Silica Fume Research Articles

Induction furnace slag as fine and coarse aggregate in quaternary blended self-compacting concrete: A comprehensive study on durability and performance

This research explores the innovative use of Induction Furnace slag Aggregate (IF-slag) as both fine and coarse aggregates in Quaternary Blended Self-Compacting Concrete (QBSCC) mixes, an area that has received limited attention in previous studies. The primary aim is to compare the durability characteristics of QBSCC mixes containing natural aggregate versus those incorporating IF-slag aggregate. A total of 18 SCC mixes were prepared in two groups: one using natural aggregate and the other using IF-slag aggregate. Each group consisted of eight optimized QBSCC mixes alongside a reference SCC mix. The QBSCC mixes were formulated using Ordinary Portland Cement (OPC) with Supplementary Cementitious Materials (SCM) such as Silica Fume (SF), Class F-Fly Ash (FAF), and Ground Granulated Blast Furnace Slag (GGBFS). Previous work by the authors analysed the fresh and mechanical properties of these QBSCC mixes. This study assesses various durability properties, including water absorption, permeable pore volume, absorption coefficient sorptivity, ultrasonic pulse velocity, resistance to chloride ion penetration, electrical resistivity, and thermal conductivity. Experimental findings indicate that SCC prepared with IF-slag exhibited inferior durability performance compared to natural aggregate. However, regardless of aggregate type, QBSCC mixes outperformed the SCC mix containing 100% OPC. Notably, the SCC-47.5 (OPC)/52.5(SCM) QBSCC mix demonstrated significant improvements in durability properties, achieving a reduction of 25% in water absorption, 24% in permeable pore volume, 48% in absorption coefficient, and 46% in sorptivity. QBSCC mixes also exhibited resistance to chloride ion penetration and enhanced electrical resistivity. Moreover, using quaternary blends reduced the thermal conductivity and improved the energy efficiency.

Artificial neural network evaluation of concrete performance exposed to elevated temperature with destructive–non-destructive tests

In this study, it is aimed to predict the performance of concretes obtained by using supplementary cementitious materials (SCM) before and after high temperature using artificial neural network. Thus, in addition to contributing to sustainable development and circular economy by using waste materials in concrete production, predicting concrete strength using artificial neural network without the need for experimental studies will provide a great advantage in practice. In addition, it will also contribute to the literature in terms of determining the optimum amount of metakaolin to be used with fly ash in concrete production. Metakaolin, silica fume and fly ash were used as SCM in different proportions in concrete mixes. Accordingly, a total of 22 concrete series were prepared, one of which was the control series. Porosity, ultrasonic pulse velocity, pressure and tensile strength tests were applied to the series at the end of 7th, 28th and 90th curing periods before high temperature. In order to determine the strength losses after elevated temperature, porosity and compressive strength tests were applied at temperatures of 400, 600 and 800 °C. Mineral additive series showed positive mechanical properties up to 20%. However, it has been observed that the use of fly ash after a certain rate causes a decrease in strength. After elevated temperature, strength loss was observed in all series due to the increase in temperature, while it was observed that the rate of being affected by elevated temperature decreased as the percentage of metakaolin increased. Optimum mineral additive usage percentages were determined as 10% fly ash and 15% metakaolin. On the other hand, the use of mineral additives above the optimum level caused the performance of the concrete to decrease. Then, the concrete compression strengths obtained at 7th, 28th, and 90th days and at 400, 600 and 800 °C temperatures are taken as the outputs of the ANN. The artificial neural network provided the closest results to experimental data. Moreover, to prove the predictive performance of ANN, a comparative analysis was made with GPR, SVM and LR and the smallest value of the RMSE value is obtained with the ANN model. Finally, a fivefold cross-validation criteria was used to objectively present the performance of the model.

