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Abstract

Reinforced Concrete cement pipes are widely used for water main sewers, culvert and in irrigation. This research review the strengthening of RCC precast pipe concrete pipe using Alkali Resistant Glass Fiber and the comparison study between the conventional RCC pipe and modified AR Glass Reinforced RCC pipe  regarding Strength, Crack control aspect in Precast RCC pipes. The present research concentrate the behavior of Alkali Resistant Glass fiber on RCC precast pipe by mixing the Alkali Resistant Glass fiber in different percentage by the weight of other Material /concrete (Cement, Coarse & Fine Aggregate And Mild steel Wire) utilized and as per the Experimental work give the necessary recommendation’s for adoption of modified Alkali Resistant Glass Fiber RCC pipe. Results show that the composite structures possess good strength, cracking control and ultimate capacity.

CHAPTER NO 1

INTRODUCTION

1

INTRODUCTION

-------------------------------------------------------------------------------------------------------

1. General:-

Glass Reinforced Concrete is a composite material comprising of cement, fine , Coarse aggregates, Steel and alkali resistant glass fibres. Since ancient times, fibers have been used to reinforce brittle materials. Straw was used to reinforce sun dried bricks, and reinforce the masonry, mortar and plaster with the help of horse hair. A pueblo house built around 1540 was believed the oldest house in the constructed by sun dried brick with straw reinforced in U.S. In more recent times, asbestos fibers  commercial use in a cement paste matrix began with the invention of the Hatschek process . Fiber in cement products are widely used throughout the world today. However, primarily fibers, alternate fiber types were introduced throughout the 1960s and 1970s.

 Recently, engineering materials of wide range (including the products like ceramics, cement, plastics, and gypsum etc ) incorporate fibers to enhance composite properties. The characteristic properties include compressive strength, tensile strength, elastic modulus, crack resistance, durability, fatigue life, crack control, resistance to impact and expansion, thermal characteristics, shrinkage, abrasion, and fire resistance.

 Experiment investigate trials and patents involving the use of discontinuous steel reinforcing material such as wire segments,  nails and metal chips to improve the properties of concrete date from 1910 . Early 1960s in the United States, the major investigation was made to evaluate the potential of steel fibers for reinforcement in concrete. After then huge amount of experimentation, research, development, and industrial and domestic use of different fiber reinforced concrete has occurred.

About Glass Reinforced Fiber Concrete: -

Application and use of glass fibers in concrete work first attempted in USSR in the late 1950s. It was quickly established that ordinary glass fibers, such as E-glass fibers, borosilicate fibers are eventually destroyed by the alkali atmosphere in the cement paste. Vide range of development work was carried to producing a form of alkali-resistant glass fibers containing zirconia. The huge use of glass fiber reinforced concrete in the U.S. is currently done for the production of architectural and structural use.

Considerable research and development work and applications for glass fiber reinforced concrete are carried out many places in the world. Industrial interest and potential business opportunities are evidenced by regularly continued new developments in the fiber reinforced construction materials. New developments are reported throughout in numerous research papers report, international symposia report, and also state-of-the-art report.

Much of the original research was performed on glass fiber reinforced in the cement paste took place in the early l960s.Many research work was carried out conventional sodalimesilica glass fibers (A glass) and borosilicate glass fibers (E glass). The chemical compositions and properties of different selected glasses are shown in the below tables in table 1.1 and table 1.2, respectively. Glass compositions of different glass fibers like E glass and A glass used as reinforcement in cement  were found to lose strength more quickly due to the very high alkalinity like around pH 12.5 of the cement based matrix. A glass and E glass composites were generally unsuitable in concrete for long-term use.

