Use Of Nanosilica Research Articles

Overview on evaluation of the mechanical, durability properties and microstructure of Nano-Silica assimilated cement composites (Nano-SAC)

The Cement composites (CC) are the ubiquitous material in the world because of nanostructured, multi-phase, composite material that ages over time. CC as a construction material is most heterogeneous and the advent of nanotechnology offers substantial advances in concrete. In this framework, the application of Nanotechnology has its prominence in the construction industry, due to the enhanced characteristics of CC. Several studies have attempted to incorporate a variety of nanomaterials in CC and investigated the enhancement of mechanical and durability properties. Most importantly, the use of Nano-Silica (NS) has high significance in enhancing the mechanical properties, making the composite a durable material due to high pozzolanic behaviour and influence on the microstructure of CC. Hence, this paper reviews the prior development and current findings of Nano-Silica (NS) incorporated CC. The effect of Nano-Silica on mechanical and durability properties of the cement composites by varying microstructural characteristics are discussed. Furthermore, due to compact microstructure and accelerated hydration, and impermeable microstructure and higher strength durability is enhanced. Finally, the paper also describes the limitation that the optimum dose of the Nano-silica varies with its size, type, and dose of admixture, water to binder ratio, which is still contradictory. Additionally, the incorporation of Nano-silica is a potential breakthrough in building materials for a specific application. This article shed light on optimum dose in cement composite for specific types and sizes of Nano-silica particles.

Nanosilica to improve the flowability of fine limestone powders in thermochemical storage units

Fine powders are the cornerstone of new energy storage solutions to assist concentrated solar power plants. Though, their ability to behave like fluid can be seriously affected at high temperatures. This work investigates the use of nanosilica in fine limestone (calcium carbonate, CaCO3) powders to mitigate the promotion of cohesion forces at high temperatures. Experiments were conducted over limestone powder samples with particle sizes around 45μm. The analysis was performed monitoring the tensile yield strength as the samples were subjected to different temperatures and consolidation stresses while varying the nanosilica content up until 0.82wt%. Temperatures reached a maximum of 500°C(close to the Tamman temperature in limestone), whereas consolidation stresses were increased up to 2kPa. Results show that nanosilica coating is an efficient solution to inhibit the enhancement of powder cohesiveness at high temperatures and consolidations. A solution that offers better control to smooth the granular flow regimes in production environments.

Influence of functionalized nanosilica with different functional groups in the properties of cementitious composites: A review

The use of supplementary nano cementitious material (SNCM) to improve the mechanical properties and durability performances of cementitious composites (cement paste, mortar and concrete) has received remarkable attention in recent studies. The use of nanosilica as SNCM is a consolidated practice in the scientific community. However, recent developments in the synthesis of monodisperse and narrow-size distribution of nanoparticles by functionalization methods provide a significant improvement to the development of silica-group nano composites (among the functional groups: amine, carboxyls and glycol groups), the so-called functionalized nanosilica (FNS). This article aims to raise a literature review on the properties of FNS in cementitious materials and the advanced techniques of nano/micro structural analysis used to characterize cementitious composites containing FNS’s.

Effects of Micro Silica & Flyash on Strength & Durability Parameters of High Strength Concrete

High strength concrete is a term used to describe concrete with special properties not attributed to normal concrete. High-performance means that the concrete has one or more of the following properties: low shrinkage, low permeability, a high modulus of elasticity, or high strength. The application of nanotechnology in concrete has added a new dimension to the efforts to improve properties of High strength concrete. Nano materials, by virtue of their very small particle size can affect the concrete properties by altering the microstructure. Concrete can deteriorate for a variety of reasons, and concrete damage is often as result of combination of factors. This causes stresses in the concrete, which can eventually have resulted in cracking, delamination, and spalling. Concrete resists weathering action, chemical attack, and abrasion while maintaining its desired engineering properties throughout its lifespan. Different concretes require different degrees of durability depending on the exposure of environment and the properties desired. Durable concrete will retain its original form, quality and serviceability when exposed to its environment. The main characteristics influencing the durability of concrete is its permeability to the ingress of water, oxygen, carbon dioxide, chloride, sulphate and other deleterious substances. It became necessary to impart knowledge about durability of concrete and factors affecting durability to the society, as the wide use of concrete as a material in the constructions. This study concerns with the use of Nano silica of size 12 nm in M60 grade of concrete to improve the compressive strength of concrete and study on various durability parameters of High strength concrete. An experimental investigation is planned to carry out with different amount of Fly ash as 15% ,20%, 25%,30% and Micro silica as 5.5%,7%,8.5%,10% in concrete by weight of concrete. have been planned to carry out are workability, compressive test, flexural test, split tensile test. To study durability parameters of High strength concrete with nano silica Rapid chloride penetration test (RCPT), Water Sorptivity test, Acid attack test, Sulphate attack test are conduct. In this study it was observed that t the durability, strength and workability are increase as the percentage of fly ash & micro silica increses

