Effect of Electrolyte Lignin and Fly Ash in Stabilizing Black Cotton Soil

Abstract

Subgrade is one of the important layers of any pavement. It must be able to support loads transmitted from pavement structure without excessive deformation under adverse climatic and traffic conditions. In this investigation, laboratory studies were carried out to evaluate the influence of a commercial electrolyte lignin stabilizer (ELS), fly ash (FA) and a combination of both, on black cotton (BC) soil procured from North Karnataka region in India. Basic geotechnical and engineering properties like unconfined compressive strength (UCS), California bearing ratio (CBR), etc. were determined for both untreated and treated soil. Dynamic repeated load test was conducted to examine the fatigue behaviour of the soil. Durability of the soil was checked by wet-dry (WD) and freeze-thaw (FT) cycle tests, and swelling properties by free swell index test. From the studies, it was observed that consistency limits, dry density, UCS and CBR values were improved for treated soil, with curing periods of 1, 7 and 28 days. Weight loss in FT test was less than 14 % for 12 cycles, which ensures that the stabilized soil has become durable. But none of the samples were observed to be withstanding above five cycles in wet-dry test. Soil stabilized with ELS and FA showed better results compared to soil with only ELS. Swelling was reduced to a great extent with 28 days curing period for the former one. From the experimental results, it can be concluded that this chemical can be used as a stabilizer for existing BC soil in site to enhance its subgrade strength.

Reduction of pavement thickness using a subgrade layer treated by different techniques

“…In this study, it was found that 20 % of fly ash is the optimum percentage. Many other studies concluded similar results by the addition of approximate percentages of fly ash [11][12][13].…”

Performance of soils enhanced with eco-friendly biopolymers in unconfined compression strength tests and fatigue loading tests

“…The test matrix of constant-amplitude fatigue loading tests is given in Table 3. The maximum stress were from 1/2 to 3/4 fractions of UCS values referring to Lekha et al [45], corresponding to medium to high stress levels. The UCS for each treatment condition was used as a basis for the calculation of fatigue stresses (e.g., r m , r a , r max , and r min ).…”

The Optimisation Analysis of Sand-Clay Mixtures Stabilised with Xanthan Gum Biopolymers

“…After compaction, the samples were extruded out of the mould as shown in Figure 1 and cured in a controlled environment (60% relative humidity and 20 • C). A curing period of 14 days was adopted as the growth rate of mechanical strength was observed to be lowered after 14 days [12,23,68]. The UCS test were conducted under the strain-controlled condition at a loading rate of 1.5%/min in accordance with ASTM D2166 at the end of 14-day curing period.…”