Improved Durability Performances in Cement Mortar with Rice Husk Ash Velu Saraswathy 1 ･ Subbiah Karthick 1 ･ Seung-Jun Kwon 2 * (Received March 11, 2014 / Revised March 24, 2014 / Accepted March 25, 2014) Currently many researches have been performed for enhancing durability of concrete. Rice husk ash has several advantages like early strength of concrete and dense pore structure. A calcium silicate hydrate (CSH) gel around the cement particles due to pozzolanic reaction of rice husk can increase the strength of concrete against cracking. Very limitedly a systematic and detailed investigation on the corrosion performance of rice husk ash and silica fume blended concrete is performed. A realistic approach has been made through compressive strength, bond strength, and split tensile strength etc. Corrosion performance was also evaluated rapid chloride ion penetration test (RCPT) and impressed voltage test, and the results were discussed in the paper. Keywords : Durability, Rice husk, Pozzolanic admixture, Silica fume, RCPT * Corresponding author E-mail: jjuni98@hannam.ac.kr 1 Corrosion Protection Division, Central Electrochemical Research Institute, India 2 Hannam University, Civil and Environmental Eng., Daejeon, 306-791, Korea Print ISSN : 2288-3320 Online ISSN : 2288-369X Copyright ⓒ 2014 by Korean Recycled Construction Resources Institute This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited J Rec Const Resources 2(1)66-73(2014) http://dx.doi.org/10.14190/JRCR.2014.2.1.066 1. INTRODUCTION Concrete is the most widely used man made construction material in the world. Ordinary Portland Cement (OPC) is used as energy intensive and costly ingredient in the production of concrete. The manufacture of OPC is expensive and skill intensive process, besides polluting the environment heavily. Production of cement mainly is associated with the emission of carbon dioxide which is a significant source of global warming. Pozzalonic materials are widely used in concrete and mortars for various reasons, particularly for reducing the amount of cement required for making concrete and mortar which lead to a reduction in construction cost. Moreover most pozzolanic materials are by-product materials and the use of these materials leads to reduction in waste and save in energy consumption to produce cement. Most recently blended and multi-blended cement by incorporating industrial by-products/ pozzolanic materials is becoming an active area of research because of their improved properties such as workability (Saraswathy et al., 2001, 2002, 2003a,b), long-term strength and durability (Muralidharen et al., 2004; Saraswathy et al., 2009; Mullick, 2007; Akaninyene et al., 2013). The common blending agents used are fly ash (FA), rice husk ash (RHA), palm oil fuel ash (POFA), slag, silica fume (SF), calcined clay etc (Song et al., 2006; Saraswathy and Song, 2006, 2007; Ahmed et al., 2008). The enhanced durability and structural performance in concrete with common mineral admixture can be found in the previous studies (Erdem et al., 2008; Chindaprasirt et al., 2005; Zhang and Gjørv, 1991). Since RHA (Rice Husk Ash) is similar to SF (Silica Fume) in terms of pozzolanic activity because the former also contains significant amount of Silicon dioxide and a highly reactive pozzolanic material. The use of RHA as a partial replacement to cement will provide an economic use of the byproduct and consequently produce cheaper materials for low cost construction materials. 22% of the weight of paddy used to produce rice is received as husk. This husk contains about