Construction and Monitoring of the Short-Term Strength Development of a Cement-Stabilized Lateritic Pavement Layer Under Tropical Climatic Conditions
Cement-stabilized lateritic soil is increasingly being adopted as the stiff cement-treated foundation layer in inverted base pavement layers for heavily trafficked roads. However, the mixing of cement and lateritic soil in the field without specialized equipment poses various challenges. In one such project, a cement-stabilized lateritic soil was specified as the foundation layer in an inverted pavement structure for a road construction project in Accra. This paper describes the mix design, the characteristics of the cement-treated lateritic soil and the results of the field trials and monitoring of the strength of the 200 mm thick cement-stabilized subbase layer over a 28-day period under tropical climatic conditions. A sample of lateritic soil was characterized, and the mix design using ordinary Portland cement as a binder was undertaken. Based on the mix design, the cement-stabilized layer was constructed first at a trial location to confirm the mixing procedures. Then, a 20 m long section on the permanent works was delineated for monitoring. The dynamic cone penetrometer test was performed on designated sections immediately after placement and after 3, 14 and 28 days to monitor the strength development. The uniformity of the mix in terms of the dynamic cone penetration test results is discussed. The changes in the unconfined compressive strength derived from the dynamic cone penetration index with pavement layer age under tropical climatic conditions is also analyzed, discussed and compared with laboratory prepared samples.
