Abstract: Method for manufacturing modular, hollow, prismatic, monolithic reinforced-concrete elements of rectangular section, which includes the stages of concreting their side walls in two horizontally arranged formwork structures, carrying out a rotation of said formwork structures so as to leave them arranged vertically on either side of a third formwork, with said third formwork horizontal, then concreting the floor slab, placing formwork between the side walls for concreting of the ceiling slab and withdrawing the modular element, so that a high degree of monolithism is achieved, a method in which all the concretings are carried out in the horizontal, and precise control is achieved over the measurements of the element obtained.

Abstract: A cementitious material delivery system may include a pump configured to pump cementitious material and an accumulator. The accumulator may be a decoupling accumulator and may contain a reservoir configured to store cementitious material, an accumulator inlet to the reservoir configured to receive cementitious material pumped by the pump, an accumulator outlet configured to deliver cementitious material from the reservoir, and a pressure applicator configured to apply pressure to the cementitious material that is delivered from the accumulator outlet.

Abstract: A method and an apparatus for automatically making conglomerated structures (6).

Abstract: A method and apparatus for casting concrete elements with varying, determined length, equipped with one or with a plurality of longitudinal hollow cores, by means of a slipforming apparatus. The apparatus is movable with respect to the bed (2), said apparatus comprising forming members (10) for forming hollow cores. The mass is fed in the first step to the portion of the slab below the hollow cores, and in the second step the hollow-core forming members being brought onto the said portion of the slab and mass is being fed between the forming members and onto them. The forming member (10) for forming a hollow core comprises an attachable extension part (22). The height of a hollow core is changed by changing the extension part of the hollow core forming member.

Abstract: A robotic system may include a movable gantry robot, and a nozzle assembly movably coupled to the overhead beam of the gantry robot. The gantry robot may include an overhead beam extending between, and supported by, at least two side members slidably mounted on a pair of rails. The nozzle assembly may be coupled to the overhead beam of the gantry robot, and may be configured to extrude material through an outlet. The robotic system may further include a position controller configured to control position and movement of the gantry robot and the nozzle assembly.

Abstract: An extrusion construction system may include an extrusion nozzle configured to extrude construction material through an outlet onto an external surface, the extrusion nozzle including an excess flow port disposed substantially adjacent an edge of the outlet, an imaging device coupled to the extrusion nozzle, and a controller configured to adjust the rate of material flow through the extrusion nozzle in response to receiving one or more images captured by the imaging device showing excess material being extruded through the excess flow port.

Abstract: A concrete wall fabrication system includes an endless track, mold carriers movably supported on the endless track for carrying a respective set of formworks for molding concrete into multiple concrete walls at a time, a concrete spouting unit set above the endless track and controlled to discharge a predetermined amount of concrete into each mold carrier, a vibrator unit set above the endless track and operable to vibrate the concrete in each mold carrier, and finished product collector unit set near one side of the endless track for collecting the finished concrete walls from each mold carrier for packing.

Abstract: Methods and apparatus for fabricating structures, extrusion units, and structures fabricated using such methods and apparatus are disclosed. The apparatus may include a support configured for rotation about a central axis, a carriage that may move along the support when the support rotates about the central axis such that the carriage may move along a first spiral path about the central axis, and an extrusion unit that may be supported by the carriage and may move along a second spiral path as the carriage moves along the first spiral path. The extrusion units may be configured to extrude a strip of material through an extrusion die as the extrusion unit moves along a previously extruded strip of material such that the extruded strip may be fused onto the previously extruded strip as the extruded and previously extruded strips pass the extrusion die.

Abstract: A self-raising form control system and method is provided that that may be used to form elevator shafts and other vertical building structures. The apparatus includes one or more form elements for defining an area to receive a formable material, such as concrete. Each element is attached to the form structure. A lift apparatus is provided for lifting the form elements. The lift apparatus comprises a measurement device for measuring the position of said lift apparatus relative to a fixed point. The lift apparatus is connected to the form structure. A control unit is provided for controlling the lift apparatus. The control unit is signal connected to the measurement device and is signal connected to the lift apparatus.

Abstract: An apparatus may include a nozzle assembly configured to extrude material through an outlet; and a controllable robotic arm coupled to the nozzle assembly, the robotic arm having at one end a gripper configured to pick up an element and deposit the element at a desired position relative to the extruded material. The element may be one of: a reinforcement member for a structure being constructed; a segment of a plumbing pipe; an electric network component; and a tile.