Hydration kinetics and apparent activation energy of cement pastes containing high silica fume content at lower curing temperature

To promote the application of silica fume (SF) in civil engineering in cold regions, relative influences from SF content and low temperature environment on the early hydration kinetics of composite cement pastes were evaluated based on the isothermal calorimetric method. The effect of high SF content on the apparent activation energy (Ea) of Portland cement and the filler effect (via the index of area multiplier) of SF on the hydration parameters was also analyzed. The results showed that the intensity of the shoulder peak (Al peak) of the hydration kinetic curve (heat flow curve) gradually grew as the SF content increased, and the double-peak phenomenon was gradually clear. The heat flow peak is delayed and lowered with the decreasing curing temperature, while the final time of the induction stage and the duration of the acceleration stage are delayed. Moreover, the duration of the acceleration stage was slightly extended with the increase of SF content. The full-width at half-maximum (FWHM) value of the heat flow curves dropped as the SF content and curing temperature increased. The low temperature environment and the inclusion of SF inhibited the growth in early hydration degree. The higher SF content mitigated the impact of low temperature on the hydration time parameter τ. The apparent Ea results also indicated that the SF reduced the temperature sensitivity of the hydration process of the composite cement pastes, which might contribute to the development of the hydration reaction at low temperatures. The AM (Area Multiplier) factor increased approximately linearly with increasing SF replacement levels. Apparent Ea decreased linearly with increasing AM, which may be attributed to a further reduction in the diffusion-controlled hydration rate of composite cement pastes with larger AM.

Carbonation Resistance of Ternary Portland Cements Made with Silica Fume and Limestone.

Ternary blended cements, made with silica fume and limestone, provide significant benefits such as improved compressive strength, chloride penetration resistance, sulfates attack, etc. Furthermore, they could be considered low-carbon cements, and they contribute to reducing the depletion of natural resources in reference to water usage, fossil fuel consumption, and mining. Limestone (10%, 15%, and 20%) with different fineness and coarse silica fume (3%, 5%, and 7%) was used to produce ternary cements. The average size of coarse silica fume used was 238 μm. For the first time, the carbonation resistance of ternary Portland cements made with silica fume and limestone has been assessed. The carbonation resistance was assessed by natural carbonation testing. The presence of coarse silica fume and limestone in the blended cement led to pore refinement of the cement-based materials by the filling effect and the C-S-H gel formation. Accordingly, the carbonation resistance of these new ternary cements was less poor than expected for blended cements.

Engineering and microstructural properties of self-compacting concrete containing coarse recycled concrete aggregate

In this paper, the possibility of utilising coarse recycled concrete aggregate (CRCA) obtained from a construction and demolition waste (CDW) plant in Delhi to make 60 MPa self-compacted concrete (SCC) was evaluated. The CRCA was used in as-collected condition and was not processed any further. The aggregate packing (bulk) density (APD) method was adopted to prepare the SCC-CRCA mixture in order to obtain an aggregate mixture exhibiting maximum bulk density/least void content (45%). In addition, SCC was made using aggregate mixtures in which the natural coarse aggregate (NCA) was replaced with CRCA at 0%, 20% and 100% of the total coarse aggregate content by weight. The cement, fly ash, silica fume and water were kept constant for all SCC mixtures. The effects of CRCA on the flow behaviour, mechanical strength, shrinkage characteristics and microstructure properties of SCC mixtures were evaluated. The test results indicated that SCC mixtures made with up to 45% CRCA replacement can be used for structural concrete, which is higher than that recommended in Indian (20%) and international specifications (35%) for traditionally vibrated (conventional) concrete.

Utilization of Silica Fume and Sodium Hydroxide in Treated Crumb Rubber for Cement Mortar

Cement mortar offers an excellent replacement for materials such as fine aggregate with tire rubber waste in the form of crumbs. It provides excellent environmental and technical benefits to concrete production using recycled materials. As such, it contributes to the sustainable development of the construction industry. This paper mainly emphasizes the strength of untreated and treated crumb rubber from waste tires in cement mortar. Crumb rubber that has been pre-treated with Silica fume (SF) and sodium hydroxide (NaOH) to improve the strength of the mortar mix. This research used a cement-aggregate mix ratio of 1:4 and a water-cement ratio of 1:2. Five different percentages of fine aggregate replacement (0, 3, 6, 9, and 12%) was selected. The compressive strength, density, and water absorption of the mortar were measured at 28 days to find optimum strength. The compressive strength of the cement mortar mixed with treated crumb rubber showed significantly higher values, with an increase of 92% for 12% treated crumb rubber by sodium hydroxide (TN12) compared to untreated crumb rubber. The density value of the mortar cube mixed with treated crumb rubber decreased when the percentage of replacement for treated crumb rubber increased. In the application of roof tiles, lower density values provide an advantage for workability during installation. For water absorption, the treated crumb rubber contributes to a lower percentage of water absorption (acceptable until 6% for SF and 9% for NaOH) compared to the control sample as untreated crumb rubber. Therefore, a mixture of mortar with treated crumb rubber, especially NaOH solution, is better than the untreated crumb rubber specimen.

