INDEX 1.INTRODUCTION 1.1 FIBER REINFORCED CONCRETE 1.2 POLYMER FIBER REINFORCED CONCRETE (PFRC) 2. FIBER REINFORCED CONCRETE 3. MATERIALS 3.1 CONCRETE MIX 3.2 POLYMER FIBERS 4. PAVEMENT DESIGN 5. PAVING OPERATION 5.1 FULLY MECHANIZED PAVEMENT CONSTRUCTION 5.2 REQUIREMENTS FOR PAVING OPERATIONS 5.3 CURING 5.4 PROTECTION AND MAINTANANCE 6. A CASE STUDY – POLYESTER FIBER WASTE IN PFRC 6.1 EXPERIMENTAL DETAILS 6.2 TESTS AND RESULTS 6.3 INFERENCES OF THE STUDY 7. ADVANTAGES AND DISADVANTAGES 7.1 ADVANTAGES 7.2 DISADVANTAGES 8. COMPARISONS BETWEEN PFRC AND NORMAL 9. APPLICATIONS OF PFRC 10. KERALA BASED PROJECTS USING PFRC 1 11. 12. CONCLUSION REFERENCES CERTIFICATE It is Certify that Abhilash mukharjee, Arun Mishra, Natasha Agarwal, Piyush Sharma, Saurabh Shukla has carried out the project work presented in entitles “POLYMER FIBER REINFORCED CONCRETE PAVEMENTS” for the award of Bachelor Of Technology form Gautam Buddh Technical university, Lucknow under my supervision. The report embodies result of original work and studies carried out by students himself and the contents of the report do not form the basis for the award of any other degree to candidate or anybody else. Mr. P.K Singh SUPERVISOR Lecturer Civil Engineering Anand Engineering College, Agra (U.P) Date: 2 ABSTRACT Road transportation is undoubtedly the lifeline of the nation and its development is a crucial concern. The traditional bituminous pavements and their needs for continuous maintenance and rehabilitation operations points towards the scope for cement concrete pavements. There are several advantages of cement concrete pavements over bituminous pavements. This paper explains on POLYMER FIBRE REINFORCED CONCRETE PAVEMENTS, which is a recent advancement in the field of reinforced concrete pavement design. PFRC pavements prove to be more efficient than conventional RC pavements, in several aspects, which are explained in this paper. The design procedure and paving operations of PFRC are also discussed in detail. A detailed case study of Polyester fiber waste as fiber reinforcement is included and the results of the study are interpreted. The paper also includes a brief comparison of PFRC pavements with conventional concrete pavement. The merits and demerits of PFRC pavements are also discussed. The applications of PFRC in the various construction projects in kerala are also discussed in brief. 3 1. INTRODUCTION In a developing country such as India, road networks form the arteries of the nation. A pavement is the layered structure on which vehicles travel. It serves two purposes, namely, to provide a comfortable and durable surface for vehicles, and to reduce stresses on underlying soils. In India, the traditional system of bituminous pavements is widely used. Locally available cement concrete is a better substitute to bitumen which is the by product in distillation of imported petroleum crude. It is a known fact that petroleum and its by-products are dooming day by day. Whenever we think of a road construction in India it is taken for granted that it would be a bituminous pavement and there are very rare chances for thinking of an alternative like concrete pavements. Within two to three decades bituminous pavement would be a history and thus the need for an alternative is very essential. The perfect solution would be POLYMER FIBER REINFORCED CONCRETE PAVEMENTS, as it satisfies two of the much demanded requirements of pavement material 4 As waste polymers which are produced in large quantities are non bio degradable they can cause immense environmental issues. 5 . to compensate for the lack of ductility and is also adopted to overcome high potential tensile stresses and shear stresses at critical location in a concrete member. It is only common knowledge that. FIBER REINFORCED CONCRETE Concrete is well known as a brittle material when subjected to normal stresses and impact loading. It also has several other advantages like longer life. This is an environment friendly approach in the field of pavement construction as almost all sorts of polymer waste can be recycled and used as a reinforcing admixture in the concrete pavements. Instead of disposing it we can efficiently make use of its properties in the pavement construction. fuel efficiency. economy and reduced pollution. concrete members are reinforced with continuous reinforcing bars to withstand tensile stresses. good riding quality. 2.” The fibers may be of steel. low maintenance cost. increased load carrying capacity and impermeability to water over flexible pavements. FRC is considered to be a material of improved properties and not as reinforced cement concrete whereas reinforcement is provided for local strengthening of concrete in tension region. with its tensile strength being just one tenth of its compressive strength. Fiber reinforced concrete pavements are more efficient than ordinary cement concrete pavement. polymer or natural materials. “FRC is defined as composite material consisting of concrete reinforced with discrete randomly but uniformly dispersed short length fibers. Fibers generally used in cement concrete pavements are steel fibers and organic polymer fibers such as polyester or polypropylene. especially.in India. Glass Fiber Reinforced Concrete SNFRC . woven fabrics and long wires or rods are not considered to be discrete fibers. discrete. Fibers are generally discontinuous. mortar or concrete with discontinuous.Natural Fiber Reinforced Concrete Fiber Reinforced concrete can be defined as a composite material consisting of mixtures of cement. which is a new form of binder that could combine Portland cement in bonding with cement matrices. randomly distributed through out the cement matrices. The introduction of fibers was brought into consideration. 