Abstract: A device (1) for manufacturing a three-dimensional object by a layer-wise solidification of a building material at positions in the respective layers that correspond to the object is provided. The device has a machine frame (2, 3, 4, 5) and support legs (51) that are mounted at the machine frame and by which the device (1) is supported on a substrate. The support legs (51) are arranged such that a three-point support of the device (1) at the substrate is given and at least two support legs (51) are mounted at the machine frame such that they are adjustable in height.

Abstract: An application device (27) for applying a layer of a building material in powder form in a device (1) for manufacturing a three-dimensional object by a layer-wise solidification of a building material at positions in the respective layers that correspond to the object is provided. An application element (61) that applies the building material in powder form in the form of a layer and a drive mechanism (59) that moves the application element (61) across a building plane (11) in order to apply the layer of the building material are provided. The drive mechanism (59) comprises an actuation piston cylinder system (69) and a brake piston cylinder system (70).

Abstract: A device (1) for manufacturing a three-dimensional object by a layerwise solidification of a building material at positions in the respective layers that correspond to the object is provided. The device comprises a machine frame (2, 3, 4, 5) and a building space (10) that is arranged in the machine frame. In the building space (10) there are arranged: an application device (27) that applies layers of the building material onto a support device (26) and a previously applied layer, respectively, by an application element (61); a dosage device (28, 29) that provides building material for the application device (27) for an application, and a heating device (31) for heating the applied layers of the building material. The application element (61) and/or the dosage device (28, 29) and/or the heating device (31) are removable from the building space (10) without a tool.

Abstract: A multi-nozzle assembly may include a first nozzle configured to extrude material through a first outlet; a second nozzle configured to extrude material through a second outlet; and a third nozzle configured to extrude material through a third outlet, the third outlet being between the first and second outlets. Related construction processes and wall structures are also disclosed.

Abstract: An apparatus for forming concrete structures includes a first truss module and a second truss module, as well as a first and a second concrete form. The apparatus further includes a first and a second actuator device. Each first and second actuator device is mounted on the respective first and second truss module, and each first and second actuator device can move the respective first and second form translationally with respect to the respective first and second truss module. A yoke connects the first truss module to the second truss module to thereby place the concrete forms in generally parallel, spaced-apart relationship. A climbing device attached to the yoke can engage a climb rod and can move the apparatus upward along the climb rod.

Abstract: A method and apparatus are disclosed for slip-form casting a concrete product, the product being made from at least two different grades of concrete so that the concrete mix grade can be changed in an uninterrupted fashion during casting at a desired point along the length of the casting bed.

Abstract: A method is disclosed for casting a concrete product using two or more different grades of concrete mix, in which method predetermined amounts of different grades of concrete mix are delivered at appropriate instants into the feeder hopper of the slip-form casting machine.

Abstract: A method is provided for use of a concrete composition and an associated apparatus. The method provides for mixing of the concrete material, accelerant powder and, optionally, an associated substance to enable the controlled hardening of the concrete material in a monolithic structure. The apparatus can dispose a slip-plane film to facilitate a relatively continuous process.

Abstract: An apparatus and a method for impressing three-dimensional patterns in a slip-formed concrete wall. At least one impression roller is provided at the discharge end of a slip form. The impression roller includes an outer periphery, provided with a layer or coating of resilient material. The layer is pre-formed or pre-cast to include an aesthetically pleasing, three-dimensional pattern. The axis of the roller is maintained in parallel relation to the plane of the exposed surface of the wall, with the outer periphery of the roller slightly depressed into the wall surface. As the uncured concrete wall emerges from the slip form, the impression roller places a pattern into the wall surface which corresponds to the pattern on the roller. Movement of the roller along the wall causes the impression roller to rotate, impressing successively formed portions of the wall with the pattern. Additional rollers may be used to impress patterns on the opposing wall surface, as well as the top wall surface.

Abstract: A method of forming a circumferentially closed wall having the same cross-section over its entire length included providing at least two circumferentially closed inner falseworks each formed of circumferentially closed inner part and a circumferentially closed climbing strip releasably securable to an upper end of the main part. A concrete wall is formed in a plurality of concrete-placing steps, with use of the inner falseworks in more than one step. In a first concrete-placing step, an initial section of a concrete wall is formed. In each subsequent concrete-placing step, a circumferentially closed concrete wall section is formed on an upper end of an already formed section of the concrete wall.

