ISSN: 2277-9655 [Vyas * et al., 7(1): January, 2018] Impact Factor: 5.164 IC™ Value: 3.00 CODEN: IJESS7 http: // www.ijesrt.com© International Journal of Engineering Sciences & Research Technology [397] IJESRT INTERNATIONAL JOURNAL OF ENGINEERING SCIENCES & RESEARCH TECHNOLOGY RETROFITTING OF CONCRETE STRUCTURES USING REACTIVE POWDER CONCRETE: A REVIEW Atreya Vyas 1 , Satyendra Gangwar 1 & Rahul Vyas *2 1 Department of Civil Engineering, MPSTME, SVKM’s NMIMS, Shirpur, Maharashtra, INDIA *2 Assistant Professor, Department of Civil Engineering, MPSTME, SVKM’s NMIMS, Shirpur, Maharashtra, INDIA DOI: 10.5281/zenodo.1147574 ABSTRACT Recent advancement are made in the retrofitting techniques to enhance the characteristics like safety, serviceability and restorability of the structure which are susceptible to damage. More recently, there has been an increased research attention towards advanced techniques which emphasizes on the use of reactive powder concrete (RPC) for maintaining the existing as well as the new structure. RPC is an ultra high performance concrete (UHPC) which is a composite material formed by using Portland cement, silica fumes, quartz sand, steel fibre and super plasticizers. RPC as a material can be used at elevated temperatures where it will serve high bond strength and durability with normal concrete than any other retrofitting material. There is no effect of thermal cycling up to certain degrees on Reactive Powder Concrete therefore it can be used in hot weather condition. This paper is an overview of previous studies done in the field of retrofitting of structure using different techniques and highlights the advantages of RPC as a retrofitting material. KEYWORDS: Retrofitting, Reactive powder concrete, Jacketing, FRP, Silica fumes, Steel fibres UHPC. I. INTRODUCTION Retrofitting of the existing structure means to improve the performance of the structure by escalating and strengthening the structural element or the whole structure. Retrofitting of the structure is done for improving structural properties of either a damaged structure to take the existing load safely or to enhance its structural properties to take an additional load. Retrofitting can be done globally or locally depending upon the extent of damage. Global retrofitting includes various means such as addition of structural walls for taking the structural loads, base isolation for preserving the structure from high intensity transverse load and use of steel bracing systems to improve the overall stability of the structure as well as its tensile strength. This all adds up to make the structure globally strong. Local retrofitting enhances the performance of individual segments of structures. This uses the techniques such as jacketing the members, wrapping of FRP and CFRP sheets, reactive powder concrete, etc. Reactive powder concrete can improve the strength, durability and ductility of concrete structure susceptible to damage. In RPC, water content is reduced by using super plasticizer whereas steel fibres are used instead of coarse aggregate and highly refined silica fumes are used to enhance the adhesion properties of the mix. The low permeability is achieved using finer material there-by making it less porous and giving the concrete a dense compact structure which in turn also enhances its ductility.RPC has gained a lot of attention as a retrofitting material because of its very high strength, superior toughness, a good bonding strength and extreme durability. RPC gives the flexural and compressive strength in the range of 30-50 MPa and 200-800 MPa respectively and Young’s modulus in the range 50-60 GPa. Thus, it can be used as a retrofitting material in retrofitting techniques. RPC can also be used to improve the seismic performance of the structure, for increasing the corrosion resistance, as a replacement of steel in compression member giving it a property of light weight members as compared to conventional members.