Article Strength and Durability Study of Aramid Fibers in Retrofitting of Reinforced Concrete Structure Dr. Rajashekhar S. Talikoti 1 , Sachin B. Kandekar 2 * 1 Professor, Sandip Institute of Engineering and Management, Nashik (MS), India, 422213; rstalikoti@gmail.com 2 Research Scholar, Late G N Sapkal College of Engineering, Nashik, (MS), India, 422212; * Correspondence: sachin.kandekar@avcoe.org; Tel.: +91-9890004028 Abstract: Fiber reinforced polymer (FRP) is one of the important material used for strengthening and retrofitting of reinforced concrete structures. The commonly used fibers are glass, carbon and aramid fibers. Durability of structures can be extended by selecting appropriate method of strengthening. FRP wrapping is one of the easiest methods for repair, retrofit and maintenance of structural element. Deterioration of structures may be due to moisture content, salt water, or contact with alkali solutions. There is significant effect of permeability, rise in temperature, chemical attack, fatigue action, micro pores on members of structures. Using FRP additional strength can be gained by structural elements. This paper investigates durability of aramid fiber subjected to acid attack and temperature rise. Concrete cubes are prepared as specimens with double wrapping of aramid fibers. Diluted hydrochloric acid solution is used for immersion of specimen for curing period of 7, 30 and 70 days. In case of fire resistance test, such specimens are kept in hot air oven at a temperature of 200 0 C at different time intervals. The effect of aramid fiber wrapping on compressive strength and weight loss of specimen is studied. Keywords: Fiber reinforced polymer; repair; retrofit; durability; aramid fiber; wrapping. 1. Introduction 1.1 Fiber-reinforced polymer (FRP) Fiber reinforced polymers are extensively used in strengthening and retrofitting of structurally deficient infrastructures. The polymer is typically an epoxy, vinyl-ester or polyester thermosetting plastic, and phenol formaldehyde resins. When two or more materials with different physical and chemical properties are comprises, forming such types of composites. There is insufficient database on FRP materials which creates difficulties for civil engineers and practitioners in using FRP material at regular basis. V. Karbhari et al. [1] studied the durability of FRP as internal reinforcement, external strengthening, seismic retrofit, bridge decks, structural profiles, and panels. FRP wrapping is very easy to handle and having rapid speed in installation. These materials are having high strength-to-weight ratio. Proper attention is required for bond between FRP material and concrete surface. Marinella and Giovanni [2] worked on the compressive behavior of clay brick masonry columns reinforced either with Basalt Fiber–Reinforced Cementitious Matrix (BFRCM) or with steel wire collaring. Installation of FRP is one of the easiest retrofitting techniques due to its high speed and less complex nature. It also creates fewer disturbances to the occupants. Compared with steel plates FRP are more durable, no risk of corrosion and highly resistant to aggressive environment as investigated by Nur Hajarul Falahi et al. [3]. Due to extensive use of FRP in construction industry their durability becomes important factor for selection of proper material in strengthening purpose. Anandakumar et al. [4] studied the durability of basalt Preprints (www.preprints.org) | NOT PEER-REVIEWED | Posted: 11 October 2018 doi:10.20944/preprints201810.0237.v1 © 2018 by the author(s). Distributed under a Creative Commons CC BY license. Peer-reviewed version available at Fibers 2019, 7, 11; doi:10.3390/fib7020011