scholarly journals Characteristics of Mortars with Blast Furnace Slag Powder and Mixed Fine Aggregates Containing Ferronickel-Slag Aggregate

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5879
Author(s):  
Sung-Ho Bae ◽  
Jae-In Lee ◽  
Se-Jin Choi

Recently, interest in environmentally friendly development has increased worldwide, especially in the construction industry. In this study, blast furnace slag powder (BFSP) and mixed steel fine aggregates were applied to cement mortars to reduce the environmental damage caused by the extraction of natural aggregate and to increase the recycling rate of steel by-products in the construction industry. We investigated the fluidity, compressive strength, tensile strength, accelerated carbonation depth, and chloride ion penetration resistance of mortars with steel slag aggregate and their dependence on the presence or absence of BFSP. Because the recycling rate of ferronickel slag is low and causes environmental problems, we considered mortar samples with mixed fine aggregates containing blast furnace slag fine aggregate (BSA) and ferronickel slag fine aggregate (FSA). The results showed that the 7-day compressive strength of a sample containing both 25% BSA and 25% FSA was nearly 14.8% higher than that of the control sample. This trend is likely due to the high density and angular shape of steel slag particles. The 56-day compressive strength of the sample with BFSP and 50% FSA was approximately 64.9 MPa, which was higher than that of other samples with BFSP. In addition, the chloride ion penetrability test result indicates that the use of BFSP has a greater effect than the use of steel slag aggregate on the chloride ion penetration resistance of mortar. Thus, the substitute rate of steel slag as aggregate can be substantially enhanced if BFSP and steel slag aggregate are used in an appropriate combination.

2020 ◽  
Vol 40 (2) ◽  
Author(s):  
Daniela Eugenia Angulo-Ramírez ◽  
William Gustavo Valencia-Saavedra ◽  
Ruby Mejía de Gutiérrez

Concretes based on alkaliactivated binders have attracted considerable attention as new alternative construction materials, which can substitute Portland Cement (OPC) in several applications. These binders are obtained through the chemical reaction between an alkaline activator and reactive aluminosilicate materials, also named precursors. Commonly used precursors are fly ash (FA), blast furnace slag (GBFS), and metakaolin. The present study evaluated properties such as compressive strength, rate of water absorption (sorptivity), and chloride permeability in two types of alkaliactivated concretes (AAC): FA/GBFS 80/20 and GBFS/OPC 80/20. OPC and GBFS/OPC* concretes without alkaliactivation were used as reference materials. The highest compressive strength was observed in the FA/GBFS concrete, which reported 26,1% greater strength compared to OPC concrete after 28 days of curing. The compressive strength of alkaliactivated FA/GBFS 80/20 and GBFS/OPC 80/20 was 61 MPa and 42 MPa at 360 days of curing, respectively. These AAC showed low permeability to the chloride ion and a reduced water absorption. It is concluded that these materials have suitable properties for various applications in the construction sector.


Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 940
Author(s):  
Se-Jin Choi ◽  
Young-Uk Kim ◽  
Tae-Gue Oh ◽  
Bong-Suk Cho

The shortage of natural aggregates has recently emerged as a serious problem owing to the tremendous growth of the concrete industry. Consequently, the social interest in identifying aggregate materials as alternatives to natural aggregates has increased. In South Korea’s growing steel industry, a large amount of steel slag is generated and discarded every year, thereby causing environmental pollution. In previous studies, steel slag, such as blast furnace slag (BFS), has been used as substitutes for concrete aggregates; however, few studies have been conducted on concrete containing both BFS and Ferronickel slag (FNS) as the fine aggregate. In this study, the compressive strength, chloride ion penetrability, and carbonation characteristic of concrete with both FNS and BFS were investigated. The mixed slag fine aggregate (MSFA) was used to replace 0, 25%, 50%, 75%, and 100% of the natural fine aggregate volume. From the test results, the highest compressive strength after 56 days was observed for the B/F100 sample. The 56 days chloride ion penetrability of the B/F75, and B/F100 samples with the MSFA contents of 75% and 100% were low level, approximately 34%, and 54% lower than that of the plain sample, respectively. In addition, the carbonation depth of the samples decreased with the increase in replacement ratio of MSFA.


2020 ◽  
Vol XVII (3) ◽  
pp. 1-14
Author(s):  
Leila Shahryari ◽  
Maryam Nafisinia ◽  
Mohammad Hadi Fattahi

The effects of simultaneous use of recycled aggregates and ground blast furnace slag as a percentage of cement-constituting materials on different properties of fresh self-compacting concrete (SCC) are investigated in this study. To this end, three series of SCC mixtures with a fixed volume of cement paste equalling 380 ltr/m3 (2.36 gal/ft3) and the replacement ratio of coarse aggregates (fifty percent and one hundred percent) and total aggregates (zero percent, fifty percent and one hundred percent) were prepared. The water content ratios in the first, second and third series were 0.4, 0.45, and 0.5, respectively. The results of the compressive strength tests for 7-day, 14-day and 28-day cubic specimens and compressive strength and Brazilian test results for 28-day cylindrical specimens were used as control parameters governing the SCC resistive quality. The results of fresh SCC tests (including slump-flow and T50 tests, V-funnel test, and L-box test) showed that the negative effect of recycled fine aggregates on fresh SCC properties is significantly more than that of recycled coarse aggregate. However, recycled SCC with acceptable properties can be obtained with a slight increase in the amount of superplasticisers used in the presence of slag.


