ABSTRACT
The cost of steel rods and cement has become so high that it is becoming increasingly difficult for an average Nigerian to build reinforced concrete houses. Even though coarse aggregates could be got locally, the cost of production is also high. Thus, fewer houses are being erected nowadays. It will not augur well for the country if this trend is allowed to continue since the population of Nigeria is increasing daily. Therefore, there is a need to look for alternative building materials. Timber is one of such materials that can be used. Timbers that are good enough for structural elements are readily available in many parts of Nigeria and relatively cheaper when compared with the cost of steel rods. The fear of the prospective users of timber in this fashion is the fire hazard. This work therefore investigated the use of timber encased with concrete as an alternative to the conventional steel renforced concrete columns in buildings, especially in low cost housing schemes. The objective is to cut down the cost of columns in buildings, since timbers are available and cheaper. A lot of saving will also be made in the amount of concrete used. The results indicate that encased timber columns have adequate load bearing capacity for use in conventional residential buildings. It has been found from test results also that the bond strength between concrete and timber is adequate (averagely 1.95N/mm2) for achieving composite action in the encased timber column. The failure loads of the columns were also computed theoretically and. the results agreed favourably with the test results.