EFFECTS OF SAND AND CHIPPING DUST ON GEOTECHNICAL PROPERTIES OF LATERITIC SOIL

Abstract

The need to ensure that lateritic soils used for the purpose of construction meets the necessarygeotechnical requirements for civil engineering application formed the basis for the study. Thestudy was undertaken to evaluate the effect of sand and chipping dust on geotechnical propertiesof laterite. Laterite was stabilized with sand in an increasing order of 2.5%, 5%, 7.5% and 10%by weight of laterite, the laterite to sand mixture was thereafter stabilized with chipping dust inan increasing order of 2.5%, 5%, 7.5% and 10% by weight of laterite. The specimen wassubjected to series of laboratory testing. Some of the tests conducted are: sieve analysis test,specific gravity test, compaction test, atterberg limit (liquid and plastic limit) test and CBR test.Results obtained from sieve analysis test revealed that the chipping dust, laterite and sand wereclassified as A-2-6, A-6 and A-2-4 according to AASHTO Soil Classification System, SM, CLand SC according to Unified Soil Classification System, the specific gravity of sand, chippingdust and laterite was 2.55, 2.76 and 2.66, the liquid limit, plastic limit and plasticity index oflaterite was found to decrease on addition of sand and chipping dust, the maximum dry unitweight of laterite was found to increase on addition of sand and chipping dust while the optimummoisture content was found to decrease on consistent addition of sand and chipping dust tolaterite. Results obtained from CBR test revealed that the CBR of laterite increased on consistentaddition of sand and chipping dust with the laterite satisfying the criterion for use as sub-basetype 1 and 2 material for pavement construction.