Slag Sand Research Articles

Influence of bagasse ash powder and marble powder on strength and microstructure characteristics of alkali activated slag concrete cured at room temperature for rigid pavement application

In this research, an attempt is made to partially replace ground granulated blast furnace Slag (GGBS) with a binder rich in SiO2 and CaO in alkali activated slag concrete (AASC) to increase workability and setting time. GGBS is replaced with bagasse ash powder (BAP) in 5%, 10%, and 15% of the binary mix, and subsequently with marble powder (MP) in 5% and 10% of the binary mix. After establishing the best mix for both binder replacements, a ternary mix with 5% BAP and 10% MP is created. The fine aggregates used in the comparison are 100 % river sand and slag sand. 10 M sodium hydroxide and the alkaline to binder ratio is 0.4, were used. Mechanical properties such as compressive strength, split tensile strength, and flexural strength are performed cured at 1, 3, 7, and 28 days samples. To further understand the intrinsic mechanism of strength development, microstructure, morphology and mineralogy on AASC are investigated. Based on the findings, it can be inferred that AASC mixes have a higher strength than OPC mixes. The mechanical strengths of the AASC binary mix with 10% MP and 5% BAP are higher. The microstructural analysis reveals the mixes developed with BAP and 100 % GGBS, had a denser microstructure than the normal mixes. The mechanical properties obtained for most of the AASC mixes are significantly higher than the IRC SP:62-2014 recommendations for rigid pavements for low volume roads.

Preparation and Properties of HUHPC with Low Shrinkage and High Impact Resistance

At present, nuclear energy is widely used to reduce pollution and clean energy. However, the radiation-proof concrete currently used to prepare nuclear shields cannot meet the protection requirements of nuclear safety. Therefore, there is an urgent need to develop radiation-proof concrete materials with high impact resistance and ultra-high strength. In this paper, the low-shrinkage, high-impact Heavy Ultra-High-Performance Concrete (HUHPC) was designed by the following innovative methods: Porous high titanium heavy slag sand (HTHS) (industrial solid waste) with “slow-water release” effect and expansion agent were synergistically used to improve volume stability; Irregular HTHS with “embedded lock” effect and steel fibers were synergistically utilized to enhance impact resistance; Heavy ilmenite sand was used to lift volume weight. The workability, mechanical properties, volume stability, impact resistance, and microstructure were studied. The results show that the designed HUHPC volume weight is more than 2,800 kg/m3 which can enhance the radiation protection performance greatly. The 180 d shrinkage of HUHPC is less than 400 µε, which volume stability is improved by more than 30%. The addition of lithium carbonate slightly decreased the 28 d strength of HUHPC, but the appropriate admixture amount (0.9%) could improve the impact resistance of HUHPC by 33%.

Experimental investigation on strength, durability and micro structural characteristics of slag based concrete

In this study, experimental investigations are conducted using 100 percent Portland Slag Cement and Processed Granulated Blast Furnace Slag sand (PGBFS, iron slag) with 100 percent and partial or full replacement of Natural Coarse Aggregates (NCA) with Ladle Slag Aggregates (LSA) with 0, 20, 40, 60, 80, and 100 percent variations. All of the materials used in the inquiry are manufactured by Jindal Steel Works' Bellary factory in India. It has been shown that aggregates containing 20 percent Ladle slag provide the highest strength. Again, 5 percent variation strength tests are conducted, and it is determined that maximum strength is attained with 20 percent variance. The XRD examination demonstrates that the intermolecular bonding between hardened aggregate and cementitious paste is mostly comprised of silicates with a high degree of crystalline order. Due to the fact that the XRD test pattern is mostly composed of quartz aligned with alite and belite, the spaces between the substrate have been minimized to a minimal extent, which may contribute to the concrete's excellent endurance. For 20 percent variance, the tests of durability are modest, as shown by the durability test. The SEM images show porous structures which suggest a limited formation of C-S-H, gel and a correlation between them. The calcium hydroxide generated during cement hydration could be the result of interaction with the reactive amorphous silica present in slag and cement, leading to the formation of C-S-H gel, which plays a role in enhancing the mechanical and durability properties of concrete.

