Silica Fume Research Articles

Structure and Properties of Variatropic Concrete Combined Modified with Nano- and Micro-silica

The lack of systematic information on the influence of the combined modification of variatropic concrete on their characteristics was revealed. The purpose of this work was to study the influence of the type of modifying additive, namely micro-silica, nano silica and their combination on the properties of concrete made using three different technologies - vibration (VC), centrifugation (CC) and vibration centrifugation (VCC). Concrete elements made using centrifugal compaction technology were subjected to additional sawing. Three types of modifiers were studied: micro-silica (MS), nano silica (NS) and their combinations. To determine the degree of effectiveness of each recipe solution, the following main characteristics were monitored: workability of concrete mixtures; density of hardened composites; compressive strength (CS) and water absorption (WA). When modifying MS, the greatest effect for VC, CC and VCC was observed with its amount of 8% instead of part of the cement. CS gains were up to 17% for VCC, and WA decreased to 25% for VCC. The NS modification showed the greatest effectiveness at a dosage of 4%. CS gains were up to 19% and WA decreased to 28% for VCC. A combined modifier of 75% MS and 25% NS showed the greatest effectiveness. CS increased up to 17% compared to effective dosages of single-component modifiers. The effectiveness of VCC, characterized by the percentage increase in CS, was up to 55% higher in comparison with VC and up to 25% higher in comparison with CC. WA of concrete decreased to 14% in comparison with effective dosages of one-component modifiers. The effectiveness of VCC, characterized by the percentage reduction in WA, was up to 30% higher compared to VC and up to 12% higher compared to CC. The greatest efficiency of all types of modifiers was observed in combination with the synthesized vibration centrifugation technology.

Enhancing the self-healing performance of engineered cementitious composites in harsh environment through cementitious matrix optimization and crack width controlling

The fragile cementitious materials can be easily cracked under service in the harsh environment, which can reduce the loading capacity of concrete structures and its expected service life. The self-curing ability of cementitious materials is thus essential for the resilience of the concrete structures in harsh environments. The purpose of the study is to enhance the self-healing ability of Engineered Cementitious Composites (ECC) in harsh environment though cementitious matrix optimization and crack width controlling. The cementitious matrix containing cement, silica fume, and fly ash is optimized based on the Simple Centroid Method. The Ultra-high Molecular Weight Polyethylene (UHMWPE) fibers have been selected as reinforcing materials due to their superior mechanical performance. The results show that the compressive strength of the ECC samples generally increases with the silica fume content, and the tensile strength rises with both the silica fume and cement content. Meanwhile, the ultimate tensile strain of the ECC samples increases and declines with the fly ash and silica fume content, respectively. The self-repairing properties of the pre-damaged ECC specimens with 5 % strain are examined through exposure in the simulated harsh environment. It is found that the exposure to the groundwater environment can improve the self-curing ability of the pre-damaged ECC specimens, while the self-curing ability can be deteriorated under exposure to the marine environment. Furthermore, the crack sealing and strength recovery ability of cementitious materials can be enhanced with higher fly ash content and lower silica fume content. Finally, the self-curing mechanism of the ECC samples is analyzed by means of the phase and microstructure analysis. Exposure to groundwater environments can promote the generation of the C–S–H gel and calcium carbonate in the self-curing product, and thus enhance the self-healing efficiency. This study can contribute the resilience enhancement of the concrete structure in harsh environments.

