THE USE OF PALM OIL FUEL ASH AS A PARTIAL REPLACEMENT OF CEMENT IN SANDCRETE BLOCK.

ABSTRACT

The ever-increasing cost of cement, coupled with the degrading environmental effects associated with mining and extraction of materials for cement and the actual manufacturing of cement has been of concern to government and private developers in Nigeria and beyond. To attend to these problems, the use of Palm oil fuel ash (POFA) to partially replace cement in sand crete blocks was investigated. An evaluation of the strength of sandcrete containing POFA and afterwards determination of the extent to which POFA can be incorporated in sandcrete blocks were carried out. To achieve study objectives, tests such as bulk density, and sieve analysis were conducted for some of the constituent materials to determine their suitability for the work at hand. Also 70 sandcrete blocks having standard size of 200 x 100 x 75mm were moulded and cured in water for 7, 14 and 28 days. The blocks were made from sandcrete blocks having 0%, 10% and 20% of cement replaced with POFA and a mix ratio of 1:6. Also, chemical analysis results show that POFA used has pozzolanic properties and that it belongs to class C pozzolans. The compressive strength results revealed an increase in strength as curing time increases for all replacement patterns. The 7- and 28-days compressive strength for 0% were 2.616Nmm2 and 2.987N/mm2 and that of 20% gave 2.160 and 2.9475N/mm2 . Though a downward trend in strength development was noticed as the percentage of POFA increases. Conclusively, POFA has pozzolanic properties and can beused to partially replace cement in sandcrete blocks. Based on the results, 10% replacement level is recommended.