Optimization of ferrochrome slag as coarse aggregate in concretes

The present study focuses on the possibility of use of alkali activated binders for use in concrete pavements. Alkali Activated Slag Concrete (AASC) and Alkali Activated Slag Fly ash Concrete (AASFC) are prepared and the properties are compared with Ordinary Portland Cement Concrete (OPCC). The Ground Granulated Blast Furnace Slag (GGBFS) and Fly Ash (FA) are blended in the ratios 100:0, 75:25, 50:50 and 25:75 as binder and activated using strong alkaline solution. Trial mixes are carried out to identify the optimal Activator Modulus (Ms) for each combination of GGBFS and FA. The mix design for the optimal activator modulus is optimised to achieve sufficient strength for Pavement Quality Concrete (PQC) and the fresh and mechanical properties are studied in detail. The results indicate the properties of AASC and AASFC are similar or slightly better than conventional OPCC and satisfy the minimum strength requirements for concrete pavements. The application of alkali activated binders will minimise the environmental hazards occurring from augmented OPC production, along with effective utilisation of industrial waste materials and conservation of natural resources.

Cement is the most significant component in concrete. Large scale manufacturing of cement consumes more energy and release harmful products (Carbon dioxide) into the atmosphere that adversely affect the environment and depletes the natural resources. A lot of research is going on in globally concentrating on the recycling and reuse of waste materials from many industries. A major share of research is focused on finding cementitious materials alternatives to ordinary Portland cement. Many industrial waste by-products such as quartz powder, metakaolin, ground granulated blast furnace slag, silica fume, and fly ash etc. are under investigations for replacement of cement in concrete to minimize greenhouse gases and improve the sustainable construction. In current research, the effects of a new generation, ultra-fine material i.e., alccofine which is obtained from ground granulated blast furnace slag are studied as partial replacement by 25% and with varying amounts of sulfonated naphthalene formaldehyde (i.e., 0.3%, 0.35% and 0.40%) on mechanical, water absorption, thermal and microstructural properties of concrete. The results showed moderate improvement in all concrete properties. Addition of SNF with combination of alccofine showed a significant enhancement in fresh, hardened properties and water absorption test as well as thermal and microstructural properties of concrete.

The paper investigated the effect of locally sourced fly ash and ground granulated blast-furnace slag (GGBS) on the compressive strength and chloride resistance of concrete. The mix proportion was cementitious material (total of ordinary Portland cement (OPC), fly ash and GGBS): sand: coarse aggregate: water of 1:2:3:0.6 in which 20% by mass of total cementitious materials was replaced by class F fly ash and GGBS. Compressive strength and rapid chloride penetration tests were conducted at 28, 56 and 120 days. The results shows that fly ash and GGBS reduce slightly the compressive strength but improve significantly the choloride resistance of concrete. Within the range of investigation, 10% of fly ash and 10% of GGBS are recommended to replace OPC as they improve the chloride resistance and maintain the compressive strength of concrete.

Influence of GGBS on the Properties of Charge Chrome Based Geopolymer Concrete in Ambient Temperature

Combined effects of supplementary cementitious materials (silica fume, GGBS, fly ash and rice husk ash) and steel fiber on the hardened properties of recycled aggregate concrete