Performance of Silica Fume as a partial Replacement on Cement Concrete Strength

Performance of Silica Fume as a partial Replacement on Cement Concrete Strength

A review on Comparative study of using Silica Fume and Areca Fiber on Soil Stabilization

Abstract The rapid expansion of urban areas and the rise in construction activities have led to a shortage of land with suitable soil conditions. This has forced people to utilize weak soils available locally for construction purposes, employing various stabilization techniques. Urban expansion and construction demand the utilization of local weak soils for building, necessitating the application of soil stabilization techniques. These methods enhance soil strength by altering its properties. This study evaluates silica fume and areca fiber as stabilizers. Silica fume is a pozzolanic and supplementary cementitious material that enhances material properties such as strength, durability, and resistance to chemical attacks and abrasion. Few studies have examined areca fiber as soil reinforcement. Areca fiber (20-30 mm in length) upto 0.6% of dry weight of soil significantly improves engineering properties of soil. Varied weight ratios of silica fume and areca fiber are used based on soil type for optimal conditions. Silica fume stabilizes, and areca fiber reinforces problematic soil, as demonstrated through compaction, UCS, and CBR tests. Utilizing such waste materials is a cost-effective and more sustainable approach in the field of engineering. This research investigates the compaction and strength properties of various problematic soils stabilized with silica fume and areca fiber, providing a comprehensive review of the findings.

Tailoring microstructure and properties of porous mullite-based ceramics via sol-gel impregnation

Nanotechnology has been introduced into the refractory industry decades ago. However, there are still some peculiarities that hinder its routine application. Poor mechanical strength is one of them. Here we present the fabrication technique for mullite porous ceramics using a calcium-free colloidal binder system followed by secondary sol-gel impregnation intended for fabrication of large up-scaled monoliths. The primary foam was prepared via direct foaming of slurry containing colloidal silica, gelling agents, surfactant, silica fume, and different types of alumina. The foam mixture was cast, de-molded and dried using a cascade drying procedure. The investigation of mullitization that occurred during the high-temperature treatment was studied by XRD and TG-DTA analysis. The optimized sintering curve was then applied to obtain the highest mechanical properties. The resulting foam (with open porosity, volume density about 900 kg/m3 and mechanical strength about 10 MPa) was further processed by the impregnation step. The applied silica or combined silica/aluminum sol and unreacted alumina underwent secondary mullitization during following high-temperature treatment, which significantly enhanced the mechanical strength (up to 18 MPa). The secondary mullitization process was also investigated by HT-XRD and TG-DTA analysis. Foam microstructure was observed by an electron scanning microscope. Thermal conductivity of as-prepared ceramics foams varied from 0.3 to 0.4 W/m·K. The foam wall porosity evolution was studied by mercury intrusion porosimeter and estimated from image analysis.

Evaluating the strength and durability characteristics of concrete incorporating steel slag, GGBS and silica fume

Evaluating the strength and durability characteristics of concrete incorporating steel slag, GGBS and silica fume

Experimental study on sustainable cement concrete paver blocks incorporating coconut shell aggregate, quarry dust, silica fume and rice husk ash.

Experimental study on sustainable cement concrete paver blocks incorporating coconut shell aggregate, quarry dust, silica fume and rice husk ash.

Strength and durability characteristics of self compacting recycled aggregate concrete incorporating crumb rubber, fly ash and silica fume

Strength and durability characteristics of self compacting recycled aggregate concrete incorporating crumb rubber, fly ash and silica fume

Influence of Silica Fume and Fly Ash with Quarry dust on Steel Fiber Concrete

Influence of Silica Fume and Fly Ash with Quarry dust on Steel Fiber Concrete

Development of treated coarse recycled aggregate-based sustainable fibrous high-strength concrete with fine recycled aggregates

