Geotechnical Properties of Lateritic Soil for Sub Base And Base Materials in Road Construction in Nyaruguru District, Rwanda
Lateritic soils have wider applications in Rwandan construction industry, especially in road-construction projects where they are used as filling materials in flexible pavement foundations. This study is aimed on to analyze the quality and suitability of the lateritic soils for Sub base and Base materials for road construction in Nyaruguru District, Rwanda. This is research utilized an experimental study design approach to implement this study. Four sites were randomly chosen throughout
... u district from which disturbed and undisturbed lateritic soil samples at a depth of 2 m were collected. The collected samples were analyzed with a series of standardized laboratory tests for soil to determine their properties and usage in road construction. The findings show that particle size distribution of lateritic soils found throughout all sample have high quantity of coarse gravelly soil the average is 46.81% apart from sample SL3 which had 26.04%, by using USC classification shown that all sites are gravelly silt except SL1 which is CL (sand lean clay with gravel). Natural moisture content range between 11.38 to 19% and mean value was observed at 15.31%. Maximum dry unit weight (MDD) and optimum moisture content (OMC) were found to be 2 KN/m3 and 2.43 % respectively. The specific gravity ranges between 2.66 and 2.93 with an average of 2.77. Liquid limits range between 23.2 to 35.5%, plastic limits 15 to 27.1% and plasticity index 6 to 10%. Average cohesion and angle of internal friction are 31.5 KN and 55.7° respectively. The CBR ranges from 14.17 to 32.9%. The results shows that lateritic soils from Nyaruguru district of Rwanda in area SL1, SL2, SL3 are suitable for sub-grade and SL1 and SL2 are also suitable for sub-base material since the geotechnical properties fairly within the regulatory standards.