Evaluation Performance of Polyurethane (PU) and Concrete Foam as Filler for Road Embankment: - A Soft Soil Treatment Solution

Abstract

Construction over soft soil has always possessed challenges for engineers as this type of soil is problematic due to its poor geotechnical characteristics. Overburden pressure over soft soil in road construction can cause cracks, ground instability, and settlement as the soil has low bearing capacity. This can reduce the quality of driving comfort to the road users, and high maintenance cost is required for repairing work. The lamination of Polyurethane (PU) and concrete foam as lightweight fill embankment can help to solve this problem due to its excellent mechanical properties such as high compressive strength. This study aims to quantify the engineering properties of Polyurethane (PU) and concrete foam as lightweight fill embankments for road subgrades through the Unconfined Compression Test (UCT), to compare the performance of natural soil and lightweight fill materials as pavement subgrades and to produce the best ratio lamination between Polyurethane (PU) and concrete foam. The laboratory test determined the physical properties of soft soil, and the Unconfined Compression Test (UCT) was conducted for natural soft soil, lamination of Polyurethane (PU), and concrete foam was tested with varied ratios of 1:4, 1:2, 1:1, 2:1, and 4:1. The laboratory test result shows that the unconfined compression test lamination of polyurethane and concrete foam significantly improves as compared with natural subgrades. The best ratio lamination was 4:1, where the achieved strength was 517.77 kPa with an axial strain of 8.57 %. It is expected that this study's result will help find a better alternative to lightweight material for road embankments. Lightweight material that is durable against high loading can overcome the ground instability preventing settlement and thus, promoting sustainability of the road pavement construction.