Effect of nanosilica and silica fume on the mechanical properties and microstructure of lightweight engineered cementitious composites

This paper proposes the use of nanosilica (NS) and silica fume (SF) to improve the mechanical properties of lightweight engineered cementitious composites (LECCs) and compensate for the drawbacks of lightweight fillers. Twelve LECC mixtures were prepared to study the effect of NS and SF on the mechanical properties of LECCs, and the influence mechanism was analyzed by microscopy. The results showed that the incorporation of NS can significantly improve the mechanical properties of LECCs. This improvement in performance derives from the nucleation and pozzolanic effects of NS. The nucleation effect promotes the hydration of cement. The pozzolanic effect consumes more Ca(OH)2 and forms more calcium silicate hydrate (C-S-H). The combined use of NS and SF was more effective in improving the performance. Incorporating SF based on a 3% NS content can consume more Ca(OH)2 and further improve the mechanical properties of LECCs.

Use of Nanosilica for Increasing Dune Erosion Resistance during a Sea Storm

Dune recovery interventions that integrate natural, sustainable, and soft solutions have become increasingly popular in coastal communities. In the present study, the reliability of an innovative non-toxic colloidal silica-based solution for coastal sand dunes has been verified for the first time by means of laboratory experiments. An extensive experimental campaign aimed at studying the effectiveness of the use of nanosilica has been conducted in the 2D wave flume of the EUMER laboratory at the University of Salento (Italy). The study was first based on a horizontal seabed and then a cross-shore beach-dune profile was drawn similar to those generally observed in nature. Detailed measurements of wave characteristics and observed bed and cross-shore beach-dune profiles were analyzed for a wide range of wave conditions. In both cases, two sets of experiments were carried out. After the first set of experiments performed resembling the native conditions of the models composed with natural sand, the effects of the injection of the mineral colloidal silica-based grout were investigated. The observations show that mineral colloidal silica increases the mechanical strength of non-cohesive sediments reducing the volume of dune erosion, thus improving the resistance and longevity of the beach-dune system.

Emergence of nano silica for oil and gas well cementing: application, challenges, and future scope.

Nanotechnology has opened up a plethora of opportunities and has acquired extreme importance in a myriad of fields to produce enhanced materials. Their special properties make them sustainable for industrial purposes. One of the most crucial processes in the petroleum and geothermal industries is cementing. Various classes of Portland cement are used according to API classifications. The conventional Portland cement fails to perform its function at high pressure and high temperature (HPHT) conditions. Hence, various admixtures are used to improve its properties. HPHT conditions not only have a bad impact on Portland cement by affecting its rheological properties but also reduce its strength, porosity, and permeability. So, additives like nano silica are used to improve its properties. Better compressive strength, low porosity and permeability, higher yield stress, and reduced setting time are some of the major properties that improve by the use of nano silica. This paper discusses in detail the different types of cement, cementing processes, failure of Portland cement, and effect of nano silica as an admixture on the compressive strength, rheology, porosity, and permeability of the cement. Furthermore, the upcoming challenges in cementing are discussed along with future potential in this field.

Nano-Silica modifier asphalt concrete under rutting resistance and shape memory component

Permanent deformation is pavement distress that has been the root cause of failure of roads globally. With the formation of a rut, follows cracking which inevitably damages the asphalt and sub-base layers. To curb the rutting distress, this study investigates the use of nanosilica, miniaturized silica particles to the power of 10-9 to modify the binder of the asphalt concrete. The nano-silica was added at 4%, 6% and 15% by weight of bitumen into the asphalt mixture. Marshall Mix design method was used to prepare the forty-eight samples used in the study. Repeated Load Permanent Deformation (RLPD) test and Shape Memory (SM) were performed at two temperatures (25°C and 40°C). It was found that the rutting resistance and shape memory had the best performance with the addition of 15% nano-silica at 40°C. Addition of nano-silica at 15% by weight of bitumen had the best amelioration of not only permanent deformation resistance but also shape retention thus enhancing pavement performance.