Although high-belite sulfoaluminate cement (HBSC) exhibits excellent environmental benefits, high-early strength, and durability properties, it is limited by high early hydration heat and cost. Blending it with ordinary Portland cement (OPC) and supplementary cementitious materials (SCMs) such as fly ash (FA) and ground granulated blast-furnace slag (GGBS) is an effective strategy to enhance its performance and cost-effectiveness. Nevertheless, the high-aluminate phase and complex ionic environment within HBSC-based binders alter the reactivity of FA and GGBS compared to conventional OPC systems, introducing uncertainties in performance. This study investigated the effects of FA and GGBS on the hydration mechanism of an optimized HBSC–OPC–gypsum ternary system and analyzed their long-term performance and economic indicators. The results show that FA accelerates early ettringite (AFt) crystallization by acting as a physical filler and providing nucleation sites. Conversely, the hydraulic activity of GGBS elevates early-stage alkalinity, which hastens the conversion of AFt to monosulfoaluminate (AFm) but later facilitates AFt regeneration. However, this regenerative effect is reversed in composite systems with high SCM dosages, where an antagonistic interaction leaves the system rich in AFm. Consequently, FA enhances workability, whereas GGBS boosts later-age strength. Both materials improve sulfate resistance through distinct mechanisms: FA by refining the pore structure through its pozzolanic reaction and GGBS by rapidly densifying the matrix, thus hindering sulfate attack. Nonetheless, their combined use can lead to excessive expansion. Crucially, incorporating 10% GGBS reduces the production cost and CO2 emissions per MPa of compressive strength by 2.0% and 4.9%, respectively.

Concrete is a combination of cement, fine aggregate, coarse aggregate, water and admixtures. According to world coal association survey over 4.1 billion tons of Ordinary port land cement (OPC) was used across globally in 2020 and also use of OPC emits CO2 to the atmosphere.In order to overcome the problem, a search for alternative materials is the need of the hour and apart from cement, fine aggregate is also important additive to concrete. Due to the speedyconstruction rate deficiency of materials occurs reduction in natural aggregates causes problems like dredging of sand in large scale which creates environmental imbalance. The solution is utilisation of Fly ash, silica fume, Ground granulated blast furnace slag(GGBS) which are comes under Industrial by-products. The disposal of Industrial by-product should done properly, else it will cause land pollution. In this present study silica fume, fly ashes are replaced in OPC and fine aggregate with Granulated blast furnace slag(GBFS). The experimental work execute in order to determine mechanical properties such as compression, split tensile and flexural strength of concrete with age 3,7 and 28 days at various combinations of cement with fly ash varies 20%,30%,40% and constant 8%of silica fume and fine aggregate replaces with Granulated blast furnace slag of 30%,40% and 50% in M40 grade concrete with water-cement ratio 0.38. As per experimental results conclusions were drawn. As per the experimental results it is recommended that OPC is replaced with 8% of silica fume, 20% of fly ash and fine aggregate replaced with 40% of GBFS achieved optimum strength.

The utilization of recycled concrete and glass aggregates in concrete production has emerged as a highly promising method to significantly increase the recycling rate of waste materials. However, the interaction between alkaline environment and silica present in concrete detrimentally impacts mechanical properties and durability of the concrete due to the significant silica content of the aggregates. This study aims to develop a high‐performance and sustainable concrete to resist alkali–silica reaction (ASR). The study focuses on the use of a blend of ground granulated blast furnace slag (GGBS) and fly ash (FA) as binder materials to mitigate negative effects of the ASR on the mechanical properties and and durability of concrete made with crushed glass sand and coarse recycled concrete aggregate (RCA). Various tests, including ASR expansion, flow, slump, density, compression, three‐point bending, water absorption, and chloride attack, were conducted. Furthermore, microanalysis using scanning electron microscopy and energy‐dispersive x‐ray spectroscopy was performed. Based on the results, it is found that the GGBS is less effective than the FA in reducing the ASR expansion of the concrete, with only 3%, 9%, and 12% decreased expansion as a result of the addition of 20%, 40%, and 70% GGBS to the concrete containing 30% FA, respectively. It is also shown that combining 20% GGBS with 30% FA in the RCA concrete containing glass sand develops similar compressive and flexural strengths and water absorption compared to that containing natural sand. This can be related to the pozzolanic reaction of the FA and GGBS, which helps to retain the alkalis for reducing the crack development and propagation in the concrete. However, further GGBS content leads to a decrease in the strengths and an increase in the water absorption of the concrete. The results of this study point to the significant potential of combining FA and GGBS at an optimum ratio to mitigate the ASR effect on RCA concretes containing crushed glass sand. This approach helps in minimizing the emission of greenhouse gases and other pollutants generated during cement production, thereby mitigating environmental pollution. Additionally, it helps the preservation of natural resources by reducing the depletion of natural sand and coarse aggregate.

