A new approach for stabilization of lateritic soil with Portland cement and sand: strength and durability

The presence of lateritic soils occurs in tropical and subtropical regions. The improvement of lateritic soils that are not suitable for a particular purpose through techniques that combine modification of grain size through the insertion of sand, incorporation of Portland cement and densification through compaction is seen as an alternative. In this context, a dosage method to use a local lateritic soil as construction material in a most rational way reducing the economic and environmental impacts related to this activity is still missing. Therefore, the current research aims to evaluate the performance of a lateritic soil via modification of grain size through the insertion of sand, incorporation of Portland cement and densification through compaction. For this, unconfined compression, and durability (wetting and drying) tests were carried out on specimens of compacted clayey gravel lateritic soil, whose granulometry was modified by the insertion of distinct amounts (from zero to 45%) of weathered sand, treated with distinct Portland cement contents (from 4 to 10%), molded at different dry unit weights (from 16.8 to 20.1 kN/m(3)) and cured for 7 and 28 days. Results of the mechanical tests have shown the significant influence exerted by cement content and dry unit weight of the blend, followed by curing time and finally sand insertion. Satisfactory correlations between the response variables (q(u) and ALM) and the adjusted porosity/cement index (eta/C-v) were obtained. Furthermore, an innovative approach to replacing the laborious durability test is proposed.