Proportions Of Silica Fume Research Articles

Combined Impact of PolypropyleneFibers and Silica Fume on M30 Concrete Grade

This research project investigates the combined influence of silica fume and polypropylene fibers on the mechanical properties of M30 grade concrete. Silica fume, known for its ability to enhance concretestrength and durability, is introduced at varying percentages (0%, 10%, and 20%), while polypropylene fibers, chosen for preventing cracks and improving strength, are added at different levels (0%, 0.5%, and 1%). The project employs systematic experimentation, testing concrete mixes with different proportions of silica fume and polypropylene fibers at various curing periods for 7 days and 28 days to assess their impact on mechanical properties. The research seeks to identify the most effective mix design for achieving desired strength outcomes in M30 grade concrete. Silica fume is recognized for its ability to enhance concrete impermeability and strength, while polypropylene fibers offer benefits such as controlling shrinkage cracking and improving impact resistance. This research contributes to advancing construction materials by optimizing the utilization of silica fume and polypropylene fibers in concrete mixes. The findings aim to provide valuable insights for industry professionals seeking to improve the quality and performance of high-grade concrete structures. The search results indicate that the inclusion of silica fume helps the dispersion of fibers and increases the specimens' strength more than the addition of silica fume alone. Polypropylene fibers are also added to improve mechanical qualities.

Utilization of discarded face masks in combination with recycled concrete aggregate and silica fume for sustainable civil construction projects

The coronavirus (COVID-19) pandemic has not only had a severe impact on global health but also poses a threat to the environment. This research aims to explore an innovative approach to address the issue of increased waste generated by the pandemic. Specifically, the study investigates the utilization of discarded face masks in combination with recycled concrete aggregate (RCA) and Silica Fume (SFM) in civil construction projects. The disposable face masks were processed by removing the ear loops and nose strips, and then cutting them into small fibers measuring 20 mm in length, 5 mm in width, and 0.46 mm in thickness, resulting in an aspect ratio of 24. Various proportions of SFM and RCA were incorporated into the concrete mix, with a focus on evaluating the compressive strength, split tensile strength, and durability of the resulting material. The findings indicate that the addition of SFM led to improvements in both compressive and split tensile strength, while no significant impact on durability was observed.

Evaluating the effectiveness of waste glass powder for the compressive strength improvement of cement mortar using experimental and machine learning methods

This study utilized both experimental testing and machine learning (ML) strategies to assess the effectiveness of waste glass powder (WGP) on the compressive strength (CS) of cement mortar. The cement-to-sand ratio was kept 1:1 with a water-to-cement ratio of 0.25. The superplasticizer content was 4% by cement mass, and the proportion of silica fume was 15%, 20%, and 25% by cement mass in three different mixes. WGP was added to cement mortar at replacement contents from 0 to 15% for sand and cement with a 2.5% increment. Initially, using an experimental method, the CS of WGP-based cement mortar at the age of 28 days was calculated. The obtained data were then used to forecast the CS using ML techniques. For CS estimation, two ML approaches, namely decision tree and AdaBoost, were applied. The ML model's performance was assessed by calculating the coefficient of determination (R2), performing statistical tests and k-fold validation, and assessing the variance between the experimental and model outcomes. The use of WGP enhanced the CS of cement mortar, as noted from the experimental results. Maximum CS was attained by substituting 10% WGP for cement and 15% WGP for sand. The findings of the modeling techniques demonstrated that the decision tree had a reasonable level of accuracy, while the AdaBoost predicted the CS of WGP-based cement mortar with a higher level of accuracy. Utilizing ML approaches will benefit the construction industry by providing efficient and economic approaches for assessing the properties of materials.

Use of Silica Fume, Bentonite, and Waste Tire Rubber as Impermeable Layer Construction Materials

To avoid the potential risks associated with all hazardous wastes, it is important that containment methods are intended to prevent the migration of liquid hazardous wastes or leaks containing hazardous components. Therefore, impermeable barriers were used to prevent contamination. In this study, geotechnical tests were performed on samples by mixing rubber and bentonite with silica fume at certain percentages. The aim of the experimental studies is to evaluate the applicability of certain proportions of silica fume, rubber, and bentonite mixtures as impermeable liner material. Possible cracks in bentonite during drying are reduced by the use of silica fume. Absorption of dynamic effects that may occur on the impermeable barrier layer is achieved by adding waste rubber in a uniform size. Several geotechnical tests were performed to examine the mixed rubber and bentonite with silica fumes. Looking at the results of the whole that mixed rubber and bentonite with silica fume yielded usable results and a blend for construction of a liner.

