Fly Slag Research Articles

Microbial Growth and Calcium Carbonate Nucleation Properties in Mineral Admixtures

In this study, steel slag powder and fly ash were used as reinforcement and modification materials, and their effects on the growth, survival, and nucleation of mineral admixtures on bacteria were analyzed. Electrical conductivity, urease activity, and zeta potential tests were conducted, and the results showed that: (1) different mineral environments had different effects on the urease activity of Sporosarcina pasteurii. The steel slag powder solution inhibited urease activity, while the fly ash solution promoted urease activity. (2) S. pasteurii showed different growth characteristics in different mineral environments, especially in the fly ash solution, which showed higher hydrolysis efficiency, urease activity, and calcium carbonate yield. (3) The zeta potential test results showed that the nucleation of mineral admixtures on bacteria started to occur when the calcium ion concentration in the mineral filtrate was higher than 15 mmol/L. Different calcium ion concentrations showed greater impacts on the nucleation rate of mineral admixtures. The results of this study indicated the adaptability of microorganisms in the steel slag powder and fly ash solutions and the nucleation characteristics of calcium carbonate on the microbial surface, providing a theoretical and experimental basis for the subsequent development of new sand-fixing materials.

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.

Possibilities of Application Cement By-Pass Dust into the Garden Architecture Elements

This article deals with the possibility of using cement by-pass dust (CBPD) in the garden architecture elements, specifically in curbs for park use. To increase the positive effect on the environment, other secondary raw materials were also used in the research, specifically blast furnace granulated slag and silica fly ash. Mixtures were based on alkali activation, where cement as a binder was 100% replaced by raw materials with waste properties. In the research, properties of used materials and also the basic physical-mechanical and durability properties of prepared mixtures were determined Part of the research focused on the effect of the tested beams on the grassland planted around the beams. Any significant negative impact was not registered, except for low pH increase of soil. Infrared spectroscopy and thermal analysis were performed on selected samples. Testing has shown that the products are in accordance with the Czech standard requirements for concrete curbs in garden architecture. The samples did not pass only the scaling test, which is, however, a condition for concrete curbs used for roads. For garden architecture this test is not required.

Behaviour of Fly Ash based Geopolymer Concrete using Nano-Material

In the Construction sector the need of cement is expanding step by step for fulfilling the need of improvement of foundation developments. The creation of Ordinary Portland concrete emanates the enormous amount of CO2 into the climate. Hence, it is basic to discover choices to make the solid eco - neighborly. Low calcium fly ash based geopolymer cement is a substitute choice for bond based cement. It is an inorganic alumina-silicate compound, blended from fly ash remains. The exploratory work on Geopolymer cement is to assess the impact of different parameters influencing its compressive quality and usefulness of cement so as to improve its general execution was extended. Basic arrangement utilized for present examination is mix of sodium hydroxide and sodium silicate. By applying the Nano Technology, expansion of Nano silica is to improve the quality of cement. The essential distinction between geo-polymer cement and Portland bond cement is the binding property. The silicon and aluminum oxides in the low-calcium fly slag responds with the soluble fluid to frame the geo-polymer concrete that ties the free coarse aggregate, fine aggregate, and other un-responded materials together to shape the geo-polymer concrete. As on account of Portland bond concrete, the coarse and fine totals possess around 75 to 80% of the mass of geo-polymer concrete. The impact of totals, for example, reviewing, precision and quality, are viewed as equivalent to on account of Portland bond concrete. Along these lines, this segment of geo-polymer solid blends can be structured utilizing the instruments as of now accessible bond for Portland concrete. The principle goal of this exploration work is to break down the carbon dioxide free cementitious material with its quality, functionality properties and their impacts on Geopolymer concrete for maintainable improvement.

