Natural Para Rubber in Road Embankment Stabilization

Abstract

This is the first study on “ribbed smoked sheets (RSS)” as a geogrid reinforcement in geotechnical engineering. An RSS is a kind of natural para rubber. RSS (grade 3) was designed as a biaxial geogrid with an aperture size of 20 mm × 20 mm and a spacing of 20 mm. The RSS was found to be a significant functional layer when applied to the subbase lateritic soil layer. The lateritic soil with an RSS reinforcing layer was greatly improved regarding the California bearing ratio (CBR). Numerical simulation using two-dimensional finite element software was used to determine the optimal number and positions of the RSS reinforcing layers in road embankment stabilization. The simulation data in terms of horizontal displacement of unreinforced road embankments was validated by the collected data from the actual construction site. The RSS reinforced layer was varied from one to three layers under 61 analysis conditions. The highest safety factor was obtained with two layers of RSS at 0.1H below the top of the road embankment and 0.4H below the first RSS layer, suggesting a suitable installation of the RSS reinforcing layer. The RSS is thus strongly recommended as a reinforcing material in low CBR lateritic soil for the road embankment.

Evaluation of Interface Shear Strength Coefficient of Alternative Geogrid Made from Para Rubber Sheet

“…The RSS, which was called the RSS geogrid, was produced from coagulated latex sheets, which are smoked in an oven at a suitable temperature [ 22 ]. The thickness of RSS was between 2.50 mm and 3.90 mm [ 18 ]. According to ASTM D6637-01 [ 23 ], the ultimate tensile strength of the RSS geogrid was tested in the machine direction (MD) and the cross-machine direction (CD), which were repeated 3 times as shown in Figure 3 a.…”

“…Hence the price of para rubber has decreased continuously. To solve this problem, the natural para rubber or ribbed smoked sheet (RSS) was studied to be used for the function of geogrid reinforcement [ 17 , 18 ]. The RSS was applied to increase the CBR of low-CBR lateritic soil.…”