HIGH VOLUME FLY ASH CONCRETE,doc

HVFAC IN ROAD PAVEMENT

Seminar report

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HIGH VOLUME FLY ASH CONCRETE

APPLICATION IN ROAD PAVEMENTS.

SUBMITTEDTO

VIVESWARAIAH TECHNOLOGICAL UNIVERSITYBELGAUM

FOR THE PARTIAL FULFILLMENT OF M-TECH (STRUCTURAL ENGINEERING)

BYB.MOHAMED RAFFI.

Reg. No: -1st Semester M-Tech Structures

Under The Guidance of:Prof. R. RUDRA PRASAD

Department of Civil Engineering

Bangalore Institute of Technology1


BANGALORE INSTITUTE OF TECHNOLOGY(Affiliated To Visveswaraiah Technological University)

Bangalore-560004

BANGALORE INSTITUTE OF TECHNOLOGYBANGALORE -560004

CERTIFICATE

This is to certify that Mr. B.MOHAMED RAFFI , bearing university USN

has submitted the report on “HIGH VOLUME FLY ASH CONCRETE

APPLICATION IN ROAD PAVEMENTS ” in partial fulfillment of the 1st semester

M-Tech course in structural engineering as prescribed by the Visveswaraiah

Technological University during the academic year 2006-2007, under the guidance of

Prof .R.RUDRAPRASAD.



Prof. K.JAYRAM Dr. M. U. ASWATH H.O.D ProfessorDept. of Civil Engg. Dept. of Civil Engg.

ACKNOWLEDGEMENT

I express my deep sense of gratitude to, Prof .R.RUDRAPRASAD,

Department of Civil Engineering, BIT, for his guidance and help through out this project work.

I will remain thankful to the head of department, PROF. K. JAYRAM

and all the faculty members of Department of Civil Engineering, BIT for their support during the

course of this work.

Finally I express gratitude to my parents, fellow students and friends.

B.MOHAMED RAFFI. M-TECH STRUCTURES

BANGALORE IN



HIGH VOLUME FLY ASH CONCRETE

APPLICATION IN ROAD PAVEMENT



HIGH –VOLUME FLY ASH CONCRETE (HVFAC)

APPLICATION IN ROAD PAVEMENT

INTRODUCTION:

The word ‘fly ash’ is commonly used as generic terminology for the waste product, düe to burning of coal in the boiler of a thermal power plant. The generic terminology for such waste products, as per IS 3812, is pulverised fuel ash. It is defined as ash generated by burning of ground or pulverised or crushed coal or lignite in boilers. Pulverised fuel ash can be fly ash, bottom ash, pond ash or mound ash.

Fly ash is the pulverised fuel ash extracted from the flue gases by any suitable process such as by cyclone separation or electrostatic precipitation.

Fly ash incorporated concrete is one of the best tools to achieve sustainable, development of a country like India.

This type of concrete, using fly ash (FA) as pozzolanic mineral, admixture in high volume, is being increasingly used in the construction of structures for large projects in many countries. Use of high Volume fly ash concrete (HVFAC) has positive effects in utilizing fly ash in an environmental friendly way preserving, resources, and above all produces concrete of better, quality & Experiences of using HVFAC in Indian condition are few and far between, though fly as suitable for use in concrete structures is available in almost all parts of India.

Experimental studies were conducted to develop and examine the behavior of HVFAC mixes using Indian ingredients, especially, the fly ash and commercially available ordinary Portland cement (OPC).

Fly ash is one such cement replacing pozzolanic material, The positive effect of using fly ash in concrete are now well known and include the following.

Producing concrete of better rheology, higher strength and enhanced durability.

Saving in energy requirements in the production of OPC.

Preservation of limestone and coal reserves.

Minimizing greenhouse gas emissions associated with manufacturing of OPC.

Utilisation of industrial waste in an eco-friendly and economical disposal of millions of tones of fly ash.



