• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1999.10c
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• pp.594-598
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• 1999

To analyze the characteristics of unconfined compressive strength of reinforced soil bricks made of clayey and sandy mixed with cement, lime, staple fiber and their combinatioin , a series of unified comparessive tests was performed. The resutls are summarized as follows ; 1) Reinforcing effect of reinforced clayed soil and that of soil brick of sandy soil mixed with cement and staple fiber is 8 times greater than no reinforced sandy sol. Therefore, the reinforcing effect seems to be greater in sandy soil than in clayey soil . 2) Lime shows a negative reinforcing effect in clayed soil but a little reinforcing effect in sandy soil. 3) It is appeared that strain at failure of soil brick reinforced with staple fiber is greater than that of unreinforced brick regrardless of soil's type.

• Journal of The Korean Society of Agricultural Engineers
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• v.47 no.6
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• pp.59-70
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• 2005

A series of resonant column test was performed to investigate the dynamic deformation characteristics of silty sand soils mixed with polypropylene fibrillated type fiber. Results show that optimum mixing ratios were $0.2\%$ for 19mm of cut fiber for shear modulus and $0.1\%$ for 60mm cut fiber fur damping ratio. As shear strain was increased, normalized values of shear modulus (G(Reinforced)/ G(Unreinforced)) of fiber reinforced soil were increased up to $10^{-3}\%\~10^{-1}\%$ ranges. However, normalized damping ratio (D(Reinforced/D(Unreinforced)) was diminished with an increase in strain beyond $10^{-3}\%\~10^{-1}\%$ for the damping capacity of soils mixed with fiber. Normalized shear modulus $(G/G_{max})$ obtained from the test was plotted in the chart suggested by Seed and Idriss. The shear modulus of silty sand was located between sand and gravel curves.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.5 no.6
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• pp.37-42
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• 2002

This study has been performed to investigate the physical and mechanical characteristics of compaction, volume change and compressive strength for reinforced soil mixed with polypropylene fiber, and to confirm the reinforcing effects with admixture such as polypropylene fiber. To this end, a series of compaction test and compression test was conducted for clayey soil(CL) and polypropylene fiber reinforced soil. In order to determine proper moisture contents and mixing ratio, pilot test was carried out for natural soil and PFRS(polypropylene fiber reinforced soil). And the mixing ratio of mono-filament fiber and fibrillated polypropylene fiber admixture was 0.1%, 0.3%, 0.5% and 1.0% by the weight of dry soil. From the experimental results, it was found that the optimum moisture contents(OMC) increased with the mixing ratio of fiber, but the maximum dry unit weight and the volume change was decreased with the mixing ratio. It means that the improvement of the workability and the reduction of the weight of embankment was done by the addition of the polypropylene fiber. And, from the compression test results, it was found that the addition of the polypropylene fiber remarkably improved the compressive strength of PFRS. And it was observed in the viewpoint of strength that the fibrillated polypropylene fiber reinforced soil was more effective than the mono-filament polypropylene fiber reinforced soil.

• Proceedings of the KSR Conference
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• 2003.10b
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• pp.73-78
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• 2003

As a fundamental study to develop the retaining wall of new type, short-fibers are mixed with soils and a series of compaction tests and triaxial compression tests for short-fiber reinforced soils are performed. From the results of compaction tests, optimum moisture content is increased and maximum dry unit weight is decreased with fiber mixing ratio. When 60mm fibrillated fiber of 0.2$\%$ mixing ratio is added to SM soil, strength increment of short-fiber reinforced soil is above 1.2 times compared to soil only. Strength increment shows maximum value for composite reinforced soil, namely, soil+short-fiber+planar reinforcement. But in case of mixing with ML soil and short-fiber, the strength of short-fiber reinforced soil is nearly the same as soil only. Internal angle of short-fiber reinforced soil is increased about $2\~3$ degrees and cohesion is also increased above 10kPa compared to soil only. Therefore, it is judged that short-fiber is a good material to strengthen the soil.

• Journal of the Korean Geotechnical Society
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• v.16 no.6
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• pp.87-95
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• 2000

A series of consolidated undrained triaxial compression testes were performed to increase field applications of soil admixtures mixed with short fiber. Kaolin clay and three types of fiber were selected and auto cutter was used to obtain reliable length of fibers. Remolded soil specimens were tested for obtaining the basic data to be applied to the reinforcement of soft clay, embankment or barrier and clay liner of wastes landfill etc. Conversion equations from weight to volume of clay mixed with short fiber are introduced and relationships between fiber content and fiber concentration are derived. It is found that reinforcing effect by aspect ratio and mixing ratio of short fiber decreases as confining pressure increases. The best efficient reinforcing effect is given at the aspect ratio of 80~120 and the fiber content of 1.2%~2.4% and the fiber diameter of 0.27mm.

