Effects of Stabilizers on the Physical and Mechanical Properties of Clays Blocks: A Case Study Using Mangu Soil (Kenya)

Abstract

SoilsfromofManguand Igeganiaandare widely locally usedin construction.These materialsare vastlyused bylocal peoplein their natural statein order for makingcompressed earth blockswhicharedevelopedover timecracks andcracksin the walls.The termsof our workfocusedon the effects ofstabilizers onthe physical and mechanicalproperties ofcompressedearthblockswith thecase studyusing Mangu soilinthesub-county Manguthika (Kenya). Geotechnical studiesconducted both in the fieldand laboratorywere used to characterizeand classifynatural materialswhich enabled us to determine the need of improvethese materialsfor the production of good blocks.Compression tests, abrasion, and capillary absorptionwere carried out ontheproductblocks to confirm their suitability for using according to the standard. From the obtained results, particle size analysis of these naturalmaterials givescurves that are partiallyfit in the granular spindle of soilusedforcompressed earth blocks. Clay contentare85% and 45% respectively both sitesIgeganiaandMangu, andsandcontentsrespective12%and 5%attestingthe dominant presence offiner particles. Thelaboratory testshelped to confirm that soils are notsuitablefor the productionofcompressed earthblocksof good quality.However, adequate formulationimprovedthe particle size ofthematerialby adding 50% sandin orderto incorporatethe grain size ofthese materialswithin thegranularspindlerecommendedby the standardsfor the production ofblocks. The addition ofbinders such ascementclass35 andhydratedlime withrespective contentsof at least 6% and 7% are required to stabilized and improve the properties of compressed earth blocksmade,hey offer better compressive strength, abrasion resistance and improve the qualities of blocks to withstand in wet area. Moreover contribution insandon materialsthese siteswouldfavoran economy inbinders (cement and lime). However, the study enabled also to confirm that the using of plastic fibers highly improved the compressive strength to the same values of strength obtained using lime and cement. Plastic fibers helped by increasing the bound between the particles against crushing of blocks in compression of blocks then they are highly useful and recommended only for dry environmentin terms of economy mostly when the matter of cost reduction come that is helpful for people from the study areas.