AVAILIBLITY OF FLY ASH IN INDIA

Projected availability of. fly ash in India is expected to reach 200 million tonnès. in. the year 2010. Considering the fact that a huge quantity of fly Ash is produced in India, its use in concrete is one of the effective ways of utilization of industrial by product in India, to meet the Infrastructure requirements of our growing population and consequential increase in industrialization and urbanization.

Fly ash can be used in cement and concrete in two different ways

First in the manufacture of Portland pozzolana cement(PPC)in the cement plant, by blending or inter grinding with cement clinker and gypsum.

Alternatively, fly ash can be added to OPC and other ingredients of concretein the concrete mixer at the construction site or an RMC plant.

Effect of the Quantity of Fly ash in concrete property:

Incorporation of Fly ash in concrete mix improves its properties both in fresh and hardened state.The phenomena,which influence the properties are principally filler effect and pozzolonic action.The filler effect is immediate,while pozzolonic action occurs later.

Initial slump increased with the increase in fly ash content, and slump retention seems to be decreasing with the increase in the fly ash content.

Pazzalonas are silicious or silicious and aluminous material which though not cementitious, react with lime when finely devided form in the presence of water.

Setting time of Fly ash concrete:

Fly ash delays the hydration process. The test results on HVFAC shows that the initial setting times of 7.5h are comparable to those of control concrete mixes made with the same water content and water / binder ratio, where as the final setting time were retarded by about 3hours as compared with that of the conrol concrete.

Effect of Fly ash characterstics on fresh concrete property:

The shape ,size, particle –size distribution and density of fly ash particle influence the properties of freshly mixed, un hardened concrete, and the strength development and other properties of hardened concrete: this is due in part to the influence of particle characteristics on the water demand of the concrete mixtures. Among other factors, the water requirement is influenced by the total surface area, surface texture and morphology( shape and size) of the ash particles.



Effect of Fly ash characteristics on Hardened concrete property:

Despite the difference in the workability of HVFAC mixtures depending on the sources of fly ash used showed excellent compressive strength development and resistance to chloride ion penetration.

Lower strength development had been observed due higher water content required to increase the workability of the mixture.

The excellent mechanical performance of Indian fly ashes in HVFAC could be surprising considering that all those ashes had a low glass content



HIGH VOLUME FLY ASH CONCRETE:

High –volume fly ash concrete (HVFC) technology was developed by Malhotra and his collegues at Canada Centre for Mineral and Energy Technology(CANMET) Canada,in the 1980s.

This technology utalises special mixture proportioning technique, and involves judicious selection of materials and chemical admixtures to minimize the amount of ordinary Portland cement required to produce high quality concrete for different applications.

This concrete has low cement content,low water/ cementitious material ratio and incorporates up to 55% fly ash.

HVFAC IN ROAD PAVEMENT:

The pozzolonic activity of a fly ash is greatly influenced by,

1. The amount and composition of the glassy phase present.

2. Mineralogical characteristics

3. Particle size of the fly ash

Application of HVFAConcrete in construction :

1. For Concrete roads

2. For Under water construction

3. For tremie seal and pylon pile cap



HVFAV CONCRETE ROADS:

India has huge infrastructure needs. Concrete roads are having proven advantage over the traditional Bituminous roads except that of high initial cost.

The use of Fly ash up to 50% reduces the initial cost of concrete road construction substantially thus bringing concrete roads almost at par with bituminous roads.

Further use of fly ash in concrete roads improves durability and performance. While on the one hand, bitumen has to be imported to meet India’s fast growing huge infrastructure needs, on the other hand, sufficient quantity of good quality of Portland cement as well as class F fly ash are available in India to meet these needs adequately.

Projected availability of fly ash in India is expected to reach 200 million tones in. the year 2010 So, to cater to India’s huge infrastructural needs, HVFA concrete road is one promising solution.