Nowadays very vast quantity of concrete is being used all over the world. Concrete is a mixture of cement, fine aggregate, coarse aggregate, and water. Fly ash, Copper slag, and GGBS are mechanical waste products in Coal, copper and iron industry respectively. Using this product, results in cost reduction of concrete and disposal solution of large waste products. In this review two combinations were taken and attempt was made to reduce usage of cement and sand content by saving cost of concrete and studied experimental behavior for strengths of M40 grade of concrete for combination of ground granulated blast furnace slag (GGBS) and Copper Slag (CS) and another combination of GGBS and Fly ash (FA). Experimental studies were performed on plain cement concrete and combination of GGBS and Copper Slag. Total 108 specimens were casted. In the first combination, four trial mixes were taken as maintaining GGBS 30% and varying Copper Slag by 10%, 20%, 30%, and 40% respectively. In second combination 4 trials were taken as maintaining fly ash 25% and varying GGBS by 40%, 50%, 60%, and 70%. A comparative analysis has been carried out for concrete in relation to Workability, Compression strength, Split Tensile strength and Flexural strength at 7,14,28 days with conventional concrete and two combinations. It was observed that replacement of cement by 30% GGBS and sand by 30% CS in combination 1 got maximum strength in all aspect than Conventional Concrete and combination 2.

This study, third in the series, following from ground limestone and Class F fly ash, evaluates, as a cement constituent, the effect of using ground granulated blast furnace slag (GGBS) on the strength development of concrete, and consequently its embodied carbon dioxide (CO2e). The paper has been built from systematically analysing, evaluating and modelling the extensive data-matrix developed, having 85,099 data points, from the information sourced from 663 studies published in English, during 1974 to 2020, by 1,672 authors, working in 718 institutions in 49 countries, globally. It is shown that, at a given water/cement ratio, in comparison to Portland cement (PC), the use of GGBS results in a reduction in 28-day concrete strength, which increases with GGBS content, at a rate determined by the strength of concrete, GGBS fineness, and curing of concrete. It is also shown that, as to achieve a 28-day design strength, a lower water/cement ratio is required with a PC/GGBS blended cement than PC, this will reduce the actual CO2e savings that can be realised with the use of GGBS as cement constituent in manufacturing concrete. Finally, it is shown that GGBS is more effective in lowering CO2e of concrete than FA and GLS.

The use of high-volume industrial by-products in high-performance concrete (HPC) production offers a promising and sustainable strategy for reducing ordinary Portland cement (OPC) consumption. However, each pozzolanic material has a unique chemical composition and physical characteristics, making ternary and quaternary binder systems an effective approach for optimizing performance. In this study, quaternary binders comprising OPC partially replaced with Class F fly ash (FA), ground granulated blast-furnace slag (GGBFS), and silica fume (SF) were designed using the Taguchi method, and the mechanical and durability properties of fine-grained HPC were evaluated. Sixteen concrete mixtures were developed considering three factors—FA, GGBFS, and SF replacement levels—each at four dosage levels. The results show that incorporating SF significantly enhanced both mechanical performance and durability. An optimal blend containing 60% OPC, 30% GGBFS, and 10% SF exhibited superior performance compared with the 100% OPC control mix. Additionally, a mixture of 40% OPC, 40% GGBFS, 10% Class F FA, and 10% SF achieved comparable compressive strength to the control, exceeding 100 MPa at 28 days. SEM observations confirmed the dense microstructure of this HPC mix. ANOVA analysis indicated that FA and SF had a significantly greater influence on HPC strength development than GGBFS. Overall, these findings demonstrate the potential of high-volume industrial by-products to produce fine-grained HPC, providing a high-performance and environmentally friendly alternative to conventional OPC-based concrete.

