This study presents the micro-physical investigation of polypropylene (PP) fiber-reinforced, and silica fume (SF) stabilized expansive soil (BC) subgrade. The coupling effect of soil, PP fiber, and SF has been evaluated under the freezing-thawing (F-T) cycle to assess the durability of treated BC Soil. The curing method and duration staggeringly influence the strength of SF treated BC soil; therefore, three different curing method, i.e., moisture-controlled curing (MC), gunny bag curing (GC), and water submerged curing (SC) to a period of 7, 14, and 28 days were considered. The BC soil has been reinforced with 0.25%, 0.50%, and 1.00% PP fiber and stabilized with 2%, 4%, 6% and 8% SF. The physical, chemical, and microstructural properties were determined before and after 2,4,6,8,10 F-T cycles. With the increase in SF content, the unconfined compressive strength of the expansive soil has been increased due to the formation of Calcium Silicate Hydrate (C-S-H) gel. The chemically inert, hydrophobic, non-corrosive nature, and higher tensile strength of PP fiber, it has a higher potential to reinforce the BC soil for durability under tensile failure. This research confirms the possibility of incorporating SF and PP Fiber in road work applications, with significant environmental benefits.

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Effect of Curing on Micro-Physical Performance of Polypropylene Fiber Reinforced and Silica Fume stabilized Expansive Soil Under Freezing Thawing Cycles.

The improvement of soils that are not suitable for a particular purpose through techniques that combine densification and the incorporation of portland cement have been extensively done for...

Durability Assessment of Soil-Pozzolan-Lime Blends through Ultrasonic-Pulse Velocity Test

Zinc leachability in contaminated soil stabilized/solidified by cement-soda residue under freeze-thaw cycles

This study presents the experimental results of the effective utilization of polypropylene (PP) fibre and silica fume (SF) to stabilize the expansive soil subgrade as a possible alternative from the environment, economic, and technical perspective. During the drying cycle, clayey soil undergoes unpredictable shrinkage deformation. The nonrecurring shrinkage behaviour of expansive soil caused the adverse effect on lightweight civil engineering structures. Therefore, expansive soil is not considered suitable subgrade material for paved structure construction. Paved structures constructed on clayey soil subgrade experience severe damages occur in its life cycle. The numerous mechanical, biological, and chemical techniques have been successfully demonstrated to reduce the swelling–shrinkage nature and improve the strength behaviour of expansive soil subgrade. This study aims to utilize industrial waste SF as chemical and PP fibre as a mechanical stabilizer. The mecho-chemical stabilization of expansive soil has been carried out by reinforcing the expansive soil with PP fibre and chemically stabilizing with SF. To evaluate the performance of waste material as a stabilizer, compaction, Atterberg’s limits, free swelling index (FSI), electrical conductivity (EC), pH, swelling pressure, and California bearing ratio (CBR) tests have been conducted on treated and untreated specimens. Over the past few years, images from digital cameras have been successfully used to study crack morphology and various parameters of soils. The image processing technique has been used to evaluate the shrinkage limit by developing the MATLAB program code. The microstructural analysis has been carried out using scanning electron microscopy (SEM) analysis. The varying percentage of silica fume (2%, 4%, and 8%) and polypropylene fibre (0.25%, 0.5%, and 1%) by weight of dry soil were used to stabilize the expansive soil. The results show that the value of CBR increases and the shrinkage area decreases with an addition of SF and PP fibre. The experimental results also show a reduction in Atterberg’s limit with the addition of SF and PP fibre; as a result, the shrinkage behaviour of clayey soil reduces exponentially. The digital image processing technique showed a higher potential to understand the soil morphology for the large area.

Engineering Characteristics and Performance of Polypropylene Fibre and Silica Fume Treated Expansive Soil Subgrade

Hydraulic conductivity of gravelly soils with various coarse particle contents subjected to freeze–thaw cycles

Freeze-thaw performance of a cement-treated expansive soil

Sustainable reuse of coarse aggregates in clay-based impervious core: Compactability and permeability

Experimental study of the mechanical behavior of frozen clay–gravel composite

The invention discloses a sample preparation device and method for tensile test of soil engineering and a testing method. The sample preparation device comprises a sample preparation mold, wherein anintermediate tensile section of the sample preparation mold and tensile fixtures at the two ends of the sample preparation mold are detachably connected. After the accurate compaction treatment is carried out on a test sample by adopting an improved layered compaction device, the intermediate tensile section of the sample preparation mold is dismantled, and the test sample, the two ends of which are clamped by the tensile fixtures, is obtained; and the tensile fixtures are connected to a testing machine, so that the tensile test of the test sample can be carried out. The sample preparation device for the tensile test of soil engineering is simple in structure and improves the precision of sample preparation and the convenience of testing.

Zhang Yonggan

Papers

Freeze-thaw performance of a cement-treated expansive soil

Hydraulic conductivity of gravelly soils with various coarse particle contents subjected to freeze–thaw cycles

Sustainable reuse of coarse aggregates in clay-based impervious core: Compactability and permeability

Experimental study of the mechanical behavior of frozen clay–gravel composite

Sample preparation device and method for tensile test of soil engineering and testing method