Use of Fly ash as per IS Code

Use of fly ash in structural concrete is acceptable as per IS456. The second revision of IS3812:2003(Part I 7 Part II) encourages use of any type of pulverized fuel ash ,as admixture in concrete. The necessary condition for using this material in construction of concrete structures is that it shall satisfy the requirements of the code. The pulverized fuel ash is to be processed when it does not satisfy the requirements of IS 3812:2003. Fly ash collected from the higher field of ESP of a thermal power plant, generally satisfies the specifications of IS3812;2003 and need not be processed.

Proportion of Fly ash used for pavement

Contrary to certain misconceptions, IS 456:2000 does not restrict the proportion of fly ash in concrete to any pre set level. The proportion of fly ash currently being used in structural concrete in India varies from 15 to 50% .It depends upon the type of construction and characteristics of the concrete

Use of concrete in which up to 70% cement has been replaced by fly ash successfully adopted in USA for road construction. Performance in the field after 18 years was reported to be good.

In India, 50% of fly ash will be used for HVFA Concrete roads for both conventionally compacted and roller compacted concrete.



HVFAConcrete Roads in India :

Extensive laboratory tests were carried out for implementing the HVFA Concrete technology for constructing the first HVFA Concrete road in India.

A sample panel of HVFAconcrete was cast at Ahmedabad laboratory, Gujarat and tested for its long term performance.



First HVFA Concrete Road in India :

Encouraged by HVFA concrete performance with indegenous material during laboratory test, for the first time in India, Gujarat Ambuja cements ltd, constructed a HVFA concrete road at ropar in the state of Punjab, India.

The road has been constructed with the use of 50 percent fly ash, available from the Ropar thermal power plant, replacing cement, and providing high-performance and durable concrete. The road was designed for Indian conditions on the line of technology used in USA and Canada.

Construction of this two lane(7m wide) 300 mm thick and 0.75 km long road was completed within two and half months, since the construction work was small no paving machine was used for the construction of this small section of HVFA Concrete road Conventional concrete mixing machine, vibrating tools & curing by ponding.

HVFA concrete has given high compressive strength of 41.6 MP and flexural strength of 7.6 MPa against the require of 4 MP The actual cores cut from the road were tested and the results obtained even exceeded the expected requirements for highway concrete road const These test results are shown in Table .



.

Chloride-ion penetration test (as per ASTM-C1202) was performed on cote actually cut from the road at.28 days and the results indicated very low chloride

The road is performing very well under heavy load vehicular (More than 500 trucks/commercial vehicles per day w an average weight of 15 to 45 t.)



HVFA concrete road Ambuja nagar:

After the successful, completion of HVFA road at Ropar, Gujarat Ambuja CementsLtd. Have also constructed about 3200 m of HVFA concrete road at Ambujanagar, Gujarat,

This HVFA road in Gujarat is also performing satisfactory under heavy vehicular traffic. (More than 550 trucks/commercial vehicles per day with an average weight of 15 to 25 t.)



HVFA concrete road at Maratha cement works plant Gadchandur:

Gaining confidence from the above two projects it was decided to adopt HVFA concrete technology for a larger area of road construction.

In June 2004, Gujarat Ambuja Cements Ltd. had completed the construction of another HVFAconcrete road at Gadchandur, Maharastra.The total area of this HVFA concrete road is about 21000m2.

For upgrading theweak soil pockets in sub –base roller compacted HVFA concrete is used . Further to overcome the common problem of surface scaling in concrete roads,top 25mm layer of the pavement was cast with 30% cement replacement by fly ash instead of 50%.The bottom 225mm layer was constructed with 50% cement replacement by fly ash.



Both the layers of concrete were vibrated together to make pavement quality concrete monolithic.

HVFA concrete road at Saurashtra University,Rajkot

HVFA concrete road at Satara-kolhapur section of NHDP .



Properties of 53 grade OPC used for construction of HVFA concrete roads.