6 . the development of micro-cracks must be controlled to produce concrete with homogenous tensile properties. as a solution to develop concrete with enhanced flexural and tensile strength. SFRC . 2. Referring to the American Concrete Institute (ACI) committee 544 .Steel Fiber Reinforced Concrete GFRC .Synthetic Fiber Reinforced Concrete NFRC . 3. uniformly dispersed suitable fibers. in fiber reinforced concrete there are four categories namely 1.Even though the addition of steel reinforcement significantly increases the strength of the concrete. 4. Continuous meshes. The amount of fibers added to a concrete mix is measured as a percentage of the total volume of the composite (concrete and fibers) termed volume fraction (Vf). fiber materials. Fibers which are too long tend to “ball” in the mix and create workability problems. whereas organic fibers include natural fibers like coconut. distribution.1 to 3%. orientation and densities. Aspect ratio (l/d) is calculated by dividing fiber length (l) by its diameter (d). nylon. jute. Fibers are usually used in concrete to control plastic shrinkage cracking and drying shrinkage cracking. Fiber reinforced concrete is defined as a composite material consisting of concrete reinforced with discrete randomly but uniformly dispersed short 7 . they help to carry the load by increasing the tensile strength of the material. abrasion and shatter resistance in concrete. If the modulus of elasticity of the fiber is higher than the matrix (concrete or mortar binder). Aramid. Within these different fibers the character of fiber reinforced concrete changes with varying concretes. They also lower the permeability of concrete and thus reduce bleeding of water. Some types of fibers produce greater impact. Fibers may generally be classified into two: organic and inorganic. sugarcane. polypropylene. carbon. It contains short discrete fibers that are uniformly distributed and randomly oriented. etc and synthetic fibers based on acrylic. and polyester. wood. bamboo. sisal. Vf typically ranges from 0. polyethylene. Inorganic fibers include steel fibers and glass fibers. Fibers with a non-circular cross section use an equivalent diameter for the calculation of aspect ratio. geometries.Fiber reinforced concrete (FRC) is concrete containing fibrous material which increases its structural integrity. fibers are distributed uniformly in concrete.95 (1 cement: 1. tapping.42: 1. Steel Fiber Reinforced Concrete Steel fibers have been used for a long time in construction of roads and also in floorings.length fibers. impact resistance. Specifications and nomenclature are important for a material to be used as the tenders are invited based on specifications and nomenclature of the items. Such nomenclature is not available in Delhi Schedule of Rates. polymer or natural materials. Fiber reinforced concrete is considered as a material of improved properties and not as reinforced cement concrete whereas reinforcement is provided for local strengthening of concrete in tension region. fatigue resistance.95 stone aggregate 10 mm and down gauge of fineness modulus 5. and finishing but excluding the cost of steel fibers which shall be paid separately. it has better properties to resist internal stresses due to shrinkage. Fibers generally used in cement concrete pavements are steel fibers and organic polymer fibers such as polypropylene and polyester. ductility also improve. particularly where heavy wear and tear is expected. As fibers improve specific material properties of the concrete. Providing and laying 40 mm steel fiber reinforced cement concrete in pavement (in panels having area not more than 1. 8 . In a work where steel fiber reinforced concrete was used for overlays just like flooring.99) over existing surface i/c cement slurry. Woven fabrics. flexural strength.95 coarse sand of fineness modulus 2. The fibers can be made of steel.5 sqm) consisting of steel fiber @ 40kg per cubic meter of concrete and cement concrete mix of 1:1.95:1. toughness. bars. and continuous wire mesh are not considered discrete fibers. consolidating. the following nomenclature can be adopted for concreting of small thickness. Since in Fiber reinforced concrete. long wires. though cannot be done in small thickness like 40 or 50 mm but can be used if thickness is 100 mm or more. 9 .45 mm in cement concrete duly cut into pieces not more than 25 mm in length. Even. no corrosion has been observed in the steel fibers. The fiber reinforced concrete has been provided in small