Reliability studies on reinforced concrete beam subjected to bending forces with natural stone as coarse aggregate

This paper presents the results of structural reliability analysis of a structural element (beam) in building using First-order reliability method (FORM) to ascertain the level of safety. The natural stone (NS) which is the by-product of Precambrian deposits of the Bida trough was used as coarse aggregate: unwashed and washed aggregates were used. A total of 80 concrete cubes of 150 mm × 150 mm × 150 mm were cast and used for this study, sensitivity analysis was conducted by varying the span, depth, effective depth, area of shear reinforcement and dead load of the beam in bending. The result of the sensitivity analysis revealed that the beam utilising unwashed and washed NS are both structurally safe at a span of 3000 mm with probabilities of failure of 9.20 × 10 –5 and 2.06 × 10 –8 and both safe at a depth of 600 mm with probabilities of failure of 4.19 × 10 –4 and 2.602 × 10 –4 , respectively, in bending.