Raker beams that support the precast risers can be designed using steel or precast concrete.  Gravity connections between the precast riser and raker assembly should be designed with field access in consideration.  Gravity connection shown allows access to connection via blockouts in riser and connection is completed from above risers.  Connections are typically designated to be fixed on one end and allow slip on the other end for seismic design.  After connection is completed, foam voids are placed over bolted connection and blockout is grouted solid from top of riser.

A riser to riser connection is located between the riser stem (vertical leg) and tread (horizontal leg).  Access to connection can be an issue as bottom side of risers are not always accessible to complete connection in field.  A grouted connection from the top side of risers is a preferred connection.  Structural bolts are installed by precaster extending up past the riser stem at consistent spacing.  Recesses are also installed in the riser tread to match bolt spacing.  Horseshoe shims are placed around structural bolts and used to set riser at correct elevation.  Once risers are set to final position, recesses are grouted from above to complete connection.

NMB splice sleeves can be used in a variety of precast products that require a type 2 coupler. Rebar is constructed protruding from foundation and then cut to a specific distance above the foundation as required by size of NMB splice sleeve.  Female slice sleeve is embedded in precast and placed over protruding foundation rebar.  Once connection is complete at desired elevation, high strength mortar (that is provided solely by NMB manufacturer) is ejected into the sleeve via grouting tubes to complete connection.