panels considering the workability. In fact the concreting has been done just like flooring item in this case over already existing hard surface.complete as per direction of Engineer in Charge (Cement to be used shall be OPC 43 grade and sand and aggregate have to be washed). Second item of fibers was provided separately as “Providing and mixing steel fibers of dia 0. Though vacuum dewatered concrete has not been done with steel fiber reinforced concrete but the same is also possible. The construction was carried out more than a decade back.” Though the item of steel fiber reinforced concrete has been provided with a design mix of concrete. in case of the concrete of more than 75 mm thickness. the stone aggregates used were of 10 mm size and below however. In such a case a bonding coat should also be provided like a coat of cement slurry. Since in the executed item. It isobserved that the performance of the concrete is satisfactory even after many years of construction (Figure 1). Vacuum dewatered concrete. it can now be used of mix like M30 or M35. stone aggregates of 20 mm grading can be used. which is almost of 1:2:2 grading. the thickness was to be restricted. It accomplishes improved durability and reduced surface water permeability of concrete. can also be used as fiber reinforcements. Recron 3s. and polypropylene. A uniform distribution of fibers throughout the concrete improves the homogeneity of the concrete matrix. which inhibits the migration of cement and sand to the surface and the benefits of the above will be harder. It also helps to achieve reduced bleeding of water to surface during concrete placement. but PFRC is a suitable material which may be used for cement concrete pavement as it possesses extra strength in flexural fatigue and impact etc. more durable surface with better abrasion resistance. greater impact resistance.2. Various forms of recycled fibers like plastic. The polymeric fibers commonly used are polyester. carpet waste and wastes from textile industry. improved ductility and distinctive post cracking behavior prior to failure. enhanced flexural strength and tensile strength of concrete. The usage of fibers in combination with concrete also results in a mix with improved early resistance to plastic shrinkage cracking and thereby protects the concrete from drying shrinkage cracks. and Forta Econo net. It also facilitates reduced water absorption.1 POLYMER FIBER REINFORCED CONCRETE (PFRC) Polymeric fibers are gaining popularity because of its properties like zero risk of corrosion and cost effectiveness. restricting the development of cracks and thus transforming a brittle material into a strong composite with superior crack resistance. It enables easier and smoother finishing. The use of polymer fibers with concrete has been recognized by 10 . Concrete pavements may be weak in tension and against impact. disposed tires. These fibers act as crack arresters. It reduces the risk of plastic settlement cracking over rebar. Polymer fiber reinforced concrete (PFRC) was used on two sites with ready mix concrete and Vacuum dewatering process. "Providing and laying ready mix fiber reinforced cement concrete of M35 grade (The concrete shall also have minimum works test beam 11 .7.the Bureau of Indian Standards (BIS) and Indian Road Congress and is included in the following Standard documents: IS:456:2000 – Amendment No. 2007 IRC:44-2008 – Cement Concrete Mix Designs for Pavements with fibers IRC:SP:76:2008 – Guidelines for Ultra Thin White Topping with fibers Vision: 2021 by Ministry of Surface Transport. Bangalore • Polymeric fibers are being used now because of their no risk of corrosion and also being cost effective (Sikdar et al. The nomenclature can be used in the works as given here. New Delhi Polymer Fiber Reinforced concrete has been approved by National bodies like: • Central Public Works Department (CPWD) • Airport Authority of India • Military Engineering Services • Defence Airfields • NF/Southern Railway • ISRO. Polymeric fibers normally used are either of polyester or polypropylene. 2005). a lot of concrete water is soaked by WBM and thus the concrete loses the water to WBM and the water which comes out during dewatering/compaction process is not in same quantity asin case of lean concrete. When dewatered concrete it has no problem of water being coming out on surface during compaction process but when it is done over WBM. fiber reinforced concrete was used over a base cement concrete of lean mix of 1:4:8 (Figure 2) while in other site it was laid over water bound macadam (WBM) (Figure 3). In lateral direction. Design Mix shall be got approved from the Engineer in Charge). It appears that it is better to provide base concrete than WBM as the base. shuttering. Both the sites are to be used for parking. brooming and normal curing etc.flexural strength of 40 kg per sqm at 28 days) in required slope and camber in panels i/c shaping at drainage points as required using cementitious materials not less than 435 kg per cum of finished concrete from ACC/L&T/AHLCON/ UNITECH or equivalent batching plant for all leads and lifts with FibercomCF/Fibermesh/Recron or equivalent (100 % virgin synthetic fiber size 12 mm long) to be mixed @ 900 grams per cum of concrete i/c finishing with screed vibration. In both the sites. vacuum dewatered concrete was used. shall be paid separately. It was later observed that cracks have developed in this direction (Figure 4). vacuum dewatering process. grooving etc. floating. No cracks were observed in the direction in which expansion joints were provided assuming this is longitudinal direction. In a site. Cost of centering. 