Nanomaterials In Concrete Research Articles

Review on Use of Nanomaterials in Concrete

Abstract: Various studies have highlighted the benefits of incorporating carbon nanotubes (CNTs) in concrete. They enhance compressive and flexural strength, prevent cracking, and improve durability. Different methods like sonication ensure uniform dispersion of CNTs in concrete. Additionally, research focuses on optimizing CNT concentrations to avoid adverse effects on properties like shrinkage and thermal conductivity. Overall, CNTs offer a promising solution to reinforce concrete and improve its mechanical properties effectively

Effect of Coarse Aggregate and Multi-Wall Carbon Nanotubes on Heat Generation of Concrete

Many researchers are developing heating construction materials to remove black ice from roads, addressing the scientific challenges associated with this issue. The use of carbon-based nanomaterials in concrete is of great interest due to the excellent electrical and thermal conductivity of this material. In this study, the incorporation of multi-walled carbon nanotubes (MWCNTs) into concrete compositions results in the formation of MWCNT bridge networks. MWCNTs exhibit a low specific heat and possess the ability to promptly generate raised temperatures with minimal power input. This characteristic has the potential to induce temperature variations in concrete. The heat generation test parameters for MWCNT concrete included the mixing concentration of the MWCNTs, the mixing ratio of coarse aggregate, the water/cement (W/C) ratio, and the presence or absence of superplasticizers. The heating performance of concrete was found to improve as the mixing concentration of the MWCNTs increased, while a heating performance decrease was observed as the mixing ratio of coarse aggregate increased, owing to the reduced dispersibility of the MWCNTs. Conversely, the heating performance improved when the W/C ratio increased due to the enhanced dispersibility of the MWCNTs. Moreover, superplasticizers assist in dispersing MWCNTs, thereby improving the heating performance. Additionally, field emission scanning electron microscopy revealed that MWCNTs form a bridge network between the cement hydrates. As a result of this study, the maximum temperature variation of concrete mixed with MWCNTs was up to 73.6 °C. Therefore, by mixing MWCNT aqueous solutions with concrete and using an appropriate W/C ratio and superplasticizer, a new construction material capable of enhanced heating performance was developed.

An Elucidative Review of the Nanomaterial Effect on the Durability and Calcium-Silicate-Hydrate (C-S-H) Gel Development of Concrete.

Concrete as a building material is susceptible to degradation by environmental threats such as thermal diffusion, acid and sulphate infiltration, and chloride penetration. Hence, the inclusion of nanomaterials in concrete has a positive effect in terms of promoting its mechanical strength and durability performance, as well as resulting in energy savings due to reduced cement consumption in concrete production. This review article discussed the novel advances in research regarding C-S-H gel promotion and concrete durability improvement using nanomaterials. Basically, this review deals with topics relevant to the influence of nanomaterials on concrete's resistance to heat, acid, sulphate, chlorides, and wear deterioration, as well as the impact on concrete microstructure and chemical bonding. The significance of this review is a critical discussion on the cementation mechanism of nanoparticles in enhancing durability properties owing to their nanofiller effect, pozzolanic reactivity, and nucleation effect. The utilization of nanoparticles enhanced the hydrolysis of cement, leading to a rise in the production of C-S-H gel. Consequently, this improvement in concrete microstructure led to a reduction in the number of capillary pores and pore connectivity, thereby improving the concrete's water resistance. Microstructural and chemical evidence obtained using SEM and XRD indicated that nanomaterials facilitated the formation of cement gel either by reacting pozzolanically with portlandite to generate more C-S-H gel or by functioning as nucleation sites. Due to an increased rate of C-S-H gel formation, concrete enhanced with nanoparticles exhibited greater durability against heat damage, external attack by acids and sulphates, chloride diffusion, and surface abrasion. The durability improvement following nanomaterial incorporation into concrete can be summarised as enhanced residual mechanical strength, reduced concrete mass loss, reduced diffusion coefficients for thermal and chloride, improved performance against sulphates and acid attack, and increased surface resistance to abrasion.

