Experimental Investigation of Mineral Composite Bonder over CFRP and GFRP Retrofits Raghavendra Vasudeva Upadhyaya Research Scholar: Engineering and Technology Central Queensland University Rockhampton, QLD, Australia T. G. Suntharavadivel Lecturer: Engineering and Technology Central Queensland University Rockhampton, QLD, Australia Abstract— The importance in rehabilitation of concrete structures is rapidly gaining popularity due to various factors. In recent years, the Fiber Reinforced Polymer (FRP) is being widely applied in structural strengthening and retrofit. In most of the FRP strengthening the epoxy resin is used as a binder. A sustainable Mineral Based Composite (MBC) was tested to be a potential replacement for the epoxy in the FRP retrofit to overcome the drawbacks associated with epoxies. FRP sheets would be used to wrap around the damaged concrete surface with the help of innovative mineral bonders. The experimental results indicate the proposed MBC bonder have comparable behavior in FRP retrofit as epoxy. Keywords— Epoxy; MBC; bonders; FRP retrofit; strengthening; debonding I. INTRODUCTION The infrastructural demand around the world is increasing day-by-day which is least concerned about the multi- disciplinary aspects such as energy, economy and environment (EEE’s). Concrete deterioration occurs due to various natural and induced phenomena resulting in global concern. The infrastructural deficiencies need immediate attention as it directly affects the operational life of the structure. The main objective of this research is to develop and implement a suitable eco-friendly bonding agent in order to eliminate the hazardous chemical resins used commercially. Fiber reinforced Polymer strengthening is a commonly practised rehabilitation technique which enhances the load- bearing capacity of the overall structure. The important issue to be addressed here is that FRP retrofit uses epoxy as a bonding agent which has been identified to cause adverse health impacts and is very toxic. A lot of published literature proves this fact. This paper aims to retrofit bi-directionally woven CFRP and GFRP materials around the damaged structural samples and extensively compare their bonding performance with that of epoxy resin and the newly developed mineral-based binder. The test specimens were subjected to various damage levels and experimented their bonding efficiency under tensile and compressive loads. The MBC material was developed after undertaking extensive literature study and implementing various rheology constraint materials and water reducing agents. After a series of trial and error, the durability and ease of availability of materials resulted in developing the final mix proportion of the sustainable composite as discussed in the paper II. LITERATURE INVESTIGATION A. Epoxy and its associated concerns Although epoxy resins are considered as the most important composite in industrial and construction activities, it allows for some demerits to add to its list. First of all, it is highly volatile and vulnerable to freeze-thaw conditions as well as extreme temperatures. Secondly, it has adverse health impacts on the people working or living with them as it fumes out toxic gases if the temperature goes above 82 0 C. Moreover, it cannot be applied on humid conditions. The health hazards investigation as per [1] exhibited by various plastics, which constitute a global production of 245 million tons annually in 2008 and shockingly doubled over the last 15 years. The most hazardous ranking of polymers falls under category 1A or 1B with examples of polyurethanes, polyvinyl chlorides, epoxy resins, and styrenic copolymers. On the other hand, [2] seemed to have conducted a patch test research on the population of North-Eastern Italy in order to investigate the effect of epoxy resins in contact with dermatitis (upper layer of the skin). It was observed that the sensitization on the human skin was 40.25%. In both sexes of woodworkers, chemical industry or construction workers, farmers and fishers, significant health effects were found due to working with epoxy resins. The study conducted by [3] established that epoxy polymer causes the angiosarcomas of the liver and creates asthma-like reactions because of the initiators that are used with epoxy resins. It is evident that there is an utmost need to eliminate epoxy in all aspects of construction activities. B. Performance of Mineral Admixtures Mineral based composites (MBC) involves the replacement of epoxy resin binder by a cementitious mortar containing admixtures like superplasticizers, viscous modifying agents, strengthening additives, etc. It should provide excellent bonding properties, along with good workability, cost efficiency and most importantly compatible with most of the FRP retrofits. The investigation of mechanical behavior performed by [4] for Carbon Fiber Reinforced Composites (CFRC), plain and mineral based composite retrofitted beams to calculate their flexural behavior. As shown in Figure 1 the plain beam showed a brittle failure whereas the fatigue resistance of CFRC and Carbon Fiber Reinforced Polymers (CFRP) retrofitted beams significantly increased. In the end, unlike CFRP retrofitted International Journal of Engineering Research & Technology (IJERT) ISSN: 2278-0181 http://www.ijert.org IJERTV7IS100085 (This work is licensed under a Creative Commons Attribution 4.0 International License.) Published by : www.ijert.org Vol. 7 Issue 10, October-2018