12 . trowelling. The groove was made in one case before setting of concrete and also panels were cast with expansion joints in one direction. complete as per standard manufacturer’s specifications and as per direction of Engineer’s in charge (All related equipment shall be arranged by the contractor. no joints were provided and the width of such panel was about 12 m. As it is known that the width of 12 m is too long for expansion/ contraction. size of panel from one side is about 4 m and from other side it is about 8m. inference can be made that grooves if made in panels of 4m x 4m. no lateral grooves were made. From the site observation. In other case. Later on the grooves were made through cutters. the contractor delayed the cutting of grooves and thereafter the area was occupied due to some urgent requirements. It has been observed that the distance of cracks in one side was almost near to 4 m and on other side at about 7 to 9 m (Figure 5). It has been observed that almost at about one–third of the panel width. horizontal line cracks have been observed indicating that the grooves in other direction are also essential. it is imperative that polymer fiber reinforced concrete should be laid in panels or grooves should be provided so that concrete acts like in panels.e. the cracks in both the directions developed. as working was not a problem due to use of vacuum dewatering process. Thus from this case study also. In both the cases. The cracks were almost in line. it would be appropriate. From this. Cutting grooves is easy as it 13 . it is therefore inferred that the panel should have the size of about 4m x 4m in the temperature conditions of Delhi however small variation can also be made as per site conditions. such cracks developed i. In both the cases. • 3. PFRC has been provided with a design mix of 1:2:2 grading. washed and stone aggregate of 10 mm size with minimum fineness modulus of 5.99 shall be used. Coarse sand of fineness modulus 2. The concrete shall have a flexural strength of 40 kg/m² at 28 days. The size of panels may be kept around 4m x 4m. 14 .can be made after casting of the concrete.1 CONCRETE MIX Cement used shall be OPC 43 grade. But it should not be delayed for long and should be made before concrete achieves its desired strength. Fly ash and ground granulated blast furnace (GGBF) slag is added along with OPC in concrete mixes because they prolong the strength gaining stage of concrete. 3.42. MATERIALS The two components of PFRC are concrete mix and polymer fibers. Water cement ratio shall be as per IS specification mentioned for M30 or M35 grade concrete. The code IRC: 44-2008 is followed for cement concrete mix designs for pavements with fibers. 1.2 POLYMER FIBERS The various polymer fibers that are manufactured specially for improving the properties of concrete that are used for construction of pavements and other construction works are: •Recron 3S •Polypropylene •Forta ferro •Forta econo net 15 .concrete mixing plant (ref:http://cebd.asce.org/cgi) 3.Fig. It should be 100% virgin synthetic fiber size 12mm long and 0. Its melting point is high (about 165 degrees centigrade). These fibers reduce plastic shrinkage and substance cracking.5 to 15 commercially used in concrete. Waste polymer fibers commonly used are: •Plastic •From carpet industry •From textile industry • From disposed tires Polymeric fibers normally used are either polyester or poly propylene. as (100 degree centigrade)for short periods without detriment to fiber properties. It shall be mixed at the rate of 900 gms per cum of concrete. This increase the toughness and post cracking integrity. Polypropylene fibers being hydrophobic and can be easily mixed. 16 . Polypropylene is one of the cheapest and abundantly available polymers. aramid.45 mm diameter. Other fibers used are acrylic. Fibers named Fiber mesh and Recron 3S are now produced by FIBERCOM-CF Company Ltd USA and in India Fibers like polypropylene and Recron 3S are manufactured by Reliance Industries Ltd. Polypropylene fibers are resistant to most chemical attacks. So that it can withstand a working temp.Polymer fiber waste can also be recycled and used for the pavement construction. carbon etc. Polypropylene short fibers in small volume fractions between 0. PAVEMENT DESIGN 17 .org/cg) 4.asce. Various polymer fibers used in concrete (ref:http://cebd.Polyester fibers Polypropylene fibers Nylon fibers Recycled plastic fibers Tire fibers mesh) Polymeric fiber (Fiber Fig 2. An antifriction separation membrane of 125 micron thickness is spread over the DLC surface so as to impart free movement of the upper slab caused due