The Role of Silica Fume in Enhancing the Strength and Transport Properties of PET Fiber–Ultra High-Performance Concrete

The Role of Silica Fume in Enhancing the Strength and Transport Properties of PET Fiber–Ultra High-Performance Concrete

Mixture composition design of magnesium oxychloride cement-stabilized crushed stone materials applied as a pavement base

Conventional binding materials, such as silicate cement and lime, present high energy consumption, pollution, and carbon emissions. Therefore, we utilize crushed stone as a stabilization material. Magnesium oxychloride cement (MOC) is modified and used as an inorganic admixture owing to its eco-friendly nature and low carbon content. We analysed the control indicators of an integrated design of MOC-stabilized crushed stone by conducting unconfined compressive strength and water-resistance tests. The optimum mixing composition of the MOC-stabilized crushed stone was determined through the response surface methodology. We determined the best approach and dosage for improving the water resistance of MOC-stabilized crushed stone by comparing the effects of four modification methods: fly ash, citric acid + silica fume, phosphoric acid + waterborne polyurethane, and dihydrogen phosphate potassium salt. We also perform a comparison with 5% ordinary silicate cement-stabilized crushed stone. The results indicate that the MOC-stabilized crushed stone exhibits a rapid increase in strength in the early stage, but this rate reduces after 28 days. The mixing design employs the 4-day unconfined compressive strength and 1-day water resistance coefficient as the technical indicators. The best mixing composition includes a 4.27% MOC dosage and a molar ratio of MgO/MgCl2 of 5.85. We use 1% citric acid + 10% silica fume in equal amounts to replace the MOC dopant method for composite modification of the MOC stabilized crushed stone. Consequently, the 1-day water resistance coefficient before water immersion is significantly increased from 0.78 to 0.91 and its 4-day unconfined compressive strength is only reduced by 0.10 MPa. This significantly improves the water resistance of the MOC-stabilized crushed stone and ensures that its strength remains unaffected, which is the optimal modification method. However, this method must ensure that a small amount of citric acid and silica fume are uniformly distributed in the MOC-stabilized crushed stone, which increases the construction difficulty of the road base.

Corrosion behavior of modified cement-based coated steel rebar subjected to different levels of tensile loads

Polymer-modified cement-based coating can provide corrosion protection for steel rebar. However, after the action of the tensile load, the connection between the polymer and the cement matrix was weakened, thus reducing its corrosion resistance. In this study, silica fume, nano-SiO2, and corrosion inhibitor were used to modify EVA (Ethylene Vinyl Acetate Copolymer) and cement-based coatings. Electrochemical experiments were used to evaluate the corrosion behavior of coated steel rebar after the action of different levels of tensile loads, and microscopic characterization and porosity experiments were applied to analyze the changes of microscopic properties of the coatings. The experimental results show that silica fume and nano-SiO2 produce more high-strength C–S–H gels through hydration reaction to improve the tensile properties and compactness of the coating, thus reducing the porosity and chloride ion permeability of the coating after tension. Tetrabasic-modified cement-based coated steel rebar with EVA, silica fume, nano-SiO2, and amino-alcohol corrosion inhibitor displayed the highest coating resistance and the lowest corrosion current density under the action of tensile load. Experimental results proves that nano-SiO2 enhances the tensile properties of the coating. The addition of corrosion inhibitor can further improve the compactness of the coating under tension, hinder the formation of chloride ion transport channel, and adsorb on the surface of steel rebar to improve the corrosion resistance of steel rebar.

Novel activation method of waste concrete powder for sustainable clinker-free binder

This study investigates the environmental and mechanical implications of incorporating silica fume into lime-activated thermo-mechanically treated waste concrete powder (TMWCP) to develop a sustainable clinker-free binder. The novel activation method involves thermo-mechanical treatment of WCP, followed by lime and calcium formate chemical activation. The results demonstrated that incorporating silica fume enhanced the pozzolanic reactivity, which led to the formation of C–S–H, pore refinement, and a dramatic increase in compressive strength. For instance, the incorporation of 20 % and 25 % silica fume exhibited compressive strength of 46 MPa and 43 MPa after 28 days of curing. The developed clinker-free binder with the addition of 20 % silica fume demonstrated a reduction in mineral resource consumption of 99.3 % and CO2 emissions of 13 % and 69.3 % compared to the sample without silica fume and ordinary Portland cement, respectively. This study offers a promising avenue for the widespread utilization of WCP as an environmentally friendly clinker-free binder.