Nano-SiO2 Recycled Concrete Anti-Sulfate Performance and Damage Mechanism Research

The use of construction waste for concrete is an effective way to reduce the environmental burden while improving the sustainability of construction materials. Nano-SiO2 (NS) has excellent volcanic ash activity, which can effectively improve the strength of concrete. In this study, the synergistic effects of NS and 30% recycled concrete aggregate (RCA) on the mass loss, compressive strength, ultrasonic sound velocity values and microstructure of RAC after 25, 50, 75 and 100 repetitions of a dry–wet cycle (DWC) of sulfuric acid were investigated. The results show that NS has a significant role in improving RAC performance. The RAC specimens showed the lowest mass loss rate, the highest compressive strength, the lowest ultrasonic velocity value and the best resistance to sulfate erosion when the NS doping was 4%. Meanwhile, under CT and SEM, RAC with NS has lower porosity and higher hydration, which can effectively inhibit the crack generation and has stable volume growth within 0–50 repetitions of DWC. In addition, the addition of NS improves not only the microstructure of the substrate but also the interfacial transition zone (ITZ). When 4% NS was added, the porosity was the lowest and the durability improvement was the best performance. This study not only improves the production performance of RAC but also provides a strong reference for the integrated application of nanomaterials in concrete.

Nanopowders as an additive for strength and durability enhancement of cement composite: Review and prospects

The interest in utilizing nanopowders in concrete to increase the mechanical characteristics of concrete, such as compressive strength and tensile strength, is gaining importance. The commonly used nanopowders to enhance composite properties are nano-SiO2 (nano-silica), nano-Fe2O3 (nano-ferric oxide), nano -TiO2 (nano-titanium oxide), nano clay, nano-Al2O3 (nano-alumina). Nanopowders are the perfect additive due to their smaller size (1 nm to 100 nm), high level of reactivity, and greater surface area than cement. Hence, the mechanical characteristics of cement-based materials with embedded nanopowders are reviewed in this article. By virtue of the low water-to-cement ratio, nanopowders are utilized to upgrade the strength and workability of the concrete. The review examined the impact of nanopowders on the enhancement of the strength, durability, and cost-effectiveness of concrete. Due to its strong reactivity, nanopowder increases the mechanical (compressive strength, flexural strength, tensile strength, and modulus of elasticity) and durability (resist weathering action, abrasion, chemical attack) properties of the cement composite. The addition of nanopowders to concrete increases the pozzolanic content and surface energy of the cement composite, resulting in the durability enhancement of the cement composite. This article explored that incorporating nanoparticles into concrete enhances its strength by 25 to 40 % on the seventh day and 7 to 14 % on the 28th day, as well as enhances the workability of the cement composite. However, the excessive concentration of nanoparticles causes particle agglomeration, which decreases the strength and durability of the cement composite. Thus, the review concludes that using nanomaterials in concrete is more favorable concerning of strength and durability advancement of the composite, as it improves their qualities and accelerates the hydration process.

Study on Fresh and Hardened Properties of Nano-Concrete Under Different Curing Conditions

In the recent days usage of nano materials in concrete are responsible in creating ultra-high-performance concrete. Curing is another important strength enhancing parameter in all types of concrete. The nano concrete was achieved by replacing cement in the conventional concrete with Nano silica (NS) in the order of 0.5%, 1%, 1.5%, 2%, 2.5% and 3%. In the present study nano concrete was experimentally explored to mechanical properties like workability, Compressive Strength (CS), Flexural Strength (FS), Bond Strength (BS), Water Absorption (WA), and Thermal Conductivity (TC) test. The mechanical properties were examined at different ages of concrete by subjecting it to four different curing conditions such as water curing, admixture curing, membrane curing and air curing. M30 grade control concrete was compared with the test results. Totally 7 mix proportions by varying nano silica volume were casted. In total 50 cubes (150mm x 150mm x 150mm), 25 prisms (150mm x 150mm x 700mm) were casted to perform the experimental study. Polyethylene glycol 400 (PEG 400) was used an internal curing admixture. Sulpho-naphthalene formaldehyde (SNF) admixture was added by 0.85% weight of cement to enhance the workability of the mix. The results proved the performance of concrete was improved when cement was replaced by 2% of NS and water curing gives the best results in all the mechanical tests performed. Addition of NS beyond 2% weight of cement reduces the fresh and harden properties due to its high Specific Surface Area (SSA). The decrease in porosity was noted with NS addition, hence water curing was best suited curing technique for Nano-concrete.

