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 its
potential as a construction aggregate. The limestone contains variable amounts of dolomite, which can be harmful to
concrete. Petrographic analysis and ACR tests showed that the dolomite content is low and the limestone has low alkali
reactivity. Engineering laboratory tests confirmed that the limestone meets ASTM and AASHTO standards for
aggregate properties. Therefore, the limestone from Dhamtaur can be used as an aggregate in concrete and asphalt
works. The results of the engineering laboratory tests indicate that limestone from the Samana Suk Formation, located
in 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 as
aggregate, aligning with the established standards of ASTM and AASHTO. A petrographic examination indicates the
presence of dolomite in a minor proportion (2-15%) with a Porphyrotopic-S type texture. Analysis of ACR results
demonstrates a slight expansion in the limestone (0-0.01%), implying low reactivity to alkali. Consequently, it is
reasonable to propose the utilization of these rocks as a source of aggregate in concrete and asphalt projects.