Showing papers on "Screed published in 1988"

Screeding apparatus and method

Abstract: An apparatus and method are disclosed for pivoting a screed assembly during screeding of placed and/or poured, uncured concrete or like loose, spreadable materials to maintain proper screeding contact by the screeding assembly with the concrete or like material by counteracting the force of concrete or other like material acting against the screed assembly as it is moved along the concrete The apparatus includes a support, preferably of the self-propelled type, a boom and boom mount, and a pivot between the boom and the screed assembly The axis of the pivot extends generally perpendicularly to the screeding direction in which the screed sassmblyis moved A power source, such as a pair of fluid cylinders, rotates the screed about the pivot axis, preferably in response to an electro-hydraulic leveling sensor mounted on the screed The lateral incline of the screed perpendicular to the screeding direction may be controlled about additional pivot axes orthogonal to the first A power operated elevation control is preferably responsive to a fixed laser beam reference plane positioned externally of the screed assembly The boom is telescoping and has multiple sections for extending and retracting the screeding assembly with respect to the support The screed preferably includes a vibration assembly vibrationally isolated from the remainder of the screed for smoothing the concrete

Portable screed with floating screed plate

Abstract: A portable screed for working concrete and having an elongated screed plate which has a flat bottom bearing surface and a width sufficient to permit the screed to float on the concrete while the screed is being guided by an operator. For imparting uniform vibrations to the screed plate for tamping the concrete, the screed includes a stiffening brace extending substantially the length of the screed, a series of rigid, spaced cross supports secured to the brace, and a vibratory mechanism connected to vibrate the screed plate through the cross supports. A motor is mounted on the screed plate for operating the vibratory mechanism.

Ultrasonic grade and auger control

Abstract: An ultrasonic grade and auger control for use on a road paving machine to compensate for uneven road surfaces is described. As the road paving machine travels, asphalt is centrally deposited along the road bed. An auger is connected to the back of the road paving machine and contains a series of spiral blades which moves the asphalt away from the center of the road bed toward its outer edges. The ultrasonic auger control apparatus detects the height of the asphalt positioned at the outer edges of the paving machine and regulates the speed of the auger to provide even distribution of the asphalt. A screed is located behind the auger to uniformly place and pack the paving material. The ultrasonic grade control apparatus regulates hydraulic actuators which control the thickness of the new road surface by adjusting the height of the screed.

Screed extender with berm-forming screed

Abstract: A screed assembly has two screed sections hingedly connected together at meeting beveled ends. The hing between the screed sections maintains a hinge axis at the soles thereof as one of the screed sections is swung upwardly to define a sloped face for a berm alongside a paving mat as a paving machine with the screed assembly progresses to form the berm and paving mat simultaneously.

Concrete screed rails

Abstract: A concrete screed rail having generally parallel spaced top and bottom edges, at least the upper one of which is provided with a finished surface, there being at least one and preferably a plurality of recesses in a web portion of the rail. The recesses in the web portion preferably are closed off by a thin layer of concrete, the concrete including that of said recess being reinforced by a mesh or plurality of short fibers. The screed rail may be in the form of a straight beam of I-section or alternatively of generally L-shaped cross-section. If desired, additional reinforcement may be incorporated in the rail.

Screed for asphalt paver

Abstract: A screed for an asphalt paver in which the bottom plate thereof is made of steel in the Brinell hardness range of 450-500 to engage road surfacing material. Stainless steel threaded studs are welded to the upper surface of the bottom plate for attachment of the screed to the asphalt paver.

Screed track for concrete slab construction

Abstract: A unitary extruded, plastic screed track is disclosed for use in connection with concrete slab construction. The screed track includes two elongated, parallel side members disposed in substantially vertical planes in close, spaced-apart relationship. An interconnecting member extends between the spaced apart side members at a point intermediate the top and bottom edges of the side members so as to form an H-shaped cross section. An elongated, bonding member projects outwardly from not more than one of the side members for anchoring the screed track to the concrete slab which is cast in place on one side of the screed track. A pair of oppositely extending flanges project outwardly from the lower edge of respective side members for transferring load between the concrete slabs cast in place on opposite sides of the screed rail.

Pavement thickness measuring device

Abstract: PURPOSE:To measure pavement thickness continuously at high precision and automatically regardless of the curvature of a road surface, by setting a sensor for measuring the levels of the road surface respectively before and after paving work. CONSTITUTION:A level sensor 10 before paving is set in front of a working position with a screed 36. A level sensor 12, after the paving, is fitted at the tip of a sensor arm taken to the rear section of a running car body 26 and is set at a position shifted positionally from the screed 36 at least. Values detected by both the sensors are fed to an arithmetic device, and pavement thickness is computed, and the computed values are fed to a display section, and are fed to the drive controlling section of a levelling arm 34 or the like, and a pavement value is kept to be a desired value.