Novel treatment method of coal bottom ash for strain-hardening alkali-activated composite

This study explored the viability of using coal bottom ash (CBA), treated as a silicate source for preparing activators, as a filler in strain-hardening alkali-activated composites. The silica content provided by CBA was approximately 30% of that provided by silica fume, and its surface morphology exhibited a rough texture after treatment. The incorporation of CBA led to an improved compressive strength, and the subsequent substitution of treated CBA up to 100% resulted in a 10% increase in the compressive strength. Furthermore, incorporating the treated CBA enhanced the bond strength and pullout energy by up to 70% and 75%, respectively, compared with those of plain composites. The treated CBA also improved the tensile performance, as the replacement rate increased. At a substitution rate of 100%, the tensile strength, strain capacity, and strain energy density increased by 168.64%, 118.3%, and 479.41%, respectively, compared with those of plain composites. Thus, utilizing CBA as an alkaline activator is a promising solution to environmental challenges in the field of construction materials.

Mitigation of zinc and organic carbon leached from end-of-life tire rubber in cementitious composites

End-of-life tire (ELT) rubber has been widely researched to replace fine or coarse aggregates in cementitious composites. While most studies paid attention to its effect on the engineering properties, very few considered chemical reactions with pore solution and the potential for environmental leachate. Recently the authors developed a methodology to remove zinc from the ELT rubber, since zinc can be toxic if it is leached into the environment. In this study, the authors utilized ELT rubber before and after the zinc extraction process to partially replace fine aggregate in a mortar. Flowability, compressive strength, flexural strength, and ultrasonic pulse velocity were measured for the engineering properties of rubberized mortars. Simultaneously, isothermal calorimetry was also employed to investigate the effects of ELT rubber on the hydration process of the rubberized mortars. In addition, the pore solution and leaching solutions were taken at different curing ages and then analyzed for elemental and total organic carbon (TOC) contents. The results showed a remarkable loss in engineering properties of rubberized mortar when ELT rubber was utilized, and the decrease in performance was more pronounced in the samples with zinc-extracted ELT rubber. The pore solution was found to contain significant quantities of zinc and TOC. However, the authors also found that using silica fume to partially replace cement could effectively recover the loss in strength and could reduce the leachability of zinc and TOC.

Experimental Study to Replace Conventional Bricks with Papercrete Bricks Incorporating Various Admixtures

The study focuses on identifying suitable admixtures that can positively impact the workability, strength, and insulation capabilities of papercrete. Various types and concentrations of admixtures, such as fly ash, glass fiber, and glass powder, silica fumes, iron powder, jute fibre etc are introduced to the papercrete mix to assess their influence on the material's overall performance. The results of this study contribute to the broader goal of promoting sustainable construction practices by improving the performance and versatility of papercrete. By identifying effective admixtures, this study offers practical guidance for architects, engineers, and builders seeking environmentally friendly alternatives in the pursuit of more resilient and energy-efficient building materials.

Preliminary investigation and life cycle assessment of artificial reefs with recycled brick-concrete aggregates

An economical and environment-friendly artificial reef concrete using fully recycled brick-concrete aggregate as raw material was proposed. This study investigates the mechanical properties, drying shrinkage, chloride ion penetration, and biological adaptability of the reef. A comparative analysis is conducted on the environmental impacts (EI), carbon emission impact and cost efficiency of artificial reefs, considering natural aggregate concrete and recycled brick-concrete aggregate concrete at the material level. The results indicate that the use of recycled brick-concrete aggregates can achieve service performance equivalent to that of natural aggregates. Field investigations involving samples immersed in seawater for six months reveal the positive trapping effects of recycled materials on aquatic organisms. The Life Cycle Assessment (LCA) results reveal that achieving a 100 % replacement rate of recycled brick concrete aggregate (RBCA) creates a positive feedback loop for carbon emissions when appropriately incorporating industrial waste materials like fly ash and silica fume. In comparison to ordinary concrete, the utilization of recycled materials can significantly reduce construction costs, up to 63.7 %, thereby presenting notable economic advantages.