Abstract: A method of constructing a rail track in which a concrete track slab is produced and rail track anchor members are inserted in the track slab by an inserter system mobile along the route of the rail track includes the following steps: using a machine for continuously pouring concrete to produce two concrete walls laterally delimiting the edges of the track slab to be poured; pouring the concrete track slab between the walls; and using the inserter system to insert anchor members in the freshly poured track slab, the tie plate inserter system being adjusted accurately by a measuring station, topographical survey points, a measuring system, and reflectors carried by the inserter system.

Abstract: A method for successive concrete of high vertical walls by using a climbing shuttering system having a support structure on which various concrete shuttering elements are loaded hanging downwards. The top supporting carrier and the climbing shuttering system can be supported on completed wall sections. There is at least one lifting device that brings about a relative movement between the too supporting carrier and a lower support carrier of the climbing shuttering system. The shuttering elements can be positioned in a substantially even surface to form a shuttering and at the same time the top supporting carrier can be positioned on the shuttering elements placing them respectively against the walls.

Abstract: Sanitary wares are pressure-cast on a single mold machine comprising a bed and two platens associated with the bed, each one supporting a respective mold half; one of the two platens is translatable along the bed in a longitudinal direction, whilst the other incorporates a tilting platen carrying the respective mold half and is rotatable about a horizontal axis extending perpendicular to the longitudinal direction; the accessibility to the mold halves and to the casting are improved and therefore the operations of demolding the green wares and transferring them to successive stages of manufacture are much facilitated, as also is the procedure for changing the mold.

Abstract: A method is provided for use of a concrete composition and an associated apparatus. The method provides for mixing of the concrete material, accelerant powder and, optionally, an associated substance to enable the controlled hardening of the concrete material in a monolithic structure. The apparatus can dispose a slip-plane film to facilitate a relatively continuous process.

Abstract: A molding device for placement of formed cementitious material such as concrete on a mounting surface. The device is used in combination with a supply of pressurized cementitious material communicated through a hose from a conventional cement pump or the like. It features a mold unit having an a compression chamber at a first end communicating with an extrusion chamber at a second end. Cement material is forced into the compression chambers from the cement pump and extruded from the exit orifice of the extrusion chamber. The device is propelled forward by the pressure from the injected cement against the front of the device and away from the formed material means control any upward travel of said mold unit caused by said internal pressure against said top wall. Weights may be added to the top of the device to limit upward travel and a steering mechanism may be added to the front of the device to steer it on a defined course.

Abstract: An apparatus for forming concrete structures includes a first truss module and a second truss module, as well as a first and a second concrete form. The apparatus further includes a first and a second actuator device. Each first and second actuator device is mounted on the respective first and second truss module, and each first and second actuator device can move the respective first and second form translationally with respect to the respective first and second truss module. A yoke connects the first truss module to the second truss module to thereby place the concrete forms in generally parallel, spaced-apart relationship. A climbing device attached to the yoke can engage a climb rod and can move the apparatus upward along the climb rod.

Abstract: An apparatus and a method for impressing three-dimensional patterns in a slip-formed concrete wall. At least one impression roller is provided at the discharge end of a slip form. The impression roller includes an outer periphery, provided with a layer or coating of resilient material. The layer is pre-formed or pre-cast to include an aesthetically pleasing, three-dimensional pattern. The axis of the roller is maintained in parallel relation to the plane of the exposed surface of the wall, with the outer periphery of the roller slightly depressed into the wall surface. As the uncured concrete wall emerges from the slip form, the impression roller places a pattern into the wall surface which corresponds to the pattern on the roller. Movement of the roller along the wall causes the impression roller to rotate, impressing successively formed portions of the wall with the pattern. Additional rollers may be used to impress patterns on the opposing wall surface, as well as the top wall surface.

Abstract: The present invention relates to a multiple foam substrate of predetermined shape and a method of manufacturing the substrate. The substrate is a multiple foam substrate which may be manufactured by the method with a mold having first and second mold cavities. The method includes injecting a first foam into the first mold cavity sufficiently to fill the first mold cavity and storing the first foam in the first mold cavity for a predetermined time sufficient to form a substantially non-mixing surface on the first foam. The method further includes injecting a second foam into the second mold cavity and onto the non-mixing surface on the first foam sufficiently to fill the second mold cavity. The method further includes storing the second foam in the second mold cavity for a predetermined time sufficient to bond the first foam to the second foam along the non-mixing surface.

