International Conference on“Structural Engineering &Construction Management” SECM-2016

Organized byDepartment of Civil Engineering MarAthanasius College of Engineering, Kothamangalam, Ernakulam, Kerala

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Int. J. Engg. Res. & Sci. & Tech. 2016 Jatin Zia and Sachin Paul, 2016

BOND STRENGTH, ABRASION ANDPERMEABILITY TEST ON FIBRE REINFORCED

REPAIR CONCRETE

The R.C.C structures are subjected to various durability problems such as spalling, erosion,wear, cracking, corrosion, etc., years after its construction. In the case of hydraulic structures,the mains causes of degradation are due to abrasive processes and cavitation damages. Thehydraulic structures mostly affected by abrasive processes are surfaces of spillways, stillingbasins, walls of upstream reservoir and hydraulic tunnels. The major characteristics a hydraulicrepair material should possess is abrasion resistance, low permeability and high bond strength.This paper aims to determine the best suitable polymer and its optimum dosage for repair ofhydraulic structures. The polymers used for the study are Acrylic polymer and SBR latex. Thefibres used were Polypropylene.

Keywords: Acrylic polymer, SBR latex, Polypropylene fibre, Repair, Spillway

INTRODUCTIONThe durability of a concrete structure is affectedby the physical and chemical effects of where itoperates. An adequate repair improves thefunction and performance of the structure,restores and increases the strength andstiffness, improves the appearance of theconcrete surfaces, provides impermeability towater, prevents penetration of aggressivespecies at the interface of concrete and steeland improves its durability. Maintenance ofstructures on surfaces of concrete dams should1 PG Student, Department of Civil Engineering, Mar Athanasius College of Engineering, Kothamangalam, India.2 Assistant Professor, Department of Civil Engineering, Mar Athanasius College of Engineering, Kothamangalam, India.

Int. J. Engg. Res. & Sci. & Tech. 2016

be done by combining the characteristics ofcoast, feasibility, performance, durability, usage,time of application of materials and compatibilitybetween them.

Abrasion is caused by the impact of elementstransported by water in the hydraulic structuresof concrete. The main factors affecting abrasionresistance of concrete are environmentalconditions, surface finish, curing conditions,dosing of aggregates, mix ratio, use of specialelements such as adding fibre 0 and fly ash. Nomatter how carefully the spillway surface is

Jatin Zia1* and Sachin Paul2

*Corresponding Author: Jatin Zia jatinzia@gmail.com

ISSN 2319-5991 www.ijerst.comSpecial Issue, Vol. 3, No. 1, April 2016

International Conference on “Structural Engineering &Construction Management” SECM-2016

Organized by: Department of Civil Engineering Mar AthanasiusCollege of Engineering, Kothamangalam, Ernakulam, Kerala

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Research Paper

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finished, the waviness creeps in resulting incavitation pitting.

Maintenance done using normal concrete willnot be economically as well as structurally befeasible as the recovery services of hydraulicstructures are usually expensive. Repair doneusing fibre reinforced concrete improves abrasionresistance but does not possess adequate bondstrength and permeability characteristics.Previous studies conducted by introducingpolymers into fibre reinforced concrete haveshown that it enhances the abrasion andpermeability characteristics of concrete. Whenthe polymers are added to the concrete, the poresget reduced or sealed by the formation of acement-polymer matrix.

The concept of polymer modification toconcrete was introduced by Cresson. The firstpatent with present concept of polymermodification was published by Lefebure in 1924.Since then, considerable research anddevelopment of polymer modification forconcrete have been conducted in variouscountries. A previous study conducted on SBRlatex revealed the optimum usage is 5% byweight and the overall porosity and pore sizedistribution of the composites vary with the SBRcontent. A study on the effect of polymer on thepaste-aggregate interface showed that thinpolymer coatings on aggregate have significanteffect on the micro-cracking behavior ofconcrete. A study on the abrasive resistance ofconcrete micro-reinforced with polypropylenefibres showed that the abrasive resistance isan inverse function of water-cement ratio. Amodified slant shear test was developed todetermine the adhesion between concrete layerscasted at different times, since the failuresobtained from the previous tests were cohesive.

The modified slant shear test was developed toenforce only adhesive failure.

MATERIALS, SPECIMENPREPARATIONS AND TESTVARIABLESMaterial CharacterizationAcrylic and SBR latex with density of 1.03 kg/land 1 kg/l are used for the study. Locally availablefine and coarse aggregates are used for the study.Specific gravity of coarse and fine aggregates arein the range of 2.78 and 2.58 respectively. Theaspect ratio of polypropylene fibres used for thestudy is 300.

Mix DesignMix proportion were selected based on the previousstudies conducted on polymer modified fibrereinforced concrete [] and the recommendationsfrom the polymer manufacturer. Like theconventional concrete mix design, aggregatescomposed 75-80% of the total mass. M 30 mixwas adopted for the entire experimental work.Polypropylene dosage was selected based on thetest results conducted with various fibre dosages(0.5%, 1%, 1.5% and 2%). Polypropylene dosageof 1% by volume of cement was kept as the fibredosage throughout the experiment since it yieldedbetter results. Both Acrylic and SBR latex wereadded at 5%, 10% and 15% dosages. The effectof polymers on fibre reinforced concrete howeverdepends on the monomer ratio of the polymers.On increasing the dosage of polymer, there wasan increase in the workability in concrete. The mixproportion details are given in Table 1.

Specimen PreparationThe specimens for compressive strength, flexureand split tensile strength were casted at variouspolymer dosages and were cured for 28 days.

