COMPARISON OF PI{YSICAL AND MICRO. STRUCTURAL CHARACTERISTICS OF VARIOUS FINE AGGREGATES IN BANGLADESTI

Abstract

Concrete is a versatile material, u,hich is a rnixture of cernentiotrs material, coatse and fine aggregate andwater. The properties ofconcrete may vary widely because ofseasonal and spatial yariations in properties of locally available Jine aggregates. As the geological and geo morphological processe,t of rock are dffirent, the aggregates formed at various places are also dffirent. The speciJic objectives of this study has been to obserue spatial variations on physical and micro-structural characteristics of Jine aggregates collected Jrom dffirent source.s in Bangladesh. Fite aggregates have heen collected from dffirent sources of Sylhet, Ktrstia, Pabna, Dinajpur and Dltaka. According to ASTM, sieve analysis, specific gravity (OD and SSD), absorptiort capacity, moisture content and unitweight have been performed in the laboratory. |{on destrtLctiye tests are perJbrmedfor micro-sttuctural characteristics oJ'Jine aggregate. In this study, X-Ray Di;fJraction (XkD) technique has been used to predict quantitative phase analysis and perceflt of-each compotmd present in the sample o/ difJbrent fine aggregate. XRD results show the presence oJ Calcite (CaCO:), Gismandine (CaAlzSi:Ot.4HQ), Mullite (AloSizOr:) and variation of Quartz (SiO) for dffirent samples. The spatial variations in the mechanical and micro-structural properties of./ine aggregates haye been observed during this study for all the tests. All the test result values of .fine aggregates have been compared with standard values of ACI, BS, AASHTO, IS and PWD.