to temperature warping stresses. which is compacted. Over that the Dry Lean Concrete of mix 1:4:8 is made. Many of the thickness design methods for cement concrete pavement adopted internationally derive their origin from the method 18 .asce. leveled and floated.The base coarse of Dry Lean Concrete (DLC) serves as working platform for supporting PFRC slabs which by slab action distributes the wheel load to larger area. Cross section of a typical PFRC pavement (ref:http://cebd. The separation membrane may be stuck to the lower layer with patches of adhesives or appropriate tape or concrete nails with washer so that polythene sheet does not move during placement of concrete. Surface of DLC is also corrected for road camber. Fig 3.org/cgi) Over the well compacted sub grade Granular Sub base is constructed using big stone boulders and mud. The DLC base layer rests on granular sub-base which rest on sub grade. 29E5 19 SR 0.evolved by Portland Cement Association (PCA).47 0.287E6 4. Table 1. it has no problem of water being coming out on surface during compaction process but when it is done over WBM. Due to repeated application of flexural stresses by the traffic loads.2E6 1.73 0.279E7 5. Stress ratio and Allowable Repetitions in cement concrete SR 0. The ratio between the flexural stress due to the load and the flexural strength is termed as the stress ratio (SR).45 0.85E5 2.71 0. When dewatered concrete is provided on lean concrete.69 0.49 0. a considerable amount of water is soaked by WBM and thus the concrete loses the water to WMB and the water which comes out during dewatering/ compaction process is not in same quantity as in case of lean concrete. It appears that it is better to provide base concrete than WBM as the base. The following table shows the experimental results relating repetitions and SR. In this technology thickness of the pavement is assumed on trial basis.53 Allowable Repetitions 6.51 0. progressive fatigue damage takes place in the cement concrete slab in the form of cracks especially when the applied stress in terms of flexural strength of concrete is high.75 Allowable Repetitions 4410 2531 1451 832 477 .67 0. texture and cure the freshly placed concrete in one complete pass of the machine in such a manner that a minimum of hand finishing will be necessary so as to provide a dense and homogenous pavement in conformity with the plans and specifications. Use of highly sophisticated electronic sensors controlled by slip form paving machines consist of power machines. consolidate.83 0. which spreads compacts and finishes the paving concrete in continuous operation.81 0.34E4 7700 0. PAVING OPERATION 5. the concrete pavement is expected to sustain infinite number repetitions.55 0.79 0. 5. of load repetitions required to cause cracking increases.61 0.1 FULLY MECHANIZED PAVEMENT CONSTRUCTION Mechanized construction of PFRC pavement is necessitated for achieving a faster pace of construction and better riding qualities which are otherwise could not be achieved by manual laying techniques.08E4 2. screed and float finish.59 0. As the SR decreases the no.0.85 274 157 90 52 30 If the SR is less than 0.77 0.63 0. 20 . This is also considered in the design of pavement.24E4 4. Concrete shall be placed with slip form pavers with independent unit design to spread.65 1.45.34E4 1. The joint groove is to be protected from ingress of dirt or any foreign matter by inserting performed neoprene sealant. The size of panels may be kept around 4m x 4m which is obtained from comparative studies. Fully mechanized pavers (ref:http://cebd. The is subsequently widened to 8mm width up to a depth of 26 mm to receive the sealant after 28 days curing. so that concrete acts like in panels.Fig 4. Cutting grooves is easy as it can be made after casting of concrete. The work of sawing joints in green concrete should continue even at night so that concrete does not become very hard and thus drying shrinkage cracks may not occur. But it should not be delayed for long and should be made before concrete achieves its desired strength.asce.2 REQUIREMENTS FOR PAVING OPERATIONS 21 . or else grooves should be provided. 5. Cutting of dummy contraction joints of 3mm width after the final set of concrete while partly removing the covering material should be commenced preferably 3-4 hours after paving in summer and 6-8 hours in winter.org/cgi) It is imperative from the studies that PFRC should be laid in panels. After about 1. 5.org/cgi) 22 .5 hours moist Hessian cloth is spread over the surface covered with curing compound spray.3 CURING Membrane curing is applied with the help of texture-cum-curing machine. (3) Concreting work in hot weather should be carried out in early or later hours. Water curing by keeping the Hessian moist by sprinkling water is ensured for 3 days. Fig 5.