Ijri cce 02 0014

International Journal of Research and Innovation (IJRI)

International Journal of Research and Innovation (IJRI) 1401-1402

EXPERIMENTAL STUDY ON THE COMPRESSIVE STRENGTH OF GLASS FIBRE CONCRETE

Durisetti Praveen1, M.Rajshekar Reddy2, K. Mythili3 1 Research Scholar, Department of Civil Engineering, Aurora's Scientific Technological and Research Academy, Hyderabad,India.

2 Assistant professor , Department of Civil Engineering, Aurora's Scientific Technological and Research Academy, Hyderabad,India.

3 Associate professor , Department of Civil Engineering, Aurora's Scientific Technological and Research Academy, Hyderabad,India.

Abstract Glass Fibre Reinforced Concrete is recent introduction in the field of concrete technology. The present day world is witnessing the construction of very challenging and difficult Civil Engineering Structures. Concrete being the most important and widely used material is called upon to possess very high strength and sufficient workability properties.

Concrete the most widely used construction material has several desirable properties like high compressive strength, stiffness, durability under usual environmental factors. At the same time concrete is brittle and weak in tension. Efforts are being made in the field of concrete technology to develop high performance concretes by using fibres and other admixtures in concrete up to certain proportions. To improve the concrete properties, the system was named alkali resistance glass fibre reinforced concrete in the present view the alkali resistance glass fibre has been used. In the present experimental investigation the alkali resistance Glass Fibres has been used to study the effect on compressive strength on M30 grades of concrete.

GFRC can be used wherever a light, strong, weather resistant, attractive, fire resistant, impermeable material is required. It has remarkable physical and mechanical assets. GFRC properties are dependent on the quality of materials and accuracy of production method. Despite its wide range applications in architecture the chief goal is to show and introduce important structural purposes, for instance: anti rust characteristics of GFRC made it a good replacement for water and sewer pipes and tanks, a thin protective layer of GFRC on concrete beams and columns can increase their durability in fire as well as low temperatures and generally it is a good replacement for susceptible materials in difficult environments. *Corresponding Author: Durisetti Praveen, Research Scholar, Department of Civil Engineering, Aurora's Scientific Technological and Research Academy, Hyderabad, India.

Published: November12, 2015 Review Type: peer reviewed Volume: II, Issue : IV Citation: Durisetti Praveen, Research Scholar (2015) "EXPERIMENTAL STUDY ON THE COMPRESSIVE STRENGTH OF GLASS FIBRE CONCRETE"

INTRODUCTION Concrete is one of the most versatile building materials. It can be cast to fit any structural shape from a cylindrical water storage tank to be rectangular beam or column in a high-rise building Conventional concrete is composed of aggregates (sand, gravel...), cement, water and admixtures where it is necessary. Concrete with a uniform structure, good plasticity and the ability of deformation by form, sound and thermal insulation and the capability of quality development by admixtures, is getting more and more popular in structural industries every day. Considering all the concrete benefits, we cannot deny its weaknesses. The first fundamental problem of concrete is low tensile strength which is approximately 10%-15% of its compressive strength nevertheless this crucial problem can be solved by the reinforcement.

In addition, reinforcement must be calculated to prevent brittle failure in order to have plastic behavior; the maxi-

mum standards must be respected to prevent corrosion of reinforcement.

Fibre reinforced concrete Fiber reinforced concrete is relatively new constructional material developed through extensive research and development work during the last three decades. The fibers are randomly oriented, discrete, discontinuous elements made from steel, glass or organic polymers (Synthetic Fibers). The fibers are introduced in the matrix as ‘micro reinforcement’ so as to improve the tensile strength by delaying the growth of cracks, and to increase the toughness by transmitting stress across a cracked section so that much larger deformation is possible beyond the peak stress. The prime objective of usual natural fibers such as straw in brick making has always been to alter and improve the properties of the brittle matrix. When two different kinds of materials with contrasting properties of strength and elasticity are combined together, they realize a great portion of the theoretical strength of the stronger component, and these combined materials are called twophase materials.

Types of Fibres Fibres are classified into two categories namely hard intrusion and soft intrusion. Fibres having a higher elastic modulus than the cement matrix can be termed as hard intrusion and fibers having a lower elastic modulus are called as soft intrusion.

