Light Rail Track Slab

[peconsultant]

I usually just do buildings, but right now I am working on a light rail track slab. I would like some advice on constructability issues for the slab. The overall depth of the slab will be approximately 24". Should I design the slab as a monolithic pour or should I include a cold joint to the bottom of the rail? What issues should I be concerned with? I know it's probably a simple question, but this job is a little out of my comfort zone. Thanks in advance for your help.

 

[graybeach]

I have seen it done with pockets below each rail. Anchor bolts are then set in the base concrete, the rails are set to the proper elevation, and then a second concrete pour is done up to the bottom of the rails. I have also seen something similar without pockets. The rails are set on the bolts, and a thin epoxy pad is then poured. You can see some typical details or this at Gantrex's website.

I worked on a light rail project where the second option was done. The contractor put joints in the pads between each clip. This was disaster because the pads became delaminated at each joint. They were redone without joints which worked out fine as far as I know.