ConvNeXt steel slag sand substitution rate detection method incorporating attention mechanism

The proportion of natural sand replaced by steel slag sand affects the volumetric stability of steel slag mortar and steel slag concrete. However, the steel slag substitution rate detection method is inefficient and lacks representative sampling. Therefore, a deep learning-based steel slag sand substitution rate detection method is proposed. The technique adds a squeeze and excitation (SE) attention mechanism to the ConvNeXt model to improve the model's efficiency in extracting the color features of steel slag sand mix. Meanwhile, the model's accuracy is further enhanced by using the migration learning method. The experimental results show that SE can effectively help ConvNeXt acquire images' color features. The model's accuracy in predicting the replacement rate of steel slag sand is 87.99%, which is better than the original ConvNeXt network and other standard convolutional neural networks. After using the migration learning training method, the model predicts the steel slag sand substitution rate with 92.64% accuracy, improving accuracy by 4.65%. The SE attention mechanism and the migration learning training method can help the model acquire the critical features of the image better and effectively improve the model's accuracy. The method proposed in this paper can identify the steel slag sand substitution rate quickly and accurately and can be used for the detection of the steel slag sand substitution rate.

Effects of incorporating large quantities of nickel slag with various particle sizes on the strength and pore structure of cement-based materials

Firstly, nickel slag sand with a concentrated particle size distribution in the range of 2.36–0.60 mm was used to replace the mechanism sand in the ratio of 0%, 25%, 30%, 50%, 70% and 100%. Second, partial particle size substitution was used to partially replace nickel slag sand with particle sizes of 2.36–1.18 mm and 1.18–0.60 mm in proportions of 0%, 30%, 50%, 60%, 70% and 100%, respectively, to optimize particle gradation of mixed sand. Cement mortar specimens were prepared using different mixed sands composed of the above two substitution methods and at a water-cement ratio of 0.5. Then, the effects of nickel slag sand with varying substitution methods on the strength and pore structure of cement-based materials were investigated by mechanical tests, mercury intrusion porosimetry (MIP) and scanning electron microscopy (SEM). Standard sand was also used as an experimental control group. The experimental results revealed that the maximum flexural and compressive strength of nickel slag sand using a full-size substitution group corresponded to an optimal dosage of 30%, while the optimal dosage of nickel-slag sand using a specific-size substitution group was 60%. The water absorption of the two particle sizes replaced the specimens decreased and then increased with the inclusion of nickel slag sand. The results showed a consistent trend with the variations in electrical resistivity and total porosity of MIP. From the SEM photographic results of the SS, MS, NF30 and NP60 specimens, the cement paste can be more tightly wrapped around the round spherical nickel slag particles. NF30 and NP60 specimens showed a denser internal structure, multi-dimensional hydration products and a lack of pores and microcracks, which is fully consistent with experimental results of mechanical properties and microstructures.

Bond strength characteristics of high strength alkali activated slag concrete mixes

Bond characteristics are influenced by several factors such as concrete compressive strength, type, diameter, and embedment length of the bar and confinement of concrete. Herein, an attempt has been made to evaluate the bond strength characteristics of a new class of high-strength, flowable, alkali activated slag concrete mixes made using the industrial by-products from iron and steel industries. Such evaluations are made using the results of direct pull out tests where again, the bond stress – slip behaviour of the trial mixes at different ages are also studied. GGBFS was used as the principal binder along with fine amorphous quartz powder in the development of the present class of high strength, flowable AASC mixes. While mixtures of steel slag sand and quartz sand were used as the fine aggregates, 12.5 mm down electric-arc furnace slag aggregates constituted the coarse aggregate fractions in all these mixes. The alkaline solutions used consisted of mixtures of specified amounts of sodium hydroxide flakes dissolved in the calculated quantity of water pre-mixed with the liquid sodium silicate solution. The experimental study was planned based on Taguchi’s design of experiments methodology. A set of AASC mixes were developed and evaluated for their workability characteristics along with compressive strengths at the ages of 3, 28, 56 and 90 days. Bond strength characteristics of a set of nine of such mixes were evaluated in an initial calibration phase. Strength prediction equations were then derived based on those initial results, the predictive capability of which were then assessed and ascertained with actual results of experiments on a set of six new mixes, in the prediction phase. Further better bond stress-slip behavior, with higher bond strength values, varying in the range of 12–14 MPa as compared to control OPC based reference concrete mix were obtained for the AASC mixes.