Steel Fibres Glass Fibre Synthetic Fibres 219

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Carbon Fibres Acrylic Fibres Aramid Fibres Nylon Fibres Polyester Fibre Polyethylene Fibre Polypropylene Fibres Natural Fibres Unprocessed Natural Fibres Processed Natural Fibres

bulk strength and weight properties are also very favorable when compared to metals, and it can be easily formed using moulding processes.

Development of fibre reinforced concrete Reinforcement, which could be moulded into shaped during the casting of concrete, or even included in the original mix, has long been the aim of many researches. The quest for new material as substitute for the existing material or finding a new or better use of known materials is very much accelerated but the socio-economic necessities. It is well-established fact that generally a material in fibrous form has much higher strength than in bulk form. Composite materials are being developed are used increasingly as they have advantaged in combining the merits of individual components and obviating their individual shortcomings as much as possible. Based on these concepts, a great amount of effort is currently put into research on use of thin, high strength fibre of steel, glass, plastic etc, in concrete mix.

General requirement of fibre reinforced concrete The most exploitable form of the fibre composites will be in the use of short discontinuous fibers in either twodimensional planner orientation as in thin section like shells, folded plate, etc, or in the random three directions as in thick sections like beams etc. Generally, economic consideration will dictate the choice and volume percentage of the fibres to be used. The basic requirement of fibres for improving the properties of concrete is high tensile strength elastic modulus, adequate extensibility, a good bond at the interface and good chemical stability.

The fibres should be capable of withstanding the stresses for a long period i.e, they should be durable. The tensile strength of fibers may not be critical, if the composite fails by the fiber pullout, but if the fibres yield on fracture, then their strength plays an important role in determining the strength capability of the composite.

Role of fibres The role of fibres is especially to arrest any advancing crack by applying pinching force at the crack tips, thus delaying their propagation across the matrix. The ultimate cracking strain of the composite is increased to many times greater than that of the unreinforced matrix.

Unlike the conventional bars, the discrete fibres are dispersed uniformly throughout the matrix hence they can be more beneficial in arresting the growth of any advancing crack.

Introduction to glass fibre reinforced concrete (GFRC) Glass fibre is a material consisting of numerous extremely fine fibres of glass. Glass fibre is commonly used as an insulating material. It is also used as a reinforcing agent for many polymer products to form a very strong and light fibre reinforced polymer (FRP) composite material called glass-reinforced plastic (GRP), popularly known as “fibre glass”. Fiberglass is a light weight, extremely strong, and robust material. Although strength properties are somewhat lower than carbon fibre and it is less expensive. Its

Glass fibre

Normal or E-glass is affected in the presence of alkalinity where as alkali-resistant glass fibre by trade name “CEM-FIL” has been developed and used. Cem-Fil alkali resistant (AR) glass fibres have been in use for 40 years in more than 100 countries worldwide to create some of the world’s most stunning architecture while offering strong and durable performance in widely varying cement and mortar based applications, including flooring, renders, top screeds, tunnels, utility poles, etc. Cem-FIL AR glass fibres are unique as a concrete reinforcement. Cem-Fil fibres have the same specific gravity as the aggregates, so assured fibre dispersion is easier to achieve than with other fibres.

CEM-FIL glass fibre The CEM-FIL glass fibres contribute to crack control, permeability and flexibility. This improves the durability of concrete.

Control of cracking CEM-FIL glass fibres prevents the shrinkage cracks developed during curing making the structure / plaster / component inherently stronger. Further when the loads imposed on concrete suddenly cause cracks and propagate rapidly. Addition of CEM-FIL glass fibres in concrete and plaster prevents / arrests such cracks.

Need for the present work The advent of high strength concrete has helped construction activity in many ways for example to build high rise buildings by reducing column sizes and increasing available space and to put the concrete into service at much earlier age etc. concrete the most widely used structural material in the world is prone to cracking for a variety of reasons. These reasons may be attributed to structural or environmental factors, but most of the cracks are formed due to inherent weakness of the material to resist tensile forces, when it shrinks and it is restrained, it will crack.

The randomly oriented fibres assist in controlling the propagation of micro-cracks present in the matrix, first by improving the overall cracking resistance of the matrix and later by bridging across even smaller cracks formed after the application of load on to the member, thereby preventing their widening into major cracks. Thus proper introduction of fibres in concrete improves both mechanical properties and durability.

Scope of present work 1. Review and research of glass fibres 2. Construct the concrete specimen by twenty seven cubes by partial replacement of cement by fibre with different percentages (0.8%, 1.2%, 1.5%) by weight of cement.

