Abstract:
Coarse Aggregate is a material vastly used in the construction industry related to concrete structures, asphalt bases and pavements. To achieve required dimensional stability, durability and strength of structures, aggregate characteristics is one of the main issues needed to be addressed. In Pakistan construction industry faces lack of required information about existing/potential coarse aggregate quarry sites as well as the properties of aggregate even from known quarry sites. Existing practice involves transportation of coarse aggregate, mostly from known quarry sites to distant places, thus increasing the project cost.
The study aims at, adopting coarse aggregates characterization methodology for various quarry sites and executing testing methodology to identify the relevant properties, thus evolving a data base for the construction industry. Seven different coarse aggregate quarry sites were selected (Maragllah, Sargodha, DG Khan, DM Jamali, Nooriabad Karaachi, Quetta and River Run River Door Abbottabad) and tested for twelve different tests. The series of test included Specific Gravity and Absorption, Shape, Chemical Composition through X-Ray Fluoresce (XRF), Microfines, Characterization of Microfines through X-Ray Diffraction (XRD), Clay lumps and friable Particles in Aggregate, Loss Angeles (LA) Abrasion, Aggregate Crushing Value, Aggregate Impact, Sodium Sulphate Soundness, Slump and Compressive Strength of Concrete. Comprehensive testing revealed no significant difference and qualifying properties as per international standards related to six quarry sites (Limestone) and even better results for Sargodha site (Basalt).
It was also identified coarse aggregate is transported beyond 400 Kms, thus increasing the project cost manifolds. As a result of this study three (DM Jamali, Nooriabad Karaachi and Quetta) new sites were identified and qualified through testing, specially will help in reducing the haulage distance and controlling projects cost. The study has not only formulated database for construction industry of Pakistan but also will help in reducing haulage distance in turn project cost, towards the South.
