Prestressed concrete sleepers type E/F.21preliminary stress measurements at a site where cracking of sleepers has occurred (E-504)

14. When considering the prestressing and the tensile strength of the concrete none of the dynamic stresses obtained were sufficiently high to cause cracking under static conditions in E/F. 21 sleepers; in fact, these particular sleepers had not cracked in service, (It is not possible to record from a strain...