Beneficial role of nanosilica in cement based materials – A review (original) (raw)
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The Open Construction and Building Technology Journal, 2022
The development of nanotechnology has made it possible to design new materials and improve existing ones. Regarding new supplementary admixtures for cement-based materials, nanosilica is more advantageous than any other nanomaterial. This is due to its high pozzolanic reactivity, besides its filling and seeding effects, which are a consequence of the higher and more reactive specific surface area of the nanosilica and its amorphous structure. Nonetheless, when used improperly or in an inadequate dosage, such a nanomaterial may negatively affect the cement admixture, compromising both fresh and hardened properties. Hence, it is fundamental to understand the nanosilica's behavior inside the cementitious medium. This review paper is based on recent literature about the incorporation of nanosilica in cementitious materials. The analyses showed that, once incorporated in the cement matrix, nanosilica tends to agglomerate. The behavior of such agglomerates influences both the pozzolanic filling and seeding effects. Therefore, a suitable dispersion of the nanoparticles must be achieved. In this sense, third-generation superplasticizers are used, usually up to 3% of cement mass. The mechanical properties of cement-based materials with nanosilica depend on the amount of nanomaterial and on its specific surface area. There is not an agreement on the optimum dosage of nanosilica, however, percentages up to 5% in cement mass seem to provide a better performance, when compared to greater ones. It is not worthy to use nanosilicas with excessive specific surface area values, because they tend to form large agglomerates, reducing fluidity and compressive strength. Particles with surface areas up to 300 m 2 /g usually present good performance. Nanosilica improves the early age strength and contributes to the pore refinement of cementbased materials. The combination of nanosilica with other nanomaterials or industrial by-products can improve the mixture's performance. Nonetheless, the use of silica nanoparticles with agricultural wastes negatively affects the mechanical properties at early ages.
MATEC Web of Conferences, 2018
Over the last years, nanotechnology is getting more attractive and nanomaterials are being used more commonly in construction industry. One of these materials is nanosilica: the nano-sized, engineered form of silica fume. The replacement of cement by these nanoparticles is said to enhance both the mechanical performance and the durability of the concrete material. In this paper colloidal silica will be used, which is nanosilica in solution. A characterization of mortar mixtures containing different amounts of silica is done and a comparison is made with respect to a reference mixture.
Impact of Nanosilica in Ordinary Portland Cement over Its Durability and Properties
Cement Industry - Optimization, Characterization and Sustainable Application, 2021
The present examination illustrates the impact on the hardened and fresh cement mortar and cement with the inclusion of nanosilica of size 40 nm in various environmental conditions (UltraTech, India). It is quite notified that an elevation in compressive strength as well as flexural strength along with an improvisation in the performance and life span of cement mortar. The samples of M5 grade blended with a ninety percentage of concrete and remaining with nanosilica was identified to have a finer working elevation in as well as in standards when collated with the conventional cement mortar. The corollary of hardened and fresh cement, strength parameters were looked upon with the aid of XRD (X-ray Diffraction). Also, the SEM (Scanning Electron Microscope) test holds a predominant role in analysis.
Effects of the nanosilica addition on cement concrete: A review
Elsevier, 2019
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 com-pressive 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 CO 2 , responsible for global warming. All these aspects make nanosilica added concrete an essential and sustainable material for construction purposes.
Research, Society and Development
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.
Individual and Combined Effect of Nano- and Microsilica on Cement-Based Product
2020
In the cement concrete industry, everybody is concerned about high-strength and high-performance behavior of concrete. These properties were improved using micro- and nano-sized pozzolanic mineral admixtures as stated by various authors. In this paper, author has emphasized mostly on using micro- and nanosilica materials with cement. Literature survey revealed that the most suited mineral admixtures for getting highest behaviors are micro- and nanosilica. Nanotechnology is nowadays a buzzword in everyone’s tips. Nanotechnology in concrete means the addition of nano-sized materials in the range of 1 and 100 nm to improve the behavior of cement and concrete. Micro- and nano-sized silica particles improve the porous behavior of concrete and also produce more calcium silicate hydrate resulting from chemical reaction of nanoparticles and calcium hydroxide. On the other hand, it makes concrete more compact in microstructure point of view, which improves density, strength, and also durabil...
