Due to chaotic nature of flow in natural open channels and the physical processes and the unknown in a river basin variable, the parameters to be used in studying the behavior of river basin to a given rainfall data cannot be measured directly for this reason, a hydrological model was calibrated and applied to simulate the hydrology of Kaduna River (7112 sq miles) North West Nigeria. Prior to the model calibration, a sensitivity analysis of the hydrognomon model to the parameters was carried out to gain a better understanding of the correspondence between the data and the physical processes being modeled.

Lateritic stones abound in the tropical and semi tropical areas of the world more than the igneous and other standard rocks that are used as concrete aggregates and road chippings. The increasing utilization of natural aggregate for concrete production have created negative impact on the environment. Therefore searching for alternative material which has potential to replace the use of coarse aggregate from normalrocks in concrete mix either wholly or partially is very much in need. This research presents the engineering properties of concrete containing lateritic aggregate as partial coarse aggregate replacement. The coarse aggregate was replaced by 10, 20, 30, 40 and 50% with lateritic aggregate. All the specimens were cured and compressive strength test were carried out at the age of 7, 14, 21 and 28 days respectively. The result revealed that replacement of lateritic aggregate up to 30% was able to produce lateritic concrete exhibiting the target strength which is 30 N/mm 2. However, the slump decreases as the percentage of lateritic aggregate in the mix increases, this may be due to the porosity of the lateritic aggregate due to absorption of the water in the mix. The result of the two way analysis of variance shows that both lateritic aggregate and curing age (days) has significant effects of the compressive strength of concrete.