STUDY ON DURIBILITY OF CONCRETE USING NANO SILICA
S udhayakumar1, P vijey abishek2, S Imran khan3, R sowmya4
1 Student-Civil Engineering, Aarupadai Veedu Institute of Technology, Chennai, India.
2 Student-Civil Engineering, Aarupadai Veedu Institute of Technology, Chennai, India.
3 Student-Civil Engineering, Aarupadai Veedu Institute of Technology, Chennai, India
4Asst. Professor-Civil Engineering, Aarupadai Veedu Institute of Technology, Chennai, India
Concrete is the most widely used construction material in India with annual consumption exceeding 100 million cubic meters. It is well known that conventional concrete designed on the basis of compressive strength does not meet many functional requirements such as impermeability, resistance to environment exposure, resistance to frost, thermal cracking adequately.
As a result, innovations of supplementary materials and composites have been developed. Therefore, it is felt necessary to improve the strength and performance of concrete with suitable admixtures to cater present need. Due to enhanced mechanical and durability properties, high performance concrete (HPC) has gained wider acceptance in the construction of tall buildings, bridges and marine structures.
In the present experimental investigation, the mechanical properties of high-strength concrete of grades M30 at various ages of curing period with admixture of cement with Nano silica 1%, 2%, 3% and are considered and the chemical like sodium Sulphate, used in 1mol/l by water. The compressive strength, tensile strength, Flexural strength of concrete was tested in laboratory after 7, 14 and 28 days.
KEY WORDS :- nano silica, compressive strength, tensile strength, Flexural strength
Portland cement-based materials like concrete, mortar, fiber reinforcement and others are widely used building materials, Portland cement was produced at 2011 and a continuous demanding could be needed, increasing the environmental impacts related with this worldwide industry. Nano-engineered cement-based materials is actual tends which could play an important role for efficient use of this binder, recently many oxide nanoparticles like nano-SiO2, nano-TiO2, nano-Fe2O3, nano-Al2O3, nano-CaCO3, nano-ZnO2, nano-cement particles of C2S (alita) and C3S (belite), nano-clays and Carbon Nanotubes have been tested, those improve the cement-based materials performance.
Although, Nano-particles have a unitary coast 100 to 1000 times bigger than the Portland cement or others conventional raw-materials employed for cemnt-based materials production, an important economic aspect for material design. But a structural efficiency, estimated by the relative strength gain and Nano-particles volume content ratio, indicates a better efficiency for low nanoparticles volume contend, illustrated by considering compressive strength of cement based materials containing nano-SiO2 and nano-TiO2 . So in order to study the Nano-particles in cement based materials, this paper objective is a review for different Nano-particles effects for cement based materials, discussing their mechanical and durability properties, microstructural and rheological aspects published in the last years.
Nanotechnology is a rising field of science identified with the comprehension and control of matter at the nano-scale, i.e. at measurements between roughly 1-100 nm. Nanotechnology includes nano-scale science, designing and innovation that included imaging, measuring, displaying and controlling at this length scale. In the serviceability record arrangement of units, the prefix “nano” implies 1-billionth or 10-9. Along these lines 1 nm is 1-billionth of a meter. Nano-powders (grain size, 1-100nm) have high surface area hence it enhances the chemical, optical and mechanical properties. It is anticipated that addition of nano powders into composites will increase strength, reduce voids, and improve self-control and cleaning.
II LITERATURE REVIEW
NANOPARTICLES IN CEMENT BASED MATERIALS: A REVIEW
AUTHORS: T.M. MENDES, D. HOTZA AND W.L. REPETTE
Major chemical product processed in the world, more than 3.6Bton at 2011, causing important environmental impacts. Several nano-particles have been tested in cement based materials in order to improve their performance and durability leading to an ecoefficiency use for this binder. Published researches for nano-particles in cement based materials have been demonstrated optimum volumetric contents considering the relative strength gain, directly related with packing and nucleation effect observed for nano-particles, and a pozzolani creaction is observed for nano-SiO2.
