
The Asian Review of Civil Engineering (TARCE)
Engineering Properties of Bentonite Stabilized with Lime and Phosphogypsum
Author : Sujeet Kumar, Rakesh Kumar Dutta and Bijayananda MohantyVolume 3 No.1 January-June 2014 pp 23-35
Abstract
The paper presents the engineering properties such as compaction, unconfined compressive strength, consistency limits, percentage swell, free swell index, California bearing ratio and consolidation of bentonite stabilized with lime and phosphogypsum. The content of lime and phosphogypsum was varied from 0 to 10% to check the improvement in the engineering properties. The results of this study reveal that the dry unit weight and optimum moisture content of bentonite + 8% lime increased with the addition of 8% phosphogypsum. The dry unit weight and optimum moisture content of bentonite + 8% lime increased with the addition of 8% phosphogypsum. The percentage swell increased and free swell index decreased with the addition of 8% phosphogypsum to the bentonite + 8% lime mix. The unconfined compressive strength of the bentonite + 8% lime increased with the addition of 8% phosphogypsum as well as increase in curing period up to 14 days. Beyond a phosphogypsum content of 8%, the unconfined compressive strength decreased. The liquid limit and plastic limit of bentonite + 8% lime increased where as the plasticity index remains constant with the addition 8 % phosphogypsum. The California bearing ratio, modulus of subgrade reaction, secant modulus increased for the bentonite stabilized with lime and phosphogypsum. The coefficient of consolidation of bentonite increased with the addition of 8% lime and no change with the addition of 8 % phosphogypsum. The improved behaviour of the bentonite-lime-phosphogypsum mixture will boost the construction of road pavements on such problematic soils.
Keywords
Bentonite, Lime, Phosphogypsum, Consistency limits, Compaction, Consolidation, Unconfined compressive strength, CBR, Free swell index