Advancements in nano-enabled cement and concrete: Innovative properties and environmental implications

As concrete is one of the most used construction materials, lowering its environmental impacts is crucial for a more sustainable built environment. The incorporation of nanomaterials in concrete is a fast-growing field of research because a small amount of nano-compounds can significantly improve some of its properties. Few works have assessed the trade-offs between concrete properties improvement and environmental impacts. This paper reviews the main nanomaterial applications in concrete over the last decade with a focus on their environmental implications. Attention is given to nanotechnology applications boosting innovative properties (i.e., self-compacting, self-cleaning, self-healing, and self-sensing) and green concrete blends incorporating residues, identifying the underlined potential environmental impacts of these applications. Finally, some research gaps and future research directions are identified.The literature analysis showed that some nanomaterials can improve the mechanical properties of concrete, increase durability, and effectively promote the reduction of cement content, which results in a decrease of CO2 emissions. To allow the comparability of studies and relate carbon emissions with mechanical properties, a carbon intensity index is suggested. Despite different environmental impacts may be reduced in nano-enabled blends, cradle-to-gate life cycle assessment studies showed an increase in other impact categories. Nanomaterial production is often highly energy-intensive, not fully optimized, and still performed at the lab scale. Despite nanomaterial incorporation in concrete is increasing, studies regarding its environmental impacts or its potential ecotoxicity and toxicity (e.g., from a safe and sustainable-by-design perspective) are still scarce and require further investigation.

Influence of nanomaterials on the water absorption and chloride penetration of cement-based concrete

This paper aims to provide a brief review on the effect of utilization of nano-SiO2, nano-Al2O3, graphene oxide, carbon nanotubes, nano-TiO2, nano-Fe2O3, nano-clay/metakaolin, and nano-CaCO3 on the water absorption and chloride penetration of cement concrete. Nano material is defined as a material with particle diameter between 1 and 100 nm. Utilization of nano materials in concrete has progressively been recognized as a high potential and fast track repair and high-performance material. The incorporation of nano materials as a partial replacement to binder or as additive improves the quality of hydration products as well as reduce the formation of micro pores. The findings from this review confirm the feasibility of using the nano-materials in cement concrete, with the required properties of building materials.

Enhancement of the Concrete Durability with Hybrid Nano Materials

The importance of the incorporation of nanomaterials in concrete has emerged as a promising research interest due to the outstanding functionalized properties of the materials at that size level. This study aims to investigate the engineering and durability properties of concrete incorporated with hybrid nanomaterials. In this study, the influence of carbon nanotube (CNT) on microstructure, mechanical, and corrosion characteristics of nano-clay-based (NC) concrete has been evaluated. The cement was replaced with CNT at different percentages of 0.01%, 0.02%, and 0.04% by weight, while NC was replaced at a constant percentage of 5%. A scanning electron microscope (SEM) was used to examine the microstructural characterization of the samples. To investigate the influence of carbon nanotubes in the fresh properties, slump and air content tests were carried out. The compressive strength, tensile strength, flexural strength, and bond strength of the hardened concrete was evaluated according to ASTM standards. The porosity of specimens was determined by carrying out the sorptivity and water penetration tests. The corrosion resistance of the steel bar embedded in concrete was assessed. The results of SEM examinations showed that incorporating CNT into the nano-clay-based concrete remarkably achieved a denser structure at all studied contents. Further, significant enhancements in the mechanical properties, durability, and chloride penetration resistance were attained when incorporating CNT in the NC concrete. Further, adding CNTs improves the corrosion resistance and has proven useful resistance to crack propagation within the concrete matrix as compared to the control mix without CNT. Results of this study prove that the incorporation of hybrid nano CNT and NC gives better performance for mechanical strength and durability properties.