Fractional Substitute of Fine Aggregates with Pozzocrete Foundary Sand

To pass on immaterial effort concrete by mixing different degrees of fine total and bond with utilized foundry sand and Pozzocrete to decrease trade and sullying issues in light of utilized foundry sand and Pozzocrete. Pozzocrete P60 is a dealt with worth guaranteed fly slag, researched for its utilization as an inadequate swap for bond in cement (1:1.48:3.21). The usage of Pozzocrete P60 as bond substitution material in cement or as included substance in strong shows different focal points from sensible, explicit and ordinary perspectives. The creative use of utilized foundry sand in solid plans as a fine total substitution material was endeavored as a decision rather than standard cement. This paper demonstrates the results of the solid of blend proportion1:1.48:3.21 in which security is for the most part supplanted with PozzocreteP60 as 10% by weight of bond, and fine hard and fast isn't completely supplanted with utilized foundry sand as 10%, 30% and half by weight of fine total. Five courses of action of blend degrees were made. First (A0) were standard blend (without Pozzocrete and utilized foundry) sand with ordinary fine total (sand) and coarse total and the second (B0) blend contained 10% Pozzocrete P60obtained from DIRK India Private Limited, Nasik, Maharashtra state. Different blends (B1, B2, and B3) contained Pozzocrete P60 (10%) despite foundry sand (10%, 30%and half) solely got from ferrous and non-ferrous metal hurling associations. The compressive quality and water support has been gotten with halfway superseding of Pozzocrete P60 with bond and foundry sand with fine total. Test outcomes demonstrate the augmentation in the quality properties of cement and decreasing water assimilation of cement up to 10% overriding of security with Pozzocrete plus30% supplanting of fine total with utilized foundry sand for quality at 7, 14 and 28 days. Moreover it might be used in non-essential parts with the low range compressive quality where quality isn't required and negligible exertion brief structure is prepared.

Utilization of Fiber Reinforcement Materials in Flexible Pavement Construction

By and by multi day's the masses and region traffic significance end up building up each day and surface rate additionally creating. On the off chance that there ought to emerge an event of bendy black-tops the mistake are occurs because of unprotected soil sub assessment and lack of customary substances. those bungle ups ascend in perspective on flinging, part, and division of roads, and so forth regularly broad soil burdens are over the top due to intermittent versions that element while in contact with water, it will swell and analysts even as water presses out. To impediment the regard we are utilizing sisal and jute fiber as stronghold material in the fly slag sub base courses laid with grasp to broad soil sub level. It wound up looked over the exploration office check consequences of changed compaction, direct shear and CBR that the most extraordinary appealing dimension of sisal and jute fiber is vague from 0.2% for fly soot material. Cyclic plate load assessments were performed inside the examination focus through setting a round metallic plate on model versatile blacktops. it's far checked that the most extraordinary weight passing on potential related to a ton less estimation of ricochet back evasion is gained for sisal and jute fiber strengthened stretch stood out from unreinforced fly red hot flotsam and jetsam stretch out inside the versatile black-top contraption laid on extensive sub grade.

Effect of Ferronickel Slag Powder on Microhydration Heat, Flow, Compressive Strength, and Drying Shrinkage of Mortar

This paper investigates the effect of ferronickel slag powder on microhydration heat, flow, compressive strength, and drying shrinkage of mortar. In South Korea, approximately two million tons of ferronickel slag, a by‐product of the nickel industry, are produced every year. However, a considerable amount of this by‐product is treated as waste and dumped in landfills. Ferronickel slag powder was used to replace Portland cement at a ratio of 15% by binder mass. In addition, the mortar test with other cementitious materials, including blast‐furnace slag powder and fly ash, was conducted and compared with the sample containing ferronickel slag powder. According to this investigation, the microhydration heat of mortar and concrete can be reduced with the appropriate use of ferronickel slag powder. In addition, in order to achieve higher concrete compressive strengths, it is apparently advantageous to use the ferronickel slag powder and fly ash together rather than using ferronickel slag powder alone.

Immobilization of Sr<sup>2+</sup>, Bi<sup>3+</sup> and Zn<sup>2+</sup> in Alkali-Activated Materials Based on Blast Furnace Slag and Fly Ash

It is well known, that alkali-activated materials (AAMs) are suitable for immobilization of heavy metals and other hazardous materials. This study is focused on the characterization of inhibition of three metals – Sr2+, Bi3+and Zn2+in alkali-activated matrices. Two type of matrices were prepared – alkali-activated blast furnace slag (BFS) and alkali-activated fly ash (FA). Sodium water glass was used as alkaline activator. The ability of these matrices to fix the metals were proved by leaching tests. Compressive strength was measured to characterize mechanical properties of the matrices. Scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDS) was used to examine distribution and chemical state of metals within the matrices. The observed metals mainly formed the insoluble compounds after alkali activation.

