Influence of Waste Agricultural Fibre Products Material and Lime on Geotechnical Characteristics of Expansive Soils

Abstract

The study evaluated the failures associated with the sampled roads of Ebiriba, Ochigba, Eneka and Isiokpo in the Niger Delta of Nigeria with the application of composite materials of plantain rachis fibre ash + lime as soil stabilizer to strengthened the poor state of the failed sections. First stage of investigations classified the clay soils as A-7-6/CH on the AASHTO classification schemes / Unified Soil Classification System with percentage passing sieve #200 as 75.55%, 75.05%, 82.85% and 69.55%, unsoaked CBR values of 6.38%, 7.75%, 8.24% and 7.85%, and soaked CBR values of 5.25%, 6.03%, 6.35% and 6.30%, unconfined compressive strength (UCS) values of 68.85kPa, 77.35kPa, 79.85kPa and 65.57kPa.Soils fell below the minimum requirement for such application as road embankment and needs stabilization to improve their properties. Comparatively results shown in table 3.1 and 3.2 on compaction test parameters indicated increased values of maximum dry density (MDD) and optimum moisture content (OMC) relative to percentage inclusion increase. In contrast to results of tables 3.1 and 3.2, stabilized clay soils California bearing ratio of unsoaked and soaked values increased with respect to composite materials of plantain rachis fibre + lime percentile ratio with the optimum percentage of 0.75% + 7.5%. Cracks and values reduction were confirmed outside optimum percentile. Comparative results are shown in table 3.2 and figure 3.5 illustrated unconfined compressive strength tests increased relative to inclusion percentile increase. Comparative results shown in table 3.1, 3.2 and figures 3.1 – 3-4 showed decreased values of the plastic index  withrespect to additives inclusion percentages. The entire results showed the good potential of using plantain rachis fibre ash + limet as the soil stabilizer.