Effects of Load Ratio Variation on the Safety of Timber Concrete Composite Floor

Abstract

This paper presents the structural reliability appraisal of timber concrete composite floor designed in line with Eurocode 5 (2004) and Eurocode 2, (2004). Limit state expressions for timber concrete composite floor subdued to tension, bending, tension and bending, shear and compression were generated and their entailed reliability degrees were assessed. The basic variables associated with the design are considered to be random variables with their properties espoused from the previous studies. Reliability analysis was performed using reliability mothed i.e. first order reliability method (FORM) owing to assess the safety levels of the composite floor structural elements by considering six different modes of failure. The analysis comprised of different selected species of softwood, hard wood and glue laminated timber whose strength class were obtained from BS EN 338, 2008 and concrete of strength class C30 from Eurocode 2. The results obtained disclosed that safety indices decrease as the load ratio steps up that led to cut down of the strength. It was detected that timber with strength classes D70, D50 and C50 are safe against all different failure modes looked at except C50 and D50 against shear failure at load ratio of 1, 1.5 and 2. It was conclude timber of strength classes D70, D50 and C50 would reliable for the construction of composite floor i.e. timber-concrete floor.