Effect of modified supplementary cementitious material on performance of mortar and concrete in marine environment

This study aims to explore the durability issues regarding chloride ion corrosion of concrete structures, and further investigates the modified supplementary cementitious material (MSCM) which acts as a significant enhancer of performance of mortar and concrete. The composition of MSCM includes mineral slag powder, fly ash and inhibitor. The microstructure, sulfate erosion resistance and electric flux of high-performance concrete are tested with MSCM, and the results show that the pore structure of concrete is improved significantly along with excellent electrochemical performance. It is observed that the substantiality of concrete after being mixed with 18% (mass fraction) MSCM is enhanced effectively. The sulfate resistance coefficient of concrete is found to be greater than 1.2, and the electric flux of concrete is less than 600C. These results have demonstrated that the MSCM possesses an excellent electrochemical performance and a wide applicative prospect in marine environment.

Effect of alkaline material on phytotoxicity and bioavailability of Cu, Cd, Pb and Zn in stabilized sewage sludge

ABSTRACTThe availability and phytotoxicity of heavy metals in sewage sludge is the key restrictive factor that limits sludge application. In this study, municipal sewage sludge was stabilized by alkaline slag or coal fly ash, then the leaching characteristic and fraction distributions of Cu, Cd, Pb and Zn were studied, and their effects on seed germination, root length, and plant accumulating were compared. The results showed that mixed sewage sludge with alkaline slag and coal fly ash decreased the percentage of available heavy metals in sewage sludge. The percentage of exchangeable Cu, Pb, Zn and Cd in stabilized sewage sludge (S1–S4) was 1.50–8.67 times lower than that in SS-only treatment. Leachate Cd, Cu, Pb and Zn from stabilized SS was much lower than the limit threshold. The addition of alkaline materials to SS reduced the inhibitory effect on seed germination and root growth. Pearson’s correlation analysis indicated that there was a significant negative correlation between pH and available heavy metals, while a significant positive correlation between the percentage of exchangeable fraction of heavy metals, the leaching potential, tissue concentration and accumulation of heavy metal and toxicity for seed germination was observed.

The Development of a Low Carbon Cementitious Material Produced from Cement, Ground Granulated Blast Furnace Slag and High Calcium Fly Ash

This research represents experimental work for investigation of the influence of utilising Ground Granulated Blast Furnace Slag (GGBS) and High Calcium Fly Ash (HCFA) as a partial replacement for Ordinary Portland Cement (OPC) and produce a low carbon cementitious material with comparable compressive strength to OPC. Firstly, GGBS was used as a partial replacement to OPC to produce a binary blended cementitious material (BBCM); the replacements were 0, 10, 15, 20, 25, 30, 35, 40, 45 and 50% by the dry mass of OPC. The optimum BBCM was mixed with HCFA to produce a ternary blended cementitious material (TBCM). The replacements were 0, 10, 15, 20, 25, 30, 35, 40, 45 and 50% by the dry mass of BBCM. The compressive strength at ages of 7 and 28 days was utilised for assessing the performance of the test specimens in comparison to the reference mixture using 100% OPC as a binder. The results showed that the optimum BBCM was the mix produced from 25% GGBS and 75% OPC with compressive strength of 32.2 MPa at the age of 28 days. In addition, the results of the TBCM have shown that the addition of 10, 15, 20 and 25% of HCFA to the optimum BBCM improved the compressive strength by 22.7, 11.3, 5.2 and 2.1% respectively at 28 days. However, the replacement of optimum BBCM with more than 25% HCFA have showed a gradual drop in the compressive strength in comparison to the control mix. TBCM with 25% HCFA was considered to be the optimum as it showed better compressive strength than the control mix and at the same time reduced the amount of cement to 56%. Reducing the cement content to 56% will contribute to decrease the cost of construction materials, provide better compressive strength and also reduce the CO2 emissions into the atmosphere.

