Journal: |
Case Studies in Construction Materials
Elsevier Ltd
|
Volume: |
volume 17
|
Abstract: |
The focus of this experimental study is to ameliorate the engineering behavior of Palygorskiterich medium Expansive soils (ES) by utilizing soda lime glass powder (SLGP). The hydrophilic
ES are problematic and tend to damage the pavements, boundary walls, and slab-on-grade
members Whereas, the accumulation of huge amounts of SLGP is responsible for multitude of
environmental issues. Therefore, SLGP was added to the ES using various dosage levels (0 %, 6 %,
10 %, 14 %, 16 %, 18 %, and 22 % by dry weight of the ES to assess the compaction, consolidation
and strength characteristics by performing geotechnical laboratory tests. Also, the effect of curing
on th unconfined compressive strength of ES (UCS-ES) after 3, 7, 14, and 28 days was studied by
considering the mineralogical changes. The microscopic mechanisms of the virgin ES and the
SLGP-treated mixtures was evaluated by X-ray fluorescence (XRF), X-ray diffraction (XRD), and
scanning electron microscopy (SEM) analyses. The results revealed that, plasticity dropped by
almost 80 % (due to filler effect, cohesionless character, and higher silica amount of the SLGP),
MDD increased from 18.25 to 19.16 kN/m3, and the OMC lowered down (due to the reduction in
volume of clay minerals and interlayer spaces). With increasing SLGP dosage levels the coefficient
of compression (Cc) decreased by 42.86 %, coefficient of volume (mv) by 60 %, coefficient of
consolidation (cv) by 91.53 %, and the pre-consolidation pressures (Pc) witnessed an increase of
240 %. The UCS-ESunsoaked values exceed than the UCS-ES soaked values, particularly at early days
of curing (1–7 days) such that UCS-ESsoaked = 13 × UCS-ESsoaked after one day, whereas UCSESsoaked = 5.25 × UCS-ESsoaked after 28 days. Similarly, a remarkable improvement (of six -fold)
in strength was recorded based on California bearing ratio (CBR) values with 16 % replacement of
the SLGP additive. Also, the compactability and strength characteristics were significantly
improved and the plasticity plummeted due to formation of C-S-H and C-A-H compounds. Thus,
the inclusion of 16 % SLGP in the medium ES was found as the optimum amount in reducing
plasticity, improving consolidation characteristics and imparting strength.
|
|
|