Microwave absorption and electromagnetic properties of ultra-high-strength cementitious materials: Influence of basalt powder and underlying mechanism

The utilization of basalt powder in ultra-high-strength cementitious materials (UHSCMs) holds significant potential for application in mitigating CO2 emissions and reducing electromagnetic pollution. This study investigated the microwave absorption and electromagnetic properties of UHSCMs incorporating basalt powder, with the silica-fume-based mix as a comparison. A comprehensive multi-scale investigation was conducted to gain an in-depth understanding of the electromagnetic properties of UHSCMs. From the results, the UHSCM with basalt powder was demonstrated to possess improved microwave absorption performance, characterized by a mean reflection loss of −8.22 dB and effective bandwidths of 58.3% (<-7.0 dB) and 26.6% (<-10.0 dB). The enhanced performance of this mixture was attributed to its superior impedance-matching capability and microwave attenuation ability. The dielectric loss peaks within frequency ranges of 7.0–8.5 GHz and 10.0–11.5 GHz were caused by the interfacial polarization of macro pores and gel pores, respectively. The natural resonance, exchange resonance, and eddy current effect were the primary mechanisms of the magnetic loss. CaFeSi2O6 particles from basalt powder contributed to the enhanced natural resonance. In addition, basalt powder had the better market potentials and lower environmental impact as a supplementary cementitious material than silica fume for enhancing microwave absorption of UHSCMs. The finding of this study demonstrated the suitability of adopting basalt powder in UHSCM production with improved greenness and electromagnetic properties.

Mix design strategy and optimization considering characteristic evaluation of geopolymer concrete

In this study, a unique strategy for mix design of geopolymer concrete (GPC) was suggested by integrating fly ash, silica fume, and GGBFS as precursors with varied alkali activator molarities in both ambient and oven curing environments. GPC's crystalline and microscopic qualities were assessed by X-ray diffraction and scanning electron microscopy tests; while its' mechanical properties were assessed using compressive strength test (CST). The experimental results showed a rising trend between the alkali activator (NaOH) concentration and the compressive strength of the GPC. GGBFS precursor based GPC had the highest compressive strength of 87.53 MPa at 14 molarity of NaOH after oven curing at 60°C. Furthermore, Artificial Neural Network (ANN) and Response Surface Method (RSM) were used to evaluate significant correlation and interaction between different parameters considered in mix design. By incorporating six input variables from the experimental test data, namely total precursor content used, secondary precursor content used, curing temperature, number of curing days, total aggregate content, and molarity of NaOH used, and compressive strength as output/response variable. The R-value for ANN found to be 0.99, while the R2 value for the RSM model was 0.98, indicating a satisfactory fit having a good interaction and optimization of GPC parameters. The optimize values of different independent parameters evaluated can obtain maximum CST value of 111.104 MPa.

Rheological behavior of 3D printed concrete: Influential factors and printability prediction scheme

The rheological properties of cementitious materials play a crucial role in determining the printability for extrusion-based 3D concrete printing. This study develops data-driven machine learning (ML) models to predict two key rheological parameters - plastic viscosity (PV) and yield stress (YS) of 3D printable cementitious composites based on the mixture composition and time after water addition. A systematic experimental study is conducted by varying the contents of cement, fly ash, silica fume, sulfoaluminate cement, superplasticizer, and water-to-binder ratio, and time after water addition. The measured rheological data is used to construct a database for training predictive models including linear regression, support vector regression, random forest, extreme gradient boosting, and multi-layer perceptron neural network. The extreme gradient boosting model achieves the highest prediction accuracy with low root mean square error and all coefficients of determination exceeding 0.9 for both plastic viscosity and yield stress. Importance analysis identifies the most influential parameters affecting the rheological properties. A printability classification scheme is proposed using the model predictions by defining a printable zone of PV and YS. The data-driven framework is validated to effectively predict printability of new mixtures without trial-and-error. This study demonstrates the potential of ML models to accelerate the design and optimization of 3D printable cementitious materials.