Composites Based on Alternative Raw Materials at High Temperature Conditions

This paper presents newly developed polymer-cement composites.The primary binder (cement) was partially substituted byuse of blast-furnace slag and high-temperature fly ash. A lightweightaggregate – agloporite (grain size in range 1–2 mm) wasused among other components. This porous aggregate is producedfrom energy by-products (fly ash). Attention was focusedon the behavior of the composites when exposed to elevatedtemperatures (400 °C–1,000°C). The influence of several differentmethods of temperature decrease was assessed – slow(in furnace 1°C/min) and rapid (laboratory ambient 22°C andwater bath 18°C). Specific dimensional changes were determined,including strength characteristics and bulk density.Structural deterioration and microstructural changes of selectedspecimens were investigated by analytical techniques (SEM andCT). Compressive and bending tensile strength changed variouslydepending on temperature changes, including severalcooling conditions. Deterioration reactions (especially cracks)which were formed in investigated composite structures correspondedwith results of physico-mechanical testing. That wasconfirmed by using the CT and SEM.The fact that the agloporite has a positive effect on thermalresistance of developed polymer-cement composites wasproved. Almost no cracks or other failures were identified (byusing CT and SEM) in interfacial transition zones of agloporiteafter thermal stress. This indicates very good bond adhesionbetween the matrix and the porous aggregates during extremetemperature conditions (in case of different cooling methods).

Characteristics of the Concrete with Blast Furnace Slag Fine Aggregate and Fly Ash and its Applications

Characteristics of the Concrete with Blast Furnace Slag Fine Aggregate and Fly Ash and its Applications

Evaluation of Modifications to the ASTM C672 Deicer Salt Scaling Test for Concrete Containing Slag Cement

Abstract The standard ASTM C672/C672M-12 deicer salt scaling resistance test has been found to be overly aggressive to concretes containing slag cement or fly ash. It was compared to the recently adopted CSA A23.2-22A test method, based on the Quebec BNQ test, as well as several modifications, including use of an accelerated curing regime developed by Virginia (VADOT). Sixteen concrete mixtures were studied using high-alkali cement, low-alkali cement, grade 100 slag and grade 120 slag with slag contents of 0, 20, 35, and 50 %. Vinsol resin air-entraining admixture (AEA) was compared to a synthetic AEA. Modifications to the test method used in this study resulted in improved deicer scaling performance of concretes containing slag and many of these modifications have been incorporated into the CSA A23.2-22A test method. While it was found that increasing the level of slag replacement resulted in increased scaling, it was found that for slag mixtures, the synthetic AEA provided an improved air void spacing factor, higher hardened air content, and improved scaling resistance compared to Vinsol resin AEA.

Low temperature synthesis of cement from ladle slag and fly ash

This study investigates the feasibility of producing environmentally friendly cement exclusively from industry wastes: ladle slag fines and fly ash. A low temperature clinkering process was implemented to produce a cement material capable of gaining early strength by carbonation and late strength by hydration. The optimum uses of fly ash and clinkering temperature were determined by undergoing meticulous parametric studies. The results of this investigation demonstrate that the higher the clinkering temperatures used, the higher the carbonation and hydration reactivity of the cement. The optimal fly ash ratio and temperature for synthesizing cement was found as 30% and 1250 °C, respectively. The composite action generated by calcium carbonates and calcium silicate hydrates eventually plays an important role in gaining the strength. Production of cement with ladle slag and fly ash at low temperature can reduce the energy consumption, the natural resources consumption, landfills disposal cost, and the total CO2 emission.

Resistance Performance of Concrete Using both Blast Furnace Slag Cement and Fly Ash against Chloride Attack and Carbonation

From the viewpoint of effective utilization of industrial wastes and reduction of CO2 emission, the use of concrete mixed with blast furnace slag and fly ash has been promoted. However, the durability of fly ash concrete using blast furnace slag cement has not been clarified enough. About chloride attack, the resistance against the penetration of chloride ions could be improved due to the dense pore structure formed by the synegetic effect of mixing both ground granulated blast-furnace slag and fly ash into concrete. In this study, resistance performance of concrete using both blast furnace slag cement and fly ash against chloride attack and carbonation was experimentally investigated. The relationship between such resistance performance and pore structure of the concrete was also examined. As a result, the combination of blast furnace slag cement and fly ash type II resulted in the decrease of pore volume over 50 nm in the diameter and reduction of the apparent diffusion coefficient of chloride ion, but the resistance performance against carbonation of the concrete was lower than the case of the normal fly ash concrete.

