International Research Journal of Engineering and Technology (IRJET) Volume: 04 Issue: 02 | Feb -2017
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e-ISSN: 2395 -0056 p-ISSN: 2395-0072
A STUDY ON STRENGTH CHARACTERISTICS OF GLASS FIBRE REINFORCED HIGH PERFORMANCE-CONCRETE Dayalan J 1Senior
Assistant Professor, Department of Civil Engineering, New Horizon College of Engineering, Bengaluru
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Abstract - Plain concrete possess very low tensile strength,
is especially dangerous when subjected to explosive force because ballistic debris is created which can create significant collateral damage. This is not the case with GRFC, as it does not experience brittle failure. The glass fiber tends to hold the material together because the fibers are dispersed randomly and lay in all directions within the material matrix. GFRC has a dramatically reduced ballistic debris profile. In this study , it is decided to experiment find out the strength and durability of the Glass Fibre Reinforced Concrete made using Portland Pozzolana Cement for assessing its suitability for Marine and Hydraulic Constructions. Deshmukh et.al.has studied in his paper ‘Effect of Glass Fibres on Ordinary Portland cement Concrete’(2012) [1] that the glass fiber of 0 %, 0.03%, 0.06% and 0.1 % by volume fraction of concrete were used and the results have shown improvement in mechanical and durability properties with the addition of glass fibers. It is observed that compression, flexural and split tensile increased with increase in percentage of glass fiber. Neel Shah stated in his paper ‘Tensile Strength of High Performance Concrete Using Supplementary Cementing Material and Glass Fiber’(2013) [2] that the concrete without any fibres will develop the cracks due to plastic shrinkage, drying shrinkage. This paper outlines the experimental investigation of Splitting Tensile Strength for HPC mixes of grade M25 and M30 by replacing 0, 30, 40, and 50 percentage of the mass of cement with Fly Ash and 0.1, 0.2 percentage of Glass Fibre and using a super plasticizer. It is observed that 0.2% glass fibre in different grade of concrete give better performance in strength aspect at the age of 7,28 and 56 days. As compared to the plain concrete of M25 grade split¬ting tensile strength reduced about 6%, 10% and 14% respectively 30%, 40% and 50% of fly ash with 0.2% glass fibre at 56 days. It is also observed that split tensile strength decrease with the high replacements of fly ash with cement in concrete. Philipp Löber conducted experiment titled ‘Structural Glass Fiber Reinforced Concrete for Slabs on Ground’(2014) [3] focussing on the design of a glass fiber reinforced concrete for structural components and the study of the suitability of this concrete in slabs on ground. Materials used include superplasticiser “Muraplast FK 43” and AR-macro glass fibers. The flexural bearing capacity of glass fiber reinforced fine concrete or mortar is determined on thin plate stripes in four-point bending tests. They found out a 40% increase of fiber content results in a 59% increase of flexural strengths. The influence of mixing time on the residual tensile strength decreases with increasing fiber content, but plays an important role in the production of
limited ductility and little resistance to cracking. Fibres when added in certain percentage in the concrete improve the strain properties, crack resistance, ductility, flexure strength and toughness of plain concrete. Majority of studies and research in fibre reinforced concrete has been devoted to steel fibers. But in recent times, glass fibers have become available, which are free from corrosion problem which is associated with steel fibers. In order to prevent the damage of concrete exposed to a marine environment and in hydraulic structures, the measures adopted include: reducing the water-cement ratio by using super plasticizers; employing Portland Pozzolana cement; use of glass fibre preventing corrosion and holding the composite together against freezing and thawing. The present study is an experimental investigation conducted on concrete composites of M30 and M40 grades, using glass fibres and Portland Pozzolana cement, best suited for marine and hydraulic structures. Cem-fill anti crack, high dispersion, alkali resistance glass fiber have been employed in percentages varying as 0.03, 0.06, and 0.1 percentage by volume of concrete. The strength and durability properties of this composite, at 7 days and 28 days curing, in terms of properties like compressive strength, flexure strength and split tensile strength were studied Key Words: Glass Fibre, Pozzolana cement, Strength properties, marine environment
1.INTRODUCTION Fiber Reinforced Concrete is a composite material consisting of a matrix containing a random distribution or dispersion of small fibres, having a high tensile strength. Due to the presence of these uniformly dispersed fibres, the cracking strength of concrete is increased and the fibres acting as crack arresters. Fibers when added in certain percentage in the concrete improve the strain properties well as crack resistance, ductility, as flexure strength and toughness. Alkali resistant glass fibre prevents corrosion and helps improve concrete properties. Like increase tensile strength, improve resistance to impact, increase shear strength, better water resisting properties. Glass fibers weight is much lighter than when steel is used in concrete. Good freeze-thaw resistance helps protect varying climatic conditions at marine environments in very cold countries. Conventional concrete has the trait known as "brittle failure" because it has a semicrystalline structure, which tends to shatter on impact. This
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