Assessment of Potential Alkali-Carbonate Reactivity and Petrographic Analysis of Limestone from Samana Suk Formation Dhamtaur Area, District Abbottabad, Pakistan to Use as Aggregate

Abstract

A detailed Limestone from the Samana Suk Formation in Dhamtaur, Pakistan, was studied to assess itspotential as a construction aggregate. The limestone contains variable amounts of dolomite, which can be harmful toconcrete. Petrographic analysis and ACR tests showed that the dolomite content is low and the limestone has low alkalireactivity. Engineering laboratory tests confirmed that the limestone meets ASTM and AASHTO standards foraggregate properties. Therefore, the limestone from Dhamtaur can be used as an aggregate in concrete and asphaltworks. The results of the engineering laboratory tests indicate that limestone from the Samana Suk Formation, locatedin the Dhamtaur area, exhibits specific gravity (2.84g/cm3), water absorption (0.0781%), Los Angeles abrasion value(20%), and sulfate soundness (2.23%). These findings strongly support the viability of utilizing these rocks asaggregate, aligning with the established standards of ASTM and AASHTO. A petrographic examination indicates thepresence of dolomite in a minor proportion (2-15%) with a Porphyrotopic-S type texture. Analysis of ACR resultsdemonstrates a slight expansion in the limestone (0-0.01%), implying low reactivity to alkali. Consequently, it isreasonable to propose the utilization of these rocks as a source of aggregate in concrete and asphalt projects.