An overview of the applications of nanomaterials in concrete

The topic of nanomaterials in concrete was addressed in this review article. Nanomaterials have recently attracted a lot of interest as a way to improve the characteristics of traditional concrete. The use of nanomaterials in concrete will eventually improve its strength and durability. Nanomaterials are described as materials with particle sizes of fewer than 200 nanometers. The application of nanomaterials must be at least 500 nm in size for the purpose of concrete research. The inclusion of ultrafine nanomaterial will aid in the reduction of cement content by partly substituting cement on a weight-for-weight basis to enhance the binding effect. The ultrafine nanomaterial particles will also aid in the reduction of micro pore development by serving as a filler agent, resulting in a highly thick concrete that will automatically decrease micro pore growth in UHPC structures. Furthermore, this article discusses the advantages and benefits of using nanomaterials to improve concrete.

Analysis of mechanical and microstructural properties of high performance concretes containing nanosilica and silica fume

The use of nanomaterials in concrete has shown promise, and the use of several types in cementitious compounds has been found to guarantee greater physical–mechanical properties and improvements in microstructure. The use of mineral admixtures, such as silica fume, ensures the improvement of the interfacial transition zone (ITZ) between aggregate and paste in high-performance concrete (HPC). Thus, this work evaluates the performance of superplasticizer additive with colloidal nanosilica suspension and slurried silica fume with HPC and its macro- and micro-structural properties. The mechanical (i.e., compressive strength and elastic modulus) and microstructural properties via (scanning electron microscopy and X-ray micro tomography) of concretes with 1.5 and 3% nanosilica and 5 and 10% silica fume included in the evaluation methods in this study. The results indicate that, with the use of mineral admixtures, the compressive strength and elastic modulus of concrete increased significantly. The concrete with the use of 10% silica fume and 3% nanosilica resulted in a showed an increased strength over 75% at 28 days. Besides that, for same w/b = 0.35 the elastic modulus increased by 36% compared with the reference concrete. The microstructural investigations show that the nanosilica and silica fume led to a densification of microstructure, which is responsible for the improvement of HPC performance.

Effect of nano TiO2-epoxy composite in bond strength and corrosion resistance of rebar embedded in micro-silica modified concrete

One of the significant drawbacks of RCC structures is Corrosion. It is a well-known term used to describe numerous interactions between a material and its surrounding environment resulting in degradation within the material properties. Reacting with ambient oxygen can cause the material to degrade by forming a more chemically stable form of oxides called Rust. A detailed literature study about the recent advances in the area of corrosion resistance of reinforced concrete has been done using nano-materials. Nano-materials can be deemed fit to be used in cement and concrete manufacture and have a wide range of applications in the civil industry. Compressive strength and ductility of concrete can be improved by blending Nano-materials in concrete. Leads to producing a very dense concrete and Decreases permeability of the concrete by micro filler effect. In the present study, nanomaterial is used in the preparation of coating material on the reinforcement bar. Higher opacity, the interaction between coating and surface, and higher durability of the coating can be achieved by adding nano-material. Different percentages of nano-TiO2 (0.5%,1%,2%) mixed with epoxy are varied to find the percentage, which gives the least rate of Corrosion. For this purpose, the specimens coated with nano-TiO2 epoxy composite are placed in two mediums such as 3.5% NaCl solution and 1M H2SO4 solution and studied the performance of corrosion resistance for every 15-day interval using LPR, Tafel plot and Electrical Impedance Spectroscopy(EIS).Characteristic properties like topography, composition, and surface morphology are studied using SEM, FTIR, and XRD analysis. To increase the mechanical properties of reinforced concrete, so industrial by-product micro-silica has been added to the cement mix. Reinforced cylindrical specimens were cast and were tested for bond strength. For micro-silica replaced concrete mix, destructive tests like compressive strength test and tensile strength tests were conducted