Evaluation of Mechanical and Durability Properties of Eco-Friendly Concrete Containing Silica Fume, Waste Glass Powder, and Ground Granulated Blast Furnace Slag

By considering the adverse environmental impacts of the cement manufacturing process, there have been many efforts for cement replacement by supplementary cementitious materials (SCMs), which can enhance the produced concrete performance while reducing cement consumption. This study evaluated the effects of various proportions of silica fume (SF), waste glass powder (WGP), and ground granulated blast furnace slag (GGBFS) on the mechanical and durability properties of concrete. The properties evaluated in this study include compressive, tensile, and flexural strength, magnesium sulfate and sulfuric acid attack, surface resistivity, rapid chloride penetrability test (RCPT), water absorption, depth of penetration of water, and microstructure analysis by scanning electron microscopy (SEM). The results of compressive, tensile, and flexural strength, chloride ion penetrability, and water absorption tests showed that adding 5% of SF to mixtures containing 10% WGP or 10% GGBFS improved concrete performance significantly due to packing density and synergistic effect; however, adding 5% of SF to concrete mixtures decreased the resistance against the magnesium sulfate and sulfuric acid attack. The binary mixture of 15% of WGP showed appropriate performance against the magnesium sulfate and sulfuric acid attack, which may be due to the sacrificial nature of WGP. In addition, the binary mixtures of 15% of WGP and 15% of GGBFS reduced the depth of penetration of water by 45%. Microstructure analysis by SEM showed that the presence of SF, along with WGP and GGBFS, improves the packing density. Finally, adding 5% of SF is suggested to improve the properties of concrete mixtures containing WGP and GGBFS.

Effect of ferrosilicon and silica fume on mechanical, durability, and microstructure characteristics of ultra high-performance concrete

This paper presents a new material that can be used as a partial substitute for cement in the production of ultra high-performance concrete (UHPC). This material is an industrial waste product of ferrosilicon (FS) alloy, which is available as furnace slag. It is used as a partial substitute for cement after grinding until it reaches the stage of microparticles with a surface area of 12,850 (cm2/gm). UHPC mixtures are designed with cement replacement ratios of 5%, 10%, 15%, 20% and 25% by FS, and same proportions of silica fume (SF). Fresh concrete properties are assessed by applying tests of air content and workability. Mechanical properties are assessed by applying tests of compressive strength, split tensile strength, flexural strength and modulus of elasticity. Moreover, transport properties are assessed by chloride penetration resistance and initial sorptivity water permeability test. Microstructure analyses are carried out by SEM-EDX and XRD tests. Results show that the increase in cement replacement rates by SF and FS by 25% of cement mass reduces slump flow to 345 and 356 mm, respectively, whereas it is 385 for the control mixture. Inclusion up to 20% FS enhances compressive strength by 210.4 MPa compared with 178.6 for the control mix at 90 days. In addition, including up to 25% FS improves the transport properties of UHPC by increasing permeability resistance compared with the control mixture.

An experimental study on the fatigue properties of Alccofine-based crumb rubber concrete

The disposal of rubber tyres is one of the common causes of environmental pollution. This problem may be solved using crumb rubber (CR) as a construction material without side effects. Therefore, an attempt has been initiated in the present experimental study to prepare green concrete by replacing various sustainable materials in multiple percentages. This study continues with fatigue and mechanical properties, crack patterns, load–displacement behaviours under cyclic load and failure modes of normal concrete, CR concrete (CRC) and Alccofine-based CRC. Nineteen different mixes are taken into account with 5 and 7% replacements of CR (10, 12 and 20 mesh) with sand and different proportions of silica fume, fly ash and Alccofine. The compressive strength and splitting tensile strength are reduced with the increase in CR content and inversely increase with the rise in CR size. Therefore, Alccofine and silica fume have been used to resolve the problems of strength reduction. The results indicate that the failure manner of CRC beams is gradual, which means enhancement of structural ductility. Finally, this study proposes the application of Alccofine- and silica-fume-based CRC for magnifying structural ductility.