Effect of nano-silica on Portland cement matrices containing supplementary cementitious materials

abstract: For a controlled granulometry, this study evaluates the effect of nano-silica on mechanical and rheological properties, as well in the microstructure of Portland cement matrices containing a fixed amount of supplementary cementitious materials and three different types of cements. The rheological behavior of cement pastes was evaluated by rotational rheometry and mechanical performance was measured througth the compressive strength. The microstructure was analyzed by intrusion mercury porosimetry and scanning electron microscopy. There was an increasing on the viscosity of the cementitious matrices, as a consequence of the reduction in the inter particle separation of these suspensions. The optimum content of nano-silica varied according to Ca/Si ratio of Portland cement matrices containing supplementary cementitious materials. The use of nano-silica allowed to modify the pore size distribution of cementitious matrices. And the structure of nano-silica in cementitious matrices has occurred in layers or agglomerates of nano-particles covered by hydration products.

Complex reinforcement potential of inorganic nanoparticles in bitumen

Although the modification of bitumen using nanoparticles has become popular in research studies recently, the degree of modification they provide is still debatable. This paper discusses the effects of three nanoparticles (silicon dioxide, titanium dioxide and calcium carbonate) on the physical properties and rheological behaviour of bitumen. The microstructural properties were evaluated using X-ray diffraction (XRD) and the physical properties were assessed through penetration, softening point and ductility tests. A dynamic shear rheometer was used to investigate the rheological properties of the bitumen, and the results were analysed through the 2S2P1D master curve model and complex reinforcement coefficient RM*. The results of XRD indicated substantial changes in the bitumen structure after adding the nanoparticles. The results showed that the physical properties and rheological behaviour of bitumen were significantly altered by adding the nanosilica to bitumen. However, using the same amount of titanium dioxide and calcium carbonate as additives was less effective than the use of nanosilica. It was also found that the 2S2P1D model and complex reinforcement coefficient RM*were very practical for satisfactory modelling and comparing the rheological properties of nanoparticle-modified binders.

Effect of nano zinc oxide and silica on mechanical, fluid transport and radiation attenuation properties of steel furnace slag heavyweight concrete

Due to the growing nuclear energy sector worldwide, it has been a global interest among researchers to improve the harmful radiation isolation properties of concrete for preserving both environment and human safety in nuclear power plant applications. While nano zinc oxide, nano-silica and steel furnace slag have high molar mass and favorable physical properties to improve high energy radiation attenuation properties of the concrete, scarce body of literature on the subject matter was reported. Hence, the study was aimed to investigate the suitability of the addition of nanomaterials such as nano-silica and nano zinc oxide for improving the mechanical, fluid transport and gamma-ray attenuation properties of heavyweight concrete (HWC) containing aggregate of steel furnace slag (ASFS). A new contribution of this study was the use of nano zinc oxide and nano-silica in concrete binder formulation to enhance the gamma ray shielding ability of concrete. A method was established for the optimization of the nano zinc oxide content used in combination with a constant amount of nano-silica to improve the various performance of heavy weight concrete. An investigation program was implemented with six concrete mixes which were prepared by utilizing ASFS with the addition of a superplasticizer, 3% of nano-silica in combination with (0.5–2.5%) of nano zinc oxide as an additive to produce high strength heavy weight concrete. The mechanical properties, fluid transport characteristics and γ-ray shielding performance were evaluated for hardened concrete samples. The inclusion of 1.5% nano zinc and 3% of nano-silica enhances the gamma-ray shielding and compressive strength by 16.3 and 6.6%, respectively, at 28 days as compared to the control mix (without nanomaterials). Besides, all the mechanical and fluid transport properties of the concrete were improved correspondingly. In conclusion, the combined use of nano-silica and nano zinc oxide is suitable to enhance mechanical strength, fluid transport and high energy radiation attenuation performance of steel furnace-slag heavyweight concrete (SSHWC).

Nano-Silica and its Role on Performance of Cement Concrete-A Review of Experimental Investigation

The researchers are generally focusing on the basic technology of cementitious materials at the nano level. In addition, the researchers are mainly aimed at enhancing the durability and strength of concrete and have found rapidly developing the mechanical and microstructural properties of cementitious materials with the introduction of nano-silica. The present paper reviewed and summarized the experimental research works carried out on the use of nano-silica in cement concrete mix as an additive or replacement of cement and its effects on rheology of the fresh concrete, and properties of hardened concrete such as strength, and durability. Thus, nano-silica is a promising material which can be used to improve the properties of the cement concrete.