(1) Use of microfilm or antifriction layer of 125 micron in between PFRC and DLC layers. (2) The DLC layer is to be swept clean of all the extraneous materials before applying microfilm which may be nailed to the DLC layer without wrinkles and holes. (4) The laying temperature of concrete should always be below 35degreeCelsius. The resin based curing compound is used at the rate of 300 ml per square meter of the slab area.asce. Completed PFRC pavement (ref:http://cebd. 5. Further. No vehicular traffic should be allowed to run on the finished surface of a new cement concrete pavement until the completion of 28 days of curing. with thickness of 10cm and 15cm were cast with plain cement concrete (PCC) and polyester fiber reinforced concrete (PFRC). 6.4 PROTECTION AND MAINTANANCE The joint groove is to be protected from ingress of dirt or any foreign matter by inserting performed neoprene sealant. water cement. To exercise a very stringent quality control the test are to be conducted on fine and coarse stone aggregates. granular sub base. Concrete cube specimens were also subjected to abrasion resistance test. concrete pavement slabs of size 3. A CASE STUDY – POLYESTER FIBER WASTE IN PFRC This involves a feasibility study on use of polyester fiber waste as reinforcing admixture in concrete for use in road works. DLC etc as per standards and specification published by Indian roads congress. The slabs were subjected to load deflection test using Falling Weight Deflectometer (FWD).5m x 3. sealing of joints and completion of paved shoulder construction.5m. In this. cube 23 . Tests were also conducted for abrasion resistance and long term compressive strength. in thickness of 100mm and 150mm.a) of 10mm and 20mm. 24 . are non biodegradable. and a pit sand (locally known as badarpur sand). Locally available quartzite aggregate with a maximum size of aggregate (m. A high range water reducing admixture. both with PCC (control concrete) and optimum PFRC (OPFRC) with experimental fibers were cast and tested for deflection by FWD after 28 days of curing. A photograph of the fibers is presented Fig 6. respectively. used in the study were tested for salient properties and the test results are presented in the Table 2.specimens were tested under compression and for their Ultrasonic Pulse Velocity after a period of 2 years. B) Materials Ordinary Portland Cement (OPC) of grade 53 conforming to IS:12269 was used for the studies. The polyester fibers used in this study is primarily a waste product from textile industry and. The discrete polyester fibers of 6 mm length. 6. were used as coarse aggregate and fine aggregate.s.1 EXPERIMENTAL DETAILS A) Methodology A preliminary study on compressive strength and abrasion resistance using different proportions of polyester fibers resulted in an optimum fiber dosage of 0.25 percent by weight of cement. In the present study. conforming to IS:9103 was used to improve the workability of concrete. The long term compressive strength test was carried out to study if there is any reduction in strength due to possible degradation of the fibers in the concrete’s alkaline environment. experimental concrete slabs of size 3500mm x 3500mm. 20 139. mm Aspect Ratio (l/D) Tensile Strength MPa Specific Gravity Test Data 0.asce.Table 2.org/cgi) C) Preparation of PCC and OPFRC mixes A PCC mix was designed for a compressive strength of 40. mm Length (l).0445 6.0 MPa as per IRC 44. The mix proportions are presented in Table 3.33 308 1. Polyester fibers used in the study. 25 .33 Fig 6. Salient properties of the polyester fibers Properties Diameter (D). (ref:http://cebd. 5 in) 870 (1466.Table 3.39) 10-4.394 in) 552 (930. the sub grade (alluvial type of soil) was duly prepared by compacting to its maximum dry density at an 26 DLC 190 (320.16) 689 (1161. The PCC and OPFRC mixes were used for laying the Pavement Quality Control (PQC) slabs.65) 12.37) 146. No 1 2 3 Mix Constituents Cement Fine Aggregate Quantity.75mm (0.25 percent (by weight of cement) fibers of 6 mm length to PCC mix.0 in) 387 (652.5-25mm (0.5mm (< 0.5-1. Mix proportions of pavement quality concrete (PQC) and dry lean concrete (DLC) Sl.787-0. The fibers were added to the dry mix first and then water was added as this method appeared to produce a uniform FRC mix.28) < 12.4 percent by weight of cement The FRC mix was prepared by adding 0.187 in) 552 (930.394-0.42) Coarse Aggregate 20-10mm . kg/ m³ PQC 400 (674.3) (0. D) Laying of experimental pavement slabs Before laying the pavement slabs.2 (256.39) 4 5 Water Super plasticizer 178 (300) 0. for preparation of test specimen for abrasion resistance test and for long term compressive strength.24) 672 (1132. The thickness of DLC was kept uniform at 100 mm. The drying shrinkage of control concrete was 0. A cross-section of the concrete slab structure is shown in fig 7. Fig 7.4 percent. The California Bearing Ratio (CBR) value of the soil was 3. it was strengthened with a base course. The slabs were cast side by side with a small gap in between without any dowel or tie bars. respectively. Typical cross section of the experimental slab. 6. No separation layer was provided between the DLC and PQC layers. as per IRC:SP-49 and its mix proportion are given in table. The shear bond strength of FRC mix with old 27 . Since a sub-grade with CBR less than 6. It also exhibited a significant reduction in drying shrinkage.optimum moisture content.03 percent.2 TESTS AND RESULTS A) Some salient properties of OPFRC from laboratory study OPFRC exhibited increase in 28 day compressive and flexural strength by about 21 percent and 6. A Dry Lean Concrete (DLC) mix was designed for a minimum compressive strength of 10.5 kg/cm2/cm.062 percent while that of the FRC was 0.0 kg/cm2/cm is considered as weak. as compared to control mix.0 MPa at 7 days. each of 3500 mm x 3500 mm size comprising of 2 PCC and 2 OPFRC slabs were laid over the DLC base course. A total of 4 PQC slabs. 