IMPACTOFDIFFERENTFINEAGGREGATESONTHECOMPRESSIVESTRENGTHOF HOLLOWSANDCRETEBLOCKS

Abstract

Sandcreteblocksarewallingmaterialsthataremadeoffineaggregates and cement. Though, sandcrete blocks are being used as building materials inmanypartsofNigeria, ithasbeendiscoveredthatmanyof theblocks produceddonot conformto theminimumcompressive strengthrequirement for suchblocks. This study, therefore, examined theeffectofusingfour (4)different fineaggregates (quarrydust, river sand, shockingsandandplasteringsand)withbindertoaggregatemix ratiosof1:6and1:4onthecompressivestrengthof sandcreteblocks. Specificgravityandparticlesizedistributionanalyseswereconducted on the fine aggregates to determine their properties while water absorptioncapacityandcompressivestrengthtestswerecarriedouton thehollowsandcreteblocks. Fivesamples fromeachaggregateofsize 450mm x 225mm x 225 mm were moulded and subjected to compressive strength tests. The water absorption capacity results revealedthat shockingsandhas thehighest capacitytoabsorbwater withavalueof8.69%.Riversand,withavalueof6.67%hasthelowest water absorption capacity. The 28th day compressive strength test resultsof1.31N/mm2, 1.10N/mm2, 0.78N/mm2and0.50N/mm2 for thesandcreteblocksproducedfromquarrydust, river sand, shocking sandandplasteringsandrespectively,withmixratio1:6,didnotmeet theminimumrequirementof2.5N/mm2specifiedbyNIS87:2007for non-loadbearingwalls.However,withmixratioof1:4, thecompressive strengthof 2.52N/mm2 and2.50N/mm2 for sandcreteblocksmade with quarry dust and river sand respectively met this minimum requirement. Itwasconcludedthatonlyquarrydustandsharpsandat mixratio1:4aresuitableintheproductionofsandcreteblocks