Strength, Durability and Permeability Studies on Cement Concrete with and without Nano-Silica (original) (raw)
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Strength, Durability & Permeability Studies on Cement Concrete with & without Nano-Silica
ASPS Conference Proceedings 1: 1583-1588 (2022), 2022
The application of nanomaterials in cement/concrete has resulted in the development of smart materials which are durable, sustainable and high performance oriented apart from being eco-friendly. Several types of nanomaterials are being used by researchers all over the world to improve the properties of cementitious system, amongst them silica nanoparticles (SNPs) have been credited with high pozzolanic reactivity and pore filling effects. It is also very well known that permeability is the major factor for deteriorations of concrete structures in the long term thus affecting its durability. A thorough study was performed on cement mortar composites and standard grade concrete with the additions of colloidal silica nanoparticles(SNPs) in various dosages starting from 0.5%,0.75%,1.0%,1.25% and 1.5% by weight of cement(b.w.c.) to understand the impact from micro-structure improvement to macro-level property enhancement. The results show that in presence of colloidal SNPs (Indian branded) having 35-40% active nano content with 5-40nm particle size the strength increase at 28 days is 32% increasing to 59% at 90 days. An influence on durability is also observed with strength increasing from 4% to 8% with the addition of more SNPs from 0.75% to 1.0% b.w.c. The microstructural investigations reveal that silica nanoparticles refines the pore structure due to accelerated hydrated mechanisms leading to the creation of more hydration products and thus to a more denser microstructure. A M-40 grade standard concrete was prepared as per IS:10262 with the addition of optimized SNPs as found for cement mortar composites strength results at 28 days maximum strength keeping the water-cement(w/c) ratio fixed at 0.4. Tests were conducted on concrete to find out the compressive strength and permeability of concrete. The compressive strength of concrete containing nano materials were found to be 24% more than that of normal cement concrete (NCC) of M-40 grade. The permeability values were found to be decreased by 57% with the addition of nano silica particles to concrete.
Effect of Nano Silica on Mechanical Properties and Durability of Normal Strength Concrete
Archives of civil engineering, 2012
Nano technology is an emerging field of interest for civil engineering application. Among the nano materials presently used in concrete, nano-silica possess more pozzolanic nature. It has the capability to react with the free lime during the cement hydration and forms additional C-S-H gel giving strength, impermeability and durability to concrete. Present paper investigates the effects of addition of nano silica in normal strength concrete. Three types of nano-silica in the form of nano suspension having different amount of silica content have been investigated. Mix design has been carried out by using particle packing method. X-Ray diffraction (XRD) analysis has been carried out to find the chemical composition of control concrete and nano modified concrete. Further, experimental investigations have been carried out to characterize the mechanical behaviour in compression, tension and flexure. It has been observed that the addition of nano-silica in normal strength concrete increased the compressive strength and decreased the spilt tensile strength and flexural strength. Also, Rapid chloride permeability test (RCPT) has been conducted to know the chloride permeability of control concrete, nano modified concrete, and nano coated concrete. It has been observed that the chloride permeability is less for nano coated concrete.
Nanotechnology has received the attention of many researchers for its ability to make use of the unique properties of nano-sized materials for obtaining favourable characteristics. The grain size of the nano particles will be in the order of 10-9 m (1-100nm). Materials at nano stage can change the whole properties of the composites to which these nano particles are added. Nano-particles exhibit unique properties that develop a stronger, more durable concrete with favorable characteristics when added to concrete. Addition of nano materials at the time of production of concrete can lead to significant improvements in the strength and life of concrete. One of the active areas of research dealing with cement and concrete is strength and durability of concrete containing nano particles. An attempt has been made to carry out an experimental investigation on strength and permeability of concrete containing nano-cement. Plasma arching, chemical vapor deposition, electro deposition, sol-gel synthesis, high intensity ball milling etc., are some of the methods reported in the literature to synthesize nano level materials. Nano-cement was made by grinding the commercially available 53 grade Portland cement using a high energy ball grinding mill. A scanning electron microscope was used to determine the particle size of the nano-cement produced. Different grades of concrete viz., M20, M30. M40 and M50 were cast. For each grade of concrete, 10%, 20%, 30%, 40% and 50% of cement was replaced with nano-cement. Tests were conducted on concrete to find out the compressive strength and permeability of concrete. The compressive strength of concrete containing nano materials were found to be more than that of normal cement concrete (NCC). The permeability values were found to be decrease with the addition of nano-cement.
