When geotechnical engineers are faced with cohesive clayey soils, the engineering properties of those soils may need to be

improved to make them suitable for construction. The aim of this paper is to study the effect of using lime, natural pozzolana or

a combination of both on the geotechnical characteristics of two cohesive soils. Lime or natural pozzolana were added to these

soils at ranges of 0-8% and 0-20%, respectively. In addition, combinations of lime-natural pozzolana were added at the same

ranges. Test specimens were subjected to compaction tests and shear tests. Specimens were cured for 1, 7, 28 and 90 days after

which they were tested for shear strength tests. Based on the experimental results, it was concluded that the combination limenatural

pozzolana showed an appreciable improvement of the cohesion and internal friction angle with curing period and

particularly at later ages for both soils.