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Int. J. Engg. Res. & Sci. & Tech. 2016 Jatin Zia and Sachin Paul, 2016

The parent concrete for Slant shear strength andCylinder splitting specimens (bond strength) werecasted with M 30 concrete. The overlay concretewas casted over the parent concrete after 28 daysof curing of the parent concrete. The slant sheartest was done in accordance to ASTM standardsC882/C882M-13a. The size of the slant shearspecimens were 100 mm × 100 mm × 300 mm.The sizes of the cylinder splitting specimens were150 mm × 300 mm. The specimens for abrasiontest were casted with a size of 68 mm × 68 mm× 30 mm. The specimens used for permeabilitytest were of size 100 mm × 100 mm × 100 mm.

RESULTS AND DISCUSSIONBond StrengthThe bond strength was higher for 15% polymerdosages of both SBR and Acrylic polymers. The

Designation Cement (kg) FA (kg) CA (kg) Water Fibre (kg) Polymer (kg)

ACP 1 & SB 1 438.78 692.957 1221.15 157.6 1.306 21.939

ACP 2 & SB 2 438.78 692.957 1221.15 157.6 1.306 43.878

ACP 3 & SB 3 438.78 692.957 1221.15 157.6 1.306 65.817

Table 1: Mix Design of Polymer Modified Fibre Reinforced Concrete

Figure 1: Roughened Surface of Specimens

Figure 2: Slant Shear Specimen

bond strength is affected by the effect ofcompressive stresses and combined shear andtheir relaxation by the polymer films formed on

Figure 3: Variation of Bond Strength of SlantShear Specimens

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Int. J. Engg. Res. & Sci. & Tech. 2016 Jatin Zia and Sachin Paul, 2016

the bonding joints. The cylinder splitting strengthshowed that with an increase in polymer content,there is an increase in the bond strength ofconcrete.

AbrasionThe abrasion resistance depends upon the typeof polymers, polymer-cement ratio, abrasion andwear conditions. The abrasion resistanceimproved by 25% for Acrylic polymer dosage and30% for SBR polymer dosage.

Figure 4: Casting of Cylinder SplittingSpecimen

Figure 5: Cylinder Splitting Specimens

Figure 6: Variation of Bond Strengthof Cylinder Splitting Specimens

Figure 7: Measurement of Thickness

Figure 8: Abrasion Testing Machine

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PermeabilityPolymer modified fibre reinforced concrete havea structure where the larger pores can be filledwith polymers or sealed with continuous polymerfilms. The effect of filling or sealing increases withincrease in polymer-cement ratio. Acrylic modifiedfibre reinforced concrete showed a decrease in58.6% permeability whereas SBR modified fibrereinforced concrete showed a 60% decrease inpermeability at 15% polymer dosage.

CONCLUSIONThe repair works of hydraulic structures areextremely expensive and the material used forthe repair work should be structurally andeconomically feasible. The polymer modifiedconcrete should not only provide resistance toabrasion and permeability but it should alsoposses adequate bond strength. The addition ofpolymers improves the structure of the concreteby filling up the pores and forms a polymer-cement matrix throughout. Even though, largevarieties of polymers are available in the market,polymers with maximum immersion ratioimproves the mechanical, bond strength,abrasion and permeability properties of concrete.Based on the experiments conducted, thefollowing conclusions were drawn.

1. There is an inverse relation between Polymer-cement ratio and water-cement ratio.

2. The addition of polymers improves theworkability of concrete.

3. The bond strength increases with the polymercontent in the concrete.

4. Abrasion resistance increases with increasein polymer dosage. The addition ofPolypropylene fibres also aids in improving theabrasion resistance.

Figure 9: Abrasive Powder

Figure 10: Percentage Decreasein Thickness

Figure 11: Comparison of Permeabilityof Various Mix Samples

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5. Polymer addition improves the microstructureof concrete by filling up the pores and therebyreduces the permeability of concrete.

REFERENCES1. Awchat G D and Kanhe N M (2013),

“Experimental Studies on Polymer ModifiedSteel Fibre Reinforced Recycled AggregateConcrete”, International Journal ofApplication Innovation in Engineering &Management (IJAIEM), Vol. 2, No. 12,pp. 126-134, ISSN 2319 – 4847.

2. Diamanti M V, Brenna A, Bolzoni F, Berra M,Pastore T and Ormellese M (2013), “Effectof Polymer Modified Cementitious Coatingson Water and Chloride Permeability inConcrete”, Construction and BuildingMaterials, Vol. 49, pp. 720-728.

3. Gengying Li, Xiaohua Zhao, Chuiqiang Rongand Zhan Wang (2010), “Properties ofPolymer Modified Steel Fiber-Reinforced

Cement Concrete”, Construction andBuilding Materials, Vol. 24, pp. 1201-1206.

4. Marinela B Arbut and Maria Harja (2008),“Properties of Fibre Reinforced PolymerConcrete”, Construct, Arhitectura.

5. Seung-Wan Son and Jung Heum Yeon(2012), “Mechanical Properties of AcrylicPolymer Concrete ContainingMethacrylicacid as an Additive”, Constructionand Building Materials, Vol. 37, pp. 669-679.

6. Vincent Morin, Mariette Moevus, IsabelleDubois-Brugger and Ellis Gartner (2011),“Effect of Polymer Modificationof the Paste–Aggregate Interface on the MechanicalProperties of Concretes”, Cement andConcrete Research, Vol. 41, pp. 459-466.

7. Zoran J Grdic, Gordana A Toplicic Curcic,Nenad S Ristic and Iva M Despotovic (2012),“Abrasion Resistance of Concrete Micro-Reinforced with Polypropylene Fibres”,Construction and Building Materials, Vol. 27,pp. 305-312.