Properties Test results

Chemical properties

Lime saturation factor 0.96

Ratio of percentage of alumina 1.35

To that of iron oxide

Insoluble residue, percent by mass 0.95

Magnesia, percent by mass 1.45

Sulphuric anhydride, percent by mass 2.24

Total loss on ignition, percent 2.25

Chloride content, percent bymass 0.041

Physical properties

Fitness, m2/kg 324.50

Setting time, minutes

Initial 125

Final 200

Expansion by

Le-chatelier metod, mm 1.00

Autoclave, percent 0.06

Compressive strength, Mpa

3-day 47.50

7-day 57.10

28-day 70.30



Properties of Hardened HVFAconcrete used in different projects

Property Ahmedabad Ropar Ambujanagar Gadchandur Rajkot

Compressive

strength, Mpa

I-day 10.5 9.5 9.2 - -

3-day 19.2 18.4 19.5 20.6 18.9

7-day 24.3 24.1 25.5 29.0 24.3

28-day 42.3 41.6 40.0 43.2 40.1

90-day 49.2 - - - -

180-day 53.7 - - - -

365-day 55.7 - - - -

Flexural strength, Mpa

28-days6.7 7.6 6.8 5.7 6.2



Concrete mixture proportions used for construction of HVFA concrete roads

Particulars Laboratory and Ambujanagar

Ropar

Punjab

Gadchandur, Maharashtra

Rajkot,

Gujrat

Grade of HVFAconcrete M40 M40 M35 M40

Ordinay Portland Cement,kg/m2

225 225 225 225

Processed fly ash kg/m3 225 225 225 225

Coarse aggregates

(crush sedimentary stone) ,kg/m2

1283 1392 1374 1374

Fine aggregates kg/m3

(river sand)

547 438 456 456

Percent absorption

of coarse aggregates

0.93 0.97 0.95 0.94

Percent absorption

of fine aggregates

1.89 2.01 1.98 2.00

Super plasticier, kg/m2 2.25 2.25 1.8 2.7

Water to cementitious

material ratio

0.32 0.35 0.33 0.33



CONCLUSION:

Based on the laboratory and field trails, the following conclusions can be drawn.

1) HVFA concrete is an economical and durable option for structural as well as general concreting purposes.

2) HVFA concrete does not require any special efforts in terms of mixing and placing and can be mixed, transported and placed using conventional means.

3) HVFA concrete can be effectively utilized in under water concrete applications where concrete is required to be cohesive enough to have anti-washout resistance.

4) The rise in temperature of concrete, particularly in case of mass concrete , can be effectively controlled with HVFA concrete.

5)Indian fly ashes may generally be perceived to be less “reactive “ compared to the Canadian ash because of their relatively lower glass content ( 50 percent on an average for Indian ashes compared to 82 percent for the Canadian one).However, this was found to be compensated , at least in some cases, by the higher fineness of the Indian ashes.

6 ) HVFA concrete provides high strength high performance and durable concrete.

7) For new roads , the cost of HVFA concrete road would be almost at par with bituminous roads.

8 ) Like the conventional concrete road, HVFA concrete road has high service life without major maintenance, needs less lighting, is not affected by rains, allows smooth traffic flow, causes low wear and tear of vehicles, provides savings in fuel, and is environment – friendly .

9) HVFA concrete pavements can provide an economical alternative for flexible pavements, and would be beneficial for developing countries.

10 ) HVFA concrete road would be ideal for national high ways , state and district high ways, and rural roads.



REFERENCES:

1. MALHOTRA, V.M. and MEHATA, P.K. High-performance, High-volume Fly Ash Concrete: Materials, Mixture proportioning, Properties, Construction Practice and Case Histories, Supplementary Cementing Materials for Sustainable Development Inc., 2002 Ottawa, Ontario , Canada, p.101

2. MALHOTRA, V.M. High performance HVFA concrete : A solution to the infrastructure needs of India , The Indian concrete journal , February 2002, Vol.76, No. 2 . pp 103-107.

3. DESAI, J.P. First HVFA concrete road in India at Ropar, Panjab, The Indian concrete journal, Apri; 2003, Vol. 77, No. 4, pp. 1022 -1025

4. The Indian concrete journal, November; 2004,

5. The Indian concrete journal, June; 2005,

6. The Indian concrete journal, March; 2006,




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