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
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
Tensile strength, ksi
Modulus of elasticity, ksi
Strain at break, percent 2.46
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
------------------------------------------------------------------------------------------------------- 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.
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.
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