A study of the durability of some shales, mudrocks and siltstones from Brazil

Abstract

In spite of the considerable area covered by argillaceous sedimentary rocks (comprising shales, mudrocks and siltstones) in Brazil and the number of engineering works associated with these materials, little is known about their geotechnical, physical, chemical, mineralogical and textural characteristics and the effects of weathering processes on them. This work presents results obtained in a research project aiming primarily at identifying degradation processes responsible for the weathering of some of these rocks in Brazil. The rocks under investigation come from two different parts of the country, each one related to a specific engineering problem and to different geoenvironments. The project involved a comprehensive laboratory testing program for basic characterization (chemical and mineralogical composition, index properties, etc.) and evaluation of durability characteristics of these rocks. The present paper describes the testing program carried out and discusses the results obtained.

Development of Rotary Abrasion Testing Apparatus for Rock Cores

“…For example, the rock specimen with high abrasivity is likely to weather upon wetting and drying compared to low abrasive rocks. The argillaceous sedimentary rocks with high clay mineral contents are prone to degrade in the presence of water (Marques et al 2005;Youn and Tonon 2010). In other words, the rock abrasivity represented by wear volume is greater in wet condition than dry condition, and the difference would increase as the rocks are more degradable.…”

Chemical, mineralogical and textural properties of the Kope Formation mudstones: How they affect its durability

“…Permeability also likely depends on the fabric and significantly affects the slake durability of a rock (Marques et al, 2005). The moisture content of the Kope Formation mudstones supports this idea.…”

Numerical Study of the Effect of Verification Core Hole on the Point Bearing Capacity of Drilled Shafts

“…weathering is another significant factor that impairs the overall stability of sub and super structures. Thus, weathering has been extensively studied (Gulla et al, 2006;Marques et al, 2005;Martin and Hencher, 1986;Taylor, 1988). The resistance of weak rocks to weathering is called durability and is usually measured by means of slaking tests.…”