Table 1.1— Chemical composition of selected glass fibers in percentage

Component A glass E glass Cem  FIL  AR  glass NEG AR glass

SiO2 73.0 54.0 62.0 61.0

Na2O 13.0 — 14.8 15.0

CaO 8.0 22.0 — —

MgO 4.0 0.5 — —

K2O 0.5 0.8 — 2.0

Al2O3 1.0 15.0 0.8 —

Fe2O3 0.1 0.3 — —

B2O3 — 7.0 — —

ZrO2 — — 16.7 20.0

TiO2 — — 0.1 —

Li2O — — — 1.0

Table 1.2— Properties of different glass fibers

Property A-glass E-glass Cem –FIL- AR -glass NEG- AR- glass

Specific gravity

Tensile strength, ksi

Modulus of elasticity, ksi

Strain at break, percent 2.46

450

9400

4.7 2.54

500

10400

4.8

2.70

360

11600

3.8 2.74

355

11400

2.5

Metric equivalent: 1 ksi = 1000 psi = 6.895 MPa

Continued work of research in this field, results in the development of a new alkali resistant fiber glass fiber that provided improved and long term durability. This system was named as alkali resistant glass fiber reinforced concrete.

  Around 1967, scientists of the Building Research Establishment in United Kingdom  began an investigation for alkali resistant glasses with modified properties. During huge research work they successfully formulated a glass composition containing around 16 percent zirconia that demonstrated and turn the glass a high alkali resistance. Properties and chemical composition of this alkali resistant glass are given in Tables 1.1 and 1.2 respectively. The patent applications for work were filed by the National Research Development Corporation for this research product. The National Research Development Corporation and Building Research Establishment discussed with Pilkington Brothers Limited for the possibility of doing further work to develop the fibers for commercial use and production.

 In 1971, Building Research Establishment and Pilkington Brothers had collaborated and the results of their work were given and licensed to Pilkington brothers for commercial use and production and distribution throughout the world. Since the introduction of alkaline resistance glass in the United Kingdom and the world in 1971 by Cem FIL, other manufacturers of alkali resistance glass have come and supply the demand.   

 In 1975 Nippon Electric Glass Company was introduced an alkali resistant glass with containing a minimum percentage of 20 percent zirconia .The higher the zirconia content better the alkali resistance.  

Alkali resistant glass fiber reinforced concrete is widely used system for the manufacture of glass fiber reinforced concrete products. Within last decade, a huge range of applications in the construction industry has been established.  

Fig  1   Photograph of  Alkali Resistant Glass fiber

Fabrication of GFRC material: -

 There are two processes method used to fabricate glass fiber reinforced concrete materials. These are the “spray-up” process method and the “premix” process method as mentioned in below.

Spray-up process of Glass fiber reinforced concrete:-

Glass fiber reinforced concrete is principally used in thin sections, it is important that composite glass fiber reinforced concrete boards have uniform properties in all directions within the plane of the board. spraying constitutes an effective process of achieving this uniformity all over. At present, the spray process accounts for the majority of all manufactured Glass fiber reinforced concrete products in the United States and other parts of world.

Premix process of Glass fiber reinforced concrete:-

Premix process consists of mixing constituent like cement, aggregate, glass fiber, water, and admixtures together into a mortar, using standard mixers, and casting with vibration, press molding, or slip forming the mortar into a product. Manufacturers of Alkali resistant glass fiber claim that up to 5 percent by weight alkali resistant glass fiber can be mixed into a cement and sand mortar without balling effect. Higher concentrations of fiber can be mixed into the mortar using high efficiency undulating mixers. Mixing must be closely controlled to minimize damage to the fiber in the abrasive environment of the mix. Flow aids, such as water reducers and high range water reducing agents, are commonly used to facilitate fiber addition while keeping the water-cement ratio to a minimum. Since the premix composites are generally not as strong as sprayed up glass fiber reinforced concrete. Premix glass fiber reinforced concrete is generally used to produce small complex shaped components  and specialty cladding panels.

About RCC Pipe

 Walter  Hume from Australia is the hume pipe inventor. Hume pipe is the concrete pipe making process using the centrifugal process and also popularly known as spun process in many parts. This is most traditional method of producing the concrete pipes.

RCC Hume pipe refers to Reinforced Concrete cement pipes. The Hume/Spun pipe process is widely used in un-developed and developing countries. Generally these spun pipes are used for sewage, drainage purposes.

Hume pipe is a process to make concrete pipe through RCC pipe making machine. The process is also known as spun pipe. Hume pipe are the traditional reinforced concrete cement pipes make from years old traditional pipe making machine. Hume process was the latest one by that time but now new technologies have overcome the issues faced during Hume process.. There are many process to develop RCC pipe through Hume process.

