STABILIZATION OF EXPANSIVE SOIL BY USING WASTE PAPER SLUDGE ASH

Abstract

Expansive soils occurring in arid and semi-arid climate regions of the world cause serious problems on civil engineering structures. Due to its expansive behavior, they need modification in engineering properties of soil. This study evaluates the suitability of waste paper sludge ash for stabilization of expansive soil. Material of waste paper sludge ash coming from paper factory sludge incinerated under controlled condition. To investigate the effect of adding waste paper sludge ash to an expansive soil, different laboratory experiments such as Atterberg’s limit test, free swell index tests, compaction tests, California bearing ratio test and unconfined compressive strength tests were performed for different percentage of waste paper sludge ash. The preliminary investigation of the soil shows that it belongs to A-7-5 class of soil based on AASHTO soil classification system which is clay soil of poor engineering properties. The soil was stabilized with WPSA in stepped concentration of 4 %, 6 %, 8 %, 10 %, 12 % and 14 % by dry weight of the soil and also the effect of curing period was evaluated over a period of four and seven days for Atterberg’s limits, compaction, UCS and CBR tests. The results from analysis show improvement of the geotechnical properties of expansive soil with waste paper sludge ash. The plasticity index, free swelling index and OMC reduce with increase in CBR, UCS and MDD value when using 10% waste paper sludge ash