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Vibratory Power Screed

A vibratory power screed is an engine-driven beam that strikes off freshly placed concrete to grade while vibrating it, consolidating the surface zone in the same pass. Vibration settles the aggregate and draws paste to the top, leaving a flat, closed surface ready for floating and finishing.

Modèles

6.7-24.4 hp on listed units

Engine power

Marques

Fonctionnement

An eccentric weight spun by a small engine vibrates the screed bar or truss as the crew draws it across the placement, riding on wet screed guides, forms or pipe rails. The vibration momentarily liquefies the top layer, letting the bar cut high spots and fill lows while consolidating the surface. Listed engine ratings in the class run 6.7-24.4 hp; larger engines drive longer or heavier beam sections across wider placements in a single pull.

Types et variantes

Wet screed (float screed): One-operator bar screed worked directly on the wet surface without forms or rails — fast setup for slabs at moderate flatness demands.
Truss screed: Sectional triangular truss spanning between forms or rails, vibrated along its length; the format for wide paving and high-spec floors.
Roller screed: Rotating tube strikes off the surface with minimal vibration — suited to low-slump mixes and pervious concrete.
Magnesium bar screed: Light hand-drawn vibrating bar for small placements, patches and confined pours.

Spécifications clés

Spécification	Plage typique	Signification
Engine power	6.7-24.4 hp on listed units	Sets how long and heavy a beam the drive can vibrate effectively, which fixes maximum placement width per pass.
Beam length	assembled from sections; varies by model	Must span the placement between supports; sectional trusses extend to match pour width.
Vibration drive	engine-driven eccentric	Vibration intensity governs consolidation depth of the surface zone and how the screed handles stiffer mixes.

Comment l'industrie le dimensionne

Screeds are sized by the width of placement they must strike off in one pass. Handheld wet screeds cover narrow slabs and strips; truss screeds assemble from sections to span wide placements between rails, with engine power scaled to beam length. Crews size the screed to the formed width so passes run continuously without cold joints between strips.

Applications

Slab-on-grade pours
Driveways, sidewalks and patios
Parking lot paving
Roadway and highway paving strips
Warehouse and industrial floor placements
Bridge deck and topping strike-off

Sécurité et opération

Screed crews work bent over at the fresh-concrete edge; footing on wet grade and rebar mats is the routine slip-and-trip exposure.
Engine and eccentric assemblies transmit vibration to the handles; rotation among crew members limits hand-arm vibration exposure on long pours.
Truss sections are assembled and moved by multiple workers; pinch points at section joints and rail supports are controlled with planned lifts.

Normes et certifications

ACI · 302.1R: Floor and slab construction guide — strike-off, consolidation and the finishing sequence that follows screeding.
OSHA · 29 CFR 1926.300: General power-tool guarding requirements applicable to engine-driven screed drives.

Questions fréquentes

What does a vibratory screed do that a straightedge does not?

It consolidates the surface zone while striking off — vibration settles aggregate and brings paste up, closing the surface in the same pass that establishes grade.

When is a truss screed used instead of a wet screed?

When placement width, mix stiffness or flatness spec exceeds what a hand-drawn bar controls — the truss spans between forms or rails and holds grade across wide pours.

What follows the screed in the finishing sequence?

Bull floating while bleed water is absent, then power troweling in stages as the slab sets. The screed establishes grade and initial closure; it does not produce the final finish.