SSRG International Journal of Civil Engineering (SSRG - IJCE) - Special Issue ICMR Mar 2019

Experimental Investigation of Concrete

R.Sundharam1, K.Pavithra2, K.Ranjitha3, K.Rasika4, S.Vinotha5 Assistant Professor 1, UG Student 2, 3, 4, 5, Kings College of Engineering, Punalkulam, Gandarvakottai Taluk, Pudukottai District, Tamil Nadu, India.

Abstract strength, ductility, creep and shrinkage, fracture Concrete is one of the most used materials in behavior and durability. various fields for arriving a structure, but still it has weakness and drawbacks. To mitigate this problem, A. Nanotechnology the nanotechnology has been implementing. This Nanotechnology is the creation of useful or paper assigns Carbon Nanotube (CNTs) in the functional materials, devices and systems through concrete to enhance its properties. It also goes over control of matter on the nanometre length scale and the sources, properties of CNTs. By revising various exploitation of novel phenomena and properties papers, for ensure that adding 0.25% and 0.5% of which arise because of the nanometre length scale. Multi Walled Carbon Nanotubes (MWCNTs) by the Nanotechnology includes the synthesis, weight of cement in the concrete mix. CNT concrete characterization, exploration and utilization of exhibit the multifunctional properties such as self – nanostructured materials. The term 'nanotechnology' strain sensing, damage sensing, improves interfacial was used first by the Japanese scientists Norio interaction and also it act as a concrete repair Taniguchi. The ―Nano‖ in Nanotechnology comes material when it is cement composite. from the Greek word ―Nanos‖ that means dwarf. Multifunctionality is attractive for cost reduction, Scientists use this prefix to indicate 10-9 or one durability enhancement, large functional volume, billionth. Nanotechnology is called a ―bottom up‖ design simplification and absence of mechanical technology by which bulk materials can be built property loss. Sonication process is carried out to precisely in tiny building blocks. Therefore, resultant achieve well dispersion of CNTs before adding it into materials have fewer defects and higher quality. The the concrete for improving the strength and branch of technology that deals with dimensions and durability of CNT used concrete. CNT concrete will tolerances of less than 100 nanometers, especially the upgrade the compressive and tensile strength of manipulation of individual atoms and molecules. This concrete compare to conventional concrete. This technology used to increase the life of concrete, paper explores more details about the create fire resistant materials and give building implementation of CNTs as reinforcement for materials qualities such as ―self – healing‖ and ―self – concrete to enhance its tensile properties. cleaning‖. Various were available and used in the construction field; some of them are Nano Keywords: Concrete - Carbon Nanotube (CNT) - Silica, Carbon Nanotube, Titanium dioxide, Carbon Sonication process - Compressive strength - Tensile fiber. Currently, the use of in strength construction is reduced, mainly for the following reasons: the lack of knowledge concerning the I. INTRODUCTION suitable nanomaterials for construction; the lack of specific standards for design of construction elements; Concrete is a brittle material, composite of high costs; the unknown of health risks associated cement, fine aggregate, coarse aggregate and water. with nanomaterials. The field of nanotechnology, in The development of crack is a major complication. general, is loosely divided into four subareas: Today, use of reinforcing steel to reduce the  micro and Nano instruments development of crack and it also arrest crack at micro  Nano electronics level as possible. The behaviours of cementitious  Nano bio systems and materials are significantly dependent on their  Nano engineered materials. configurations at the Nano-level. Nanotechnology was first started with a talk entitled by physicist B. Nanoparticles RICHARD P. FEYNMAN at an American Physical The fundamentals of nanotechnology lie in Society meeting at the California Institute of the fact that properties of substances dramatically Technology (CalTech) on December 29, 1959, long change when their size is reduced to the nanometer before the term nanotechnology was used. The range. When a bulk material is divided into small size cementitious materials at the nanolevel have a great particles with one or more dimension (length, width impact on the characteristics of concrete such as: or thickness) in the nanometer range or even smaller,