3 MPa indicating that the OPFRC was suitable for repair work. The cubes were water cured for 28 days and then left exposed to the laboratory environment. 8000kgf and 12000kgf. 5000kgf. The average of three test specimens was calculated.concrete was 3. which involves impinging the test specimen with a standard sand (abrasive charge) driven by air pressure at 0. The ultrasonic pulse velocity (UPV) of the OPFRC specimen was tested as per IS: 1311-Pt 1 at the respective ages of 28 .e. B) Pavement slab deflection The pavement slabs were tested for deflection under load applied through Dynatest 8000 FWD. The deflection of pavements was measured as per ASTM D 4695-1996 at four impact loads viz. i. centre. The deflections of PCC slabs at centre for thickness of 100 mm and 150mm were observed to be 180 im and 149 im respectively. The deflections are well within maximum deflection limit of 1250 im suggested by the IRC:58.15 percent while the PCC mix resulted in an abrasion loss of 0. The corresponding deflection values for FRC slabs are 207 im and 157 im respectively.20 percent. 4000kgf. The FRC mix exhibited an abrasion loss of 0. edge and corner. D) Long term compressive strength OPFRC cube specimens of 150mm size were also cast at the time of laying of the slabs. The test results indicate that addition of fibers to PCC mix increases the abrasion resistance by 25 percent. at three locations on each slab.14 MPa. The cubes were tested for compressive strength as per IS: 516 after 24 months. C) Abrasion resistance of concrete The abrasion resistance test was carried out on 100 mm concrete cube specimens in a pneumatic sand blasting cabinet conforming to IS: 9284-1979. 28 days and 24 months. indicating that there is no reduction in compressive strength of FRC. concrete sample were taken on eight occasions. The 24 months duration included one summer and one winter season. and M4 was NMFRC.41 km/sec at the age of 28 days and 24 months. They were taken from the chute discharge of the truck and carried in wheelbarrows to the material testing site which was a few hundred feet from the placement location. The OPFRC cube specimens yielded compressive strength of 60.M5 and M7 were control concretes without fibres. three steel fibre reinforced concrete(SFRC). when tested at an age of 28 days and 24 months. Mixtures M1.0 MPa and 60. E) Physical inspection of concrete slabs A visual inspection of slabs after 24 months revealed satisfactory condition of the surface with no cracks or any other defects.4 MPa. There was total of 8 different mixtures: three plain concrete. This indicates that there has not been any surface degradation of FRC slabs. The test specimen exhibited UPV of 4. Mixtures M2. The peak summer day temperature was about 45 degree C and the lowest temperature during winter was around 2 degree C.81 and 4. During the construction. respectively. The concrete samples were taken from randomly selected different trucks. 29 .M3 and M8 were SFRC . 30 . 31 . 32 . 33 . 4. The polyester FRC in thicknesses of 100mm or more can be used for pavements or other similar applications. The polyester fibers are resistant to the strong alkaline conditions in concrete.6. There is no decrease in long term compressive strength or UPV of PFRC. The results of this study promote effective disposal of these non bio-degradable synthetic fibers.3 INFERENCES OF THE STUDY The following inferences are made from this study on FRC made with polyester fibers of 6mm length: 1. 34 . 2. The use of polyester fibers increases the abrasion resistance of concrete by 25 percent making it more suitable for pavements. 3. 1 ADVANTAGES (1) Water logging is a major reason for potholes in roads. (2) Implementation of sensors in roads will be easier while using polymer fibers for concrete. (3) Environmental load of PFRC pavement was found to be significantly lower than the steel fiber reinforced pavement. savings may be up to 35%.7 ADVANTAGES AND DISADVANTAGES 7. WBM and Asphalt roads are permeable to water which damages the road and sub grade. (7) The use of PFRC produces concrete of improved abrasion resistance and impact resistance. (8) PFRC also enhances ductile and flexural toughness of concrete. (6) Fibers reduce plastic shrinkage and substance cracking. Fibers also provide residual strength after cracking occurred. skid resistant pavement. (9) The use of fibers in concrete can result in cement saving up to 10% and in the presence of fly ash. 35 . (4) Maintenance activities related to steel corrosion will be reduced while using PFRC. (5) In fresh concrete polymer fibers reduces the settlement of aggregate particles from pavement surface resulting in an impermeable