INFLUENCE OF NANO-SILICA PARTICLES ON MECHANICAL PROPERTIE AND PERMEABILITY OF CONCRETE
AUTHORS: MOSTAFA. KHANZADIMOHSEN. TADAYON
Recently, nano particles have been gaining increasing attention and have been applied in many fields to fabricate new materials with novel functions due to their unique physical and chemical properties. In this paper the influence of nano silica particles on the mechanical properties and durability of concrete has been studied through measurement of compressive and tensile strength, water absorption, and the depth of chloride penetration. The experimental results show that the mechanical properties measured, and the durability of the concrete mixed with the nano particles were better than that of a plain concrete, also the SEM study of the microstructures showed that the nano particles filled the cement paste pores and, by reacting with calcium hydroxide crystals from calcium silicate hydration, decreased the size and amount of these crystals. Therefore the results indicate that nano scale silica behaves not only as a filler to improve microstructure, but also as an activator to promote pozzolanic reaction.
2 MATERIALS USED
53 grade Portland cement
2.2 coarse aggregate
aggregate of size more than 4.75mm
2.3 fine aggregate
Sand of size less than 4.75mm
Cement Fine aggregate Coarse aggregate water
1 1.912 2.953 0.48
3 The conventional mix proportion
3 EXPERIMENTAL INVESTIGATION
3.1 EXPERIMENTS CONDUCTED ON FRESH CONCRETE
3.1.1 specific gravity of cement
3.1.2 initial setting time of cement
3.1.3 final setting time of cement
3.1.4 slump cone test
3.2 EXPERIMENTS CONDUCTED ON HARDEND CONCRETE
MIX DESIGN PROCEDURE
MIX DESIGN FOR M30 GRADE CONCRETE
1. Grade designation = M30
2. Type of cement = OPC 53 Grade
3. Maximum size of aggregate = 20mm
4. Minimum cement content = 300kg/m3
5. Maximum water – cement ratio = 0.5
6. Workability = 100mm(slump)
7. Exposure condition = Moderate
8.Type of aggregate = Crushed angular aggregate
9. Maximum cement content = 450kg/m3
TEST DATA FOR MATERIALS:
Cement used = OPC 53 Grade
Specific gravity of cement = 3.15
Specific gravity of coarse aggregate = 2.76
Specific gravity of fine aggregate = 2.64
Water absorption of coarse aggregate = 0.54%
Water absorption of fine aggregate = 1.24%
i) Free (surface) moisture coarse aggregate = Nil
ii) Free (surface) moisture fine aggregate = Nil
Slump test on concrete
The object of this test to find out workability of freshly mixed cement concrete. Workability is the capacity of being worked without extra labour and loss in strength. The strength of cement concrete entirely depends upon the correct percentage of water. This experiment gives the percentage of water and slump. It is the fall vertical height of a freshly prepared concrete with respect to its standard mould height.
Slump test results
Percentage of nano silica (%) Slump Value (mm)
Compression strength test
The specimen is tested by compression test machine after 7 days, 14 days and 28 days curing. Load should be applied gradually at the rate of 140kg/cm2 per minute till specimens fails. Load at the failure divided by area of specimen gives the compressive strength of concrete
Compressive strength(7 days test results)
0% Nano silica 22.1
1% Nano silica 23.2
2% Nano silica 24.3
3% Nano silica 23.6
Compressive strength (14 days test results)
0% Nano silica
1% Nano silica 28.6
2% Nano silica 30.1
3% Nano silica 29.6
Compressive strength (28 days test results)
0% Nano silica
1% Nano silica 34.6
2% Nano silica 36.3
3% Nano silica 35.2
Compression strength test
Split tensile test
The tensile strength of concrete is one of the basic and important properties. Splitting tensile strength test on concrete cylinder is a method to determine the tensile strength of concrete.
The concrete is very weak in tensile due to its brittle nature and is not expected to resist the direct tension. The concrete develops cracks when subjected to tensile forces. Thus, it is necessary to determine the tensile strength of concrete to determine the load at which the concrete members may cracks.