Abstract This research aims to develop sustainable high-strength concrete (SHSC) by replacing 100% fine and/or coarse aggregates with fine recycled aggregate (RA) and/or coarse RA. Due to the high surface water absorption of coarse RA, a surface treatment method was adopted, consisting of immersing it in a cement and silica fume slurry. Moreover, to improve the performance of the produced SHSC, steel fibers were employed at a relatively low volume fraction (0.5%). Eleven blends were cast and tested in this experimental study. A control SHSC mix (without RA) and ten other mixtures, including fine natural and RA, treated and untreated coarse RA, with and without steel fibers, were prepared. Compressive, splitting, and flexural strengths, water absorption, density, and ultrasonic pulse velocity (UPV) of the resulting SHSC were conducted. The results indicated that the use of RA in SHSC resulted in an average drop of 25% in its mechanical properties and an increase of about 30% in water absorption. However, using treated RA compensated the compressive and tensile strength reductions in SHSC by 9% and 7%, respectively, compared to mixes containing untreated RA. On the other hand, adding fibers helped improve compressive, flexural, and splitting tensile strengths by about 8%, 23%, and 31%, respectively, compared to the corresponding control mix. Consequently, the results showed that it is possible to produce durable SHSC made from 100% RA and 0.5% steel fibers with a reduced density and improved mechanical performance to a comparable level or even superior to high-strength concrete (HSC) with only natural aggregates (NAs).

Performance Evaluation of Self-Compacting Glass Fiber Concrete Incorporating Silica Fume at Elevated Temperatures

In this work, the properties of self-compacting concrete (SCC) and SCC containing 0.5 and 1% glass fibers (with lengths of 6 and 13 mm) were experimentally investigated, as well as their performance at high temperatures. With a heating rate of 5 °C/min, high-temperature experiments were conducted at 200, 400, 600, and 800 °C to examine mass loss, spalling, and the remaining mechanical properties of SCC with and without glass fibers. According to the results of the flowability and passing ability tests, adding glass fibers does not affect how workable and self-compacting SCCs were. These findings also demonstrated that the mechanical properties of samples with and without glass fibers rose up to 200 °C but then decreased at 400 °C, whereas the mixture containing 0.5% glass fibers of a length of 13 mm displayed better mechanical properties. Both SCC samples with and without glass fibers remained intact at 200 °C. Some SCC samples displayed some corner and edge spalling when the temperature reached about 400 °C. Above 400 °C, a significant number of microcracks started to form. SCC samples quickly spalled and were completely destroyed between 600 and 800 °C. According to the results, glass fibers cannot stop SCC from spalling during a fire. Between 200 and 400 °C, there was no discernible mass loss. At 600 °C, mass loss starts to accelerate quickly, and it increased more than ten times beyond 200 °C. The ultrasonic pulse velocity (UPV) of SCC samples with glass fibers increased between room temperature and 200 °C, and the mixture containing 0.5% glass fibers of a length of 13 mm showed a somewhat higher UPV than other SCC mixtures until it started to decline at about 400 °C.

Towards improved flexural behavior of plastic-based mortars: An experimental and modeling study on waste material incorporation

A considerable fraction of solid waste, which is harmful, chemically reactive, and infectious, is generated globally. The frequent deposition of these wastes in landfills has significant environmental and health consequences. This study aims to develop an environmentally conscious approach by incorporating finely ground waste materials, namely marble powder (MP), glass powder (GP), and silica fume (SF), into plastic waste (PW) based mortar to assess their efficacy in improving flexural strength (FS). Plastic waste mortar samples were cast using shredded PW, replacing sand in amounts ranging from 5 % to 25 %. The FS of these samples was measured after 28 days and used as a reference. MP, GP, and SF were individually incorporated into PW-based mortar formulations in varying quantities of 5–25 %, with increments of 5 %, by replacing cement. In PW-based mortar formulations, waste materials were also utilized in various combinations, including GP+SF, MP+SF, MP+GP, and MP+GP+SF. In addition, prediction models, including decision tree (DT) and artificial neural network (ANN), were constructed utilizing experimental data for the FS of PW-based mortar. The substitution of PW with sand reduces the FS of mortar samples. The research findings emphasize that optimal replacement levels for MP, GP, and SF in PW-based mortar mixtures, based on their ability to enhance FS, were 15 %, 10 %, and 15 % by cement mass, respectively. However, the cumulative incorporation of MP, GP, and SF in PW-based mortar suggests cement should not be replaced beyond 15 %, as it reduces the FS. Both prediction models exhibited a high degree of correlation with the coefficient of determination (R2) value of 0.925 for ANN and 0.959 for the DT model. The findings showed that MP, GP, and SF may be used in PW-based mortar to improve the FS while producing eco-friendly building material.

