Investigation of buried full-scale SFRC pipes under live loads

Several studies investigated the mechanical performance of steel fibre-reinforced concrete (SFRC) pipes under the Three-Edge Bearing Test (TEBT). However, the field performance of buried full-scale SFRC pipes is yet to be duly investigated. This study is an exploratory investigation providing first time data on the behaviour of buried full-scale 600-mm diameter SFRC pipes under actual and simulated live loads. The first phase of this study monitored the behaviour of SFRC pipes under standard CL 625 truckloads. In the second phase, the post-cracking behaviour of SFRC pipes under artificial live loads was examined. Results showed that the current design recommendations for the pipe wall thickness in ASTM C76 for Type C wall are overly conservative. In addition, it was found that the SIDD method overestimates the vertical soil stress at the pipe crown and underestimates the horizontal soil stress at pipe spring-lines by 73% and 272%, respectively. Cracked SFRC pipes incorporating a relatively high fibre dosage exhibited less deformation than that of cracked regularly reinforced concrete pipes. Moreover, the post-cracking behaviour of SFRC pipes was more sensitive to the type of bedding installation rather than the type of steel fibres.