Effectiveness of polycarboxylate as a dispersant of carbon nanotubes in concrete

Excellent multifunctional properties of Carbon Nanotubes (CNTs) have brought interest of concrete analyst towards the use of nano materials in concrete. One of the most conventional problems accompany the usage of CNTs in concrete is spreading of the material which is known as dispersion in concrete which significantly affect the mechanical properties of concrete and results in large size of combined CNTs. To achieve dispersion of CNTs in cement concrete, many ways have been adopted. In this paper a study is considered to check the dispersion of CNTs into the concrete with the use of chemical process by considering polycarboxylate as a dispersant. To compare the observations samples with and without polycarboxylate were considered. Mechanical properties like compressive strength, indirect tensile strength and flexural strength were considered with proportions of CNTs as 0.1%, 0.2%, 0.3%, 0.4% and 0.5% of total cementitious materials. Results suggest the effectiveness of polycarboxylate as a dispersant.

Durability Enhancement of Concrete Using Nanomaterials: An Overview

Different initiatives have evolved over the years to improve the durability of concrete, and one of the promising areas gaining attention in recent years is the use of nanomaterials in concrete. Though most of the applications of nanomaterials to improve the properties of concrete has been restricted to laboratory applications, it is anticipated that in few years to come more commercial and large-scale applications will ensue. This overview explored different types of nanomaterials already used in concrete and their effects on the durability of concrete. It was found out that nanosilica is the most used nanomaterial in concrete. And all types of nanomaterials currently used, enhance the durability of concrete significantly compared to other methods employed before the advent of nanomaterials in concrete. However, the use of other nanomaterials such as nanotitania and nanoalumina is attracting great attention. But the use of nanomaterials in concrete is faced by several challenges such as its high cost, production process, toxicity, etc. It is expected that with more research and application in the use of nanomaterials to enhance the properties of concrete, cheap and user-friendly nanomaterials can be developed. In addition, this review shows the possibility of enhancing the current durability properties with the use of nanomaterials.

Air Pressure Test on Concrete with Nano-Cement

Nanotechnology is an emerging area of research that has received a lot of attention for its ability to make use of the unique properties of nano-sized materials. The grain size of the nano particles will be in the order of 10–9 m (1–100 nm). Due to the very small particle size and extremely large specific surface area, nano particles have same remarkable properties. The use of nano materials for making concrete is of recent origin. Addition of nano materials in concrete can lead to significant improvements in the strength and durability of concrete. For nuclear power plants, concrete with high compressive strength, high split tensile strength, low porosity and high density are required. An attempt has been made to increase the compressive and split tensile strength of concrete by replacing a portion of cement with nano cement. M20, M30, M40 and M50 grades of concrete were cast. For each of these mixes, 10%, 20%, 30%, 40% and 50% of cement was replaced with nano- cement. Nano-cement was made by grinding the commercially available 53 grade pozzolona cement in the ball grinding mill. A scanning electron microscope was used to determine the particle size of the nano-cement produced. A hollow cylinder of the concrete was made with concrete containing nano materials. The Air pressure test was carried at on hardened concrete and the results were compared with that of normal cement concrete. The safe internal pressure for M50 concrete with 50% replacement of cement with nano-cement was found to be 13.3 kg/cm2, which 31.6% higher than that of the normal M50 concrete.

A Review on Nano Materials in Concrete

A Review on Nano Materials in Concrete

Effect of nano-CaCO 3 slurry on the mechanical properties and micro-structure of concrete with and without fly ash

Abstract The effect of nano-CaCO3 slurry on the mechanical properties and microstructure of concrete with and without fly ash was studied in this paper. Experimental results showed that nano-CaCO3 slurry was helpful to increase the mechanical strength of concrete with and without fly ash at early ages due to the acceleration of cement hydration from seeding effect and the more compact microstructure of cement paste from nano-filling. However, the efficacy of nano-CaCO3 slurry on the concrete without fly ash was quite limited at the late ages just like other nano-materials. This may well affect the application of nano-materials in concrete. On the other hand, nano-CaCO3 slurry was still helpful to enhance the mechanical strength of concrete with fly ash at late ages. Furthermore, the enhancement degree of mechanical strength of concrete with fly ash at 56 days increased with the increasing content of fly ash when 2% fly ash was substituted by nano-CaCO3. The results of X-Ray diffraction analysis and SEM observation indicated that the pozzolanic reaction degree of fly ash could be accelerated by nano-CaCO3 slurry at late ages. Therefore, a feasible technique for the usage of composite nano-materials in concrete may well be provided by using nano-CaCO3 with fly ash due to the acceleration hydration of cement at early ages and that of fly ash at late ages.