Effect of dispersibility of carbon nanotubes by silica fume on material properties of cement mortars: Hydration, pore structure, mechanical properties, self-desiccation, and autogenous shrinkage

In this study, the effect of dispersibility of carbon nanotubes (CNTs) by silica fume on the material properties of cement mortars were experimentally analyzed. Cement mortar specimens incorporating different proportions of silica fume and CNTs were fabricated, and tests were conducted to measure their hydration kinetics, pore structure, compressive strength, elastic modulus, internal relative humidity, and autogenous shrinkage. Additionally, scanning electron microscopy analysis was performed to observe the morphology of the CNTs in the cement matrix. The results revealed that the dispersibility of the CNTs was enhanced with the increasing replacement ratio of silica fume. Furthermore, well-dispersed CNTs resulted in a decrease in the self-desiccation by varying the pore structure and hydration kinetics, and an increase in the modulus of elasticity, thereby reducing the autogenous shrinkage of the cement mortar specimens.

Effective reuse of waste material as an amendment in composite landfill liner: Assessment of geotechnical properties and pollutant retention capacity.

The effective reuse silica fume (S), a by-product from the silicon manufacturing industry, as an amendment in the composite landfill liner along with natural clay (C) and bentonite (B) was investigated in the present study. Experiments were conducted with various proportions of silica fume (10%-50%) to clay and bentonite to get mixtures C-B-S1 to C-B-S5. The study indicated significant improvement in the geotechnical and pollutant retention capacity by silica fume addition. The maximum dry density of the mixtures ranged from 1.568 to 1.732 g cm-3. Permeability was in the order of C-B<C-B-S1 to C-B-S5<clay. Unconfined compressive strength of the C-B mix increased with the addition of silica fume from 10% to 25%, with a maximum value of 241.31 kPa. The free swell index decreased to 3.6 and the cation exchange capacity increased to 83 meq/100 g with the addition of 50% silica fume. The percentage removal of copper with C-B-S1 to C-B-S5 was 91.2%, 92%, 93.5%, and 95.2%, respectively, when the initial copper concentration was about 30 mg L-1. Based on the assessment of geotechnical and pollution abatement capacity C-B-S3 with 25% silica fume addition was proposed as the composite liner material for the naturally available clay at the landfill site.

Experimental Investigation on Performance of Waste Cement Sludge and Silica Fume-Incorporated Portland Cement Concrete

An experimental investigation on improvisation of the conventional concrete mix by way of incorporating waste by products in view of facilitating partial substitution of concrete ingredients has been reported. The mechanical and durability properties of concrete mix incorporated with waste cement sludge and silica fume were test verified, and the optimal cement replacement proportion was identified. Based on test results, the technical feasibility and performance were assessed. The cement sludge content was partially replaced from 2 to 10% at an increment rate of 2% by weight of cement. The optimum cement sludge content has been identified as 4%. The optimal replacement percentage of silica fume along with 4% cement sludge was experimented up on. The silica fume content was varied from 3 to 12%, yielding dependable and optimal proportions of silica fume at 8% by weight of cement. Relationship between the 28-day compressive and flexural strength was established using an empirical correlation equation.

Combination of Biochar and Silica Fume as Partial Cement Replacement in Mortar: Performance Evaluation Under Normal and Elevated Temperature