Discharge fitting for a tiled floor of a sanitary shower

Abstract: The plastic gully (15) is manufactured by casting into a concrete slab (10) consisting of polyester concrete, inclined surfaces (13) leading from the slab edge to the gully, which is offset somewhat to the side. A sealing sheet (20) is fitted, fixedly connected, on the inclined surfaces (13), which sheet projects and with the aid of which a connection to the seal on the screed (3) can be produced. On the sealing sheet and the screed, tiles (2) are laid as far as a grate (19). The structural unit ensures a geometrically precise foundation and a step-free connection of the tile covering with the necessary gradient.

Machine for redeveloping the constructional layers of roads

Abstract: A machine is provided for constructing, in particular, redeveloping, the constructional layers of roads, preferably by re-using the old material removed from the road; wherein a receiving silo for the old material, which is mounted on a chassis of a motor-driven running gear, is feedable, preferably in regulatable quantities, to a horizontal stream crusher; said crusher being in connection, via a dosaging conveying device, with a mixer, also mounted on said chassis, whereto additional material components from at least one additional tank or silo, supported on said chassis, may be fed and wherefrom the prepared material ready for distribution is fed, by way of a conveyor worm, to a screed drawn along behind said chassis. Such a machine permits, in addition to the cold recycling of asphalt, also the construction of cold-mix foundation layers as well as a stabilization and a direct distribution of practically any supporting-layer materials.

Adjustable pipe screed support

Abstract: A screed chair having a base member and at least one threaded vertical member mounted therein supports a screed pipe on a yoke offset from the vertical member such that the yoke and pipe are isolated from rotation during rotation of the vertical member to adjust the height of the screed pipe.

Double-bearing shaft for a vibrating screed

Abstract: A portable vibrating screed includes a driven, vibratory rotatable shaft assembly mounted on an elongated frame equipped with means for screeding concrete. The shaft assembly includes a plurality of bearing assemblies spaced along the length of the shaft. Each bearing assembly includes a pair of separate bearing elements mounted on the shaft and supported in bearing supports secured to the frame. Failure of any single bearing element allows a companion bearing element in the same assembly to absorb all of the load imposed on such assembly to prevent shutdown and without impairing the needed vibration.

Paver with rotating disc floor

Abstract: A ground-travelling paver (10) for spreading aggregate over a surface includes a collecting hopper (30) for receiving material from a dump truck. Rotating discs (56, 58) form a portion of the floor of the collecting hopper (30). On operation of the discs (56, 58) aggregate is moved to cascade from a rear edge (52) of the collecting hopper (30) into a feed hopper (124, 120, 118). Material flows from the feed hopper (30) to a region in advance of a screed (100) in the paver. The collecting hopper (30) is also tiltable fully to clean aggregate therefrom.

Screed frame and stiffening apparatus

Abstract: The present invention includes a concrete screed frame having a first screed blade, a second screed blade and a camber top member arranged in a triangular cross section. A plurality of frame supports are transversely mounted between the first and second screed blades. A plurality of braces are mounted between the top camber member and the first and second screed blades. A telescoping tube assembly having a first tube and a second tube is mounted transversely between the first and second screed blades at the approximate midpoint of the length of the frame. A pin selectively fixes the relative position of the first and second tubes. Elongated structural means illustrated as a chain assembly is mounted to a screed blade and a tube to stiffen the screed frame and provides a chain-formed truss with the screed frame.

Device for the production and conveying of floor screed

Abstract: In the case of a device for the production and conveying of floor screed, comprising a motor-driven mixing device, a device for compressed-air build-up in the mixing device, a conveying hose connected to the outlet of the mixing device and a feed shaft opening into the mixing device, to obtain a high throughput with low personnel outlay and a uniform screed quality, it is provided that a supply and metering device (supply vessel 12) for the screed components is arranged exchangeably above the feed shaft (10).

Screed for finishing the surface of freshly laid road construction material

Abstract: A screed for finishing the surface of freshly laid road construction material, having a supporting beam which comprises a lower supporting plate resting on the finished surface and is fixed at the free end of tension arms which are articulated on a laying machine, and having a compacting element which is arranged in front of the supporting beam in the laying direction and is intended for exerting a compacting action on the road construction material by means of oscillating movements generated by a drive, is characterised in that the compacting element comprises a compacting beam which performs the oscillating movements, is aligned parallel to the supporting beam and has a lower compacting plate which acts in a flat manner on the road construction material. In its dimensions, the compacting plate is approximately equal to the supporting plate. The compacting element is held adjustably with respect to the set angle of its compacting plate to the bearing plane of the supporting plate of the supporting beam.