Investigation of basic properties, microscopic characteristics, and optimized ratio prediction model of ultra-high steel fiber reinforced concrete

Ultra-high steel fiber reinforced concrete (UHSFRC) has poor workability and a low cost-performance ratio, and the application of active admixtures can overcome these shortcomings of UHSFRC. This work investigated the feasibility of fly ash (FA) and silica fume (SF) to improve the performance of SFRC and evaluate the effects of FA and SF on the workability, mechanical properties, microstructure, and economic/environmental performance of UHSFRC. The results showed that FA and SF can increase the slump, compressive, and splitting tensile strength of UHSFRC. Compared with control tests, the slump, 28-d compressive, and 28-d splitting tensile strength increased by 43.25 %, 29.35 %, and 55.72 %, respectively. More importantly, microscopic analysis showed that FA and SF have balling, filling, and adsorption effects, and increase peak intensity of C-S-H gel and ettringite, promoting secondary hydration of cement. According to the experimental data and mechanistic analysis, an innovatively optimized ratio prediction model is adopted to establish the relationship between the slump, compressive, and splitting tensile strength of UHSFRC and the content of FA and SF, and the testing error was less than 5 %, indicating that the model is feasible. Moreover, the effect of FA and SF content on cost-performance ratio, carbon emission, and energy consumption of UHSFRC was predicted. The economic/environmental analysis showed the mixing of FA and SF can improve the cost-performance ratio of UHSFRC and reduce carbon emission and energy consumption. This study can provide theoretical guidance for the improvement of the workability and mechanical properties of UHSFRC, and have important research implications for the improvement of the life cycle assessment of UHSFRCs. The results of the study also have some limitations, and further validation is needed for normal steel fiber concrete (compressive strength of 30–60 MPa, with fibers with a length of 30–60 mm and diameter of approx. 1 mm).

Clinker-free CaO-activated silica fume as a cementitious binder for pavement application

Ordinary Portland cement (OPC) production requires heating limestone up to 1450 °C and produces 0.5–0.9 kg of carbon dioxide for every 1 kg produced. Moreover, the massive volume of cement manufactured around the world every year adds to the urgent need to look for sustainable alternatives. This work proposes a novel calcium oxide (CaO)-activated high-volume silica fume mixture as a cementitious binder for pavement application that can address the sustainability concern with cement (because producing CaO requires a much lower calcination temperature than OPC, and that CaO is also used in low-volume in the binder). The combination of low-volume CaO and high-volume silica fume, particularly as a pavement binder has not been studied in the literature before. The compressive and flexural strength results showed that even by using a small fraction of CaO in the binder, it is possible to obtain acceptable strengths that satisfy ASTM pavement design guidelines, while OPC is unable to provide similar strengths at such low dosage. The mix having CaO content as 30 % of the silica fume content (CSF-30) shows the highest compressive strength (28d: 18.4 MPa) and flexural strength (28d: 4 MPa). In contrast, the maximum OPC-silica fume compressive and flexural strengths observed are 13.9 MPa and 2.9 MPa respectively at 28d From the microstructural results, it was seen that CaO–silica fume develops strength due to formation of calcite and calcium silicate hydrate. Almost all CaO–silica fume mixes exhibited lower porosity compared to their OPC-silica fume counterparts; CSF-30, the mix having the best mechanical performance showed the lowest porosity at 28d (2.8 %). A comparative sustainability analysis followed by a 5D analysis considering all the parameters studied in this work revealed that CSF-30 is the best binder alternative (overall score: 5.24). The results of this work will be useful for pavement users, designers, researchers, engineers, and relevant government officials, in having a sustainable clinker-free alternative pavement binder to OPC, particularly for low-volume roads, that satisfies the pavement design guidelines.