3. Investigation and laboratory testing on concrete cube.

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4. Analysis the results and recommendation for further research work.

Summary In this chapter, theoretical study on ordinary Portland cement, Glass Fibre Reinforced Concrete and materials and classification. Also the scope and objective of the present study are discussed. Based on the objective of the present study, research papers were collected and studied.

The review of research papers is discussed in the next chapter.

LITERATURE REVIEW The applications of Glass Fibre Reinforced Concrete are getting wider day by day. This research is going on in many countries and some reviews are as follows: Shah and Naaman (1976) carried out an investigation to determine the tensile, flexural and compressive strengths of concrete specimens reinforced with different lengths and volumes of steel and glass fibres. The tensile or flexural strengths of reinforced specimen was at most two to three times that of plain concrete while the corresponding strains or deflections were as much as ten times that of plain concrete. The stresses and strain at first cracking were not significantly different from those of plain concrete. Extensive micro cracking were observed on the surface of failed flexural specimens indicating a significant contribution of the matrix even after the first cracking.

For steel fibre reinforced specimens, the peak loads and deformations appear to be linearly related to the fibre parameter: Vf L/D. after failure, steel fibres pulled out while most of the glass fibres broke.

Swamy and Stravrides (1979) carried out an investigation to determine the influence of fibre reinforcement on restrain shrinkage and cracking of concrete. A ring type of restrain shrinkage test is reported to demonstrate the ability of short, discrete fibres such as polypropylene, glass, and steel to control cracking and resist tensile stresses arising from restrained shrinkage. Three series of free and restrained shrinkage tests are reported with different matrices, types of fibres, and fibre contents. It is shown that the presence of fibres exercises a clear but small restraint to free shrinkage, and reduces drying shrinkage by up to 20 per cent. When shrinkage is restrained, fibre reinforcement delays the formation of the first crack, prevents sudden failure observed with unreinforced matrices, enables the composite to suffer multiple cracking without failure, and reduces crack widths substantially. The fibre reinforced specimens were able to resist 50 to 100 percent more tensile stresses, and continued to resist the shrinkage stresses even after 8 to 12 months.

Applications of GFRC worldwide Cladding Much earlier, in the late 1970’s, GFRC panels were used on exterior wall of prefabricated timber frame houses constructed to meet the shortage of dwellings in Scotland.

Road and rail sound walls Throughout the world, new highways and mass transit rail systems compete for space in already developed urban areas. The result is that major traffic routes are found closer to commercial and residential areas and it becomes necessary to suppress noise pollution to the

surroundings. GFRC noise barriers are being increasingly used since they are light in weight and offer simplicity and speed of erection without requiring the use of heavy lifting machinery.

Ducts and Channels For drainage and transporting liquids represent another application for GFRC. A commercially available high volume, rain-water drainage channel used in parking lots, road and highway applications. These channels are designed for optimum flow capacity and are available in different cross-sectional sizes with lengths ranging up to 2 meters (6.6 feet). Further, these channels are lightweight, easy to install in long sections with reduced excavation, maintenance free, and require fewer silt traps or manholes due to their superior hydraulic performance. The channels are produced by vibration casting an AR fibers mix into a two-part mold.

EXPERIMENTAL PROGRESS General The experimental program was carried out to evaluate the mechanical properties i.e, compressive strength and split tensile strength with replacing glass fibre. The program involves casting and testing of total specimens. The specimens of standard cubes of 150mmx150mmx150mm and cylinders of 150mmx300mm are casted with and without glass fibre. In first batch the specimens were cast with 0% fibre content and remaining four batches were cast by using fibre varying with 0.8%, 1.2%, 1.5% by the weight of the cement.

Study of materials The materials that are used for the current project are 1) 2) 3) 4) 5) 6)

Cement Fine aggregate Coarse aggregate Glass fibre Water Admixture

Cement Cement is defined as the product manufactured by burning and crushing to powder an intimate and well-proportioned mixture of calcareous and argillaceous materials.

The cement, which is generally used for preparing concrete, is the Ordinary Portland Cement. But for special purposes other qualities of cement such as Low Heat Cement, Rapid Hardening Cement, High Alumina Cement, White Cement, Blast Furnace Slag Cement, Sulphate Resisting Cement, etc. are also used.

The selection of a particular type of cement to be used for manufacturing of concrete, depends upon the following factors : a) The required strength of the concrete structure. b) The type of structure. c) The conditions under which the construction of structure is to take place.