СТРОИТЕЛЬНЫЕ МАТЕРИАЛЫ И МИНЕРАЛЬНЫЕ ВЯЖУЩИЕ ВЕЩЕСТВА НА ОСНОВЕ ГИДРАТИРОВАННЫХ ЗОЛОШЛАКОВЫХ ОТХОДОВ УГЛЕСЖИГАЮЩИХ ЭЛЕКТРОСТАНЦИЙ И ОТХОДОВ УГЛЕОБОГАЩЕНИЯ

The results of scientific research on the development of a comprehensive technology for processing waste from coal mining and coal refining, including in building materials and mineral binders, are presented. The technology of extraction of underburning, slag sand, iron-containing concentrate and microspheres has been tested in production conditions.

Self - Compacting Concrete Using Slag Sand as Fine Aggregate

Self - Compacting Concrete Using Slag Sand as Fine Aggregate

Effect of slag sand as river sand and its influence on compressive strength of the cement mortar

Cement mortar is widely used in all construction activities due to its strong binding and durable properties. Sand is the main ingredient in preparing cement mortar in different ratios from 1:1 to 1: 8 for various elements in construction. As we are facing a shortfall for river sand, an alternate crushed stone as M−sand is used everywhere for river sand. Mining, crushing rock particles, and stone quarrying also have long-term effects on the environment. Industrial effluents from the manufacturing of steel, copper, and coal also possess some aggregates properties, dumping them as waste, leading to disposal challenges & adverse environmental impacts. Hence researchers are trying different ways to minimize waste disposal and address the scarcity of river sand in construction activities. One such trial is attempted in this study to utilize the waste effluent slag sand obtained from the steel industry as a replacement for sand. The experimental investigation is conducted by replacing slag sand in various percentages from 0 to 100% in the ratio of 1:3 cement mortar. A microstructure test was performed on slag sand to check its feasibility compared to M−sand, and the compressive strength of mortar was analyzed at 3, 7, and 28 days of curing. Also, an Ultrasonic pulse velocity test is performed to evaluate the quality of the mortar. Test results revealed that slag sand increases strength with age. But slag sand absorbs more water compared to M−sand, making the mix stiffer. Adding the extra water corresponds to water absorption percentage, and strength increased further at all ages of curing and improved cement mortar quality. Thus, the optimum percentage of slag sand as a replacement for M−sand is 50% in cement mortar. Thereby helping minimize the disposal challenge by producing eco-friendly mortar and reducing the construction cost. This slag sand proves as a sustainable material for futuristic constructions.

Compressive-Tensile Mechanics and Energy Consumptions of a Cementitious Composite with High Utilization of Steel Slag

In response to the National Development and Reform Commission's “Guiding Opinions on Comprehensive Utilization of Large Solid Wastes during the Fourteenth Five Year Plan”, further expand the use of steel slag as concrete admixture in construction projects and other fields, and gradually improve the comprehensive utilization ratio, a cementitious composite with high utilization of steel slag (CHS) was developed, which is with the cement replaced by high-content super-fine steel slag powder (SSP) (replacement ratio υ ≥ 30%) as the cementitious materials, steel slag sand (SS) as the only aggregate and environmentally basalt fiber (BF) for toughening. It improves the utilization percentage of steel slag (SSP and SS) and reduces the consumption of natural resources such as cement and natural sand. Use BF to achieve better strength and toughness. In order to better understand the performance of CHS and make it better used in the engineering field. Study the influence of each component on the strength and energy consumption of compression and splitting tension, and strive to find the optimal proportion and lay the theoretical foundation for its application. Through the tests, the effects of high replacement ratio υ (30%–50%), low binder-aggregate ratio γ (0.31–0.44), and BF content ρv (0%–2%) on the aspects of peak strength, force-deformation curve and energy consumption were analyzed. The results show that the standard curing fck and ft,s can reach 40 MPa and 5 MPa respectively. With the increase of υ, the maximum axial compressive strength fck and splitting tensile strength ft,s decreased insignificantly. The γ has an important influence on fck and ft,s. When it increases from 0.31 to 0.44, fck increases linearly by 63.1% to 40.4 MPa, while ft,s increases by 52.8% to 5.18 MPa. As ρv increases, fck and ft,s show a trend of first increasing and then decreasing. ρv exerts a significant impact on the descending segments of stress-strain response curves of the compression which expressed as bilinear and trilinear models with different ρv after normalization. The energy consumptions of peak, total, and residual (Epeak, Edisp, Eres) show a slight downward trend with the increase of υ, a significantly upward trend with the increase of γ. With the increase of γv, and Edisp increase first and then tend to be flat, while Eres always increases and the percentages of Eres/Edisp in the compressive test increase from 22.6% to 38.5%, reflecting the improvement of the compressive toughness of BF.

