Sustainable subgrade reinforcement for low-volume roads: Bamboo vs Geosynthetics

Abstract

Unpaved roads constructed on weak soil subgrades have often suffered severe damage, necessitating regular maintenance and repairs. While geosynthetics like geogrids and geotextiles have traditionally been used for soil stabilisation, their high cost has driven interest in sustainable alternatives. Bamboo grids have proven to be a viable alternative to synthetic materials for strengthening subgrades in low-volume road applications, offering environmental and economic benefits. Three test sections measuring 50 × 50 sq. cm have been constructed for dynamic cone penetration tests (DCPT) to assess in situ strength and penetration resistance. The effectiveness of bamboo in subgrade stabilisation has been assessed by comparing its performance to that of geogrid, geotextile, and unreinforced soil subgrade. A reduction in DCPI values has been observed in the bamboo-reinforced test sections compared to the unreinforced section. Test results have shown that bamboo grid reinforcement has reduced penetration depth by 65% compared to unreinforced soil and has matched the performance of geotextile reinforcement. These findings from the present study indicate that bamboo grids offer a viable, sustainable replacement for subgrade reinforcement and are locally available