New technology includes vertical cast process which is much better than spun pipe process and majority used in developed countries. Hume Pipe process is an old process and very much laborious involving many resources in low production. Quality mainly depends on the skill of operator. Thus need best skilled operator for good production. automization is less and more human involvement tends to more errors in production. The process is slow and tedious. But this was the only way of producing RCC concrete pipe till the end of nineteen century.

Fig 2   Photograph of  RCC Hume Pipe

Benefits of Vertical Cast Process:-

Now, with the modification, advancement and high involvement of latest computer technology in pipe production  have found a latest technique called vertical cast process  method used mostly in developed country where human resources are less and costly. This is the best automatic technique used in production of RCC pipe.  This process required limited labor, better consistency in quality and faster production are the main advantages of this method. Developed countries use this technique but developing countries are also using this technology in joint venture to the multi nationals company of the developed country for better and fast production of quality concrete pipe for long term usage. RCC concrete pipes are mainly used for drainage purpose. Thus it needs high quality production of Reinforced concrete cement pipes to make the sewage and draining system more powerful and cost effective.

CHAPTER NO 2

  LITERATURE REVIEW

2

LITERATURE REVIEW

------------------------------------------------------------------------------------------------------- 2.1    LITERATURE REVIEW

G. Barluenga et al ( 2007) showed results of maximum crack length pointed out that low amounts of the AR glass fibers, studied control cracking due to concrete drying shrinkage at early ages, acting as a local reinforcement when concrete cracks. when  any short fibers is added to fresh concrete, two main different patterns of relative positions between the fibers and cracks were observed during investigation. Crack grows perpendicular to a fiber in concrete, its cracking control capacity is high and limit crack growth. If the crack appears parallel to a fiber, crack can progress easier, producing de bonding between fiber and concrete matrix.

A.K. Asthana et al (2010) Based on the present experimental investigation conducted by the author and the analysis of test results, the following  conclusions are drawn.

1. Higher percentages of Glass fibers from 1.0 percentage affect workability, and may require the use of super plasticizers (workability agents) to maintain the workability. For the nominal M20 mix with a water cement ratio of 0.5, the workability of concrete is only marginally affected the total fiber content of 1.0 percent by volume. Steel fiber of 1 mm diameter and length of 55 mm having an aspect ratio of 55 can be satisfactorily mixed along with glass fiber having an aspect ratio of nearly 857, to increase the strength and other characteristics.

2. The compressive strength of ‘‘Cemfil Anti crack HD’’ fiber concrete is found to be maximum at 1.5 percentage of fiber. With this percentage there is an increase of 17.49 percent for M20 Grade mix at 28 days.

3. The Split Tensile strength of ‘‘Cemfil Anti crack HD’’ fiber concrete is found to be maximum at 1.5 percent of fiber mix and there is an increase of 65.45 percent for M20 Grade mix at 28 days.

4. The Flexure strength of ‘‘Cemfil Anti crack HD’’ fiber concrete is also found to be maximum at 1.5 percent of fiber, and there is an increase of 45.56 percent for M20 Grade mix at 28 days.

5. The compressive strength of dual fiber concrete is maximum at 1.0 percent total fiber content of steel. With this percentage there is an increase of 29.03 percent at 28 days compared to plain concrete. With a total of 1.0 percent glass fiber by volume the increase of compressive strength at 28 days is 21.53 percent compared to plain concrete. There is substantial increase in the compressive strength for mixed fiber combination As the percentage of steel fiber is reduced and glass fiber is increased, the compressive strength is getting reduced compared to that of 100 percent steel fiber in the matrix.

6. The split tensile strength of dual fiber concrete is maximum at 1.0 percent total steel fiber content. With this percentage there is an increase of 31 percent at 28 days compared to plain concrete. With a total of 1.0 percent glass fiber by volume the increase of split tensile strength at 28 days is 22.77 percent compared to plain concrete. As the percentage of steel fiber is reduced and glass fiber is increase, the split tensile strength is getting reduced compared to that of 100 percent steel fiber in the matrix.