Utilization of waste derived materials to replace part of cement is an effective strategy for cost effective and sustainable concrete constructions. This study investigates a blend comprising of different proportions of silica fume (SF) and biochar, prepared from wood (MWBC) and food waste (FWBC) respectively, to replace 10 wt.% of cement in mortar mixes. Mechanical and permeability properties of the developed cement-biochar composites were tested under normal and elevated temperature (500 °C). Experimental results show that combination of biochar and silica fume enhance compressive strength (by up to 18–20%) and structural efficiency (strength to density ratio) compared to control mixtures. Water permeability results confirmed that blend of biochar and silica fume play a significant role in reducing capillary water absorption by 50–60% compared to control mortar, which is attributed to filler effect and water retention by fine biochar particles. Mortar with combined admixtures (biochar and SF) had higher resistance to damage at elevated temperature, which was evident from 22% higher strength and lower permeability (22–24%) compared to control mix after thermal damage. Finally, economic analysis highlights that using blend of biochar and silica fume to replace cement is more economic than using only silica fume, due to relatively lower cost and waste recycling associated with biochar production. In summary, this study suggests that biochar may be a sustainable and economic alternative to reduce usage of cement and more expensive pozzolanic fillers in cementitious composites.

Evaluation silica fume addition on some properties of cold bitumen emulsion mixtures (CBEMs).

Cold mix asphalt is an alternative to hot mix asphalt that consists of aggregate and filler with asphalt emulsion as a binder material rather than asphalt cement.It has many benefits such as save energy and less emissions.The major objective of this paper is determining the effects of adding silica fume on some properties of cold bitumen emulsion mixtures (CBEMs). This was done by adding three proportions of silica fume (1, 2, and 3%) as a replacement for limestone dust and then conducting tests including indirect tensile strength, compressive strength, Marshall stability, flow test, bulk specific gravity (Gmb), and air voids, The mixtures were also evaluated for moisture sensitivity by means of their tensile strength ratios, retained Marshall stability, and a double punch shear test.The results showed that the addition of silica fume increased the indirect tensile strength, compressive strength, Marshall stability, and bulk specific gravity (Gmb) by (18.5, 68, 78.4, and 0. 4) %, respectively, and decreased the flow values and air voids to about 13.5 and 6.6) %, respectively for 3% of replacement. Moreover, the addition of silica fume gave different behaviours in terms of moisture resistance; in general, there was an improvement in moisture resistance compared to that seen in the control mix.

A comparison of the effects of pozzolanic binders on the hardened-state properties of high-strength cementitious composites reinforced with waste tire fibers

Experimental and statistical analyses were conducted to examine the effects of partially replacing ordinary Portland cement (OPC) with pozzolanic binders (silica fume and fly ash) on the hardened-state characteristics of high-strength cementitious concrete reinforced with steel fibers recovered from waste tires. The variables used in the analyses were the concentration of recycled steel fibers (volume fraction = 0.5% and 1%) and the proportion of silica fume or fly ash used to replace OPC (weight = 10%, 20%, and 40%). The effects of combining fibers at two volume fractions with pozzolanic binders in 14 mixtures were investigated through an experimental program carried out in two stages. First, the effects of replacing OPC with silica fume or fly ash on the matrix were determined by assessing the heat of hydration, the formation of the crystalline phases using X-ray diffraction analysis, the gel structure and mass loss at elevated temperatures with thermogravimetric, and differential thermogravimetry analyses, and porosity structures of pastes with using the mercury intrusion porosimetry test. Second, the effects of adding recycled steel fibers on the hardened-state properties of OPC-based concretes containing pozzolans were explored by evaluating the water absorption by immersion and capillary rise, ultrasonic pulse velocity, compressive strength, splitting tensile strength, flexural strength, and impact resistance of the reinforced mixtures. The experimental results were subjected to linear regression and statistical analysis to correlate the mechanical and impact properties of the mixtures and identify probability distributions, respectively.The findings showed that using pozzolanic binders enhanced the mechanical and impact properties of the mixtures reinforced with fibers from waste tires, thereby affecting the fibers’ frictional pull-out behavior. Therefore, significant differences on the impacts of fiber content were found on the post-peak responses of the mixtures under flexural loading. In general, using silica fume had higher impact on enhancing the hardened-state characterizations than fly ash. The greatest enhancement in mechanical properties was observed when OPC was replaced with 40% silica fume.The analytical results confirmed that silica fume was better fitted to the normal distribution than fly ash, while fly ash produced a higher coefficient of correlation between mechanical and impact resistance than did silica fume.