Reliability based partial safety factor of concrete containing nano silica and silica fume

The influence of combination of nano silica and silica fume, as partial cement replacement materials, on the properties of concrete has been studied through the measurement of compressive strength. The compressive strength of concrete in terms of mean, standard deviation and with-in-test coefficient of variation related to the variation in the nominated parameters have also been developed. The compressive strength data developed experimentally has been analyzed using normal-probability distribution and partial safety factors of composite concretes have been evaluated by using first order second moment approach with Hasofer Lind's method. The use of Nano silica and silica fume in concrete decreases the partial safety factor of concrete i.e., increase the reliability of concrete. The experimental results show that the properties of concrete having nano silica and silica fume in combination were better than that of a plain concrete. The SEM test results showing the level of Ca(OH)2 in plain concrete and consumption level Ca(OH)2 of concrete containing nano silica & silica fume have also been presented.

Nano Silica and Metakaolin Effects on the Behavior of Concrete Containing Rubber Crumbs

The excessive production of worn tires remaining from the transportation system and the lack of proper procedures to recycle or reuse these materials have caused critical environmental issues. Due to the rubber’s toughness, this material could be implemented to increase concrete toughness, and by crushing the tires concrete aggregates can be replaced proportionally with rubber crumbs and large quantities of scrapped rubber. However, this substitution decreases the concrete strength. In this study, crushed rubber with sizes from 1 to 3 mm and 3 to 6 mm were replaced by 5%, 10%, and 15% sand; the combination of two additives of nano silica and metakaolin additives with optimum values was used to compensate the degradation of the strength and improve the workability of the concrete. Moreover, the compressive strength, tensile behavior, and modulus of elasticity were measured and compared. The results indicate that the optimum use of nano silica and metakaolin additives could compensate the negative effects of the rubber material implementation in the concrete mixture while improving the overall workability and flowability of the concrete mixture.

Rheological investigation of asphalt binder modified with nanosilica

The study investigates the use of nanosilica as a potential binder modifier. Nanosilica can be produced from rice husk and silica fumes and therefore is a cost-effective and environment-friendly modifier. Different percentages of nanosilica (0%, 0.5%, 1% and 3% by weight of asphalt binder) were added to VG-10 binder in a high-speed mixer. The influence of temperature, strain rate and frequency on viscosity was evaluated. Different rheological tests like time-temperature sweeps, Superpave rutting parameter (G*/sinϕ), Multiple Stress Creep and Recovery (MSCR) Test, Creep tests, and Zero shear viscosity (ZSV) tests were performed on base asphalt binder and nanosilica modified asphalt binders. The addition of nanosilica enhanced the rutting potential of the asphalt binder. Fatigue evaluation using Linear Amplitude Sweep test showed that incorporation of nanosilica arrests the micro crack nucleation and therefore enhanced the fatigue performance of asphalt binder. Nanosilica particles act as a potential heating barrier and protect the host polymeric chains of the asphalt binder, thus improving its aging resistance. Nanosilica modified binders also showed an enhanced self-healing capability.

Use of Nanosilica and Cement in Improving the Mechanical Behavior of Disintegrated Carbonaceous Mudstone.

This study aims to examine the mechanical behavior of disintegrated carbonaceous mudstone modified with nanosilica and cement (DCMNC). Many DCMNC specimens with various nanosilica contents were prepared. The X-ray diffraction (XRD) analyses and scanning electron microscopy (SEM) observations were performed on some of the specimens. Afterwards, triaxial tests were carried out on the remaining specimens to determine the mechanical behavior of DCMNC. The results showed that the cohesion exhibited a positive correlation with nanosilica content while the angle of internal friction presented a negative correlation with nanosilica content. The peak deviatoric stress, residual deviatoric stress and brittle modulus of DCMNC showed an increase followed by a decrease as nanosilica content varied from 0 to 8%, and all of them reached corresponding maximums at a nanosilica content of 2%. Thus, 2% was considered to be the optimum nanosilica content. The modification mechanism of DCMNC could be explained by the pozzolanic reaction related to nanosilica and the filling effect of nanosilica.