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Tests on Cement

Gradation of fine aggregates

Field tests on cements are carried to know the quality of cement supplied at site. It gives some idea about cement quality based on colour, touch and feel and other tests.

Fine aggregate

Testing of cement

The following are the field tests on cement: a) The colour of the cement should be uniform. It should be grey colour with a light greenish shade. b) The cement should be free from any hard lumps. Such lumps are formed by the absorption of moisture from the atmosphere. Any bag of cement containing such lumps should be rejected. c) The cement should feel smooth when touched or rubbed in between fingers. If it is felt rough, it indicates adulteration with sand. d) If hand is inserted in a bag of cement or heap of cement, it should feel cool and not warm. e) If a small quantity of cement is thrown in a bucket of water, the particles should float for some time before it sink.

Ordinary Portland cement available in local market of standard brand was used in the investigation. Care has been taken to see that the procurement made from a single batch and is stored in airtight containers to prevent it is being affected by atmospheric, monsoon moisture and humidity.

Cement brand

Jaypee

Specific gravity

3.15

Fineness

3200m2/kg

Soundness

1.9cm

The gradation of sand is given by sieve analysis. The sieve analysis is done by passing sand through a set of standard sieves and finding out cumulative passing percentage through each sieve. The IS 383 – 1970 -Table 4, (clause 4) classifies fine aggregates in 4 zones starting from zone I representing coarse sand, to zone IV representing the finest sand. The limits of cumulative percentage passing for each sieve for above zones are given in table 4 of IS 383 The fineness of sand found by sieve analysis governs the proportion of sand in concrete. The overall fineness of sand is given by factor called fineness modulus. Fineness Modulus is given by division of the summation of cumulative retained fractions for standard sieves up to 150-micron sieve size by 100. The fineness modulus of sand varies from 2.0 to 4.0; higher the FM coarser is the sand.

Fineness modulus of sand Fine – 2.0 to 2.8 Medium – 2.8 to 3.2 Coarse – 3.2 and above Coarse aggregate Machine Crushed angular granite metal of maximum size of 20mm retained on 4.75mm I.S. sieve confirming to I.S. 383-1970 was used in the present investigation. It is free from impurities such as dust, clay particles and organic matter etc. The coarse aggregate is also tested for its various properties.

Tests and results on cements

Following are the tests for sand: 1. Silt Content Test of Sand: The maximum quantity of silt in sand shall not exceed 8%. Fine aggregate containing more than allowable percentage of silt shall be washed so as to bring the silt content within allowable limits.

10mm coarse aggregate

2. Grading of sand: On the basis of particle size, fine aggregate is graded into four zones. Where the grading falls outside the limits of any particular grading zone of sieves, other than 600 micron IS sieve, by a total amount not exceeding 5 percent, it shall be regarded as falling within that grading zone.

20mm coarse aggregate

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RESULTS

Specific Gravity

2.76

Fineness Modulous

8.34

Dry Loose Bulk Density

1.6

Tests on coarse aggregate

Water As per IS 456-2000 recommendations, potable water was used for mixing of concrete.

Slump test:- In the case of slump test, firstly the internal surface of the mould is cleaned and moistened with damp cloth. The mould is then filled with concrete in three layers where each layer is around one third height of the specimen and each layer is tamped 25 times with tamping rod during filling. The surface concrete is rolled off then the mould is removed immediately by raising it slowly in vertical direction. Measure the height if the slump which is the difference between the height of the mould and the average height of the mould and the average height of the top surface of concrete .

Water is the least expensive but most important ingredient of the concrete. The water, which is used for making concrete should be clean and free from harmful impurities like oil, alkalis, acids etc. in general, the water which is fit for drinking should be used for making concrete.

Admixture Super Plasticizer: Conplast P211(M) Conplast P211(M) is a chloride free water reducing admixture based on selected sugar-reduced lignosulphonates.

It is supplied as a brown solution which instantly disperses in water.

Uses • To improve the effectiveness of the water content of a concrete mix.

• Higher dosages provide effective means of reducing concrete permeability and thereby reducing water penetration.

Advantages • Allows specified strength grades to be met at reduced cement content or increased workability.

• Water reduction significantly improves compressive strengths at all ages and enhances durability through the production of low permeability concrete.

• Minimises the risk of segregation and bleeding and assists in the production of a dense, close textured surface, improving durability.

