Analysis of Cracking Behavior of Composite Landfill Liners

Abstract

This study aims to quantify the cracking behaviour of composite landfill liners easily, quickly and in better mode using image analysis technique. The disturbed soil samples were collected from a selected waste disposal site at Rajbandh, Khulna, Bangladesh. The mixing proportions of 10, 20, 30, 40, 50 and 60% of brick dust as well as 20, 30, 40, 50, 60 and 70% of fly ash by dry weight with soil samples were used to prepare composite liners. Steel circular molds having 30 cm diameter with different thicknesses of 10, 20 and 30 mm were used. The amount of water content equal to liquid limit, plastic limit and optimum moisture content of mixing soil were considered. The wetting-drying cycles were subjected on specimens to simulate the field behavior of liners. The cracking behaviour such as crack intensity factor (CIF), crack density factor (CDF) and crack areas were measured through MATLAB and ImageJ technique. The maximum CIF, CDF and crack area were obtained in control soil. The CIF, CDF and crack area decreases with the increase of fly ash and brick dust content in liners. Result reveals CIF, CDF and crack area increase with the increase of water content. The liners with water content equal to liquid limit showed maximum CIF, CDF and crack area. Moreover, the CIF and crack area decrease with the increase of specimen thickness except for CDF. With the multiple wetting-drying cycles experiment, the amount of cracking did not significantly change after 2nd wetting-drying cycle.