STRENGTH AND PERMEABILITY STUDIES ON CONCRETE WITH NANO-CEMENT
Nanotechnology has received the attention of many researchers for its ability to make use of the unique properties of nano-sized materials for obtaining favourable characteristics. The grain size of the nano particles will be in the order of 10-9 m (1-100nm). Materials at nano stage can change the whole properties of the composites to which these nano particles are added. Nano-particles exhibit unique properties that develop a stronger, more durable concrete with favorable characteristics when added to concrete. Addition of nano materials at the time of production of concrete can lead to significant improvements in the strength and life of concrete. One of the active areas of research dealing with cement and concrete is strength and durability of concrete containing nano particles. An attempt has been made to carry out an experimental investigation on strength and permeability of concrete containing nano-cement. Plasma arching, chemical vapor deposition, electro deposition, sol-gel synthesis, high intensity ball milling etc., are some of the methods reported in the literature to synthesize nano level materials. Nano-cement was made by grinding the commercially available 53 grade Portland cement using a high energy ball grinding mill. A scanning electron microscope was used to determine the particle size of the nano-cement produced. Different grades of concrete viz., M20, M30. M40 and M50 were cast. For each grade of concrete, 10%, 20%, 30%, 40% and 50% of cement was replaced with nano-cement. Tests were conducted on concrete to find out the compressive strength and permeability of concrete. The compressive strength of concrete containing nano materials were found to be more than that of normal cement concrete (NCC). The permeability values were found to be decrease with the addition of nano-cement.
Exploratory Investigation of Nanomaterials to Improve Strength and Permeability of Concrete
Transportation Research Record: Journal of the Transportation Research Board, 2010
Concrete containing various supplementary cementitious materials (SCMs) such as silica fume, fly ash, and slag has improved properties. Nanomaterials, new SCMs with possible applications in concrete, have the smallest particle size (less than 100 nm). Nanomaterials are reactive because of the small size and large surface area of the particles, and they have great potential in improving concrete properties such as compressive strength and permeability. This study evaluates the use of a variety of nanomaterials in concrete compared with conventional concrete and concrete containing common SCMs. The potential benefits of using nanomaterials over other SCMs are high reactivity and cost-effectiveness; in addition, smaller amounts are necessary, resulting in less cement replacement. Concretes containing nanosilica and nanoclay were prepared in the laboratory. They were compared with concretes containing silica fume, fly ash, slag, or only portland cement. Specimens were tested for compres...
2019
The application of nano materials in concrete is being researched tremendously with an objective to enhance properties of concrete at micro structural level. The addition of nano materials in concrete improves its microstructure due to its smaller particle size and high reactive surface areas. One such nano material which is used for cement replacement or as cement additive is silica fines. Nano-silica is a commercially produced silica fine which is used in concrete and its addition significantly improves mechanical and durability properties of concrete. This paper reviews the use of nano silica and its effect on compressive and flexural strength. The micro structural changes due to addition of nanosilica and the effect of nano-sized particle on the hydration mechanism are discussed in this paper. Durability properties such as chloride penetrations, water absorption and sorptivity are seen to improve with addition of nano-silica. This paper reviews the published literatures to analy...