EXPLORATION AND COMPARISON BETWEEN REGULAR CONCRETE AND CONCRETE WITH MINERAL ADDITIVES

Concrete is a fundamental building material with critical properties such as durability, strength, and versatility. In recent years, there has been increasing interest in enhancing concrete performance and sustainability by incorporating mineral additives such as fly ash, slag, and silica fume. This study explores and compares the characteristics of regular concrete and concrete with mineral additives to evaluate their suitability for various construction applications. The research focuses on the mechanical properties, durability, and environmental impacts of both types of concrete. Laboratory tests will be conducted to compare the compressive strength, tensile strength, resistance to freeze-thaw cycles, chemical attacks, and workability of regular concrete and concrete with mineral additives. Additionally, life cycle assessments will be performed to analyze the environmental implications of using mineral additives in concrete production. One of the main advantages of mineral additives is their potential to improve the strength and durability of concrete. Fly ash, slag, and silica fume have been shown to enhance long-term strength, reduce permeability, and increase resistance to chemical attacks in concrete mixtures. Furthermore, using mineral additives can reduce the reliance on cement, a primary component of concrete with a significant carbon footprint, leading to reduced greenhouse gas emissions and resource depletion. Index Terms – Concrete, Mineral additives, Durability, Strength.

Experimental investigations on physico-mechanical properties of kaolinite clay soil stabilized at optimum silica fume content using clamshell ash and lime

This investigation examines the effect of clamshell ash (CSA) and lime additives on the physico-mechanical characteristics of kaolinite clay soil stabilized at the optimum silica fume content. Laboratory tests were performed to assess plasticity, shrink-swell characteristics, compaction characteristics, unconfined compressive strength (UCS), shear strength characteristics, mineralogical and morphological microstructure characteristics of stabilized soil specimens. The kaolinite clay soil was stabilized at its optimum silica fume content (6%) to produce the highest strength and was altered with three non-identical proportions of clamshell ash and lime (3%-9%). Cylindrical soil specimens, 76 mm in height and 38 mm in diameter, were moulded and treated for curing periods of 1, 7, 14, and 30 days to examine the strength of the altered soil. The findings revealed that, adding clamshell ash and lime significantly alters the plasticity, shrink-swell, maximum dry unit weights, and optimum moisture contents of the silica fume-stabilized soil. In terms of strength, the beneficial effects of CSA and lime additives were found to be more significant with more extended curing periods. Incremental increases in curing periods resulted in further enhancements in UCS, cohesion, and internal friction angle, indicating continued strength development over time. Microstructural analysis using field emission scanning electron microscopy and X-ray diffraction provided insights into the interparticle bonding mechanisms and microstructural changes induced by the addition of CSA and lime. The emergence of cementitious phases and pozzolanic responses between soil particles and stabilizers contributed to the densification and strengthening of the stabilized soil matrix. The findings of this study provide valuable insights into the potential of clamshell ash and lime additives to enhance the engineering properties of kaolinite clay soil stabilized with silica fume. These results have implications for sustainable soil stabilization practices, offering a promising approach to improve the performance of soils for various engineering applications, including construction and geotechnical projects.

Compressive Strength, Permeability, and Abrasion Resistance of Pervious Concrete Incorporating Recycled Aggregate