• Chloride free, safe for use in prestressed and reinforced concrete.

Description Conplast P211(M) is a chloride free water reducing admixture based on selected sugar-reduced lignosulphonates.

It is supplied as a brown solution which instantly disperses in water.

Conplast P211(M) disperses the fine particles in the concrete mix, enabling the water content of the concrete to perform more effectively and improving the consistency of the concrete. This produces higher levels of workability for the same water content, allowing benefits such as water reduction and increased strengths to be taken.

Workability test The two tests used to measure the workability of concrete are

Slump test

Summary In this chapter, the study of materials used, their properties, mixing procedures of the concretes, the phases of experimental program and the procedures for testing of fresh and hardened concretes was discussed. The results of the experimental program discussed in this chapter is tabulated and studied in the next chapter.

CONCRETE MIX DESIGNS General The process of selecting suitable ingredients of concrete and determining their relative amounts with the objective of producing a concrete of the required, strength, durability, and workability as economically as possible, is termed the concrete mix design. The proportioning of ingredient of concrete is governed by the required performance of concrete in 2 states, namely the plastic and the hardened states. If the plastic concrete is not workable, it cannot be properly placed and compacted. The property of workability, therefore, becomes of vital importance.

Requirements of concrete mix design The requirements which form the basis of selection and proportioning of mix ingredients are : a ) The minimum compressive strength required from structural consideration b) The adequate workability necessary for full compaction with the compacting equipment available. c) Maximum water-cement ratio and/or maximum cement content to give adequate durability for the particular site conditions d) Maximum cement content to avoid shrinkage cracking due to temperature cycle in mass concrete.

1. Slump test.

2. Compaction factor.

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Concrete Mix Design – M 30 Grade of Concrete

Thus,

Requirements

Net water content = 180.42 Kg/cum Net sand percentage = 33 %

a) Specified minimum strength = 20 N/Sq mm b)Durability requirements i)Exposure= Moderate ii) Minimum Cement Content = 300 Kgs/cum c) Cement (Refer Table No. 5 of IS:456-2000) i) jaypee cement ii) Type OPC iii) Grade 53 d) Workability i) compacting factor = 0.8 e) Degree of quality control Good Test data for materials supplied a) CEMENT i) Specific gravity = 3.05 ii) Avg. comp. strength 7 days = 46.5 more than 33.0 OK 28 days = 55.0 more than 43.0 OK b) COARSE AGGREGATE i) 20mm Graded Type Crushed stone aggregate Specific gravity = 2.68 Water absorption = 1.46 Free (surface) moisture = 0 c) FINE AGGREGATE (Coarse sand) i) Type Natural (Ghaggar) Specific gravity = 2.6 Water absorption = 0.5 Free (surface) moisture = 1.4

Adjustments

RESULTS AND DISCUSSIONS General Series of tests were carried out on the concrete specimens to obtain the strength characteristics of concrete cubes with different percentages of fibre glass. This chapter discusses on the results that obtained from the testing. This results such as compressive test, slump test.

Compressive Strength Compressive strength of the concrete is the key property of concrete. Compressive strength of concrete is taken as a basis for evaluating various other property of the concrete. Thus cube compressive strength of concrete mixes was determined at 7 and 28 days age is carried out to verify target strength. It is observed that with increase in fibre percentage, the compressive strength also increases with age.

Cube specimens were tested for compression and the ultimate compression strength was determined from failure load measured using the compression testing machine.

The average values of specimens for each category at the age of 7 and 28 days are tabulated. The compressive strength of CEM-FIL Anti Crack HD glass fibre concrete is found to be maximum at 1.5% of fibres.

Sieve analysis results

Target mean strength (TMS) a) Statistical constant K = 1.65 b) Standard deviation S = 4.6 Thus, TMS = 27.59 N/Sqmm Selection of w/c ratio a) As required for TMS = 0.5 b) As required for ‘Moderate’ Exposure = 0.55 Assume W/c ratio of 0.5 Determination of water & sand content For W/C = 0.6 C.F. = 0.8 Max. Agg. Size of 20 mm a) Water content = 186 Kg/cum b) Sand as percentage of total aggregate by absolute volume = 35 %

Split Tensile test Tensile strength is important property of concrete because concrete structures are highly vulnerable to tensile cracking due to various kinds of effects and applied loading itself. However,tensile strength of concrete is very low in compared to its compressive strength.

