Showing papers on "Screed published in 1975"

Paving machine with thickness and leveling control

Abstract: A paving machine of the towed type having an undercarriage and a hopper adjustably positioned thereon with a screed adjustably secured to the hopper is provided with sensors engaging the supporting surface on which the undercarriage travels and means responsive to the actuation of the sensors for adjusting the hopper and screed relative thereto

Barrier levelling attachment

Abstract: A barrier levelling tool intended to be attached to median barrier forming continuous casting machines which provides a reinforced chute-like extension bridging the cast barrier and trailing the casting machine and which is adjustable from the face of the barrier casting machine so as to gauge and screed the flow of concrete in a smooth manner and in elimination of unsightly dips and peaks and so as to provide a constantly level top surface fully screeded and complete as it leaves the trailing chute. The present invention is a barrier levelling attachment for levelling continuously cast barriers and which trails behind the extruder head or gate of the casting machine and confines and levels the crown or upper surfaces of the barrier in avoidance of previously experienced sudden dips and peaks and in unlevel upper surfaces. The structure is adjustable and is sufficiently rigidified as to provide a supplemental screeding and finish trowelling effect on the concrete barriers as they are continuously cast.

Concrete screed means for aligned moulds

Abstract: Concrete screed means for discharging and screeding of wet mix concrete into a series of aligned moulds for the moulding of concrete sleepers having a hopper with two side walls a front wall and a rear wall but not base, a rearwardly extending flow guide plate having a vibrator secured to it but there being no vibrator on either of the side walls, and resilient means joining the flow guide plate to the rear wall of the hopper so that vibration of the guide plate is not transmitted to the remainder of the hopper.

Trolley for dispensing a mortar screed - for using a low viscosity resin modified mortar delivered by a pump

Abstract: Trolley with a reservoir for continuously accepting a fluid mortar pumped via a hose where the reservoir slopes down towards a broad low-level outlet blocked by a doctor plate which controls the deth and surface of the mortar deposited as the trolley moves along The trolley is used for depositing flooring screeds continuously without need for subsequent spreading or depth control

Effects of the clary screed and tube float on rigid pavement construction

Abstract: Effects of the Clary screed and the tube float, used as finishing devices on portland cement concrete pavement placed with a slipform paver, were examined on six construction projects. Alternate sections were finished with and without the Clary screed on three projects, and on three others with either none, two, four, or six tube float passes. Pavement roughness was measured with a California profilograph and surface mortar samples were tested for compressive strength. The screed, used without additional water, resulted in reduction of roughness and was not considered detrimental to the surface mortar. The tube float, normally used with a fog-spray of water, had little effect on roughness, and resulted in a substantial reduction in quality (compressive strength) of the surface mortar. Both devices helped close the pavement surface.