Abstract: An adjustable reinforcement insertion guide is installed within the slip form mold of a mobile concrete slip form machine, for guiding steel reinforcement screens into the mold interior during the casting of continuously poured concrete barrier walls (i.e. “Jersey Walls”). The guide is vertically adjustable, in order to clear curbs, open cut joints, etc, as required. Additional adjustment is provided for a series of laterally adjustable outlet panels on the back of the guide, which provide additional accuracy and adjustment in guiding the steel mesh or screen which passes through the guide. The guide is fixed to the mobile slip form machine (with the exception of the vertical adjustment of the guide relative to the slip form machine), and travels with the machine as fresh concrete is introduced into the slip form mold of the machine.

Abstract: The invention concerns a climbing shuttering system having a supporting structure on which various concrete shuttering elements are loaded hanging downwards. Said structure is connected at least to a first top supporting carrier that underprops it. The top supporting carrier has the means, to support it laterally to a completed wall section. The climbing shuttering system also has at least one lower supporting carrier, that can be supported on a completed wall section. There is at least one lifting device that brings about a relative movement between both supporting carriers. According to the invention, the top supporting carrier is designed to be supported on a substantially even surface.

Abstract: A method and apparatus for constructing a shelter from ice or snow. A slip form allows snow or ice to be formed in situ into building blocks that form the shelter. The slip form comprises two vertical side pieces and incorporates an end cap that holds the side pieces together and allows the slip form to separate upon impact rather than fracture. A telescoping pole is attached at one end to one of the side pieces of the slip form, and at the other end to a spike that is driven into the ground to provide a reference point for the construction of the shelter. The telescoping pole incorporates two or more sections. The first section comprises a series of predetermined apertures that receive a tab or pin integrated into the second section of the telescoping pole. The outer diameter of the second section is smaller than the inner diameter of the first section, thus allowing the pole to retract by placing the second section into the first section.

Abstract: Pre-stressed concrete railroad ties are manufacture by the slip form process in the absence of mold members, other than the slip form itself. Tie casting occurs on a portable casting soffits between portable soffit anchored deadmen supporting the pre-stressed tie tensile members immediately overlying the casting soffit. Tie formation occurs with the slip form passing around and over the pre-stressed tension members. Track fastening hardware is vibrationally inserted through windows of the slip form to place the track fastening hardware to precise measured dimension along the route of slip form movement and to configure that portion of the tie adjacent the track fastening hardware. End of tie locations as well as tie batch identification are likewise marked during the slip form process. Upon cure, the ties are cut at their marked end location.

Abstract: The present invention relates to a concrete forming system and method permitting a series of stacked concrete slabs to be formed at a work site. The system includes a vertical support member configured to the work surface, concrete form members for defining a desired shape for a concrete slab and horizontal adjustment members for attachment of the form members to the vertical support member. Through use of the system, a series of stacked concrete slabs can be successively poured one on top of the other.

Abstract: An elongated structural member suitable for use as a marine piling includes a continuous, extruded plastic body having rebar disposed within the plastic body and extending in the lengthwise direction of the structural member. The structural member is formed by continuously extruding a molten plastic into a die so that the molten plastic surrounds and bonds to rebar fed into the die.

Abstract: Pre-stressed concrete railroad ties are manufactured by the slip form process in the absence of mold members, other than the slip form itself. Tie casting occurs on portable casting soffits between portable soffit anchored deadmen supporting the pre-stressed tie tensile members immediately overlying the casting soffit. Tie formation occurs with the slip form passing around and over the pre-stressed tension members. Track fastening hardware is vibrationally inserted through windows of the slip form to place the track fastening hardware to precise measured dimension along the route of slip form movement and to configure that portion of the tie adjacent the track fastening hardware. End of tie locations as well as tie batch identification are likewise marked during the slip form process. Upon cure, the ties are cut at their marked end location.

Abstract: An apparatus for coating the outer surface of an elongated body (10), such as a rod or tube, with a layer of concrete (30) includes a frame structure (21). Pipe or tube sections (10) may be supplied to a tilting device (27) in a horizontal position on a carriage (12) and tilted to a vertical position within the tower-like frame structure (21). The apparatus comprises means (24, 27) for retaining the elongated body (10) in the upright position within the frame structure and an annular mould (26) for surrounding the upright elongated body so as to define an annular space between the elongated body and the annular mould, and concrete may be fed to the annular mould space by feeding means (28, 29). The mould may include an upper funnel-like part, which is rotatable about the axis of the annular mould relative to the remaining part of the mould so as to distribute the concrete mixture peripherally in the annular mould space.

