07-10-2014, 01:15 PM
Abstracts: For the design of flexible pavement, the sub-grade soil strength is estimated with California Bearing Ratio test (IRC-37-2001). In 1929, this test was developed by California State Highway Department (U.S.A.) for evaluating the bearing capacity of sub grade soil for design of flexible pavement and also used to the suitability of the materials used in sub-grade, sub base and base course. In this project only strength aspects of pavement sub-grade have been considered. In this study, laboratory investigations have been carried out on a number of soil samples procured from different roadwork sites. By Standard proctor test such as optimum moisture content & maximum dry density test, we can find moisture content in soil samples. CBR tests have been conducted for same samples under various conditions of soaking, with due emphasis on moisture content parameters in the soil sample. In this study for the purpose of comparison two different types of soils have been considered to study the variations. We can find out Soaked CBR value range from analysis is 3% to 5% for black cotton soil, 4% to 7% yellow soil & 5% to 7% for red soil and unsoaked CBR value 5% to 8% for black cotton soil, 8% to12% for yellow soil & 8% to 11% for red soil in particular Surat & Tapi Districts.