The number of waste-producing industries has been increasing consistently and, at the same time, natural resources are depleting simultaneously. Reusing the wastes produced in the industry is definitely more beneficial than their disposal. At present, the construction sector is using a lot of natural resources, which could be reduced by proper utilization of industrial wastes. The waste products generated in the industry has been widely accepted in concrete manufacturing. As the demand for cement, which is a major component of concrete, will continue to increase daily, it is essential to use alternative cementations materials in order to reduce carbon emission. Other materials which come as the industrial waste like fly ash, construction and demolition waste, red mud, silica fume, ground granulated blast furnace slag, ferrochrome ash, ferrochrome slag, brick aggregate, marble waste, etc. are to be utilized in the cement concrete industry. All these are industrial waste products and are harmful to the environment. The objective of this study is to utilize and optimize the benefits of using various types of waste for replacement of cement along with identification of substitute materials for use as aggregates in concrete.

The present thesis studies the effects of rice husk ash (RHA) as a pozzolanic admixture and the combination of RHA and ground granulated blast-furnace slag (GGBS) on properties of ultra-high performance concrete (UHPC). The ultimate purpose of this study is to replace completely silica fume (SF) and partially Portland cement by RHA and GGBS to achieve sustainable UHPC. To reach this aim, characteristics of RHA in dependence of grinding period, especially its pozzolanic reactivity in saturated Ca(OH)2 solution and in a cementitious system at a very low water binder ration (w/b) were assessed. The influences of RHA on compatibility between superplasticizer and binder, workability, compressive strength, shrinkage, internal relative humidity, microstructure and durability of UHPC were also evaluated. Furthermore, synergic effects of RHA and GGBS on the properties of UHPC were investigated to produce more sustainable UHPC. Finally, various heat treatments were applied to study the properties of UHPC under these conditions. All the characteristics of these UHPCs containing RHA were compared to those of mixtures containing SF.

Geopolymer concrete (GPC) emerging as the most innovative construction material, which not only reduces the requirement of Ordinary Portland cement (OPC) but also enhances the properties of the concrete as well, and decreases the ejection of harmful gases into the atmosphere like Carbon dioxide (CO2), Nitrogen, and Sulphur, Which is a prime concern for the environment. The need for concrete is raising uncharacteristically and so does for the OPC, to minimize the demand for OPC cementitious materials like Fly ash, Ground Granulated Blast Furnace Slag (GGBS), Silica Fume, Alccofine, Metakaolin, namely mineral admixtures used as partial or full replacements to the OPC. This present paper reports the properties of GPC made with Flyash, GGBS, and Alccofine for Mix M40- grade concrete the outcomes were contrasted with Nominal concrete which is made using 100 percent cement, Fly ash content of 50% was kept constant throughout the investigation whereas GGBS and Alccofine content varied with an interval of 5%. The concrete was tested for workability, strength, and durability aspects, an increment in the slump, and in the strength was noted, and great resistance was observed under the acid attack test for a GPC mixes, a combination of 50% Fly ash, 35% GGBS, and 15% Alccofine GPC mix was shown optimum results.

Now a day’s construction industry is focusing on various wastes from other industries to use them as substitutes for construction materials which will reduce their initial cost and impact on the environment. Use of industrial waste materials in concrete is a substitute for the shortage of natural resources. Waste disposal from steel manufacturing industries and power plants are increasing day by day and creating a lot of environmental pollution due to lack of utilizing them. There is a lot of wastes from industries like fly ash, GGBS, and slag-based compounds which can be used as replacement materials for aggregates. The present experimental investigation examines the possibility of replacing coarse aggregate with ferrochrome slag waste obtained from steel manufacturing industries and cement with fly ash obtained from power plants in concrete mix design for many construction practices. The experiments were conducted on the concrete mix in which natural coarse aggregate is replaced with ferrochrome slag to achieve optimal replacement of ferrochrome slag and the effect of fly ash along with the optimal ferrochrome slag on the mechanical properties of concrete.