New achievement in moisture sensitivity of nano-silica modified asphalt mixture with a combined effect of bitumen type and traffic condition

Moisture damage is a critical problem of asphalt pavements. Some factors affecting the moisture sensitivity of asphalt mixtures include bitumen properties, air void content, and the type of anti-stripping additive. This study investigated the use of nano-silica for improving the properties of different bitumens and to increase the moisture resistance of asphalt mixtures at different traffic loading conditions. Two types of bitumen (60–70 and 85–100 pen grade) were modified with various percentages of nano-silica (0, 0.2, 0.4, 0.7, and 0.9% by the weight of the bitumen), and physical and rheological tests were conducted to determine the optimum nano-content. Then, the optimal content was used to prepare asphalt mixtures at three different air void contents (4, 5, and 6%) to simulate the heavy, medium, and low traffic loading conditions. Indirect tensile strength (ITS) and compressive strength tests were performed on the specimens in dry and wet conditions, and the effect of air void content and the type of bitumen on the moisture sensitivity and compressive strength of unmodified and nano-silica-modified asphalt concrete was investigated. The results showed that nano-silica improved the moisture sensitivity of asphalt mixtures with 60–70 and 85–100 pen grade bitumens at all air void contents and the effect of nano-silica was higher on the moisture sensitivity of asphalt mixtures with 60–70 than 85–100 pen grade bitumen.

STRENGTH AND DURABILITY PERFORMANCE OF FLY ASH BASED GEOPOLYMER CONCRETE USING NANO SILICA

With the increasing infrastructure development across the globe, the demand of cement production increases day by day. However, the production of cement is associated with the emission of large amount of CO2 causing global warming. Scientist and engineers are in search of a green eco friendly alternative for concrete production. Geopolymers are rapidly emerging as an alternative to Portland cement as the binder of structural concrete. In this respect, the fly ash based geopolymers shows considerable prospect for application in concrete industry as an alternative binder to the Portland cement. Development of geopolymer concrete using class F fly ash brings many advantages like; enhancing workability, durability, better strength as well as lowering the price. There is not only a reduction in the greenhouse footprint but, also considerable increase in strength and resistivity to adverse conditions.
 In order to enhance the performance of Geopolymer concrete, the use of Nano-silica is found to be suitable and practiced by researchers. 
 Use of Nano materials as fillers in the concrete matrix has proven effective in increasing mechanical and durability properties. This research is based on performance evaluation of geopolymer concrete using different percentage of Nano-silica.. It was observed that Geopolymer concrete with Nano-silica ( GPC-N) shows good compressive strength as well as durability under aggressive conditions.
 The materials performance were also investigated using X-Ray Diffraction technique. (XRD). Results show that the presence of nano silica enhanced the performance of Geopolymer concrete with respect to strength and durability purposes.

Effects of the nanosilica addition on cement concrete: A review

Nanotechnology has given a new dimension to the concrete world. Among the nanomaterials used as partial replacement of cement, nanosilica (NS) has been used immensely. This review paper summarizes the preparation of nanosilica useable for concrete production, effects of nanosilica addition on cement concrete in terms of varied components, fresh state as well as hardened state and physical properties like workability, setting times, etc. The nanosilica addition hinders workability as the surface area occupied by the nanosilica is quite large. The setting time reduces to a great extent. It gives an in-depth review of nanosilica added concrete prepared using various other additives. The mechanical properties like compressive strength, split tensile strength, flexural strength, and elasticity modulus are discussed in details. Also, the durability aspects of the nanosilica added concrete, the microstructural characterization, and the reduction of structural micropores are discussed in detail. The addition of nanosilica increases the strength properties as well as the durability but reduces the structural micropores. Further, the present scenario and the recommendation for future works of nanosilica application on cement concrete are presented. The use of nanosilica can reduce the consumption of cement, which releases CO2, responsible for global warming. All these aspects make nanosilica added concrete an essential and sustainable material for construction purposes.

The Effects of Single and Combined Nanoparticles in the Properties of Air Lime Pastes

ABSTRACT The present research work is an effort to evaluate the contribution of different nanoparticles in the properties of air lime pastes. The use of nano-silica (NS), nano-alumina (NA) and nano-calcium oxide (NC) can contribute differently in physico-mechanical properties and microstructure. Nanoparticles enhanced compressive strength and open porosity, whilst did not affect significantly the capillarity. Moreover, it was proved that the different mechanisms of nanoparticles’ action lead to different carbonation degrees of nano-modified air lime. The microstructure clarified the physico-mechanical results and revealed nano-scale differences in composites. The improvement of the properties of lime-based materials when nano-modified, is the aim of this work in order to improve the inherent weakness of lime and increase the application fields.