Durability assessment of weak rock by using JAR slaking test

Abstract

Jar test is a simple test developed to determine the reaction of weak rock material to water during a certain period of time which can be tested on irregular bulk samples. It indicates the porosity, grain interactions and density of the material. The total index observed during a 10 minutes, 15 minutes, 30 minutes and 60 minutes sequence was found to be a good indicator for the classification. This should enable the classifying of the weak rock material to be carried out based on the slaking index. The r eaction of the rock matter was inevitable after immersing the sample in the jar with water. The slaking index or changes in the sample also depend on the duration of the immersion time. By the observation of the changes caused by the immersing process the rock can be classifi ed and the description for shale and sandstone. The jar slaking test was found to be more suitable to measure durability of weak rock especially in highly weathere d (grade IV) and completely w eathered (grade V) states as compared to slake durability index (Id 1 or Id 2 ) which was found to be unsuitable to test the durability of such weak rock