Physico-mechanical and petrographic insights of Lockhart Limestone, sections of Islamabad, Pakistan

This paper investigates physico-mechanical and petrographic attributes of Paleocene Lockhart Limestone which is measured, sampled and described from Rumli (RUM) and Shah Allah Ditta (SAD) sections of Islamabad. Petrographic analysis delineates that the limestone is categorized mainly into mudstone and wackestone microfacies and dominant presence of the micrite matrix favors the strength of the rock, whereas; veins, microfractures and porosities adversely affect the stability of the rock. Based on the UCS and PLT analyses, limestone samples incorporating the lowest porosities partnered with bioclasts encompass the highest UCS and PLT values and vice versa. The physico-mechanical analyses reveal that the limestone aggregates are within limits of the respective standards (ASTM, AASHTO, BS and NHA) for utilization in wearing, coating, cement concrete. The limestone of both sections can be utilized for geotechnical purposes like crushed material and aggregate source. Simple regression analysis was employed and based on these correlations; the limestone of the studied formation is designated as moderately strong and recommended for road or bridge construction purposes.

Automated summary

This paper studies the physico-mechanical and petrographic attributes of Paleocene Lockhart Limestone in Islamabad's Rumli and Shah Allah Ditta sections. Petrographic analysis reveals the limestone mainly consists of mudstone and wackestone microfacies, with the micrite matrix enhancing its strength while veins, microfractures, and porosities affecting its stability. Based on UCS and PLT analyses, limestone samples with lower porosities and bioclasts exhibit higher UCS and PLT values. Physico-mechanical analyses show that the limestone meets the standards for wearing, coating, and cement concrete. It can also be used for geotechnical purposes. Simple regression analysis designates the limestone as moderately strong and suitable for road or bridge construction.