ABSTRACT
Over the years excessive energy consumption is one of the major problems associated with burnt bricks production. This study assessed the characteristics of burnt bricks containing polythene and sawdust as additives. Trial test was prepared from standard mix obtained from literature. It was done for different percentages of additives (0%, 5%, 10%, 15%, and 20%) blend of sawdust and polythene. A total of 324 bricks samples were cast out of which 216 were used for dry and wet compressive strength. Specimen samples were fired at temperatures of 8000C-13000C. The results obtained showed that the highest dry compressive strength obtained in the control samples fired at 11000C with 15N/mm2 and a minimum dry compressive strength of 12N/mm2 when fired at 8000C. Specimen samples A containing 20% polythene fired at 11000C had dry compressive strength of 13.1N/mm2 and a minimum of 7N/mm2 at 8000C. Samples E containing 20% sawdust fired at 11000C had a dry compressive strength of 6N/mm2 and a minimum of 4N/mm2 at 8000C. It was observed that there was a decrease in compressive strength as the percentage of polythene decreases and sawdust increases. It further reveals that the control at temperatures of 8000C, 9000C and 10000C exhibited low water absorption capacity of 11%, 11.6% and12.8% respectively, compared to the polythene and sawdust with 13%, 13.5% , 14% and 15%, 15.2 and 15.4% respectively. However both the control and samples containing additives showed 0.5% resistance to abrasion at firing temperatures of 8000C-10000C. The research concluded that regarding the dry compressive strength, wet compressive strength and abrasion resistance, the samples met the minimum strength requirement specified by (IS: 1077) at temperatures of 8000C, 9000C, 10000C and 11000C considered and have good resistance to abrasion according to (Gupta and Gupta, 2004) hence are suitable for use in the construction of buildings as a walling material. It was also concluded that samples with additives are more stabilised before firing than the control, though higher strength was obtained in the control than the samples with additives and both met the specification by (IS 1077: (1992).The research recommends that bricks with polythene and sawdust are badly distorted at temperature of 12000C which may be attributed to the internal heating contributed by the additives.