International Research Journal of Engineering and Technology (IRJET)
e-ISSN: 2395 -0056
Volume: 04 Issue: 04 | Apr -2017
p-ISSN: 2395-0072
www.irjet.net
EFFECT OF COIR FIBER AND POLYVINYL ALCOHOL FIBER ON DURABILITY PROPERTIES OF ENGINEERED CEMENTITIOUS COMPOSITES R.Sathishkumar 1, S.Ranjith 2 1post
graduate,Dept. of civil engineering,EBET Group of Institutions,Kangayam,Tamilnadu,India Professor, Dept. of civil engineering,EBET Group of Institutions,Kangayam,Tamilnadu,India
2Assistant
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Abstract - Traditional concrete is considered as brittle and rigid, also conventional concrete is not highly durable. The lack of durability of concrete is on account of the presence of calcium hydroxide and the transition zone, which represents the interfacial region between the particles of coarse aggregate and the hardened cement paste. Coir bars are used in concrete members to keep cracks as small as possible. But they are not small enough to heal, so water and deicing salts can penetrate to the coir, causing corrosion that further weakens the structure by affecting the durability. This result is development of engineered cementitious composites. The purpose of this project is to study the Durability properties of Engineered Cementitious Composites. To verify that, in this project Coir fiber and polyvinyl alcohol fiber with various proportions of mineral admixtures such as rice husk ash and silica fume has been used in ECC to study its structural performance and durable properties.
this project, in order to study the durability properties of ECC, the transition zone which exists between the cement paste and coarse aggregate was removed by replacing the coarse aggregates completely with Coir fibers and PVA fibers and their structural performances were studied separately
1.2 Engineered Cementitious Composites
1.INTRODUCTION
ECC is ductile in nature. ECC was prepared in ready mix plant and transported to construction sites and can be placed without the need for vibration due to its selfconsolidating characteristics. ECC is a special type of high performance fiber reinforced cementitious composites that can be designed effectively with the guidance of micromechanics models. ECC has high strain capacity of about 3 to 5% compared to 0.01% for normal concrete. The large strain capacity of ECC is contributed by sequential development of multiple cracks, instead of continuous increase of crack opening. The damage tolerance and controlled crack width of ECC improve the serviceability and durability performance of Infrastructures. ECC has variety of unique properties, including tensile properties superior to other fiber reinforced composites.
Concrete is the most preferred and the single largest building material used by the construction industry. Concrete is basically made of aggregates, both fine and coarse, glued by a cement paste which is made of cement and water. There might be the usage of admixtures in special cases. Concrete can be molded into any shape and size. Conventional concrete is brittle and rigid in nature. It has high compressive strength, low tensile strength, ductility and it is not highly durable. This above property of concrete might lead to some problems if it is practiced in construction sites. The search for an alternative, in order to overcome above problems lead to the formation of Engineered Cementitious Composites (ECC) which is a breed of highperformance fiber reinforced cementitious composites featuring significant tensile strength and ductility. Engineered Cementitious Composites also contributes to high durability. Thus ECC Contribute to safer, more durable and sustainable concrete infra-structure that is cost effective and constructed with conventional concrete equipment. In
These properties are largely due to the interaction between the fibers and cementing matrix, which can be custom-tailored through micromechanics design. In the mix of ECC concrete, the coarse aggregates are deliberately not used because of property of formation of micro cracks with large deflection. The fiber usage creates many micro cracks with a very specific width, rather than large cracks. This micro cracking behavior leads to corrosion resistance as well as to self-healing. In the presence of water, unreacted cement particles that are exposed due to cracking forms a number of products that expand and fill in the cracks. This is the tightly controlled crack width seen in ECC that ensures all cracks thoroughly heal when exposed to natural environment. The pseudo-strain-hardening behavior is associated with the appearance of sequence of matrix cracks increasing in density until composite peak load is reached. The short fiber reinforced composites designed to provide pseudo-strain-
Key Words: engineered cementitious composites, Durability properties, Coir fiber and polyvinyl alcohol fiber, rice husk ash and silica fume
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