7. The flexural strength of dual fiber concrete is found to be maximum at 1.0 percent total steel fiber content. With this percentage there is an increase of 31 percent at 28 days compared to plain concrete. With a total of 1.0 percent glass fiber by volume the increase of flexural strength at 28 days is 21.74 percent compared to plain concrete.

8. The ductility characteristics have improved with the addition of glass fibers. The failure is gradual compared to that of brittle failure of plain concrete. The Ductility characteristics improved by adding Steel fibers also.

9. Cracks can be controlled by introducing glass fibers. Cracks have occurred and propagated gradually till the final failure. This phenomenon is true with all the percentages of glass fiber. Glass fiber also helps in controlling the shrinkage cracks. Compared to metallic fibers like steel, alkali resistant glass fiber gives corrosion free concrete.

 Dr. T. Seshadri sekhar et al (2012) explained durability of concrete from the aspect of resistance to acid attack on concrete increases by adding AR glass fibers in concrete. It was observed that there was no effect of sulphates on concrete. Chloride permeability of glass fiber reinforced concrete shows less permeability of chlorides into concrete when compared with ordinary concrete .The glass Fiber bridge across the cracks causing interconnecting voids to be minimum.

Yogesh Iyer Murthy et al (2012) investigated the compressive strength, flexural strength and workability of concrete having varying proportions of glass fiber as replacement of fine aggregate is studied. The result is compared of these parameters of standard M30 grade concrete. The increase in compressive strength is nominal while the flexural strength significantly increased as expected with the increase in percentage of glass fiber. Slump value decrease of the glass fiber reinforced concrete was observed with increase in glass fiber content. The primary investigations shows that the use of this industrial waste is not only improving the properties of concrete but also  safe and efficient means of disposal of such non-biodegradable wastes.

Nemkumar Banthiaet al (2012) explained fiber reinforced concrete is a composite material made of hydraulic cement, water, fine and coarse aggregate, short, uniformly dispersed discontinuous fibers. Fibers may be of polymeric materials, carbon, steel, glass, cellulose, and so forth, and their lengths vary from 3 to 64 mm (0.12 to 2.52 in.). The diameters may vary from a few µm to about 1 mm (0.04 in.). The sections may be polygonal, triangular, crescent shaped, round, oval, or even square depending on the manufacturing process and the raw material used.

The two broad categories of fibers are micro and macro. Microfibers have diameters or equivalent diameters less than 0.3 mm (0.012 in.), and macrofibers have diameters or equivalent diameters greater than 0.3 mm.  FRC is used in a broad range of applications. Care must be taken to suitably match the fiber with the intended purpose. In all cases, the chosen fiber provides select benefits that were not possible either with conventional reinforcement or with an alternate fiber system.

Prof. Ram Meghe et al (2013) Glass fiber reinforced concrete (GFRC) is a recent introduction in the field of civil engineering. So, it has been extensively used in many countries since its introduction two decades ago. This product has advantage of being light weight and thereby reducing the overall cost of construction, ultimately bringing economy in construction. Steel reinforcement corrosion and structural deterioration in reinforced concrete structures are common and prompted many researchers to seek alternative materials and rehabilitation techniques. So, researchers all over the world are attempting to develop high performance concrete using glass fibers and other admixtures in the concrete up to certain extent. In the view of global sustainable

scenario, it is imperative that fibers like glass, carbon, aramid and poly-propylene provide very wide improvements in tensile strength, fatigue characteristics, durability, shrinkage characteristics, impact, cavitations, erosion resistance and serviceability of concrete. The present work is only an accumulation of information about GFRC and the research work which is already carried out by other researchers.

CPHEEO Manual (2013) Sewerage and Sewage Treatment Systems Chapter 6 of CPHEEO Manual & IS 458 Specification for RCC Precast Concrete Pipe The structural design of a sewer is based on the relationship that the supporting strength of the sewer as installed divided by a suitable factor of safety must equal or exceed the load imposed on it by the weight of earth and any superimposed loads.

The essential steps in the design and construction of buried sewers or conduits to

provide safe installations are therefore:

(i) Determination of the maximum load that will be applied to the pipe based on the    trench and backfill conditions and the live loads to be encountered.