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the individual particles exhibit unexpected properties, II. PHYSICAL PROPERTIES OF CNT different from those of the bulk materials. This type of particle is known as . Bulk materials A. Electrical Conductivity possess continuous physical properties. But when The structure of a carbon nanotube determines particles assume nanoscale dimension, the principles how conductive the nanotube is. When the structure of classical mechanics are no longer capable of of atoms in a multi walled carbon nanotube describing their behaviour (movement, energy, etc). minimizes the collisions between conduction The same material at the nanoscale can therefore electrons and atoms, a carbon nanotube is highly have properties (eg. Optical, mechanical, electrical, conductive. The strong bonds between carbon atoms etc) which are very different from (even opposite to) also allow carbon nanotubes to withstand higher the properties the material has at the macro scale electric currents than copper. Electron transport (bulk). One nanometer is one billionth meter that is occurs only along the axis of the tube. Multi walled about 10000 times smaller than the diameter of a nanotubes can route electrical signals at speeds up to single human hair.The particles exist on a Nano 10 GHz when used as interconnects on semi- meter scale (i.e., below 100 nm in at least one conducting devices. Adding carbon nanotubes to the dimension). They can possess physical properties cement matrix, the electrical resistivity of such as uniformity, conductance or special optical cementitious composites changes with the stress properties that make them desirable in materials conditions under static and dynamic loads. strength and biology. It have certain properties which make them different from that of the bulk materials, B. Thermal Conductivity and Expansion including large fraction of surface atoms, high The strength of the atomic bonds in Multi Walled surface energy, spatial confinement and reduced carbon nanotubes allows them to withstand high imperfection. temperatures. Because of this, multi walled carbon Types of nanoparticles: nanotubes have been shown to be very good thermal  Carbon based nanoparticle conductors. Compared to copper wires, which are commonly used as thermal conductors, the multi  nanoparticle walled carbon nanotubes can transmit over 15 times the amount of watts per meter per Kelvin. The  Metal nanoparticle thermal conductivity of carbon nanotubes is dependent on the temperature of the tubes and the  Semiconductor nanoparticle outside environment.

 Polymeric nanoparticle C. Field Emission Carbon nanotubes possess small radius of  Lipid – based nanoparticle. curvature at the tip, high mechanical strength all of which are favourable for field emitters. To obtain low C. Carbon nanotubes (cnts) operating voltages as well as long emitter lifetimes, New shapes for molecules of carbon, known the nanotubes should be multi-walled and have as the bucky ball, which are round and consist of 60 closed, well-ordered tips .The SWNTs degrade carbon atoms. This led to the discovery of related substantially faster. And it was observed that opening molecular shape known as the carbon nanotube in their ends seriously degrades emission performances 1991. Carbon nanotubes are still one of the most of MWNTs. The large field amplification factor promising areas of nanotechnology as they are about arising from the small radius of curvature of the 100 times stronger than steel but just a sixth of the nanotube tips is partly responsible for the good weight; they have unusual heat and conductivity emission characteristics. It can be concluded that the characteristics. Carbon nanotubes are large molecules density of states at the tip of carbon nanotubes is non that are long shaped like tubes as thin as 1 - 3 metallic, appearing in the form of localized states nanometres and 10 – 15 nm in diameter. This tubes with well defined energy levels and that the presence are made up thick sheets of carbon called graphene of such states influences greatly the emission which were up to form a seam less cylinder. The behaviour. properties of CNTs are high stiffness, reduce porosity, increases in flexural strength, compressive strength D. Aspect Ratio and durability. The two main challenges to encounter in

Types of CNT: order to achieve an effective CNTs/cement composite are, well dispersed CNTs within cement paste matrix  Single Walled Carbon Nanotube (SWCNTs) and the bonding between nanotubes and the cement  Double Walled Carbon Nanotube paste. High aspect ratio and strong surface attraction between CNT particles make it extremely difficult to  Multi Wall Carbon Nanotube (MWCNTs) ensure uniform dispersion within the cement paste. The effect of different concentrations of long multi-

ISSN: 2348 – 8352 http://www.internationaljournalssrg.org Page 2 SSRG International Journal of Civil Engineering (SSRG - IJCE) - Special Issue ICMR Mar 2019 walled carbon nanotubes (MWCNTs) is high forms are packed with steel reinforcement. Second, length/diameter aspect ratios of 1250 to 3750 and the mix must produce a hardened concrete of short MWCNTs aspect ratio of about 157 in cement specified strength at 28 days (or similar specified paste. time) that is durable and provides good serviceability.

