽  
Yahui Zhang ◽  
...  

Abstract Traditional building materials have disadvantages such as high pollution and high energy consumption, so it is particularly important to develop new environmentally friendly materials. In this paper, foamed glass-ceramics are prepared by high-temperature melting method with iron tailings, blast furnace slag, and desulfurization slag as the main raw materials, and CaCO3 as foaming agent. The effects of three kinds of basic glass scheme, the content of the foaming agent and heat treatment system on the degree of crystallization, micro-morphology, and crystal phase composition of foamed glass-ceramics are studied. The nucleation temperature and crystallization temperature of the basic glass are determined by differential thermal analysis curve to be 730 ℃ and 1000 ℃, respectively. Orthogonal experiments show that the optimal composition ratio of the prepared base glass is CaO: 22.25 wt.%, MgO: 4.57 wt.%, Al2O3: 6.19 wt.%, SiO2: 41.8 wt.%. The optimized scheme is based on a base glass prepared with 45 wt.% iron tailings, 25 wt.% blast furnace slag, and 30 wt.% desulfurization slag, added with 10% CaCO3 and sintered to 1000 °C for 3 h. The bending strength, fracture toughness, and elastic modulus are 95.73 Mpa, 53.09 Mpa·m1/2, 28023.55 Mpa, respectively.


Author(s):  
Зиен Ву Ким ◽  
Dien Vu Kim ◽  
Ван Танг ◽  
Van Tang ◽  
С. Баженова ◽  
...  

Blast furnace slag is a waste of metallurgical industry which can be used in production technology of concretes and mortars. The expedient use of blast furnace slag as a component for new building materials will improve the environmental situation and increase the economic efficiency of production. The authors reaserch blast furnace slag processing technology of factories "Hoa Phat" (Vietnam) and "Thai Nguyen" (Vietnam) to produce mineral additives. As a result of the conducted researches the chemical and mineralogical composition of slags are received, their physical and mechanical characteristics are considered and defined: specific surface area, density, water demand, and others. According to standard of Vietnam and Russia, slag activity index is calculated when considering the possibility of using blast furnace slags to replace part of the binder. The relationship between the strength of the cement-sand mortar and density affected by the binder are reveald (where; binder = Portland cement + Granulated blast furnace slag). Comparison chart of slag activity index IR (%) has been shown. The paper uses the Vietnamese standard TCVN 11586: 2016 to analyze the possibility of using blast furnace slag (Vietnam) in the technology of concrete and mortar construction.


2018 ◽  
Vol 174 ◽  
pp. 02002
Author(s):  
Elżbieta Janowska-Renkas ◽  
Jolanta Kowalska

The study presents the state of knowledge regarding physical and chemical properties, as well as trends for application of fly ashes from combustion in fluidized bed boilers in building materials. Clinker - slag - ash based binders were tested that contained up to 40 mass % of fly ashes from combustion in fluidized bed boilers. It was demonstrated that fluidized bed combustion fly ashes (FBC fly ash), apart from granular blast furnace slag, could be the ingredient of low clinker Portland cements (ca. 20% by mass). These cements, compared to CEM I Portland cement, have higher water demand and durability in the corrosive environment, and a lower compressive strength value. Based on test results of binders with various content of blast furnace slag and fly ash, the clinker - slag - ash based binder was singled out, which demonstrated the higher durability in the corrosive environment. It was found that production of clinker - slag - ash based binders was possible in the strength class 32.5 even with 30% by mass of FBC fly ash content.


Sign in / Sign up

Export Citation Format

Share Document