Evaluating the strength of blended pavement materials stabilized with cement or lime additive

Abstract

The primary objective of this research was to evaluate the to evaluate the maximum strength of blended pavement materials stabilized with cement or lime additives, investigate the impact of blending RAP, CRR, Lateritic Gravel with cement or lime on the strength of resulting mixtures, and determine the optimum cement or lime content required to stabilize blended mixtures and come up with recommendations. It was involved carrying out experimental tests (Particle size gradation, Atterberg limits, MDD and CBR respectively). It was quantitative in nature. The laboratory work was based on the experimental design showing percentage proportions of the different samples explaining the variation of the information under conditions that are hypothesized to reflect the variations. Where there is 0% and 100% of respective samples indicate the control points in this study. The initial characterization of Neat gravel material was carried and then compared with characterization of blended and stabilized samples using cement or lime depending the experimental matrix. The particle size distribution exhibited an increasing GM as more CRR and RAP were added. However, the stabilized material sample registered a decreasing GM on addition of lime or cement because of increased fines. The test results exhibited an increase in the values of MDD with additions of RAP and CRR aggregates with a corresponding decrease in the OMC values. Similarly, there was increase in the strength for all additions in different percentages. The Liquid Limit, Plastic Limit and Plasticity Index decreased with the addition of RAP material, CRR and different percentages of Lime and Cement. This decrease in PL of the material sample is an indication of the chemical effect of calcium ion migration into the material sample which led to dehydration of a result of evaporation of moisture. The decrease was only noticed with addition of 1% of lime and cement respectively which later increased with addition of 3% and 5% of cement and respectively, this could have been as a result of an error in sample handling.