E. Absorbent NORMAL CNT S.NO TESTS MWCNT/Portland cement (PC) composites CONCRETE CONCRETE have been prepared to evaluate their electromagnetic 1. Slump cone 160 mm 170 mm wave absorbing properties. The effects of MWCNTs 2. Flow table 52 % 70 % content and sample thickness were discussed in the 3. Compaction 0.93 0.95 frequency ranges of 2–18 GHz. The absorbing factor electromagnetic wave properties of MWCNTs- reinforced cement mortar were explored in the V.TEST ON HARDENED CONCRETE frequency ranges of 8–18 GHz using the radar cross- section (RCS) method. Concrete can be described as a two phase system, comprising of cement paste and aggregate. III. MECHANICAL PROPERTIES OF CNT Aggregates are inert, while the structure of the A. Strength hydrated cement paste keeps evolving over time. The It is observed that the addition of carbon structure of the hydrated cement paste and the nanotubes to cement can enhance its compressive different forms of water held within it are described strength, tensile strength and flexural strength of in the Cement. One aspect of primary importance is concrete. This enhancement is due to the the zone at the interface of the paste and aggregate – improvement of material microstructure. MWCNTs that is simply called the ‗Interfacial Transition Zone fill the fine pores and decrease the porosity of cement (ITZ)‘. According to researchers, the porosity of the composites. The dispersion of CNTs in a concrete paste as well as the proportion of calcium hydroxide mix results in cresting a strong covering for solid in this zone is considerably higher than in the bulk particles including cement and fillers, which causes paste. Furthermore, the ITZ sees a shift from a these particles to be more interlocked with the component of high stiffness (aggregate) to a aggregate surfaces. Carbon nanotubes are stiffest and component of low stiffness (paste). This mismatch strongest materials. In the case of individual, the can cause crack formation in the ITZ at low load carbon Nanotubes shows that strength will have levels, or even as a result of indirect effects such as extremely high and weak interactions between the shrinkage or thermal stresses. Thus, this zone forms adjacent shells because of its aspect ratio. Due to this the weak link in the concrete, both from a strength sometimes carbon Nanotubes will reduces the and durability point of view. strength and the carbon Nanotubes bundles will down NORMAL CNT S.NO TESTS to only a few GPA. Multi-walled carbon Nanotubes CONCRETE CONCRETE the strength will reaches up to 60 GPA and 17 GPA Compressive 1. 20 N/mm2 30 N/mm2 for double walled carbon Nanotubes. strength Tensile 2. 2 - 3 N/mm2 15 N/mm2 B. young’s modulus strength Carbon Nanotubes has high stiffness and axial strength as a result of its carbon-carbon sp2 bonding. VI. SONICATION The case of utilization of these carbon Nanotubes requires the fracture, elastic response, yield strength, Sonication is the act of applying sound energy to inelastic behaviour and buckling. Carbon Nanotubes agitate particles in a sample, for various purposes will have the stiffest fibre with young‘s modulus of such as the extraction of multiple compounds from 1.4 TPA and also the elongation failure of 20-30% plants, microalgae and seaweeds. The enhancement which will have a tensile strength of 100 GPa .In case in the extraction of bioactive compounds achieved of the young‘s modulus the steel will have 200 GPa using sonication is attributed to cavitations in the and the tensile strength will lies between 1GPA-2 solvent, a process that involves nucleation, growth, GPa. and collapse of bubbles in a liquid, driven by the passage of the ultrasonic waves. Ultrasonic IV.TEST ON FRESH CONCRETE frequencies (>20 kHz) are usually used, leading to Concrete is one of the most common construction the process also being known as ultra-sonication or materials and consists of two phases: mortar phase ultra-sonication. comprised of concrete, water, air and the aggregate In the laboratory, it is usually applied using phase comprised of coarse and fine aggregates. There an ultrasonic bath or an ultrasonic probe, colloquially are two key considerations when designing a concrete known as a sonicator. In paper machine, an ultrasonic mix. First, the concrete must be workable and easy to foil can distribute cellulose fibres more uniformly cast in the forms in its fresh condition, even when the and strengthen the paper. Sonication has numerous

