Jordan Journal of Civil Engineering

Paper Detail

Impact of Randomly Distributed Hay Fibers on Engineering Properties of Clay Soil

Volume 14, No. 3, 2020
Received: 2020/06/28, Accepted:


Abdulrahman Aldaood; Amina Khalil; Ibrahim Alkiki;


Natural fibers had been used as reinforcing elements since 3000 BC. Recently, reinforcing soil with natural fibers has become of key significance in investigations. Hay fiber has been selected for this study because of its tensile strength and bulk availability. Thus, it is anticipated that the strength of reinforced soil would increase and cracking of the soil would be minimal. To verify that, a series of experimental tests have been performed on natural and hay fiber-reinforced soil specimens. Four different percentages of hay fibers (0.25, 0.5, 1.0 and 1.5% by weight) were used in this study and various experimental test, including unconfined compression test, P-wave velocity test, free swell test, soil-water retention test and microstructural test, were conducted on natural and hay fiber-reinforced soil specimens. Results show that the strength behavior of soil specimens depends considerably on the hay fiber content. It is found that the unconfined compressive strength (UCS) increases as the hay fiber content increases up to 1.0%, then it decreases for higher hay percentage used in the current study. It is noticed that the interaction between hay fiber and soil compounds could control the mechanism of the reinforcement benefit. Consequently, the swelling potential decreases significantly as the hay percent increases. The water-holding capacity of soil specimens increases with hay content. Furthermore, the parameters of soil water retention curve (SWRC): volumetric water content and corresponding air entry value depend directly on the texture of the hay fiber. Microstructural test explains the variations in SWRC parameters. It is observed that these parameters are significantly affected by the change in the pore size distribution of hay fiber-reinforced soil specimens.


Hay fiber, Clay soil, Compressive strength, Microstructure, Water retention behaviour, Soil reinforcement.