Distributor for concrete screed, and screed assembly comprising same

Abstract: A distributor frontally mountable on a screed to minimize or eliminate the manual distribution and leveling of freshly poured concrete which is otherwise required prior to screeding. The distributor comprises a rotatable body bearing an array of circumferentially and axially staggered plate elements. The plate elements may be swept back and are staggered so that only selected ones of the plate elements in the array are in contact with the wet concrete at any point in time of operation, with the direction of travel of the plate elements being toward the screed in the upper quadrants of rotation of the rotatable body, and away from the screed in the lower quadrants of rotation.

Sound-insulation bordering strips

Abstract: According to the invention, sound-insulation bordering strips for ceiling or floor structures are provided with an additional strip which, after laying of an insulating-layer covering, can be adhesively bonded thereto, with the result that any floating screed applied cannot run into the footstep-sound insulation.

Concrete path paver

Abstract: The concrete path paver of the invention comprises a generally rectangular open-ended box having a front wall and an inwardly sloped rear wall rigidly connected between a pair of side walls to define a bottom opening. An adjustable screed is positioned underneath the sloped rear wall from the rearward side of the bottom opening and extends a significant distance beyond the lower edge of the rear wall to form a slip-form mold. A platform is affixed rearwardly of the rear wall above the screed allowing an operator to stand thereon and control the flow of concrete from the cement truck into the box. The concrete path paver further comprises an arcuate or flat plate affixed to the lower front edge of the front wall of the box. The front plate functions as a ski to push and smooth dirt along the path that may have been disrupted by the tires of the cement truck. Thus, the tire tracks made by the cement truck as it pulls the paver are filled in and smoothed over prior to the concrete being laid. Further, the concrete path paver includes a pair of skids affixed along the lower edges of the sides to prevent the edges from digging into the dirt during pulling of the box.

Permanent plastic foil form for the production of the superior floor of a hollow floor

Abstract: of EP01270371. Permanent shuttering for the production of a cavity floor which rests on the subfloor by means of supporting feet, the upper part of the floor together with the supporting feet being formed by pouring a screed material, which in the fluid conditions is initially workable and subsequently sets, onto plastic sheets (10) which are arranged next to one another, have indentations (12) corresponding to the supporting feet, form the permanent shuttering and whose adjoining edges are connected to one another, characterized in that the adjacent sheets (10) are connected to one another in articulated manner by means of a plastic strip (14) which is attached in their edge regions and has a lower stiffned than the plastic sheets.

Process and means for filling undesired cavities and cracks during the production of composite screed, supports, joists, prefabricated compound units, etc., consisting of concrete

Abstract: During the production of screed and other structural parts consisting of concrete, cavities and cracks, which do not ensure 100% strength, often occur in the structural parts. Processes for filling such cracks, etc., the latter being filled by means of resin from the outside via dowels, produce unreliable results, are very expensive and cause a lot of dirt due to the resin. The disadvantages are eliminated by the introduction of a plastic hose into the part which is to be concreted, which hose is perforated and permits synthetic resin to be guided, by means of a pump, from the inside to hollow locations and cracks in the structural part in order to close up the latter, without harmful dust particles, air, etc. being able to penetrate during this sealing. The cracks which are visible from the outside (visible cracks) are closed off by a sealing composition which is removed again after the seal has hardened. In this arrangement, there is no dirt and no follow-up work.

Means for forming an edge zone between wall and screed

Abstract: For sound-insulation, a separating element in the form of a spacer strip is provided between wall and screed. The separating strip is fastened on the wall such that it is insulated via a retaining part, it being possible to produce the connection via corresponding latching elements. The separating element extends as far as the region above the screed, and at least the upper end region is configured in a resilient manner with respect to the wall as a retaining leg for a skirting-board wall which can be plugged on and clamped.

