Rice Lake Truck Scales - Manual (Page 17)

Pour and Finish Concrete Deck 13
7.0 Pour and Finish Concrete Deck
With a concrete crew of three experienced workers, a 70'-90' scale 14' wide can
be poured and finished in approximately three hours. Access to only one side of
the scale is necessary as most concrete trucks carry extension chutes at least 16'
long. If possible, order concrete in front-unloading trucks. The truck will be
moving slowly while filling each bay and the improved driver-visibility with
front-unloading makes that process faster and more accurate.
To protect against unsightly concrete splatters on the inside of the siderail beams,
you may want to tape 4-6 mil plastic against the inside surface of the siderails
starting at the finished deck level (top of cross beams) and running up the siderail several inches. If applied
carefully, the bottom tape strip can serve as a screed guide for the concrete deck surface against the siderails.
Rather than rest the weighbridge on the load cells, you may wish to raise the
siderails a fraction of an inch and rest them on temporary blocks as shown at
right. This is rarely necessary, but may prevent damage from a concrete redi-mix
truck accidentally backing into the scale frame and damaging the load cells with
a large lateral shock force.
With as little water added by the driver on-site as possible, mix the concrete in
the truck for a standard 4" slump.
Position the unloading chute at the far side of the scale over the first bay. Begin
filling the first bay, having the truck slowly move away from the scale to fill the
bay uniformly.
To ensure concrete flowing evenly into beam cavities and encasing all Nelson
studs and rebar, a concrete vibrator is highly recommended. These units are
available for rent at most construction equipment rental sources. They work very
quickly to level concrete, settle out surface stones, and leave a stone-free
“cream” layer at the top surface to make finishing easier.
After vibrating to approximate level, screed the concrete to the level of
the cross beams with a 2x4 board cut to the appropriate length. As this
first bay is too narrow to use a wide bull float, the final surface leveling
should be done with a magnesium hand float.