and more durable. (10) All these advantages result in overall improved durability of concrete. But PFRC roads are highly impermeable to water so they will not allow water logging and water being coming out on surface from sub grade. being a relatively new technology poses a threat of a high initial cost of construction. No 1 2 3 4 5 6 7 8 9 10 Properties Strength Flexural Strength Split Tensile Strength Impact Resistance Abrasion resistance Drying Shrinkage Water Percolation Gain over Normal Concrete Compressive + 12 to 16 % + 7 to 14 % + 7 to 14 % + 40 to 140 % + 25 -48 to 80% -44 to 60 Permeability Nil K. cm/sec Fatigue Life (cycles) Damping under 36 Higher by 230 % 26 % . COMPARISONS BETWEEN PFRC AND NORMAL CONCRETE Sl. 8.2 DISADVANTAGES (1) The use of PFRC.7. APPLICATIONS OF PFRC •Slab On Grade: All types of pavements and overlays.7 % 55 % 9. roads. industrial floors. hangars.2 % 23. etc. taxi ways. 37 .dynamic load) 11 12 13 Energy absorption Young’s Modulus Concrete Strength – NDT by Rebound Hammer 14 Bond strength of old concrete 15 Durability in At par with control concrete after 30 cycles of terms of strength of FRC 16 Checks expansion stress Significant in crack control heating/cooling At par with new concrete + 22. UTL etc •CIAL Airports: Turning Pad Concrete. •Water retaining Structures: RCC retaining walls. ETPs. NCB. 10. cross drains. DGMAPs projects Kochi •Southern Railway: Platforms at Quilon.•Structural Concrete: Foundations (deep and shallow). ports. check dams. jetties. Kochuveli. hydel projects. water tanks. swimming pools. Cargo storage complex •MES: GE Air Force – Tvm Projects. KERALA BASED PROJECTS USING PFRC •ICTT Vallarpadam: Jetty Construction 8000 cub mtr concrete slab/Simplex infra •Cochin Port Trust: Mattanchery Warf. etc •Kerala PWD: Store Purchase of 5000kg – Building and bridges projects •KITCO: Cargo Complex & Arrival bldg of CIAL Airport •Harbour Engineering Dept: Vipin Jetty wearing coat 38 . column beams and lintel. sunken toilets. canal lining. slabs. New Arrival Bldg. bridge decks and girders etc. etc. machine foundation. spillways etc. •Water proofing in rooftops. Its high time that we overcome the resistance and reach for the peaks. Resistance to change though however small disturbs our society. hence we are always reluctant to accept even the best.• IT Parks: Leela IT Park TVM. PFRC requires specific design considerations and construction procedures to obtain optimum performance. Technopark Phase 3 & Technopark Quil 11. communication and in turn contribute to growth and development. road networks ensure mobility of resources. making PFRC cheaper than flexible pavement by 30-35%. CONCLUSION PFRC can be used advantageously over normal concrete pavement. PFRC opens a new 39 . In a fast developing and vast country like India. The higher initial cost by 15-20% is counterbalanced by the reduction in maintenance and rehabilitation operations. Polymeric fibers such as polyester or polypropylene are being used due to their cost effective as well as corrosion resistance. pp194-195 40 . NBM&BW vol 12 pp76-93 3.S. 12. Tata Mc Grawhill Publishing company ltd.S.K. REFERENCES 1. March 2007. “Fiber Reinforced Concrete in Pavements”.AGRAWAL. NBM&CW vol 12.K.hope to developing and globalizing the quality and reshaping the face of the “True Indian Roads”. B.M Soni.Seehra.” An Innovative concrete technological development of fully mechanized construction of cement concrete pavement”. Indroduction to Engineering Materials”. pp 178-181 2. Dr. 4th edition. May 2007.Dr. 111-144. Oxford. Journal for composite for construction vol 8 no. Recent Advancements in Concrete Fiber Composited.1982. South Dakota Department Of Transportation.Ramakrishnan. 1993. Pierre. Singapore. 1995.K. Gopal Krishna. 1995. NBM&BW vol 13. SD94-04-I.. 12. Concrete Fiber Composites For The Twenty-First Century. 1527. BUDHINSKI. July 2007.6 pp 48-488 8. BUDHINSKI. pp. Nov/Dec 2004. 9. SD. Singh. V. st. 12. ACI Committee 506. ACi 544. Ramakrishnan. Reis. V. Editor: G. Nov 2006..”Fracture and flexure characterization of natural fibersreinforced polymer concrete” Construction and Building Materials vol 20 pp 673-678 7.”Key role of chemical admixtures for pavement quality concrete”. Report submitted to the 3M company. Concrete International: Design and Construction. Performance Characteristics of 3M polyolefin Fiber Reinforced Concrete. v. 1993. Concrete Lecture – 1993. Amnon Katz. pp. 2R. December 1984. pp166-169. Singapore Chapter. ACI Manual of Concrete Practice.MN. Real Woeld Concrete. State of the Rt Report on Fiber Reinforced Shotcrete. U.4. 8th edition. 13. American Concrete Institute. 41 . Elsevier Science Ltd. ACI committee 544. 6. Part 5. Measurement of Properties of Fiber Reinforced Concrete.” Engineering materials-Properties & selection”. KENNETH G. 11. V. 10.78. pp 194-195 5. Ramakrishnan. MICHEL K. Ramakrishna... “Environmental impact of steel and FRP reinforced polymer”. V.M. J. 319 pages. paul.L..6 No. Report No. Evaluation of Non-Metallic Fiber Reinforced Concrete in PCC pavement and Structures. Prentice Hall India.
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