www.ijecs.in International Journal Of Engineering And Computer Science ISSN:2319-7242 Volume 3 Issue 4 April, 2014 Page No. 5471-5494 D.B.Eme 1 IJECS Volume 3 Issue 4 April, 2014 Page No.5471-5494 Page 5471 PREDICTION OF ELASTIC MODULUS FROM COMPESSIVE MODULUS OF LIME STABILIZED LATERITIC SOIL FOR MECHANISTIC DESIGN USING THE SPLIT CYLINDER 1 D.B.Eme, 2 J.C.Agunwamba 1 Department of Civil Engineering, University of Port Harcourt Nigeria 2 Department of Civil Engineering, University of Nigeria Nsukka ABSTRACT In recent years there has been a change in philosophy in flexible pavement design from the more empirical approach to the mechanistic approach based on the elastic theory. The mechanistic approach is in the form of layered elastic theory which is being used by many agencies. Elastic theory based design methods require as input, the elastic properties of these pavement material for an effective design. In this study laterites were gotten from seven (7) local government areas in Rivers state. The laterites were classified using the AASHTO classification system, the properties obtained from the laterites indicates that it is an A -5 soil which is a silty-clay material. The material was mixed with different lime contents of 0,2,4,6,and 8% and compacted at the energy of Standard Proctor in 100mm diameter by 80mm long split cylindrical moulds, the compacted specimens were moist - cured and tested after 7, 14 ,21 and 28days. The CBR machine was used to load the specimen to failure through static load application. The failure loads as well as the horizontal and vertical strains were measured and used to predict Elastic modulus from compressive modulus using the SPSS programme, the result show that the Elastic and Compressive modulus increases with an increase in lime content up to 8% lime content, also the predicted values were close to the measured values with an average R 2 value of 92%, indicating that the predicted Elastic modulus can be used for mechanistic design of flexible pavement. KEYWORDS: Prediction, Elastic Modulus, Compressive Modulus, Lateritic Soil, Mechanistic Design, Split Cylinder. 1. INTRODUCTION In recent years there has been a change in philosophy in flexible pavement design from the more empirical approach to the mechanistic approach based on the elastic theory [7], [9] and [8]. Proposed by [11], this mechanistic approach in the form layered elastic theory is being used by increasing numbers of agencies. Elastic theory based design methods require as input the elastic properties of these pavement materials for an effective design. In contemporary flexible pavement design ,methods based on elastic theory requires that the elastic properties of the pavement material be known [5] concluded from their work that among the common methods of measurement of elastic properties which are (youngs, shear, bulk, complex, dynamic, double punch, resilient, and shell nomograph moduli) the resilient modulus is more appropriate for use in multilayer elastic theories. Pavement materials include Portland Cement Concrete; Asphalt Concrete Cement bound materials, compacted soils, rocks and sub-grades. They are materials that terminate by fracture at or slightly beyond the yield stress generally referred to as brittle materials. They are isotropic (ie displays the same properties in all directions) and are assumed to be linearly elastic up to a certain stress level (referred to as the elastic limit). Therefore knowledge of the elastic properties of pavement is very essential in elastic theory for the mechanistic design of flexible and rigid pavements, including overlays, in this design method the