An Investigation of Lateritic Soil Cement for Sustainable Pavements

Shortage of crushed rock as pavement base course for road construction and an increase in fuel cost have prompted the search for alternative materials. In this regard, improvements of the lateritic soil cement (LSC) have been investigated. Many researches have focused on study of the properties of the stabilized soil. However, more researches have to be done in order to explain how soil properties have improved. The production of crushed rock involves drilling, blasting, crushing and transportation, which are the cause of environmental problems. The objective is to use the improved lateritic soil instead of crushed rock as the base course material for highway pavement construction. In order to understand why the LSC has higher strength, microstructure of LSC composite was investigated by X-ray diffraction machine (XRD) and the Scanning Electron Microscope (SEM). The improvement of the unconfined compressive strength (UCS) of LSC composite was also evaluated. As regards the application aspect, the results show that cement mixed lateritic soils are suitable for base course construction. The investigation also shows that increase in UCS was attributed to the cement hydration within soil mass, resulting in the formation of reaction products as analyzed by XRD. It was also found that UCS was proportionally increased with the amount of the major reaction products such as calcium silicate hydrate (CSH).