Concrete building construction

Abstract: A tubular frame is made of pieces of tubing (2) made of perforated paper or plastics, interconnected with junction pieces (4), and the base (8) of the frame is embedded in a concrete screed (6). Perforated reinforcing sheets (10) made of paper board (or of plastics or fabric) are attached to the framework e.g. by clips, and a mould is constructed from cardboard sheets which are spaced from each other by spacers passing through reinforcements in the reinforcing sheet (10); further folded sheets are placed around apertures such as doors or windows. Through openings in the top edge of the resultant mould, light-weight concrete is poured into the mould and fills it, so that the frame therein becomes an integral part of the concrete which also flows through the perforations in the reinforcing sheet (10). Walls, ceiling and roof can all be formed at the same time. After the concrete is dry the clips which attach the moulding sheets and these sheets are removed. The exposed surfaces may be treated with a resin as a protective coating. Houses can thus be constructed, preferably by using pre-cut reinforcing sheets of modular sizes, and a house can thus be built rapidly, and the mould materials can be re-used.

Asphalt paver operation targets smooth mats

Abstract: It is noted that while other factors such as mix design and compaction affect the final result, it is the mobile operation of the asphalt paver that can most dramatically affect the future performance of a roadway. The angle of attack, constant paver speed, and head of material are the important factors in the operation. Each of these factors are discussed in some detail. The angle of attack determines the amount of material which will pass under the screed. Problems with the head of mix in front of the screed are responsible for 80 to 90% of mat problems. Slowing down the paver will cause the screed to react, with the mat becoming thicker and developing a little higher density. Grade and slope controls are also discussed.

Screed with reinforcing elements

Abstract: The screed exhibits, in contrast to hitherto conventional sheet-like grid reinforcements, reinforcements (21) only in the border region of the screed slab (15), the reinforcement being effected by reinforcing elements (20) which give rise to static reinforcement of the screed slab (15) with respect to force components directed perpendicularly to the plane of the screed slab, and whose border regions, or borders, running out into the screed layer exhibit through-passages, protrusions or indents which produce a clamping connection to the screed material of the screed slab (15).

Calcium nitrite as a corrosion inhibitor in reinforced concrete bridge decks

Abstract: The use of calcium nitrite as a corrosion-inhibiting admixture in reinforced concrete has been studied on two bridges - the Kentucky 152 Bridge in Washington County and the Gose Road Bridge in Boyle County. Calcium nitrite was added to concrete used in the slabs, diaphragms and barriers of the KY 152 bridge and only in the slab of the Gose Road bridge. Construction of both structures was monitored in the fall of 1986. Placement of concrete on both bridges was satisfactory; however, problems were experienced in finishing the concrete. The finishing problems were related to: 1) concrete "stickiness"; 2) use of spinning-drum screed; 3) use of tyning for deck grooving; and 4) contractor inexperience with the concrete. The finishing problems included: 1) pulled or exposed aggregate; 2) pull cracks; 3) unclosed surface voids; and 4) irregular grooves. Compressive strength of the calcium-nitrite admixed concrete for both bridges exceeded 6,000 psi at 28 days. Freeze-thaw tests of specimens from the Gose Road bridge concrete (that incorporated a super water reducer) indicated no deterioration at 360 freeze-thaw cycles. Half-cell, corrosion-potential tests were conducted on both bridge decks in March 1987. Those tests revealed no active corrosion in either bridge. In July 1987, corrosion-potential and polarization-resistance tests were performed using stainless-steel reference electrodes buried in concrete across the deck of the Gose Road bridge. Those tests revealed that reinforcing steel in the bridge was in a passive state and that no active corrosion was occurring. Recommendations are included on remedying concrete-finishing problems. It is recommended that other experimental bridges be constructed using calcium nitrite.

Concrete ribbed slab for building construction, and process for producing and mounting the same

Abstract: The reinforced-concrete ribbed slab can be used, in particular, as a floor for building construction. It can, including the room-sized screed slabs transverse to the rib direction, be prefabricated cost-effectively in works producing precast concrete compound units.

Constructing method for crushed stone foundation and apparatus therefor

Abstract: PURPOSE:To obtain the foundation of high precision, by a method wherein a preload is applied to a spud to be pressed into the sea-bottom foundation to adjust the level of a rail beam device, and wherein the crushed stone foundation is constructed by means of screed construction. CONSTITUTION:A spud 3 is inserted and retained in a retainer 5 to adjust water in a tank 30 set on a rail beam device 4, and the device 4 is suspended to be moved down on the sea-bottom. Then, after the tip of the spud 3 is fitted on the sea-bottom 40, a spud-pressing-in device 20 is driven and a preload is applied to the spud 3 to be pressed in. After the rail beam device 4 is set on a specified level, crushed stones in a hopper 7 are fed to a screed via a tremie, and a crushed stone foundation is constructed. As a result, the rail beam device can be laid on a desired level at high precision and the construction of high precision can be accomplished.