A study of moisture distribution and volume changes in a Road-bed of black cotton soil Volume 1

Abstract

The object of the investigation was to study the variations of moisture distribution and volume changes in a subgrade of Black Cotton Soil. the decision to carry out the investigation was taken by the Transport and Road Research Laboratory of United Kingdom in order to compare the results with those obtained from their investigation on more permeable Red Coffee Soil which was started at Muguga in Kenya in 1961. That investigation revealed that the best choice for the verge cover for a road on Red Coffee Soil was a well compacted lateritic gravel and grass should be used if cost precludes the use of good gravel. The effect of increasing the slope of the shoulders was to reduce the amount of water infiltrating into the permeable subgrade. It was therefore decided that an experiment on more expansive clay such as the Black Cotton Soil should be carried out to see if the verge slope affect subgrade moisture distribution