Statistical mixture design of ternary blends for controlling ASR

Supplementary cementitious materials (SCMs) are long proven to control alkali–silica reaction (ASR) in concrete. Some SCMs such as slag and high-calcium fly ash are less effective than others and need high replacement levels, which may not be practical for various construction purposes. Combining two SCMs with Portland cement (i.e. ternary blend) offers design flexibility for the desired performance. This study investigates the use of statistical mix design in formulating ternary blends for ASR. Thirty-one mixtures were prepared based on statistical mixture design and tested using the accelerated mortar bar method. Five groups of ternary blends were investigated: Portland cement/metakaolin/brick powder, Portland cement/metakaolin/high-calcium fly ash, Portland cement/metakaolin/low-calcium fly ash, Portland cement/high-calcium fly ash/low-calcium fly ash and Portland cement/high-calcium fly ash/slag. The performances of the ternary blends were analysed using statistical models. The results showed that SCMs can be effectively combined in ternary blends to control ASR and the statistical mixture design can be a beneficial tool in formulating ternary blends for ASR performance. It was also found that 0·20% expansion at 28 d in an accelerated mortar bar test can be used as a second threshold for mixes containing SCM.

Gas and particle flow characteristics in the gas reversing chamber of a syngas cooler for a 300 MWe IGCC process

The gas reversing chamber (GRC) is the top part of a syngas cooler in the Shell coal gasification process, in which the quenched syngas flowing from the gasifier is turned downward into evaporator channels. Using computational fluid dynamics (CFD), this study investigated the detailed gas/particle flow and heat transfer characteristics in the GRC of an integrated gasification combined cycle (IGCC) process with 300 MWe capacity for operational loads between 50 and 100%. The gas flow rapidly changed its direction to downward after impinging onto the wall opposite to the inlet. This led to the formation of a higher velocity region along the opposite side, increasing the gas flow rate in the outer channel of the evaporator. In contrast, a region with low velocity below 2 m/s developed towards the inlet side above the evaporator, which may lead to the significant deposition of fly slag particles onto the structural elements. Larger wall heat flux appeared along the main gas stream with a maximum of 180 kW/m2 at full load. Convection accounted for about 70% of the total heat transfer rate, of which the coefficient was correlated to Nu = 8.778 Re0.435Pr0.3. Many particles impinged onto the wall along the main gas stream, especially at the joint connecting the transfer duct and the GRC. However, erosion by fly slag was not expected to be significant, mainly due to the reduced gas velocity at the high operating pressure (43 bar).

IGCC 합성가스 급속 냉각시스템의 운전 압력에 따른 열유동 및 입자 거동 특성 연구

In a coal gasifier for IGCC, hot syngas leaving the gasifier at about 1550oC is rapidly quenched by cold syngas recycled from the gas cleaning process. This study investigated the flow and heat transfer characteristics in the gas quench system of a commercial IGCC process plant under different operating pressures. As the operating pressure increased from 30 bar to 50 bar, the reduced gas velocity shortened the hot syngas core. The hot fly slag particles were retained within the core more effectively, and the heat transfer became more intensive around the hot gas core under higher pressures. Despite the high particle concentrations, the wall erosion by particle impaction was estimated not significant. However, large particles became more stagnant in the transfer duct due to the reduced gas velocity and drag force under higher pressures.

Durability and Mechanical Behaviors of Steel Slag Powder Concrete

The mechanical behaviors and durability of concrete containing steel slag powder (SSP), silica fume (SF) and fly ash (FA) were presented in this study. The fresh concrete properties, compressive strength, split tensile strength, elastic modulus, stress-stain curve, chloride permeability as well as carbonation of concretes mixed with different SSP contents or concretes containing compound mineral admixture were tested. The experimental results reveal that the mechanical behaviors and durability of concrete with 10% SSP replacing cement are both improved than that of the reference concrete. Mechanical behaviors and durability of concrete with 20% SSP replacing cement are similar to the reference concrete. Concrete with compound mineral admixture of SSP and SF obtain the highest enhancement in both strength and chloride resistance.