Pakistan Journal of Science (Vol. 65 No. 1 March, 2013) 90 PERFORMANCE STUDY OF LOCALLY AVAILABLE COARSE AGGREGATES OF AZAD KASHMIR Z. A. Siddiqi, R. Hameed, M. Saleem, Q. S. Khan and I. Ishaq Civil Engineering Department, University of Engineering and Technology Lahore, Pakistan Corresponding Author, E-mail: rashidmughal@uet.edu.pk , cell # +92-322-3064000 ABSTRACT: This paper presents results of an experimental study carried out to investigate the suitability of using locally available coarse aggregates in Azad Kashmir to make concrete. Aggregate samples were collected from three different quarries according to ASTM sampling procedure. The experiments were performed on collected samples of coarse aggregates to evaluate their physical and mechanical properties as per ASTM and BS standards. Concrete compositions made using the same aggregates were tested for mechanical properties (compressive strength and tensile strength). The results of this study showed that the concrete made using locally available aggregates in Azad Kashmir performed satisfactorily in terms of mechanical properties. Moreover, their performance was found to be quite similar to those aggregates commonly available and used in Pakistan such as Margallah and Sargodha aggregates. Key words: Concrete; coarse aggregate; physical properties; mechanical properties; ASTM. INTRODUCTION Approximately three quarters of the volume of concrete is occupied by the aggregates. The strength, durability and structural performance of concrete are greatly affected by the properties of fine and coarse aggregates (Ayub et al. 2012; Joseph et al. 2012). Aggregates are formed either by the natural process of weathering and abrasion or by artificially crushing parent rock. Thus many properties of the aggregate such as chemical and mineral composition, specific gravity, hardness, strength, physical and chemical stability and porosity depend on the properties of parent rocks (Tasong et al. 1998; Elsharief et al. 2003; Makani, 2011). In addition to above mentioned properties, some other properties which are not dependent on parent rocks such as particle size distribution, surface texture and absorption considerably influence the quality of concrete in fresh and hardened state (Neville, 2005; Akçaoglu et al. 2004; Basheer et al. 2005, Makani et al. 2010; Meddah et al. 2010). The use of locally available construction materials in any area may reduce the cost of the project appreciably. There are many quarries of aggregates in Azad Kashmir and the aggregates obtained from these sources are being used by the local construction industries in rigid pavements and buildings. However, no detailed and scientific research study has yet been carried out to determine the suitability of locally available aggregates to make concrete of required strength and durability. The present research study deals with determination of physical and mechanical properties of three different types of aggregates collected from Azad Kashmir. Moreover, mechanical properties of concrete made by using the same aggregates have also been studied. The mechanical properties of concrete which were studied include compressive strength, tensile strength, and modulus of rupture. For this study, three quarries named as Hajira, Kamser and Arja in Azad Kashmir were explored. Hajira is a tehsil of district Poonch, 29 km from the south east of Rawalakot. Kamser is a place 10 km north of Muzaffarabad city and is situated near Nisar camp on Nelum valley road. Arja is located 16 km North West of district Bagh and 30 km from district Poonch. MATERIALS AND METHODS A comprehensive experimental program was designed and carried out to determine physical and mechanical properties of aggregates. In addition to that, tests on hardened concrete made using aggregates from Azad Kashmir and also commonly used aggregates in Pakistan (Sargodha and Marghallah crush) were also performed under the scope of this experimental study. Physical Properties of Aggregates: Following physical properties of aggregates were studied:  Specific gravity and water absorption  Unit weight and voids  Flakiness and elongation index Specific gravity and water absorption: Specific gravity and water absorption of aggregates under investigation were determined using ASTM standard C-127. The values of specific gravity and water absorption of aggregates investigated in this experimental study have been graphically presented in Fig.1 and Fig.2,