10 th International Congress on Civil Engineering, 5-7 May 2015 University of Tabriz, Tabriz, Iran 1 Durability aspects of recycled aggregate mortar mixtures Ali Mardani-Aghabaglou 1 , Ahsanollah Beglarigale 2 , Halit YazﾕFﾕ 2 , Kambiz Ramyar 1 1- Department of Civil Engineering, Ege University, Bornova-Izmir, Turkey 2- Department of Civil Engineering, Dokuz Eylul University, Buca-Izmir, Turkey Corresponding Author’s E-mail :kambiz.ramyar@gmail.com Abstract In this study the effects of recycled glass and recycled concrete fine aggregates on the compressive strength, water absorption, chloride-ion penetration, freeze-thaw and sulfate resistance as well as ASR expansion of mortar mixtures were investigated comparatively. For this purpose, 9 different mortar mixtures were prepared by replacing 25, 50, 75 and 100 wt% of crushed-limestone fine aggregate with recycled aggregates. Test results demonstrated that, compared to the control mixture, compressive strength of the mortar mixture decreased with increasing the recycled aggregate replacement level. The transport properties of recycled concrete aggregate-containing mixture were lower than those of the other two series. Frost resistance of mortar mixture improved by using both of the recycled aggregates. ASR expansion increased with increasing recycled glass aggregate replacement level. Mortar mixtures containing more than 50% recycled concrete aggregate showed higher sulfate resistance than the control mixture. This was attributed to the accumulation of ettringite in pores of the RC aggregate resulting in lower expansion. Keywords: Compressive strength, transport properties, freeze-thaw resistance, sulfate resistance, ASR expansion. 1. INTRODUCTION Recently many scientific research papers were published about the utilization of waste materials such as old concrete and glass as aggregate in concrete or in cement based composites [1-6]. Growing environmental concerns which is related to the huge quantity of construction and demolition waste is the main driving force to promote the recycling of concrete demolition waste in the concrete production [7]. In addition, there has been growing interest in the recycling of waste glass which is a non-biodegradable material [8, 9]. It creates a problem for solid waste disposal into landfills which does not provide any environment-friendly solution [9, 10]. Safiuddin et al. emphasized that utilization of waste glass in construction materials can be a worthy solution to the solid waste-related pollution [9]. On the other hand, production of construction materials (concrete, bricks, hollow blocks, solid blocks, pavement blocks and tiles) requires continuous exploration and depletion of existing natural resources. Besides, high demand, scarcity of raw materials, and high price of energy lead to increasing the cost of construction materials, hence, the use of alternative ingredients in construction sector is now a global concern [9]. The main drawback of recycled concrete (RC) and recycled glass aggregate (RG) is related to the interfacial transition zone (ITZ). The smooth surface and sharper edges of the glass particles lead to a weaker glass- paste ITZ which affects the mechanical and durability properties of the RG aggregate-containing mixture. [11-13]. In the case of RC aggregate, there are two ITZs. It has an old ITZ between RC and old adhered mortar and also a new one between RC and new matrix. The mechanical performance of RC aggregate- containing concrete is a consequence of dual performance of the both ITZs [14]. The porous nature of adhered mortar at the surface of the RC and also the fissures formed in the crushing process can affect negatively the performance of the RC aggregate-containing concrete [14-16]. Many researchers have dealt with the mechanical properties of RC- and RG aggregate-containing concrete and mortar. Besides, the durability of these materials was investigated in some studies. Thomas et. al. [17] reported that the mechanical and durability performance of the RC aggregate-bearing mixture were lower than those of the control mixture. However, Kwan et. al. showed that the course RC aggregate-bearing