(ii) Computation of the safe load carrying capacity of the pipe when installed and bedded  in the manner to be specified using a suitable factor of safety and making certain the design supporting strength thus obtained is greater than the maximum load to be applied.

(iii) Specifying the maximum trench widths to be permitted, the type of pipe bedding to be obtained and the manner in which the backfill is to be made in accordance with the conditions used for the design.

(iv) Checking each pipe for structural defects before installation and making sure that only sound pipes are installed and

(v) Ensuring by adequate inspection and engineering supervision that all trench widths, sub grade work, bedding, pipe laying and backfilling are in accordance with design assumptions as set forth in the project specifications.

Proper design and adequate specifications alone are not enough to ensure protection from

dangerous overloading of pipe. Effective value of these depends on the degree to which the design assumptions are realized in actual construction. For this reason thorough and

competent inspection is necessary to ensure that the installation conforms to the design

requirements. There are three type of construction of Sewer (a) embankment condition (b)

trench condition and (c) tunnel condition. (Para 6.1 & 6.31 of CPHEEO Manual)

Ramkumar.V.R et al (2013) The following salient conclusions are drawn from the investigations are as:-

1)The permeability index value get reduced due to addition of glass fibre, it is about 6.4% by the addition of 0.5%, 12.6% by the addition of 1% and 26.3% by the addition of 1.5% of glass fibre in M25 concrete when compared to control concrete.

2) Similarly for M50 concrete, the permeability value is about 8.7% by addition of 0.5% of glass fibre, 15% by addition of 1% of glass fibre and 30.1% by addition of glass fibre to that of control concrete.

3) The compressive strength increased by about 16.4% by the addition of 0.5%, 24.7% by the addition of 1% and 47.3% by the addition of 1.5% of glass fibre in M25 concrete when compared to 0% of glass fibre in concrete.

4) Similarly for M50 concrete, the permeability value is about 14.3% by addition of 0.5% of glass fibre, 22.3% by addition of 1% of glass fibre and 43.5% by addition of glass fibre to that of 0% glass fibre in concrete.

5)   The addition of glass fibre in concrete will have better effect on high grade of concrete for permeability and lower grade of concrete for compression test due to quantity of cement content, water-cement ratio and the ratio of fine aggregate to coarse aggregate.

6) Based upon the experiment results a regression analysis was done to formulate an exponential equation, the present equation can able to calculate the permeability index for the required concrete strength more accurately.

Shrikant M. Harle et al (2014)Though the initial cost is high the overall cost is greatly reduced because of the good properties of fiber reinforced concrete. The glass fiber reinforced concrete     showed almost 20 to 25 % increase in compressive strength, flexural and split tensile strength as compared with 28 days compressive strength of plain concrete. While  to improve the durability from the aspect of acid attacks on concrete the use of AR glass fibers had shown good result. So, the GFRC can be used for blast resisting structures, dams, hydraulic structures.

Prof.Navanath Phadtare et al (2014) showed compressive strength performance of glass fiber reinforced concrete is studied for different percentage of fibers. The fiber percentage is varied from 0.5 to 5 with an variation of 0.5%.The compressive strength of plain cement concrete is found to be 22.10 N/mm2 and Maximum compressive strength of glass FRC is 40.66 N/mm2 obtained at 5% of fiber content. The maximum compressive strength achieved is glass fibre concrete is 40.66 compare to 22.10Mpa of strength of plain cement concrete. . In general, the significant improvement in various strengths is observed with the inclusion of glass fibbers in the plain concrete. . The maximum flexural strengths achieved is 4.44Mpa at 5% glass fibre 2.9Mpa of strength of plain cement concrete.