Abstract: Overall production line equipment is utilized in producing many large concrete panels, in an initial horizontal position, during each day of many operational days, with these panels preferably being later installed vertically with other like panels to form a sound barrier alongside a vehicle way. Each concrete panel has its own integral pilasters at respective edges, in turn having respective tongue and groove edges; respective patterns and color accents on each side, with the pattern on the then top side being formed by using a rockable stamp subassembly, mounted on a cart; reinforcing throughout the panels, inclusive of the integral pilasters; lifting subassemblies; and anchoring subassemblies, adapted to be later mated with a receiving subassembly anchored in a concrete footing, located where the panel with other panels forms a sound barrier alongside vehicle ways.

Abstract: A device for vertical slipforming of concrete walls includes a rigid frame and at least one slipform assembly suspended from and vertically displaceable with respect to the frame. Concrete is delivered to the interior of each slipform assembly which is incrementally raised as the concrete sets and further concrete is supplied. Thus, concrete panels having a vertical orientation are progressively cast in the slipform assemblies at a job site.

Abstract: A concrete leveling machine is provided which propels itself over the surface of laid concrete and by use of rotating augers or oscillating stabilizers and a temper, levels and finishes the surface to a prescribed level and condition. A laser reference beam transmitted over the surface is detected by detectors attached to the leveling section of the machine and deviation of the level of the detectors from a reference level is adjusted so that the leveling section is also brought to a level required to produce the desired surface level. The machine is turned by a turntable integral with the main body which lifts the machine allowing it to turn by differential drive to its drive wheels.

Abstract: An extrusion machine for making hollow elongated articles of concrete has an eccentric compaction disc that reciprocates and rotates to compact and release air from zero slump concrete. The machine avoids having to have a high frequency converter which is both expensive and noisy. At least one extruder screw is provided in the machine to feed concrete and form the elongated article. The screw has a die former at the outlet end to form a cavity in the elongated article. An eccentric compaction disc is positioned between the outlet end of the extruder screw and an input end of the die former, the input end of the die former is eccentric and coplanar with an eccentric disc face mounted for movement in a circular orbital path about the extruder screw axis. The output end of the die former is concentric with the extruder screw axis.

Abstract: An apparatus and method for forming hollow concrete structures or shells in which the top, bottom and sides are formed into an integral unitary structure by rotating an assembly of reinforcing members to enable the concrete forming the top, bottom and side to each be finished in a substantially horizontal position with a minimum of forms. Openings for doors and windows may be formed by using suitable blanks that are prepositioned prior to pouring the concrete. Also, suitable end closure members can also be formed in a flat or horizontal position inside the unitary structure for subsequent erection in a vertical position.

Abstract: A method for mounting floors in a shell whose concrete wall is erected by a continuous self-climbing shuttering installation and a continuous self-climbing shuttering installation for implementing the method, includes appropriate vertical and horizontal movements of certain assemblies (I.sub.1 -I.sub.2), (I.sub.3 -I.sub.4) of self-climbing brackets (2) and of their shuttering and concreting walkways (P.sub.1, P.sub.2, P.sub.3) so as to provisionally align the brackets (2, 2b) vertically in twos, and thus reduce the number of peripheral clearances to be provided in the floors to be laid at intervals inside the wall of the shell to be erected. The installation includes lateral transfer carriages (14, 14') providing the horizontal lateral transfers of the brackets, the vertical transfers being provided by the normal self-climbing system.

Abstract: Apparatus for stripping a header from a cast concrete section to which it is adhered adjacent to a site for contiguous concrete section comprising a vertical track in direct association with the header; the track having an opening facing the site; and impact tool adapted to move slidingly within the track to predetermined locations therein; and the impact tool being further adapted to be displaced horizontally within the track to apply a separation force through the track to the header to disrupt adhesion of the header with the concrete.

Abstract: A method and apparatus for forming a hollow column of concrete on a floating offshore platform by applying successive layers of concrete and reinforcing to a single surface slipform which outlines the inner or outer contour of the column. The column is intermittently or continuously lowered by means of gravity under the control of one or more cables. The column may be round, oval, rectangular or of any cross section, or any combination thereof, and may be open or closed at either end or at intermediate levels. The column may be segmented into sections and have relatively thin walls as in an OTEC cold water pipe, an outfall sewer, or an underwater tunnel; and a method is described for safely deploying such columns at great depth on to an uneven seabed. The column may be monolithic with walls thick enough to support a structure above the surface or to maintain the hollow interior at amospheric pressure and provide access to an undersea habitat or to gas and oil well equipment.