The Effect of Nanosilica on the Mechanical Properties of polymer-Cement Composites (PCC)
Procedia Engineering, 2015
In the last decade nanomaterials due to their unique physical and chemical properties, have attracted the interest of researchers to fabricate new building materials with novel functions. One of the most referred to and used cementitious nanosized materials is nanosilica (nSiO 2). Although the number of publications devoted to the influence of nanosilica on the properties of cementitious composites has increased over the course of the last decade, the field of polymer-cement composites (PCC) has remained under-studied. Therefore, this paper will deal with the potential application and the influence of nanosilica (nSiO 2) on the mechanical properties of PCC. In this study the influence of diameter (100 nm and 250 nm) and quantity (1%, 3%, 5% by weight of cement) of nSiO 2 on the consistency and mechanical properties of polymer-cement mortars (PCC) have been examined. Moreover, the hydration of cement compounds was followed by X-ray diffraction (XRD). Studies have shown that the addition of nanosilica has great potential to accelerate the pozzolanic reaction, thus reacting more with the CH and increasing conversion of C-S-H, and having the potential to improve mechanical properties of PCC. The obstacle overcome is the high water demand of nanosilica particles, leading to significant deterioration of consistency. Finer particles of nSiO 2 seem to be more effective and cause fewer problems with the consistency of fresh mortars.
Effect of Partial Substitution of Highly Reactive Mineral Additions by Nanosilica in Cement Pastes
Journal of Materials in Civil Engineering, 2019
The phenomena involved in portland cement hydration and interactions with nanosilica are very complex and not yet fully understood. In addition, few papers have currently proposed to investigate the microstructure and mechanical properties of ternary mixtures using portland cement, colloidal nanosilica, and highly reactive mineral additions. This article investigates, for the first time, the behavior of different highly reactive mineral additions (silica fume and metakaolin) when partially replaced by colloidal nanosilica in the microstructure and hydration of cementitious materials. For the study of the cementitious material microstructures, a Langavant calorimeter, compressive strength, Xray diffraction, thermogravimetry, infrared spectroscopy, and mercury intrusion porosimetry were used. The pastes with a 1% substitution of highly reactive mineral additions by nanosilica showed higher compressive strength and more refined porosity than the pastes with only silica fume or metakaolin. The results show that nanosilica appears to have better synergism with metakaolin than with silica fume.
CHARACTERISITC STUDY OF NANOSILICA IN DURABILITY ON VARYING WATER-CEMENT RATIO
IAEME PUBLICATION, 2019
The purpose of this work is to describe the effect of durability aspect of Nano silica when added to concrete. The use of Nanosilica in concrete is to reduce the cement content in concrete mix since the design consumes almost the total cement production in the world. Nanotechnology is one of the most active research areas which has wide applications in almost all the fields. Researchers are focusing to improve the durability and sustainability of concrete by incorporating Nanosilica. This paper summarizes the effect of Nanosilica addition on compressive strength, chloride penetration test, electrical resistivity and carbonation resistance test in varying water-cement ratio of 0.65, 0.55 and 0.5 and NS in 0%, 0.5%, 1% and 1.5% by weight. The effect of certain NS dosage on compressive strength and durability properties for high strength concrete mix was dif erent than low strength mixes.
Effect of nanosilica on characterization of Portland cement composite
Materials Science and Engineering: A, 2006
Both the filling effect and the pozzolanic reaction make siliceous materials as one of major ingredients of high-performance Portland cementbased composites. Hence, the introduction of nanosilica with finer particle size and larger silicon dioxide to the composite becomes a great deal of interest in recent years. In this study, a liquid-form of nanosilica particle with a spherical diameter of about 20 nm was incorporated into the Portland cement paste at five different dosages and analyzed at four different ages to identify the nanosizing effects on the microstructures and material properties of composite cement paste. Experimental results show that the Portland cement composite with 0.60% of added nanosilica by weight of cement has an optimum compressive strength, in which the increase of compressive strength is about 43.8%. Moreover, the corresponding nanosilica paste of one portion of water mixed with nanosilica of 1.08 wt.% of water has the maximum absolute value of zeta potential of 41.3 mV. Properties through the analyses of NMR, BET and MIP also indicate that the microstructure of Portland cement composite with nanosilica evidently has a more solid, dense and stable bonding framework.