o r g a n i z a t i o n , t e c h n o l o g y a n d m a n a g e m e n t i n c o n s t r u c t i o n · a n i n t e r n a t i o n a l j o u r n a l · 4(2)2012 474Saw dust ash, Pozzolan, Workability, Compressive strengthKeywords this research considered the use of saw dust ash as a pozzolan in the production of concrete. the study investigated the physical properties and chemical composition of saw dust ash (SDA) as well as the workability, and compressive strength properties of the concrete produced by replacing 5%, 10%, 15%, 20% and 25% by weight of ordinary Portland cement with SDA. Slump and compacting factor tests were carried out on the fresh concrete and compressive strength test on hardened concrete. The concrete cubes were tested at the ages of 3, 7, 28, 56 and 90 days. The results showed that SDA is a good pozzolan with combined SiO2, Al2O3 and Fe2O3 of 73.07%. The slump and compacting factor decreased as the SDA content increased indicating that concrete becomes less workable as the SDA content increased. The compressive strength decreased with increasing SDA replacement. The compressive strength of concrete with SDA was lower at early stages but improves significantly up to 90 days.An optimum value of 23.26N/mm2 at 90 days was obtained for concrete with 5% SDA replacement. It was concluded that 5% SDA substitution is adequate to enjoy maximum benefit of strength gain. Saw Dust Ash as Partial Replacement for Cement in Concrete INTRODUCTIONThere is need for affordable building materials in providing adequate housing for the teaming populace of the world. The cost of conventional building materials continue to increase as the majority of the population continues to fall below the poverty line. Thus, there is the need to search for local materials as alternatives for the construction of functional but low-cost buildings in both the rural and urban areas. Some of the local materials that have been used are earthen plaster (Svoboda and Prochazka, 2012), lateritic interlocking blocks (Raheem et al., 2012) and Palm kernel shell (Raheem et al., 2008).Continuous generation of wastes arising from industrial by-products and agricultural residue, create acute environmental problems both in terms of their treatment and disposal. The con-DOI 10.5592/otmcj.2012.2.3 Research paper 475 struction industry has been identified as the one that absorbs the majority of such materials as filler in concrete (Antiohos et al., 2005). If these fillers have pozzolanic properties, they impart technical advantages to the resulting concrete and also enable larger quantities of cement replacement to be achieved (Hossain, 2003). Appropriate utilization of these materials brings ecological and economical benefits.Saw dust is a waste material from the timber industry. It is produced as timber is sawn into planks at saw mills located in virtually all major towns in the country. This process is a daily activity causing heaps of saw dust to be generated after each day. The need to convert this waste product into a useful by-product is the fo...