Effect of Geosynthetic Reinforcement on CBR Strength of Soft Soil-Aggregate System

Abstract

AbstractIn the last few decades, geosynthetics have gained major popularity in improving the design and maintenance of roads. The various physical properties of geosynthetics have significantly influenced the road qualities and their construction methods. This paper evaluates the impact of geosynthetic reinforcement on the bearing strength of soft soil-aggregate systems using California Bearing Ratio (CBR) tests. Different geosynthetic materials, viz. woven and nonwoven geotextile, geogrid, and geogrid with woven and nonwoven geotextile (geocomposite) were used to reinforce the soil-aggregate system. The results showed that with the application of geosynthetics, the soil-aggregate system can sustain higher applied loads. While the use of geotextile prevented the intermixing of aggregates into the soil layer and vice versa, the reinforcement of woven geotextiles gave higher CBR values than nonwoven geotextiles. The better interlocking and lateral restrain of the aggregates in geogrid reinforcement yielded an increment of 43% in CBR strength. Improvement factor and reinforcement ratio were defined to analyse the impact of geosynthetic reinforcement on the bearing strength of the soil-aggregate system. The combination of geogrid and woven geotextile had maximum load-bearing capacity among all the reinforcing arrangements with an improvement factor of 1.85. The use of geosynthetic proved to be useful in limiting the pavement thickness, making road projects economical.KeywordsGeosyntheticGeotextileGeogridBearing strengthReinforcementCBR