ISSN: 2348 – 8352 http://www.internationaljournalssrg.org Page 3 SSRG International Journal of Civil Engineering (SSRG - IJCE) - Special Issue ICMR Mar 2019 effects, both chemical and physical. The chemical effects of ultrasound are concerned with understanding the effect of sonic waves on chemical systems, this is called sonochemistry. The chemical effects of ultrasound do not come from a direct interaction with molecular species. No direct coupling of the acoustic field with chemical species on a molecular level can account for sonochemistry or sonoluminescence. Instead, in Fig. 2 sonication sonochemistry the sound waves migrate through a medium, inducing pressure variations and cavitations V. CONCLUSION that grow and collapse, transforming the sound waves Addition of 0.25 % of dipersing MWCNT by the into mechanical energy. Sonication can be used for weight of cement improve the load carrying capacity the production of nanoparticles, such as Nano and thus enhance the mechanical property of emulsion, nanocrystals, lipsomes and wax emulsions, concrete. In CNT concrete, the compressive strength as well as for wastewater purification, degassing, increase by 32% and tensile strength by 42% extraction of seaweed polysaccharides and plant oil, respectively. Because of the tiny nature, it behaves as extraction of anthocyanins and antioxidants, a filler materaial to improve bond strength and to production of biofuels, crude oil desulphurization, resist crack propogation. Enhancement in tensile cell disruption, and epoxy processing, strength reduce the usage of steel in structural adhesive thinning, and many other processes. It is components. CNT increase the life of structure due to applied in pharmaceutical, cosmetic, water, food, ink, the high modulus of elasticity. paint, coating, wood treatment, metalworking, , pesticide, fuel, wood product and REFERENCES many other industries. In biological applications, sonication may be [1] Rashad Al Araj and Adil K.Tamimi, (2017) ―Sustainability of Carbon Nanotube-Reinforced Concrete‖. sufficient to disrupt or deactivate a biological [2] Dr. B.Vidivelli , B.Ashwini (July 2018) ―A study on carbon material. For example, sonication is often used to nanotube (CNT) in concrete‖. disrupt cell membranes and release cellular contents. [3] A.Ziauddin, Dr.S.K.Beebi, Dr.N.A.Siddiqui, Dr.Kanchan This process is called sonoporation. Sonication is (Sept 2014) ―Carbon nanotubes – Production, Properties and health effects‖. commonly used in nanotechnology for evenly [4] Maria del Camacho, Oscar Galao, Francisco Javier Baeza, dispersing nanoparticles in liquids. Additionally, it is Emilio Zornoza and Pedro Garces (Feb 2014) ―Mechanical used to break up aggregates of micron-sized properties and durability of CNT cement composites‖. colloidal particles. Sonication is the mechanism used [5] Grigory Yakovlev, Grigory Pervushin, Irina Maeva, Alexander Korzhenko, Sergey Senkov, Arina Shaybadullina in ultra cleaning—loosening particles adhering to (2013) ―Modification of construction materials with multi- surfaces. Soil samples are often subjected to walled carbon nanotubes‖. ultrasound in order to break up soil aggregates; this [6] Ali Akbar Firoozi, Guney Olgun, Ali Asghar Firoozi and allows the study of the different constituents of soil Shariat MoBaser, (2016) ―Carbon nanotube and civil engineering‖. aggregates without subjecting them to harsh chemical [7] Shubham Ashish Jha, Somesh Jethwani and Dheeraj treatment. Sonication is also used to extract Sangtiani (2016) ―Carbon nanotube cement composites‖. microfossils from rock. [8] Giuseppe Ferro, Jean-Marc, Tulliani Simone Musso (2011) ―Carbon nanotubes cement composites‖. [9] Mahmud Abdulmalik Abdulrahaman, Oladiran Kamaldeeen Abubakre, Saka Ambali Abdulkareem, Jimoh Oladejo Tijani, Ahmed Aliyu and Ayo Samuel Afolabi, (2017) Effect of coating mild steel with CNTs on its mechanical properties and corrosion behaviour in acidic medium‖. [10] saptarshi sarmal, bhuvaneshwari,nagesh r.iyer (oct 2013) carbon nanotubes make wonders in civil/stuctural engineering‖.

Fig. 1 CNT dispersion in water after sonication

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