A Comparative Investigation on Cement Stabilized Lateritic Soil Admixed with Sugarcane Bagasse Ash and Saw Dust Ash for use in Road Base

Abstract

- The study dealt with the effects of adding sugar cane bagasse ash (SCBA) and saw dust ash (SDA) in cement-stabilized lateritic soil on index properties, compaction characteristics and strength development. Unlike previous studies which focused on the effects of adding these materials without a comparative analysis, this investigation compares the behavior of lateritic soil cement when SCBA and SDA are added separately. Untreated lateritic soil, cement-treated lateritic soil, cement sugarcane bagasse ash and cement saw dust ash-treated lateritic soil(LS) for low-volume road suitability were studied based on Kenyan Pavement Design Guideline for low-volume sealed roads. A number of unconfined compressive strength (UCS) tests were performed initially as follows (0%, 3%, 5%, 7% and 9%) for different curing periods of 7, 14 and 28 days. According to Pavement Design Guideline for low-volume sealed roads, the study suggested 7% cement as the optimum cement content based on their 1.999 MPa UCS values which satisfied the requirement of 1.5MPa for UCS for road base for low-volume sealed roads in Kenya. The next study involved partially replacing the optimum cement content with sugar cane bagasse ash (SCBA) in the following proportions 0%, 2%, 4%, 6% and 7% to obtain the optimum cement & SCBA content required for optimum stabilization of lateritic soil for use in road base for low volume sealed roads. The final segment of this investigation involved partially replacing the optimum cement content with saw dust ash (SDA) in the following proportions 0%, 2%, 4%, 6% and 7% to obtain the optimum cement-SDA content required for optimum stabilization of lateritic soil for use in road base for low volume sealed roads. A number of tests were conducted, which included the Atterberg limits, compaction properties, California bearing ratio and unconfined compressive strength. According to the Kenya Pavement Design Guideline for Low Volume Sealed Roads, 5% cement and 2% SCBA was found sufficient to obtain a UCS of more than 1.5MPa for low volume sealed roads construction, and 5% cement and 2% saw dust ash was found adequate to obtain a UCS of more than 1.5MPa for low volume sealed roads construction, therefore sugar cane bagasse ash and saw dust ash acting singly as an auxiliary additive in cement can be used in the construction of lateritic soil road base for low volume sealed roads in Kenya.