Abstract: A beam clamp system for securely engaging a pair of concrete form panels for maintaining them in generally vertical position against inadvertent dislodgment or dislodgment due to outward pressure from recently poured liquid concrete. Each clamp has a horizontal portion and two long vertical members, brackets to slidably engage concrete form panels, and rods to securely and adjustably hold these form panels in place while concrete is poured and is curing. The form panels include a frame and a sheet with at least one smooth synthetic surface. In addition, this system includes a scaffolding system built into the beam clamp system. The system also includes a hanger system for supporting and positioning "re-bar" between the concrete form panels while liquid concrete is being poured and while it cures. Also a shepherd crook-shaped truss strap is part of the system and attaches to the "re-bar" hangers and the re-bar.

Abstract: A collection of sheet-metal, flanged, arcuate panels is provided which panels can be assembled in belts of generally circular cross-section commencing from the bottom of the manhole to provide a complete form structure for casting a concrete liner with a minimum thickness of about three inches and including openings created by sectional cylindrical inserts, all of which can be assembled, then disassembled after the concrete liner has set. An extensive variety of panels to accomodate different shapes of manholes includes panels for forming right conical belts, for forming offset conical belts, and for forming wedge-shaped belts to make transitions between vertical and tilted sections of the manhole. A key-panel for these various belts is provided to prevent capture of the panels by the poured concrete liners which includes a relatively narrow portion with vertical flanges fixed at an angle to one another which angle diverges toward the center of the form structure.

Abstract: A forming device includes two opposite form boards, an upper fastening unit mounted on the first and second top ends of the form boards, an upper hydraulic drive unit cooperably connected to the fastening unit and a lower hydraulic drive unit mounted on the bottom end of the first or second form board. The fastening unit includes a slide device to permit the first and second form boards to move away from one another or to approach one another. The slide device includes a slide bar fixed to the first or second top end of the form board, and a support bar fixed to the second or first top side. An upper hydraulic drive unit is cooperably connected to the slide bar and the support bar. A lower hydraulic drive unit is mounted on the bottom end of the first or second form board to move the form board relative to the formed concrete. The form boards can be stripped from a formed wall in a proper direction without causing the boards to swing and possibly damage the projecting portions of the formed wall.

Abstract: An apparatus for producing foam-filled stud walls. The apparatus has a main frame, including a substantially vertical backplate against which the sheathing bears, a carrier unit moveable vertically on the main frame, and a dam carried on the carrier unit parallel to the backplate, moveable towards and away from the backplate. Hydraulic actuators are located between the carrier unit and main frame, and between the dam and the carrier unit, to hold the dam against the stud wall when the stud wall is positioned with its sheathing against the backplate, and to move the carrier unit and thus the dam vertically while it is so held against the stud wall.

Abstract: A concrete wall forming apparatus is described that facilitates formation of an elongated concrete wall between opposed sheet forms. An assemblable frame mounts the sheet forms in upright opposed orientations. The frame supports pairs of driven rollers that move against external surfaces of the sheet forms along the length of the wall as concrete is being poured. Each pair of rollers is driven by a selectively removable drive assembly including a single motor drive and gear arrangement by which both rollers of the pair are driven simultaneously. At least one of the rollers is connected to the driving gears through a clutch arrangement. The clutch may be selectively operated to disengage the roller at the inside of a corner, thereby allowing that roller to remain stationary while the remaining roller rotates to move about the outward radius of the corner.

Abstract: An apparatus for the instant cutting of hollow-cored concrete slabs wherein the cast cored slabs are subjected to an instant cutting operation prior to the hardening of the concrete mix in such a manner that exposes the cores and the ends of the cores are filled to avoid jointing mix from intruding into the cores. The instant cutting is performed by driving two sheet-shaped cutting blades (3), which are mutually placed in a V-shaped posture, through the slab to make cutting tips (10) of the blades (3) meet at the bottom of the slab. A cutting knife (1), whose sides (16) face the mix and are disposed essentially parallel to the cutting blades (3), is driven through the slab, between the cutting blades (3), towards the cutting tips (10) of the blades (3).