Nanotechnology Reviews, 2021
Nano-silica (NS) is one of the most important nanomaterials in recent years. It is used as a new cement-based composite reinforcement in building materials because of its high volcanic ash activity. In order to achieve the goal of carbon peaking and carbon neutralization, combined with the research idea of cementitious materials-reducing admixture for concrete, under the condition of reducing the amount of cement in concrete by 20%, the influence of different dosages of NS on the setting time and mechanical properties of concrete was analyzed. In addition, the shrinkage performance, impermeability, and resistance to chloride-ion permeability of concrete were also studied. The results show that under the same curing conditions and ages, when the NS dosage is 2.5%, the compressive strength and splitting tensile strength of the specimen after 28 days of curing are the highest, reaching 40.87 and 3.8 MPa, which show an increase by 6.6 and 15.15%. The shrinkage performance of concrete in...
International Journal of Concrete Structures and Materials, 2015
The influence of powdered and colloidal nano-silica (NS) on the mechanical properties of cement mortar has been investigated. Powdered-NS (*40 nm) was synthesized by employing the sol-gel method and compared with commercially available colloidal NS (*20 nm). SEM and XRD studies revealed that the powdered-NS is non-agglomerated and amorphous, while colloidal-NS is agglomerated in nature. Further, these nanoparticles were incorporated into cement mortar for evaluating compressive strength, gel/space ratio, portlandite quantification, C-S-H quantification and chloride diffusion. Approximately, 27 and 37 % enhancement in compressive strength was observed using colloidal and powdered-NS, respectively, whereas the same was up to 19 % only when silica fume was used. Gel/space ratio was also determined on the basis of degree of hydration of cement mortar and it increases linearly with the compressive strength. Furthermore, DTG results revealed that lime consumption capacity of powdered-NS is significantly higher than colloidal-NS, which results in the formation of additional calcium-silicate-hydrate (C-S-H). Chloride penetration studies revealed that the powdered-NS significantly reduces the ingress of chloride ion as the microstructure is considerably improved by incorporating into cement mortar.
An Overview on the Influence of Nano Silica in Concrete and a Research Initiative
2013
Nano science and technology is a new field of emergence in materials science and engineering, which forms the basis for evolution of novel technological materials. Nano technology finds application in various fields of science and technology. This article presents a critical review of the literature on the influence of nano silica in concrete and its application for the development of sustainable materials in the construction industry and to study the pore filling effect and its pozzolanic activity with cement towards improvement of mechanical properties and durability aspects. Thus, there is a scope for development of crack free concrete towards sustainable construction.
Impact of nano silica on the cementitious systems of built environment
Materials Today: Proceedings 65, 2022
In today’s scenario, most of the construction materials are man-made and are naturally sourced but have limitations, especially with regard to their impact on environment. Further, the conventional materials and technologies for construction are unsustainable and less durable with fast depletion of natural resources, pollution of environment and heavy economic cost. Silica Fumes or its more finer counterpart Nano silica, made from waste materials have excellent pozzolanic, pore filling and nucleating properties and proposes to be the most promising sustainable nanomaterial aiming the ultimate solution in built environmental applications. Work presented by many authors reveal that the Silica Fumes improve the performance of cement composites and concretes through micro-level contributions but Nano silica additions have brought in further improvements. This paper reports the effect of adding colloidal Nano Silica (NS) of 5–40 nm dia. sized particles & adding them to cement: sand ratio of 1:3 with a water-cement ratio of 0.4. Due to the continued hydration mechanism of cement particles, mechanical strength results of the cementitious composites were taken at all terms up to longer term of 365 Days. The optimized quantity of NS as found in cement composites is then added to fly ash-based cement composites for compressive strength testing at both shorter, standard & longer terms following Indian standard protocols. This paper aims to investigate and analyse the mechanical performance for both blended & ordinary cement and the corresponding microstructures of Nano silica additions in ordinary cement composites. Results reveal that the non-standard mortar strength and its rapid strength gaining are particularly in favour for fly ash PPC blended cement with Nano Silica additions.