2014 ◽  
Vol 600 ◽  
pp. 227-239
Author(s):  
Hanan A. El Nouhy

This research investigates the influence of high temperature on the properties of bricks containing non-ground granulated blast-furnace slag (GBFS) as fine aggregate replacement. Replacement percentages were 0%, 25% and 50% by dry weight of fine aggregates. The manufactured bricks were exposed to 200°С, 400°С, 600°С, and 800°С for a constant duration of two hours after 28 days of curing. Tests were conducted according to both Egyptian Standard Specifications (ESS) and American Society for Testing and Materials (ASTM) in order to determine compressive strength, absorption percentage, oven-dry weight, and ultrasound pulse velocity. Also, loss in weight was performed. Compressive strength limit regarding load-bearing units was met by mix 1 at all tested temperatures. Mixes 2 and 3, resulted in compressive strength that satisfied the requirement for load-bearing units at temperatures ranging from room temperature to 600°С.Compressive strength obtained regarding mixes 2 and 3 met the requirements of non-load bearing units at 800°С. The control mix resulted in normal weight bricks when tested at the various temperatures till 600°С. At 800°С, mixes 2 and 3 yielded light weight and medium weight bricks, respectively. There was a significant reduction in mass when comparing the mass at 800°С with the corresponding mass at room temperature concerning the three mixes. Results showed that it is feasible to partially replace fine aggregate with GBFS even when bricks are subjected to elevated temperature.


2012 ◽  
Vol 575 ◽  
pp. 100-103 ◽  
Author(s):  
Dong Sheng Shi ◽  
Ping Han ◽  
Zheng Ma ◽  
Jing Bo Wang

In this paper, the experiment about compressive strength of concrete using granulated blast furnace slag as fine aggregate was introduced. In this experiment, granulated blast furnace slag fine aggregates that were produced by two different steel factory and natural river sands that came from two different producing area were been used, and compressive strength of concrete for testing were four levels from ordinary strength level to high strength level. As results, the compressive strength of concrete that used granulated blast furnace slag as fine aggregate increase with increasing of concrete age as good as the concrete used nature river sand. At the early age of 3 days and 7days, whether water-cement ratio, the compressive strength of concrete using slag fine aggregate is always lower than concrete using river sand. At the long age of 91 days, the compressive strength of concrete using slag fine aggregate exceed the concrete using river sand when water-cement ratio was greater than 30%. The compressive strength of concrete using granulated blast furnace slag as fine aggregate can exceed 80N/mm2, the granulated blast furnace slag can be used in high-strength concrete.


Author(s):  
A. Chernil'nik ◽  
D. El'shaeva ◽  
Y. Zherebtsov ◽  
N. Dotsenko ◽  
M. Samofalova

In conditions of dense urban development and a variety of engineering and geological conditions, the use of concretes with a combined aggregate of a rationally selected composition will solve the existing problem of reducing the mass of reinforced concrete structures of buildings and structures and maintaining the required strength and deformability. In this paper, studies have been carried out on the choice of a rational formulation of lightweight concrete based on expanded clay gravel, natural crushed stone and granulated blast furnace slag by varying the volume content of porous coarse aggregate and the volume content of fine aggregate in relation to the mixture. In total, 9 series of prototypes and 1 series of control samples are manufactured and tested. One series of samples includes three cubes with dimensions of 10x10x10 cm. All samples are tested in terms of density and compressive strength, the coefficient of constructive quality is determined. The results of the study shows that the introduction of expanded clay gravel into the composition of heavy concrete instead of part of the dense coarse aggregate and the replacement of the fine dense aggregate with granular blast furnace slag leads to an increase in the structural quality factor, that is, a decrease in the compressive strength of concrete is compensated for by an even more significant decrease in the density of the material, and means weight reduction. The increase in the coefficient of constructive quality of concrete based on expanded clay gravel, natural crushed stone and granulated blast-furnace slag in comparison with the control composition is 15.6 %.


2010 ◽  
Vol 168-170 ◽  
pp. 17-20
Author(s):  
Qiang Song ◽  
Bao Jing Shen ◽  
Zhi Jun Zhou

Under different content of blast furnace slag and steel slag powder, cements were mixed to investigate the effect of dosage of these two mineral admixtures on strength, autoclave expansion and the relationship between strength and volume fraction of pore. The results indicated that the ratio of clinker content to ground granulated blast furnace slag(GGBS) content is the crucial factor for compressive strength of mortars incorporated GGBS and steel slag at 28d. With different dosage of steel slag, the compressive strength of 1:1 mixes of clinker and GGBS has the maximum strength. With the steel slag mixed in cement, the porosity of cement pastes was increased. With the blast furnace slag mixed in cement, the porosity and pore size of cement pastes was decreased. Compressive strength of mortars was closely related to the content of pore in the sizes greater than 50 nm at 28d. Incorporating GGBS can significantly decrease the autoclave expansion of cement deduced by blending steel slag.


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