Extensive use of cement in the construction industry increases CO2 emissions and has a negative impact on the environment. In this work, recycled coarse aggregate (RCA) from construction and demolition wastes (C&amp;DW) was used to fabricate sustainable pervious concrete (PC). In order to mitigate the environmental hazards of excess cement waste and to improve the engineering properties of PC, silica fume (SF) and ground granulated blast-furnace slag (GGBS) were added. The effects of SF and GGBS on the compressive strength, permeability coefficient, porosity, and abrasion resistance of recycled aggregate pervious concrete (RAPC) were investigated. The results show that the incorporation of GGBS and SF effectively improves the compressive strength of RAPC but reduces the permeability coefficient and porosity. Moreover, due to the filling effect and pozzolanic activity, the incorporation of GGBS and SF significantly enhances the abrasion resistance of RAPC. Furthermore, the relationships between the compressive strength, permeability coefficient, porosity, and abrasion resistance of RAPC are clarified. The optimum replacement is achieved when the SF content is 7%, and the GGBS content is 20%, respectively, which results in the highest compressive strength (28.9 MPa) and the lowest permeability coefficient (1.2 mm/s) at 28 days, and the lowest mass loss rate (12.1%) after the Cantabro abrasion test.

Utilizing bio-based and industrial waste aggregates to improve mechanical properties and thermal insulation in lightweight foamed macro polypropylene fibre-reinforced concrete

This research intends to examine the potential of incorporating waste materials in place of coarse aggregates to augment the mechanical characteristics and thermal insulation of lightweight foamed concrete (LWFC), along with the inclusion of polypropylene (PP) fibres. The PP fibre exhibits excellent tensile strength and enhancement on thermal insulation properties of cementitious materials. In this study, eco-friendly bio-based oil palm shell (OPS) and robust solid polyurethane (SPU) aggregates derived from industrial waste were utilized as substitutes for conventional aggregates. Additionally, silica fume was partially incorporated as supplementary cementitious materials. The addition of PP fibre impacted the workability of the LWFC with the inverted slump value decreased by 1.7 %–17.5 %. The inclusion of PP fibre proportion increased from 0 % to 0.5 % revealed a positive result in mechanical properties and thermal insulation performance. The OPSSPU/0.5 showed the significantly increment of 40.4 % compressive strength, 102.9 % of splitting tensile strength, and 70.8 % flexural strength, respectively. The optimum result was obtained in the OPSSPU/0.5 mixture, which exhibited 3.74 MPa residual compressive strength. Furthermore, utilizing PP fibres brought about a significant reduction in thermal conductivity in the environmentally sustainable LWFC, leading to improvements ranging from 0.2 % to 16.3 % when compared to the control composition. Thus, these findings are essential for encouraging the adoption of such practices in the construction industry and contributing to the reduction of environmental impacts associated with sustainable concrete production.

Application of fume silica nanoparticles to improve high-temperature rheological performance of terminal blend rubberized asphalt

This study aims to evaluate the impact of fume silica nanoparticles (FSNPs) on the high-temperature rheological properties of terminal blend rubberized asphalt (TBRA). In this study, FSNPs were utilized to modify TBRA asphalt with three different CR contents (30%, 40%, 50%). The micro-morphology of FSNPs was observed through Scanning Electron Microscopy (SEM) experiments. The effects of FSNPs on the high-temperature rheological properties of TBRA were assessed using temperature sweep tests, Multiple Stress Creep Recovery (MSCR), and rotational viscosity tests. Furthermore, the influence of FSNPs on the chemical and thermal properties of TBRA was analyzed through Fourier Transform Infrared Spectroscopy (FTIR) and Thermogravimetric Analysis (TGA) tests. Rheological tests and SEM results indicate that FSNPs can effectively enhance the high-temperature elasticity, fatigue resistance, and deformation resistance of TBRA binders. This improvement is attributed to the unique branched network structure of FSNPs, which plays a pivotal role in enhancing the elasticity within the TBRA asphalt matrix. Additionally, the degradation of TBRA's low-temperature performance due to FSNPs is minimal. Considering the optimal viscosity for FSPN-modified TBRA, recommended ratios are: TB30/6%, TB40/4%, and TB50/2%. FTIR and TGA results demonstrate that the modification of TBRA by FSNPs is primarily physical blending, and the addition of FSNPs enhances the thermal stability of TBRA.