Crack Resistance under Compressive Stress of Concrete Made Using Granulated Blast-furnace Slag Sand

Crack Resistance under Compressive Stress of Concrete Made Using Granulated Blast-furnace Slag Sand

Workability and Strength of Ceramsite Self-Compacting Concrete with Steel Slag Sand

This study focuses on the workability and compressive strength of ceramsite self-compacting concrete with fine aggregate partially substituted by steel slag sand (CSLSCC) to prevent the pollution of steel slag in the environment. The SF, J-ring, visual stability index, and sieve analysis tests are primarily employed in this research to investigate the workability of freshly mixed self-compacting concrete containing steel slag at various steel slag sand replacement rates. The experiment results indicate that CSLSCC with the 20% volume percentage of steel slag (VPS) performs better workability, higher strength, and higher specific strength. The 7-day compressive strength of CSLSCC with the 0.4 of the water-binder ratio (W/B), decreases with the increase of steel slag content, while the 28-day compressive strength increases significantly. The ceramsite self-compacting concrete with good comprehensive performance can be obtained when the substitution rate of steel slag sand for fine aggregate is less than 20% (volume percentage).

Experimental Study on the Properties of Mortar and Concrete Made with Tunnel Slag Machine-Made Sand.

Machine-made sand is gradually replacing natural sand to achieve sustainable development. Experimental studies and gray-correlation analysis were used to study the properties of tunnel slag machine-made mortar and concrete. The properties of machine-made mortar with different stone powder content were analyzed through experiments. By analyzing the performance of machine-made sand concrete with equal amounts of cement replaced by stone powder, the optimum replacement ratio is obtained. Gray-correlation analysis was used to compare the degree of influence of fineness modulus and stone powder content on the performance of concrete. Scanning electron microscopy (SEM) and X-ray diffractometry (XRD) were used to analyze the microstructure of tunnel slag sand concrete. The test results showed that the flexural and compressive strengths of the machine-made sand concrete were greater than the standard sand with the same stone powder content. The 28-day flexural and compressive strengths had a maximum difference of more than 30%. The best stone powder content of the machine-made mortar is in the range of 5% to 8%. When the replacement cement content of stone powder is about 6%, the mechanical and working properties of machine-made sand concrete achieve the optimal state. The lower the stone powder content, the closer the mechanical and working properties of machine-made sand concrete and river sand concrete. The correlation between the performance of machine-made sand concrete and fineness modulus is the largest. When the stone powder content is low, it has almost no effect on the compressive strength of concrete. The results point out the direction for the quality control of tunnel slag machine-made sand concrete.

The Durability and Leaching Behavior of Granulated Blast Furnace Slag, Fly Ash, and Waste Foundry Sand Geopolymers

Waste generation and management in industries is a major problem worldwide. In this study, granulated blast furnace slag (GBFS), fly ash (FA) + cement (CM), and de-silicated foundry sand (DFS) based geopolymers were developed and their leachability studied. The elemental composition showed that the raw materials studied had the highest compositions in SiO2 and Al2O3, which are the constituents desired for the formation of a geopolymer. The GBFS geopolymer had the highest unconfined compressive strength (UCS) of 30.977 MPa, followed by the FA + CM geopolymer with 16.704 MPa. The DFS geopolymer recorded the lowest strength. The mineralogy of GBFS geopolymer showed the presence of an amorphous phase which consisted predominantly of grossite. The FA + CM-based geopolymer had an amorphous and crystalline phase predominated by sillimanite. The DFS-based geopolymer consisted mainly of sodium silicate hydrate. The leaching tests showed that the concentrations of the elements in the leachates were all below the regulatory limits. All of the developed geopolymers were considered environmentally friendly. This study showed that GBFS geopolymer and fly ash + CM-based geopolymers have good durability and leaching behavior, with DFS-based geopolymers possessing poor durability but good leaching behavior. The studied geopolymers are suitable for use as building wall materials and paving bricks without compromising and polluting the environment.