Performance Evaluation of M30 Grade Concrete Using Silica Sand as Partial Replacement of Cement in Concrete

Abstract: This study explores the improvement of concrete parcels, particularly strength and continuity, through the partial substitute of cement with silica fume (SF). The exploration addresses the environmental and health issues caused by artificial waste disposal, similar to covering ash and copper slag, by incorporating silica sand into concrete. A literature review reveals that SF significantly improves the mechanical and continuity characteristics of concrete, enabling the product of highperformance concrete suitable for these soundings. This paper investigates the strength parameters of concrete with 0 –15% SF relief in increment of 5%, comparing the results with conventional concrete. Findings indicate that the optimal compressive strength and split tens are achieved at 10% SF relief, beyond which strength decreases. This study aims to inform civil masterminds about the benefits of SF- modified concrete composites.

Influence of feature-to-feature interactions on chloride migration in type-I cement concrete: A robust modeling approach using extra random forest

Understanding the chloride transport mechanism is crucial for enhancing the durability of structures exposed to chloride-rich environments. This study assessed various machine learning (ML) algorithms for predicting the chloride migration coefficient in type I Portland cement-based concrete. The fine-tuned extra random forest model demonstrated satisfactory predictive capability, with the majority of tested-predicted data points falling within the ±30 % tolerance margin. This calibrated model was employed to explore feature-to-feature interactions affecting concrete resistance to chloride ingress. Examination of partial dependence plots revealed that an increased sensitivity with decreasing water–binder ratio (WB), reaching saturation beyond 0.40 WB, and the increase in curing age substantially reduced chloride diffusion (DN). Further, an augmented dosage of silica fume (SF) decreased DN, with a more pronounced effect of slag (SL) at higher WB, and the impact of superplasticizer (SP) decreased DN at high WB ratios. Concrete incorporating SF showcased optimal resistance to chloride permeability with the highest SF content (20–30 kg/m3). Similarly, high SL content (>150 kg/m3) enhanced resistance. The interactive influence of SF and SP on DN was marginal at low SF dosages (<20 kg/m3) but became complex at higher levels, with potential minimum values observed in the range of 0.5–1.0 kg/m3 SP. For SL-containing concrete, achieving the lowest DN was possible with PC and SL dosages around 200–400 and exceeding 100 kg/m3, respectively. For concrete incorporating Type I PC, an increase in SP content generally had a negligible impact on DN, with a slight tendency to raise values observed at higher cement amounts (exceeding 380 kg/m3). The optimal combination for achieving the minimum DN involved compositions of PC, fine, and coarse aggregate at 200–300, 100–150, and 250–500 kg/m3, respectively.

Effect of Silica Crystalline State on Hydration Products of Tricalcium Silicate at High Temperatures.

The mechanical performance of grade G oil well cement stones declines significantly when subjected to temperatures exceeding 110 °C; the strategy to mitigate the impact of high temperatures is by incorporating siliceous materials. However, it is important to note that the crystalline properties of siliceous materials vary, leading to different effects on the temperature reduction. This study focuses on tricalcium silicate (C3S), the primary component of oil well cement. The impact of different types of silica, including amorphous silica (nanosilica, silica fume) and crystalline silica (quartz sand), on the hydration of C3S was investigated using 1H NMR, XRD, TGA, and SEM-EDS analyses. The results show that siliceous materials can significantly prevent the strength decrease of C3S hardening products at high temperatures and inhibit the rise of porosity and permeability. Adding excessive amorphous siliceous materials, such as nanosilica, can cause agglomeration, resulting in a porous structure of C3S hardening products and hindering their strength. Amorphous silica fume is more reactive than crystalline silica sand and can rapidly initiate a pozzolanic reaction with calcium hydroxide. Siliceous materials also convert high-Ca/Si of C-S-H (hillebrandite, jaffeite, and reinhardbraunsite) into low-Ca/Si of C-S-H (gyrolite, okenite, tobermorite, nekoite). Siliceous materials reduce the porosity and permeability of C3S hardening products and enhance their mechanical properties through the filling and transformation of hydration products.

Experimental Study on Workability, Strength &amp; Durability of Geopolymer Concrete with use of Fly ash, Ground Granulated Blast Furnace Slag &amp; Silica Fume

Abstract: Geopolymer concrete, crafted from a blend of Fly Ash, GGBS, and Silica Fume activated by sodium silicate and sodium hydroxide, demonstrates excellent workability and strength over time. It proves resilient against acid, chloride, water absorption, and carbonation, making it a sustainable choice for construction projects seeking durability and performance. These qualities position geopolymer concrete as a promising alternative to traditional concrete methods.