EPS Form Liners

This page documents a section of the bridge construction on U.S. Highway Route 12 in the southeastern Washington town of Waitsburg. Hotwire Direct became involved through a local concrete contractor who wanted to try foam as an alternative to building up the traditional wood forms for the form liner. The only machine used on this project was a CNC cutter with a straight wire.


Hotwire Direct: Before EPS expanded polystyrene foam for cast in place concrete bridge

This is the bridge with diverted traffic, before the concrete railing is poured.


Hotwire Direct: EPS expanded polystyrene foam cut for cast in place concrete bridge

The truck is loaded up with the shapes for the foam molds.


Hotwire Direct: 8700 CNC cuts EPS foam for cast in place concrete bridge

Hotwire Direct's 8700 CNC cuts the form liner (4 blocks at a time) in about 38 minutes using 2 wires.


Hotwire Direct: fill voids of EPS expanded polystyrene foam for cast in place concrete bridge

The fasteners are covered up prior to pouring.


Hotwire Direct: Attaching EPS expanded polystyrene foam to form of cast in place concrete bridge

The expanded polystyrene (EPS) foam is fastened by mechanical method.


Hotwire Direct: EPS expanded polystyrene foam for cast in place concrete bridge

The forms are put into position surrounding the rebar.


Hotwire Direct: EPS expanded polystyrene foam for cast in place concrete bridge

One side of the form has the EPS foam insert in place.


Hotwire Direct: pour concrete into EPS expanded polystyrene foam for cast in place concrete bridge

Pouring the concrete.


Hotwire Direct: EPS expanded polystyrene foam for cast in place concrete bridge Rebar

Close up view looking down on the rebar and the cavity that will take the concrete.


Hotwire Direct: After EPS expanded polystyrene foam for cast in place concrete bridge

Here is the finished bridge freshly poured with the forms removed.