Effect of Keratin Structures from Chicken Feathers on Expansive Soil Remediation

Table 1

Natural fibers used as reinforcement for modified soils.

Natural fiber	Percentage	Effect of reinforcement	Reference
Coconut (coir)	Data not included in reference	Reducing the swelling tendency of the soil.	[9]
	0.5, 1.0, 1.5, and 2	Reducing the resilient strain for soils.	[15]
Sisal	4	Imparted considerable ductility and also increasing slightly its compression strength. Prevention of shrinkage cracks due to the drying process.	[16]
	0.25, 0.5, 0.75, and 1	Reduces the dry density of the soil due to a low specific gravity and unit weight of sisal fiber. The shear stress is increased nonlinearly with increase in length of fiber. Increase in length reduces the shear stress. Cohesion is increased.	[17]
Palm	0.25 and 0.5	Cohesion increases linearly with fiber content. The increase in the length of fiber increases the value of internal friction angle. Coating fibers increase the shear strength of the soil.	[18]
Jute	0.25, 0.5, 0.75, and 1	Contributes to the resilient modulus of native soil under the freezing and thawing conditions.	[19]
	0.2 to 1	Reduces the maximum dry density while increasing the optimum moisture content. California Bearing Ratio value is increased more than 2.5 times.	[9]
Flax	0.6 and 0.8	Enhances the ductility of the material and eliminates the catastrophic failure pattern displayed by specimens without fiber-reinforcement.; An enamel paint coating was applied to the fiber surface to increase its interfacial bond strength with the soil.	[20]
Barely straw	1	Decreasing shrinkage, reducing the curing time, and enhancing compressive strength. Flexural and shear strengths were also increased and more ductile.	[9]
Bamboo	Data not included in reference	The root rhizomes of bamboo are excellent soil binders which can prevent erosion.	[9, 21]
Hay	0.5, 1, and 1.5	The dry density decreases. The optimum water content, the unconfined compression strength, shrinkage limit, and the swelling decrease with increasing hay addition.	[22]