An investigation on the stiffness of timber sleepers for the design of fibre composite sleepers

This paper presents an experimental investigation on timber railway sleepers with a view to select a suitable stiffness and a modulus of elasticity for the design of a fibre composite railway sleeper. Eight full size timber sleepers were tested using a four point bending test arrangement. An overview of existing material for railway sleepers is also presented. Based on the tests, it is concluded that timber sleepers have significant variation in strength and stiffness as can be inferred from the modulus of elasticity (Esleeper) which ranged between approximately 9520 MPa and 27600 MPa. It is desirable to develop a concept fibre composite sleeper within a similar range of modulus of elasticity. Based on the statistical analysis, it is proposed to use the lower tail value that is 12000 MPa as design modulus of elasticity for the fibre composite railway sleeper.