International Journal of Innovative Research in Advanced Engineering (IJIRAE) ISSN: 2349-2763 Issue 09, Volume 3 (September 2016) www.ijirae.com _________________________________________________________________________________________________ IJIRAE: Impact Factor Value – SJIF: Innospace, Morocco (2015): 3.361 | PIF: 2.469 | Jour Info: 4.085 | Index Copernicus 2014 = 6.57 © 2014- 16, IJIRAE- All Rights Reserved Page -20 GEOPOLYMER AS REPAIR MATERIAL - A REVIEW Afis Ali Job Thomas Nidhin B Parappattu Department of Civil Engineering Department of Civil Engineering Department of Civil Engineering M G University CUSAT M G University Abstract — Cement is the world's most used construction binder material. Cement production emits large amounts of CO2 and consumes significant amount of energy. As a result, it is necessary to find a new concrete material to replace traditional Portland cement concrete, which is environmentally stressful, yet provides an effective building material. Geopolymer is an emerging alternative binder to Portland cement for making concrete. Geopolymer concrete is principally produced by utilizing industrial by-product materials such as fly ash, blast furnace slag, and other aluminosilicate materials. RCC structures undergo serious durability problems like spalling, erosion, wear, cracking, corrosion etc. years after the construction. Repair to damaged concrete are important not only to ensure the planned useful life, but also to provide good performance and security. This paper review the literature related to the studies conducted on geopolymer and repair materials. Keywords — Geopolymer concrete, Bond strength, Repair materials, Slant shear test, Cylindrical splitting test, Substrate I. INTRODUCTION Cement is the world's most used construction binder material. Cement production emits large amounts of CO 2 and consumes significant amount of energy. Production of one ton of Portland cement releases one ton of CO 2 into the atmosphere. The global cement industry contributes around 6% of all CO 2 emissions. It is a common viewpoint that finding an alternative material to the Portland cement is imminent. Some researchers have stated that CO 2 emission could increase by 50% compared with the present scope. Therefore, the impact of cement production on the environment issues a significant challenge to concrete industries in the future. As a result, it is necessary to find a new concrete material to replace traditional Portland cement concrete, which is environmentally stressful, yet provides an effective building material. Promoting low-emission concretes is essential in order to face the crucial challenge to reduce the environmental impact of the construction sector and the concrete industry and to limit the impact of climate change. One way of reducing these CO 2 emissions is the use of blended cements in which a part of the Portland cement clinker is replaced with supplementary cementitious materials (SCMs). The most common SCMs used in high-volume applications are fly ash (FA) and ground granulated blast furnace slag (GGBFS). Fly-ash-based and GGBFS based blended cements are extensively used but limits are imposed on the OPC replacement. In most cases, blended cements still contain more OPC clinker than SCM. On the other hand, geopolymer is a new construction material which could be produced by the chemical action of inorganic molecules, without using any Portland cement. The geopolymer binder could be produced through chemical reaction between alumino-silicate materials such as fly ash or metakaolin that are rich in SiO 2 and Al 2 O 3 and alkaline solutions such as Sodium Hydroxide or Sodium Silicate. Fly ash is a suitable material for making geopolymeric binder because of its pertinent silica and alumina composition and low water demand. Low-calcium fly ash-based geopolymer concrete cured in high temperature has been reported to have good mechanical properties in both short and long term tests. The structural behaviour of heat-cured fly ash geopolymer concrete was found to be similar or superior to that of OPC concrete when tested for reinforced columns and beams, bonding and fracture properties. The hardening mechanism for geopolymers essentially contains the polycondensation reaction of geopolymeric precursors, regularly aluminosilicate oxides, with alkali polysilicates yielding a polymeric silicon –oxygen aluminium framework.