 S.R.Nawale et al (2014)  studied the  glass fiber reinforced moderate deep beam with and without stirrups have been presented. Six tee beams of constant overall span and depth 150mm, 200mm, 250mm, 300mm with span to depth (L/D) ratios of 4,3,2.4, &2 and glass fibers of 12mm cut length and diameter 0.0125mm added at volume fraction of 0%, 0.25%, 0.50%, 0.75% & 1 %.The beams wear tested under two point loads at mid span. The results showed that the addition of glass fiber significantly improved the compressive strength, split tensile strength, flexural strength, shear stress and ductility of reinforced moderate deep beam without stirrups. The increase in average compressive strength for GFRC is found 24.73 %. Compared to PCC. The maximum compressive strength is achieved with 0.75% fiber volume fraction. Overall observation of this study shows that it advantageous to use 0.75% of Glass fibers which gives satisfactory results in all conducted tests for concrete Grade M25.

Amjad Khabaz et al  (2014) showed friction forces between glass fiber and the concrete in the case of Fiber Reinforced Concrete F.R.C are considered as the main factor to generate the bonding between these two building construction materials. In the case of using glass fiber as reinforcement material to improve the resistance capacity of plain concrete under an axial or flexural tension forces, bonding forces at the interface between the glass fiber and the concrete matrix must be satisfactory. Bonding forces between these two materials are generated due to friction forces at the interface; therefore the final evaluation of the bonding forces is related with the real value of the friction forces, consequently the friction coefficient value between glass fiber and the concrete is important to evaluate and calculate the real value of friction forces. This paper is devoted to introduce an experimental studies about the mechanism of glass fiber removing from concrete matrix which are named (pull-out tests) as well as a programming simulations prepared to represent this mechanism too, theses laboratory experiments and computer simulations have been used in determination process of the friction coefficient value between the glass fiber and the concrete matrix Friction Predicted value of friction coefficient between glass fiber and the concrete equal to 0.2. Evaluation of bonding forces between glass fiber and the concrete is related directly with the value of friction coefficient between these two building construction materials.

2.2 Critique :-

 From the past researches it is observed that the use of Alkali Resistant Glass fiber is implemented in concrete, but the use of Alkali Resistant Glass fiber concrete composites are quite small. It is reviewed that Alkali Resistant Glass fiber concrete causes less deterioration in the structure as compared to plain concrete, but the Alkali Resistant Glass fiber concrete improves the overall performance of the structure and also prevents the structure from the corrosion.

So in the present research work to improve the properties of RCC Precast Pipe composites some new techniques are implemented. Including steel bar reinforcement with Alkali Resistant Glass fiber are used to improve Quality.     

2.3 Objectives of the study :-

The current investigation aims to study the behavior of Alkali Resistant Glass Fiber on Strength of Precast RCC Pipe mainly used in Underground Sewerage collecting  Network / culverts  .

The main properties of interest is comparison study  between the conventional  and Modified Alkali Resistant Glass Reinforced RCC Pipe  regarding  Strength, Crack control in Precast RCC pipes.

CHAPTER NO 3

PROBLEM FORMULATION AND METHODOLOGY

3  

PROBLEM  FORMULATION AND METHODOLOGY

3.1 Problem Formulation  &  Methodology -

 Designing the Proposed Grade of concrete M35 as per IS-10262 :2009 and casting the  Cube of different content Percentage of Alkali Resistant Glass Fiber  with respect to weight of Concrete (e.g  0% , 0.25% , 0.50% , 0.75% & 1 %) and after testing the compressive strength & Flexural strength  at 7 days and 28 (days with the help of accelerated curing tank)  plot the graph for the Optimum Percentage of Alkali Resistant Glass Fiber content and At the Optimum Content Casting RCC pipe as per IS 458 :1982 specification of Precast RCC Pipe and Testing pipe and compare the conventional Precast RCC  pipe & Modified Alkali Resistant Glass fiber Concrete pipe and compare the results.

3.2 Alkali Resistant Glass Fiber Reinforced concrete

Alkali Resistant Glass Fiber Reinforced concrete is a composite material made from combination of both concrete and Alkali Resistant Glass fiber which bonded together produce a composite with exceptional resistance to wear and tear. Glass reinforced  concrete has relatively good strength and resistance to impact. When used in  construction in developing countries, it can provide better resistance to fire, earthquake, and corrosion than traditional materials. It has been popular in developed countries because the technique can be learned relatively quickly.

3.3 Preparation of Glass fiber reinforced concrete :-

It includes two types of preparation Methods

• Spray up Glass Fiber reinforced Concrete.

