ABSTRACT
This study is an investigation into the effect of elapsed time after mixing on the properties of modified laterite. The modifiers used are portland cement and hydrated lime. The laterite was modified with 1, 2 and 3 percent of portland cement and hydrated lime. The elapsed time used for this study ranges from 0 to 3hours, with tests conducted at 1.0 hour intervals. Details of test methods and evaluation criteria are given. Preliminary result presented show that the laterite is classified as an A-6 soil, whose properties are such that they are not economically stabilizable or usable in their natural state for pavement works. Detail result presented show that with increased in elapsed time after mixing, optimum moisture content, maximum dry density, liquid limit, plasticity index, cohesion and angle of internal friction decreased while the grain size and plastic limit increased. Based on the grain-size and plasticity criteria of the Highway Research Board (HRB) limits for soils that can be stabilized with portland cement, and the Millard and O'Reilly free-flow criteria , the soil can be modified with 2% lime and 3% cement. Also, considering the effect of elapsed time after mixing on the modified laterite, acceptable modification is achieved at 2.0 hours for 1% lime and cement using the Highway Research Board criteria and 1.0 hour for 1% lime and 3.0 hours for 1% cement using the Millard and O'Reilly criteria.