Performance and life-cycle assessment of high-volume fly ash concrete mixes containing steel slag sand

The present study discusses the performance of high-volume fly ash concrete (HVFAC) mixes containing slag sand which is a solid waste obtained from basic oxygen steel making industry. The design of such mixes was optimized to attain sufficient strength for structural purposes and then cement and natural sand in them were replaced with fly ash and slag sand up to 50%. Other than temperature developments, their fresh and hardened properties like slump, air content, compressive and tensile strengths, elastic modulus, strain softening response under uniaxial compression, shrinkage, water permeation, sorption and absorption, chloride ions diffusion and migration, and bulk electrical resistance at different ages were also studied in detail. The impact of fly ash and slag sand on the sustainability of such mixes were assessed and their co-effects on concrete microstructure were discussed with the results of scanning electron microscopy and Mercury intrusion porosimetry. The HVFAC mixes displayed a slower strength increase at early ages, but they were found to be highly workable, durable, and temperature rise in them was comparatively lower. The strength and durability of these mixes at early ages were found to enhance in the presence of slag sand which is generally capable of strengthening the aggregate-paste interface. India is the second largest producer of cement in the world. Both the fly ash and slag sand possess a lower energy requirement and their inclusions led to the production of eco-friendly concrete which is highly desirable for Indian conditions.

Influence of Industrial By-Product Materials on Bituminous Concrete Mixes

In this research work, laboratory studies are aimed at using copper slag and foundry sand as mineral fillers and fine aggregates as partial replacement of traditional mineral fillers and fine aggregate particles and will help in building sustainable roadways. The aggregate gradation corresponding to the bituminous concrete mid-limit grading-2 was adopted in accordance with Section 500 of Table No. 500-18 of MORT&H's Fourth Amendment Specifications in order to examine the mix design characteristics. From the laboratory investigation it is observed that the stability, tensile strength, water resistivity, dynamic stability, resistance to rut depth, resistance to proportional rut depth, and resistance to wheel tracking slope of the bituminous concrete mixtures improved with increasing CSMF, FSMF, and CSFAMF content in BC-2 mixture. However, the poor interlocking property of FSFAMF reduces its strength. Thus, the research study has indicated that the application of copper slag and foundry sand would minimize the quantity of traditional aggregate required in highway construction.

Predicting Slump Values of Concrete Made by Pozzolans and Manufactured Sand using ANN

Large amounts of natural fine aggregate (NFA) and cement are used in building, which has major environmental consequences. This view of industrial waste can be used in part as an alternative to cement and part of the sand produced by the crusher as fine aggregate, similar to slag sand (GGBFS), fly ash, metacaolin, and silica fume. Many times, there are issues with the fresh characteristics of concrete when using alternative materials. The ANN tool is used in this paper to develop a Matlab software model that collapses concrete made with pozzolanic material and partially replaces natural fine aggregate (NFA) with manufactured sand (MS). Predict. The slump test was carried out in reference with I.S11991959, and the findings were used to create the artificial neural network (ANN) model. To mimic the formation, a total of 131 outcome values are employed, with 20% being used for model testing and 80% being used for model training. 25 enter the material properties to determine the concrete slump achieved by partially substituting pozzolan for cement and artificial sand (MS) for natural fine aggregate (NFA). According to studies, the workability of concrete is critically harmed as the amount of artificial sand replacing natural sand grows. The ANN model's results are extremely accurate, and they can forecast the slump of concrete prepared by partly substituting natural fine aggregate (NFA) and artificial sand (MS) with pozzolan.

Impact of construction & demolition waste and slag sand on the properties of high strength self - compacting concrete

This Research mainly focuses to explore the characteristics of High Strength self-compacting concrete developed using industrial waste steel slag sand and construction demolition waste. The purpose of this study is to examine both rheological and hardened properties by incorporating steel slag sand and C&D waste as a substitute to M−Sand in different proportions along with comparison of the three sands in equal quantities. The test results exhibited good flow ability, passing and filling abilities for all the combinations adopted which satisfied the EFNARC Guidelines. The results showed that compression, split-tensile and flexural strength of High-performance self -compacting concrete has declination with higher percentages of steel slag sand and C&D Waste. The maximum declination was observed at complete replacements of slag sand with respect control mix. Utilization of adopted materials in equal proportions exhibited promising results compared to control concrete and this can be considered optimum.

Recycling of Water Quenched Slag and Silica Sand Tailing for the Synthesis of an Eco-Friendly Permeable Material

Recycling of Water Quenched Slag and Silica Sand Tailing for the Synthesis of an Eco-Friendly Permeable Material

Influence of Granulated Blast Furnace Slag Sand as Fine Aggregate on the Resistance Against Sulphate and Chloride Solution of Self-Cured Geopolymer Concrete

Influence of Granulated Blast Furnace Slag Sand as Fine Aggregate on the Resistance Against Sulphate and Chloride Solution of Self-Cured Geopolymer Concrete