• Pre mix Glass Fiber reinforced Concrete.

3.3.1    Spray up Glass Fiber reinforced Concrete:-

In the spray-up method, cement/sand mortar and chopped glass fibers are simultaneously pre-mixed and deposited from a spray gun onto a mold surface. The GFRC architectural panel industry sets an absolute minimum of four percent AR-glass fibers by weight of total mix as a mandatory quality control requirement. The spray-up process can be either manual or automated. Virtually any section shape can be sprayed or cast. This enables architects to design and manufacturers to produce aesthetically pleasing and useful component.

Fig 3.1 Photograph of Spray up Glass reinforced Concrete

3.3.2 Pre mix Glass Fiber reinforced Concrete:-

The premix process consists of mixing cement, sand, chopped glass fiber, water  together into a mortar, using standard mixers, and casting with cast-molding, the mortar into a product.

Fig   3.2   Photograph of Pre mix Glass reinforced Concrete

3.3.3 Raw material test for Concrete:-

1) For Aggregate 10mm Size :- Method of Test as per IS:2386 (Part I)

Sr No. IS Sieve Size

(mm) Actual Wt. Retained  (gm) Cumulative  Wt. Retained  (gm) Cumulative  % Wt. Retained  (gm) Percentage Passing

(%)

1 12.5 0 0 0.00 100

2 10 481 481 9.62 90.38

3 6.3 3850 4331 86.62 13.38

4 4.75 538 4869 97.38 2.62

5 2.36 103 4972 99.44 0.56

6 Pan 28 5000 100.00 0.00

Conclusion :-

Properties Result Method of Testing

Water Absorption (%) 0.64 IS:2386 (Part III)

Specific Gravity 2.73 IS:2386 (Part III)

Bulk Density 1.386 IS:2386 (Part III)

2) For  Fine Aggregate  :- Method of Test as per IS:2386 (Part III)

Sr No. IS Sieve Size

(mm) Actual Wt. Retained  (gm) Cumulative  Wt. Retained  (gm) Cumulative  % Wt. Retained  (gm) Percentage Passing

(%)

1 4.75 105 105 10.50 89.50

2 2.36 72 177 17.70 82.30

3 1.18 110 287 28.70 71.30

4 600 mic. 350 637 63.70 36.30

5 300 mic. 240 877 87.70 12.30

6 150 mic. 86 963 96.30 3.70

7 75 mic. 17 980 98.00 2.00

8 Pan 20 1000 100.00 0.0

Conclusion :-

Properties Result Method of Testing

Zone II IS:383

Fineness Modulas 3.05 IS:383

Water Absorption (%) 1.30 IS:2386 (Part III)

Specific Gravity 2.55 IS:2386 (Part III)

Bulk Density 1.65 IS:2386 (Part III)

3) For Cemet :- Kamal cement SRC as Per IS:4031

Sr. No. Test Conducted Testing Result Requirement as Per IS:12330

1 Standard Consistency (%) 28.50 28 – 32

2 Fineness (%) 3.0 10 (Max.)

3 Initial Setting time (minutes) 185 30 (Min)

4 Final Setting time (minutes) 220 600 (Max.)

4) Mix Design:- M-35 Grade of concrete

Grade Designation M-35

Type of cement SRC

Maximum size of Aggregate 10 mm

Workability 40mm Slump

Exposure condition Very sever

Method of Concrete Placing Manual

Degree of supervision Good

Test data for Material:-

Cement Used Kamal SRC

Specific Gravity of cement 3.15

Specific Gravity of Coarse Aggregate-10 mm 2.79

Specific Gravity of Fine Aggregate 2.55

Water Absorption of Coarse Aggregate10mm 0.64%

Water Absorption of Fine Aggregate 1.34%

Target Mean strength of concrete                   : 43.25 N/mm2

Water Cement Ratio                                        : 0.45

Cement Concrete Mix Proportion by volume :  (1:1.35:2.37)

Slump                                                               :40 mm

Material Required Per Bag of cement :

1) Cement                               :50 Kg

2) Fine Aggregate                   :67.26 Kg

3) Coarse Aggregate (10mm) :118.20 Kg

4) Water                                  :24.15 Kg

After  complete the mix design we have decide the dosage (as 0%,0.25%,0.50% & 1%) for alkali resistant glass fiber in the concrete & tested  for compressive & flexural strength at 7 days and 28 days with accelerated curing tank .