• Journal of the Korean Geotechnical Society
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• v.31 no.6
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• pp.15-25
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• 2015

This study aimed at the strength increase of the soft ground and analyzed the strength characteristics of clay soil reinforced with hair fiber which is environmentally friendly. The study varied the length of hair fiber, the amount of hair fiber, the amount of cement, and curing days to investigate both the compressive and tensile strengths and the stress-strain relationship of hair fiber mixed clay soils. The test results indicated that both the compressvie and tensile strengths increased with hair fiber mixed, especially in the tensile strength. In addition, the hair fiber mixed clay soil allowed larger displacement to failure. Based on the test results, it is thought that the environmentally friendly hair fiber could be utilized practically to increase the clay strength in the future.

• Journal of the Korean GEO-environmental Society
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• v.17 no.2
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• pp.23-29
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• 2016

This study was carried out with a view to increasing the tensile strength of sand soil and examined the characteristics of the tensile strength of sand soil reinforced by hair fiber which is environmentally friendly. The study investigated the change of the tensile strength and the stress-strain relationship varying the length of hair fiber, the amount of hair fiber, the amount of cement, and curing days. The test results indicated that the tensile strength increased significantly with hair fiber mixed. In addition, the sand soil mixed with hair fiber had larger displacement at failure. Based on the test results, it is appeared that the environmentally friendly hair fiber could be utilized practically to increase the tensile strength of sand soil in the future.

• Magazine of the Korean Society of Agricultural Engineers
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• v.45 no.6
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• pp.162-171
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• 2003

Traditional methods of earth reinforcement consist of introducing strips, fabrics, or grids into an earth mass. Recently, discrete fibers are simply added and mixed with the soil, much the same as cement, lime or other additives. The advantages of randomly distributed fibers is the maintenance of strength isotropy, low decrease in post-peak shear strength and high stability at failure. In this study, new composite reinforcement structures which consist of geotextile and randomly distributed discrete fibers were examined their engineering properties, such as shear strength of the composite reinforced soil and permeability of short fiber reinforced soil. The increments of shear strength of composite reinforced soils were the sum of increments by fiber and woven geotextile, respectively. The permeability of short fiber reinforced soil was increased with fiber mixing ratio.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1998.10a
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• pp.382-387
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• 1998

Triaxial compression tests were run to study on the undrained strength characteristics of fiber mixed kaolin clay(Hadong). The influence of various test parameters such as amount and aspect ratio(ratio of length to diameter) of fiber, confining stress was also investigated. Test results showed that the increase in aspect ratio was increased in deviator stress at failure, but no effect on pore water pressure at failure. Deviator stress at failure was also increased at 0.5％ mixing ratio(weight fraction of fiber to that of soil solid) of fiber but it was, thereafter, decreased and wits reached to constant after 2％ mixing ratio. On the contrary, Pore water pressure at failure was increased as mixing ratio of fiber was greater than 1%. Deviator stress and pore water pressure of both clay and fiber mixed clay(FMC) at failure were increased as confining stress was increased. Deviator stress of FMC at failure was about 10％ larger than that of clay, but pore water pressure of FMC at failure was almost similar to that of clay.

• Fashion & Textile Research Journal
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• v.2 no.4
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• pp.339-345
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• 2000

The effects of protease and/or lipase on the removal of protein soil and oily soil were investigated in this study. Cotton, rayon, nylon, and PET fabrics were soiled by padding of fresh bovine blood and spotting of mixed artificial sebum evenly. The soiled fabrics were aged at $130^{\circ}C$ for 30 minutes. The fabrics were washed by using Terg-O-Tometer at various conditions. Protease and/or lipase were added in the alcohol ethoxylate (AE) detergent solution. The removal efficiency was evaluated by analysis of protein and/or oil on the fabrics before and after washing, respectively. The detergency of protein and/or oil on the fabrics was discussed with enzyme concentration, washing time, washing temperature, pH of washing solution and fiber characteristics. The hydrolysis of protease improved effectively the removal of oil as well as protein by increasing removal of protein-oil mixed soil at the same time. The effect of lipase added detergent solution was slightly shown on the removal of oil and/or protein. The removal of mixed soils from cotton fabrics was very low because of large amount of residual soils caused by the physical characteristics of cotton fiber.