COMPRESSIVE TEST RESULTS Percentage of replacement

7 days

28 days

0

22.71

39.66

0.8

24.39

41

1.2

26.89

37.25

1.5

23.95

35.21

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International Journal of Research and Innovation (IJRI)

SPLIT TENSILE TEST RESULTS Percentage of replacement

7 days

28 days

0

1.2

2.96

0.8

1.5

3.1

1.2

1.2

2.87

1.5

1.1

3.13

Summary In this chapter, the results obtained from the experimental program are tabulated and are represented in the form of graphs. The results were studied and based on this study, the conclusion were drawn. The conclusions for the present study are given in the next chapter.

Scope for further investigation 1. To strengthen the observations and conclusions made in the present investigation, more number of cubes with higher grades, and varying percentages of fibres may be investigated.

2. Mathematical formulations may be developed to verify the experimental observations 3. Further research can be carried out to study the mechanical properties of glass fibre reinforced self compacting concrete.

Conclusion This research project is to determine the strength characteristics of glass fibre reinforced concrete for potential application in the structural concrete. Based on the experimental results the following conclusions were drawn.

1. The compressive strength of CEM-FIL Anti Crack HD glass fibre concrete is found to be maximum at 1.5% of fibre.

2. This is an indication of higher toughness which is a measure of ability to observe energy during deformation.

3. Higher percentages of glass fibres from 1.5% affect the workability of concrete, and may require super plasticizer to maintain the workability.

4. With the use of glass fibre in concrete it has shown an improvement in mechanical properties such as compressive strength for M20, M40, M60.

5. Cracks could be controlled with addition of glass fibre.

Cracks have occurred and propagated gradually till the final failure. This phenomenon is true with all the percentages of fibre. Glass fibre also helps in controlling shrinkage cracks.

Reference • ASTM C-1018 (1997) “Standard Specification for flexural toughness and first crack strength of fibre reinforced concrete & shotcrete” American society for testing and materials • “Measurement of Fibre Reinforced Concrete,” ACI Com225

International Journal of Research and Innovation (IJRI)

mittee 544, American Concrete Institute Materials Journal, Vol. 85, No. 6, pp. 583-593, American Concrete Institute 1988.

Author

• I.S: 10262-1982 “Indian code for recommended guidelines for concrete mix design • I.S 456-2000 “Indian code of practice for plain and reinforced concrete (Fourth Revision)”.

• I.S 516-1959 “Indian code for method of tests for concrete”.

• Bayasi, Z. Bhatacharya, R. and Posey, M. (1989) "Fibre Reinforced Concrete: Basics and Advancements," Proceedings, Symposium on Advancements in Concrete Materials, Bradley University, pp. 1-1 to 1-27.

Durisetti Praveen, Research Scholar, Department of Civil Engineering, Aurora's Scientific Technological and Research Academy, Hyderabad,India.

• Craig, R., S. Mahadev, C.C. Patel, M. Viteri, and C. Kertesz. "Behaviour of Joints Using Reinforced Fibrous Concrete." Fibre Reinforced Concrete International Symposium, SP-81, American Concrete Institute, Detroit, 1984,pp. 125-167.

• Craig, R. McConnell, J. Germann, N. Dib, and Kashani, F. (1984) "Behaviour of Reinforced Fibrous Concrete Columns." Fibre Reinforced Concrete International Symposium, SP-81, American Concrete Institute, Detroit,pp.

69-105.

M.Rajshekar Reddy, Assistant professor , Department of Civil Engineering, Aurora's Scientific Technological and Research Academy, Hyderabad,India.

• Gopalakrishnan, S. Krishnamoorthy, T.S. Bharatkumar,B.H. andBalasubramanian, K.(December 2003) “Performance Evaluation of Steel FibreReinforced Shotcrete” National seminar on advances in concrete technologyand concrete structures for the future, Annamalai University • Marc vandevalle, N.V. (1998) “Tunnelling the world” Dramix referencemanual • Parameswaran, V.S. (October 1996) “Research and applications of FRC inIndian scenario” Indian concrete journal, , pp.553-557

K. Mythili Associate professor , Department of Civil Engineering, Aurora's Scientific Technological and Research Academy, Hyderabad,India.

• Sivarama Sarma, B. (1997) , “Investigations on laced reinforced concretebeams with normal and fibre reinforced concrete under monolithic and cyclicloading” Ph.D Thesis, IIT, Madras.

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