Split Tensile strength (N/mm²)
Nano silica 1%
Nano silica 2%
Nano silica 3%
14 days 2.74 2.86 2.9 2.82
28 days 3.18 3.57 3.91 3.62
“Flexural strength is one measure of the tensile strength of concrete. It is a measure of an unreinforced concrete beam or slab to resist failure in bending. It is measured by loading 100mm x 100mm x 500mm concrete beam”.
Flexural strength (N/mm²)
Nano silica 1%
Nano silica 2%
Nano silica 3%
14 days 3.81 3.94 4.2 3.82
28 days 4.17 4.25 4.38 4.15
For 1% of Nano silica, the compressive strength has increased to about 34.6 N/mm2 from 33.1 N/mm2 for M30 when compared to conventional concrete.
For 2% of Nano silica, the compressive strength has increased to about 36.3 N/mm2 from 33.1 N/mm2 for M30 when compared to conventional concrete.
For 3% of Nano silica, the compressive strength has increased to about 35.2 N/mm2 from 33.1 N/mm2 for M30 when compared to conventional concrete.
Split tensile strength
For 1% of Nano silica, the split tensile strength has increased to about 3.57 N/mm2 from 3.18 N/mm2 for M30 when compared to conventional concrete.
For 2% of Nano silica, the split tensile strength has increased to about 3.91 N/mm2 from 3.18 N/mm2 for M30 when compared to conventional concrete.
For 3% of Nano silica, the split tensile strength has increased to about 3.62 N/mm2 from 3.18 N/mm2 for M30 when compared to conventional concrete.
For 1% of Nano silica, the flexural strength has increased to about 4.25 N/mm2 from 4.17 N/mm2 for M30 when compared to conventional concrete.
For 2% of Nano silica, the flexural strength has increased to about 4.38 N/mm2 from 4.17 N/mm2 for M30 when compared to conventional concrete.
For 3% of Nano silica, the flexural strength has increased to about 4.15 N/mm2 from 4.17 N/mm2 for M30 when compared to conventional concrete.
From the results it can be conclude that by increasing the percentage of Nano silica the different strength properties are increased up to 2%, more over beyond 2% the properties of concrete are decreased gradually.
Nano concrete should control the carbon dioxide emission from the earth which is proven with the aid of the usage of Nano silica concrete products in place of cement concrete. for this reason, the Nano particles that’s in the form of silica can easily react with cement particles which might be commonly in Nano scale initiate the CSH response and consequently its tend to boost up the compressive energy of concrete.
Nano-silica consumes calcium hydroxide crystals, Nano-silica may be followed as ordinary Portland cement substitute for concrete guidance. the usage of the test effects, it may be concluded that with the increase in the percentage of nano-silica the various electricity traits of concrete extended up to 2%. it’s miles very interesting to be aware that the variation of compressive energy, split tensile power, and flexural strength of M30 grade with nano-silica suggests the similar trend.
The numerous power characteristics of concrete can be improved through the addition of 1-3% nano-silica content. it is able to be concluded that the cement content can be reduced without compromising the power of concrete with the aid of the use of nano-silica at the right share.
Ali N. and Riahi S., “TiO2 nano-particles effects on properties of concrete using ground granulated blast furnace slag as binder”, Sci China Tech Sci, Vol. 54, No 11, 2011, pp. 3109-3118.
Balaguru, P. N. (2005), “Nanotechnology and Concrete: Background, Opportunities and Challenges.” Proceedings of the International Conference – Application of Technology in Concrete Design
Bhuvaneshwari B., Saptarshi S, Baskaran T, Iyer N. R. “Role of Nano Oxides for Improving Cementatious Building Materials”, Journal of Civil Engineering and Science Vol. 1, 2 June 2012, pp. 52-58.
Chandra S, Bjornstrom J, ‘Influence of cement and superplasticizers type and dosage on the fluidity of cement mortars – Part I, cement and Concrete Research, 32, (2002), 1605 – 1611.
Freda Christy and D Tensing. (2010). “Effect of Class F Fly Ash as Partial Replacement with cement” IJEMS, Vol 17 pp 140 – 144