Strength and Durability of the Pandrang Quartzite and the Chisapani Quartzite Units of the, Central Nepal Lesser Himalaya

Abstract

ABSTRACT: This study focuses on the characterization and evaluation of quartzites sourced from the Pandrang Quartzite and the Chisapani Quartzite belonging to the Bhimphedi Group of the Lesser Himalayan sequence for their potential use as railway aggregates. The objective of the research is to assess the physical, mechanical, and durability properties of these crushed rock aggregates, considering their suitability for railway applications. The quartzites, classified as medium-grained, monomictic quartzites and belonging to the Precambrian Age, exhibit white to yellowish or brownish white colour, and rough surface texture. The investigation gives away consistent and similar physical properties in both quartzite samples, including narrow ranges in density, specific gravity, and water absorption. While the quartzites demonstrate varying levels of strength, with a majority falling into the strong to very strong category, some exhibit medium strong and extremely strong characteristics. Additionally, the aggregates show a range of values for the Aggregate Impact Value (AIV) and Aggregate Crushing Value (ACV), indicating variations in toughness.

The quartzites show the high resistance to slaking, minimal weight changes during slake durability testing, and superior resistance to freeze and thaw weathering. Moderate hardness and abrasion resistance suggest their suitability as durable aggregates for ballast. Despite comparable ranges in density and aggregate crushing value, the Pandrang Quartzite generally exhibits higher strength and durability than the Chisapani Quartzite, suggesting superior quality. Except for crushing resistance, the quartzites meet the requirements specified by (American Railway Engineering and Maintenance-of-Way Association (AREMA) and British Railway Standards, making them suitable for railway applications. The study provides valuable insights into the physical, mechanical and durability characteristics of quartzite aggregates, guiding their potential utilization in railway infrastructure with an emphasis on durability and strength.