STUDI PERILAKU KUAT GESER BALOK BETON BERTULANG MEMADAT SENDIRI DENGAN SERAT “POLYPROPYLENE”

This paper presents a study of the behavior of self compacting reinforced concrete with polypropylene fiber. Four self compacting reinforecd concrete beam specimens were cast and tested in this study. Two beams were cast without fiber and two beams were cast with polypropylene fiber. The proportion of polypropylene fiber was 0.9 kg/m of the weight of concrete and the proportion of silica fume was 10 % of the weight of portland cement. The dimension of the beam was (180×260) mm with 2000 mm length. Two longitudinal bars with O10 mm were placed at the top of the beam as compressive bars and three longitudinal bars with O10 mm were placed at the bottom of the beam as tensile bars. Shear reinforcement with O8 mm with spacing of 150 mm were placed at the midle, and there were no stirrups at the shear region. Several cylinder specimens with size of (150×300) mm and beam without reinforcement with size of (200×200×700) mm were also cast and tested to determine the mechanics properties of concrete such as compressive strength, tensile strength, modulus of elasticity and modulus of ruptures. The result show that the compressive strength and modulus of elasticity of self compacting concrete with polypropylene fiber were decreased 26.98 % and 9.98 %, respectively compare to the self compacting concrete without fiber. While the tensile strength and modulus of ruptures of the self compacting concrete with polypropylene fiber were increased 2.76 % and 3.65 %, respectively compare to the self compacting concrete without fiber. The shear capacities of the self compacting concrete beams without fiber were 62.76 kN and 63.44 kN. While the shear capacities of the self compacting concrete beams with polypropylene fiber were 60.77 kN and 50.61 kN.

Fly ash based geopolymeric foams using silica fume as pore generation agent. Physical, mechanical and acoustic properties

The aim of this work is the development of a porous geopolymeric foam with sound absorbing properties using silica fume as the pore generation agent. The samples were manufactured using a coal combustion fly ash as source material for the geopolymerization reaction, an alkaline solution as activating solution and silica fume as pore forming agent. Three parameters were studied: silica fume proportion (0, 20 and 40 wt%), activating solution (potassium silicate and potassium hydroxide) and setting temperature (40 and 70 °C). Once the samples were prepared, the experimental study of the most important physical, mechanical and acoustic features were carried out. The increase in the proportion of silica fume in the mixture and setting temperature produced a reduction in setting time and a raise of open void porosity, reducing the compressive strength at 28 days up to a half but increasing the sound absorption. The influence of activating solution in open porosity and sound absorbing properties was not very important.

Crumb Rubber and Silica Fume Inclusions in Pervious Concrete Pavement Systems: Evaluation of Hydrological, Functional, and Structural Properties

Abstract The main objective of this research study was to comprehensively investigate the hydrological, functional, and structural characteristics of 21 pervious concrete (PC) mixtures encompassing four dosages of crumb rubber (CR), four proportions of silica fume (SF) contents, and three distinct aggregate gradations. A total of 126 PC cylindrical specimens were available to measure density, porosity, permeability, abrasion resistance, and compressive strength properties. The inclusions of CR and SF in the PC enhanced the compressive strength and abrasion resistance compared to the control unmodified PC specimens. However, CR-modified PC showed reduced permeability because of a decrease in the porosity of those mixes. Nonetheless, the study results did not reach any optimum values of CR or SF replacement and indicated that there is more scope to replace the coarse aggregate with CR and cement with SF so as to identify the optimum dosages of these two modifiers in future. The use of CR in PC as a partial replacement of aggregate can become a potential way of conserving the natural aggregates that are becoming scarce. Furthermore, SF can be used as a partial replacement for cement that will eventually reduce carbon dioxide emissions from cement production, thus being able to achieve the significant use of renewable resources in producing green pavement systems.

