Suitability of light coloured silicate metamorphic rocks of Sri Lanka in construction industry

Abstract

Conventionally, in the local construction industry, darker coloured (melanocratic) rocks are preferred over light coloured (leucocratic) rocks without proper scientific reasoning. Hence, the objective of the study is to assess the suitability of leucocratic rock types in construction applications as raw materials by analyzing desirable properties. Rock samples ranging from dark colour to light colour collected by visual inspection. The degree of light colouredness was determined through a microscopic analysis. Unconfined Compressive Strength (UCS) test, Point Load Index (PLI) test, Los Angeles Abrasion Test (LAAV) and Aggregate Impact Value Test (AIV) were carried out on samples prepared according to the standard methods. Concrete mixtures made out of different aggregates with varying leucocratic contents were also tested for strength and rate of strength gain by concrete cube testing. Test results were analyzed with respect to the degree of light colouredness to identify the desirable aggregate properties to be used in construction industry.