Structural performance of a façade precast concrete sandwich panel enabled by a bar-type basalt fiber-reinforced polymer connector

In this study,a novel diagonally inserted bar-type basalt fiber reinforced polymer(BFRP)connector was proposed,aiming to achieve both construction convenience and partially composite behavior in precast concrete sandwich panels(PCSPs).First,pull-out tests were conducted to evaluate the anchoring performance of the connector in concrete after exposure to different temperatures.Thereafter,direct shear tests were conducted to investigate the shear performance of the connector.After the test on the individual performance of the connector,five façade PCSP specimens with the bar-type BFRP connector were fabricated,and the out-of-plane flexural performance was tested under a uniformly distributed load.The investigating parameters included the panel length,opening condition,and boundary condition.The results obtained in this study primarily indicated that 1)the bar-type BFRP connector can achieve a reliable anchorage system in concrete;2)the bar-type BFRP connector can offer sufficient stiffness and capacity to achieve a partially composite PCSP;3)the boundary condition of the panel considerably influenced the out-of-plane flexural performance and composite action of the investigated façade PCSP.

Effect of earth reinforcement,soil properties and wall properties on bridge MSE walls

Mechanically stabilized earth(MSE)retaining walls are popular for highway bridge structures.They have precast concrete panels attached to earth reinforcement.The panels are designed to have some lateral movement.However,in some cases,excessive movement and even complete dislocation of the panels have been observed.In this study,3-D numerical modeling involving an existing MSE wall was undertaken to investigate various wall parameters.The effects of pore pressure,soil cohesion,earth reinforcement type and length,breakage/slippage of reinforcement and concrete strength,were examined.Results showed that the wall movement is affected by soil pore pressure and reinforcement integrity and length,and unaffected by concrete strength.Soil cohesion has a minor effect,while the movement increased by 13–20 mm for flexible geogrid reinforced walls compared with the steel grid walls.The steel grid stresses were below yielding,while the geogrid experienced significant stresses without rupture.Geogrid reinforcement may be used taking account of slippage resistance and wall movement.If steel grid is used,non-cohesive soil is recommended to minimize corrosion.Proper soil drainage is important for control of pore pressure.