A novel Self-Compacting Ultra-High Performance Fibre Reinforced Concrete (SCUHPFRC) derived from compounded high-active powders

This study addresses a novel Self-Compacting Ultra-High Performance Fibre Reinforced Concrete (SCUHPFRC) derived from compounded high-active powders, including experimental study and mechanism analysis. The SCHUPFRC skeleton is designed based on particle densely packing model, and different proportions of silica fume (SF) and metakaolin (MK) are employed to generate compounded high-active powders. Then, the fresh and hardened behaviors of the developed concrete are evaluated and analyzed. The obtained results show that a UHPFRC with self-compacting ability can be produced based on optimized application of powder materials and particle packing model. Moreover, the effect of hybrid use of SF and MK on UHPFRC properties can be attributed to physical and chemical influences. On the one hand, the utilized MK is more efficient than SF in promoting the hydration kinetics of UHPFRC cementitious system. On the other hand, excess amount of MK can enhance the shrinkage and viscosity of UHPFRC mixture, which result in that its microstructure development may be disturbed by shrinkage caused micro-cracks and trapped bubbles. Hence, to develop a SCUHPFRC with advanced properties, the use of appropriate compounded high-active powders is a crucial factor.

Effect of silica fume and solid borax waste on compressive strength of fired briquettes

It is a well-known fact that industrial solid wastes which are commonly employed in construction sector make a significant contribution in reduction of environmental pollution. In this study, solid borax waste and silica fume were used as additive materials. In the briquette compositions, 3, 5 and 10% proportions of solid borax waste and 2, 5 and 10% proportions of silica fume were used in mixtures. In order to determine material characterization, micro structure (SEM) analyses of solid borax waste and silica fume were performed besides of physical and mechanical tests. Moreover, DTG analyses were implemented to specify material’s behavior under high temperature loads. According to the test results, the values of maximum compressive strength and minimum bulk density were obtained using mixtures with proportions of 2% silica fume and 10% solid borax waste. Additionally, it was determined that the briquettes having low density and high compressive strength could be produced using aforementioned all mixtures.

Preparation of SiC Powders by Carbonthemal Reduction Method at Low Temperature

The stable slurry was prepared by ball-milling with a certain proportion of silica fume as silicon source,glucose as carbon source and metal niobium (Nb) as additives mixed with alcohol water. After the slurry was dried and pulverized, put the powder into a tubular furnace heated to 650℃ for 2h under nitrogen atmosphere to prepare precursor, the heating rate was 5℃/min. Treated the precursor under vacuum by carbothermal reduction method to prepare silicon carbide (SiC) powder. The effect of temperature and additive content on the morphology of synthesised silicon carbide and the impurity removal order on product purity were explored. After firing at 1300℃,1400℃,1500℃ for 2 h, the 3C-SiC powders are detected, and as the temperature increased, the crystallinity of the product become better. When the content of the additive is 1% of the quality of the silica fume, the particle size of the silicon carbide synthesized at the temperature of 1500℃ is even and the dispersion is better. As for the impurity removal order, removed SiO2 first, then removed C can effectively remove the impurities in the product.

Investigation of Properties of High-Performance Fiber-Reinforced Concrete: Very Early Strength, Toughness, Permeability, and Fiber Distribution

Concrete cracking, high permeability, and leaking joints allow harmful solutions to intrude into concrete, resulting in concrete deterioration and corrosion of reinforcement. The development of durable concrete with limited cracking is a potential solution for extending the service life of concrete structures. Optimal design of very early strength (VES) durable materials will facilitate rapid and effective repairs and thus reduce traffic interruptions and maintenance work. The purpose of this study was to develop low-cracking durable materials that could achieve a very early compressive strength of 3,000 pounds per square inch within 10 h. Various proportions of silica fume, fly ash, steel fibers, and polypropylene fibers were used to evaluate concrete durability and postcracking performance. In addition, toughness, residual strength, permeability of cracked concrete, and fiber distribution were examined. VES durable concretes could be achieved with proper attention to mixture components (amounts of portland cement and accelerating admixtures), proportions (water–cementitious material ratio), and fresh concrete and curing temperatures. Permeability values indicated that minor increases in crack width, greater than 0.1 mm, greatly increased infiltration of solutions. Adding fibers could facilitate control of crack width. An investigation of fiber distribution showed preferential alignment and some clumping of fibers in the specimens and highlighted the need for sufficient mixing and proper sequencing of the addition of concrete ingredients into the mixer to ensure a uniform random fiber distribution. Results indicated that VES and durable fiber-reinforced concrete materials could be developed to improve the condition of existing and new structures and facilitate rapid, effective repairs and construction.