3.4      Casting of  Concrete Cube & beam by pre mix method

The beam was prepared by using Compressive & flexural strength testing mould and use accelerated curing tank for testing. Some specifications for casting of beams are as follows,

• Beam size taken - 150mm*150mm*700mm

• Cube size taken - 150mm*150mm

• Mix proportion for concrete – (1:1.35:2.37) (For M35 grade concrete)

• Water: cement ratio (by mass) - 0.45

Fig 3.3: Casting of Glass fiber Reinforced Beam

Fig 3.4: Casting of Glass fiber Reinforced Cube

Casting the IS standard Concrete cube & Beam with alkali resistant Glass fiber and without containing the alkali resistant Glass fiber(By pre mix method) with different percentage to the weight, weight of concrete and mix the glass fiber properly uniformly distributed thoroughly throughout the concrete , so it is dispersed uniformly in concrete and working properly the fiber which have perpendicular to the loading causes more resistant and crack resistant  compare to the fiber which was dispersed parallel to the loading then find the optimum percentage of Glass fiber (e.g 0% , 0.25% , 0.50% & 1.0% ) .Based on the above experimental investigation it is found that at 0.75 % of Alkali resistant glass fiber show optimum effect of glass fiber in Glass fiber reinforced concrete which is used in further for making the Alkali resistant glass fiber reinforced RCC Spun (Hume)  pipe of different Diameter and observe the effect of glass fiber in RCC spun (Hume) pipe.

3.5    Accelerated curing tank.

The advantages of accelerated curing tank is that give the early 28 days compressive strength in 28 hours as per instruction given in IS code  9013 : 1978  as  well  as also give the 28 days flexural strength also in 28 hours as per instruction  given in IRC 85 :1983. There are two methods to use the accelerated curing tank one is warm water method and another is boiling water method .In this research work we have use the boiling water method in acceleration curing tank to find out 28 days compressive and flexural strength within early 28 days. Accelerated curing tank test procedure as per IS 9013:1978 in which the casted specimens (cubes and beam ) kept in a humid environment  (90% humidity and 27+2oC temperature for 23 hours + 15 minutes ) time  counted from the time of addition of water into the other ingredients.  Casted specimens gently and slowly lowered into the accelerated curing tank containing boiling water and kept in that condition for 3 ½ hours + 5 minutes. After this specimens removed from the boiling water in accelerated curing tank, then removed from the mould and cooled by put in curing pond in water (27+2oC temperature)  for  2 hours.  The specimens tested for compressive and flexural strength.   

Fig 3.5: Accelerated Curing tank with specimen

3.6      Economics

 Initially cost is high comparatively but overall advantage of Glass fiber concrete structures is that they are stronger and more durable than some traditional concret. Glass fiber reinforced concrete structures with critical complicated shape can be built quickly by spray up as well as premix process, which can have economic advantages but also time saving. In odd weather conditions, the ability to withstand and  durable . Glass fiber reinforced concrete is used often because the constructions made from it  also resistant to earthquakes. Earthquake resistance is dependent on good construction technique and additional reinforcement of the concrete.

3.7     Advantages

The advantages of a well built Glass fiber Reinforced concrete construction are the low weight, reduced maintenance costs and long lifetime in comparison with purely steel constructions. When a Glass fiber concrete is mechanically overloaded, it will tend to fold instead of break or crumble like stone or pottery. So it is not brittle. This is also durable and give well performance in acidic as well as alkaline condition. Much depends on techniques used in the construction.

(a) Its basic raw materials are readily available in most countries including alkali resistant glass fiber.

(b) The manufacturing process is very simple without use of any heavy or complicated equipment.

(c) It can be used in saline and alkaline areas very effectively due to alkali resistant glass fiber.

(d) This is very effective in the water logged areas to reduce the ground water table use as a porous pipes.

(e) The initial cost is high but its give better performance overall like strength and durability aspects.

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