Chloride Resistance Behavior on Nano-Metaclayed Ultra-High Performance Concrete

Nowadays, the application of nano materials is getting attention to enhance the conventional concrete properties. The ultrafine particles of nano material also will help reducing the formation of micro pores by acting as a filler agent, produce a very dense concrete and will reduce the growth of micro pores in the UHPC structures. The introduction of nano materials in concrete is to increase the strength and durability of concrete. One of the most important factor affecting concrete durability is chloride penetrability. The purpose of this study was to evaluate the chloride permeability and chloride penetration depth by using rapid chloride permeability test (RCPT) and colorimetric method, respectively. The study was conducted for normal performance concrete (NPC), high performance concrete (HPC), ultra-high performance concrete (UHPC) and a series of UHPC (nano metaclayed-UHPC) incorporating different replacement levels of nano metaclay. All the tests were performed at ages of concretes from 3 up to 365 days. The results showed that the presence of silica fume in HPC and nano metaclay in UHPC reducing the Coulombs passed on the 56-days up to 365-days. The experimental results also revealed the depth of chloride ion penetration for nano metaclayed-UHPC concretes are much lesser than those concretes. As regards to the results, nano metaclay led to noticeable benefit in term of chloride resistance.

A Review of Effect on Compressive Strength of Concrete After Addition of Nano-Silica

The research mainly focusing on the use of nanomaterials in concrete. Further researchers are continuing to improve the durability and sustainability of concrete and have realized significant increment in mechanical properties of concrete by incorporating nano-silica. The review paper summarizes the effect of nano-silica addition compressive strength on concrete. It provides the current development of application of nano-silica in paste, mortar and concrete. Finally, the future trend/potential and implication of nanosilica in cement-based materials is discussed. A great number of researches have been performed to understand the nature of nanomaterials and their effect on the properties of concrete. A number of Research & Development work dealing with the use of nanomaterials like Nano silica, colloidal Nano Silica (CNS), AlO3,TiO 2 , ZrO2,Fe2O3, carbon nanotubes (CNT) in cement based materials are discussed in the literature.

STUDY OF STRENGTH PROPERTIES OF CONCRETE BY USING MICRO SILICA AND NANO SILICA

Concrete is the most versatile material due to the persistent and continuous demands made on concrete, Engineers are continually pushing the limits to improve its performance with the help of innovative chemical admixtures and supplementary cementitious materials like fly ash, silica fume, granulated blast furnace slag and steel slag etc… The use of large quantity of cement produces increasing co2 emissions and consequence the green house effect. A method to reduce the cement content in concrete mixes is the use of silica fume which is an amorphous (non-crystalline) polymorph of silicon dioxide, silica. It is an ultra fine powder collected as a byproduct of the silicon and ferrosilicon alloy production with an average particle diameter of 0.1 to 0.5 µ. The past investigations reveled that silica fume was an excellent pozzolanic material in producing High performance concrete (HPC). Nano technology is one of the most promising areas of science. The use of nano materials in concrete is new revolution. Nano materials like nano silica, nano titanium oxide, carbon nano tubes, nano alumina etc… which are presently used in concrete to modify its strength properties. In the present study strength properties such as Compressive strength, split tensile strength and flexural strength of M40 and M50 grades of concrete with the use of micro silica (5%, 7.5%, 10%, 15%) and nano silica (1%, 1.5%, 2%, 2.5%) as partial replacement of cement were studied. It was found from the experimental study that concrete composites with superior properties can be produced using micro silica, nano silica and combination of micro silica and nano silica.