780 results about "Screed" patented technology

Embodiments of the represent disclosure provides a multi-purpose screed device suitable to provide draining and / or ventilation at various locations of exterior walls in a building. The multi-purpose screed device is compatible with exterior walls with a rain screen disposed outside a weather-resistant barrier layer. The multi-purpose screed device may use a foundation weep screed, overhang soffit screed, and soffit ventilation.

A method is provided for adjusting a temperature of a screed plate of a paving screed of a road paver, wherein the paving screed comprises a heating element for heating the screed plate. The method may include measuring temperature of the screed plate over a time interval using a temperature sensor, and adjusting a target temperature of the heating element, depending on a time profile of the temperature of the screed plate, using a control unit of the road paver.

The invention relates to the technical field of cast-in-place pile construction, and provides efficient construction equipment for a cast-in-place bored pile and a using method of the efficient construction equipment. The drilling machine body is used as a basic installation component of the whole equipment and is used for installing and assembling all matched use mechanisms and structural parts of the matched use mechanisms; the power head is mounted on one side of the drilling machine body and used as a power source to enable the drill rod to rotate; the rotating assembly is mounted on the drill rod and is used for moving the mounted mechanism and the structural member to which the mechanism belongs; and the smoothing mechanism is mounted on the rotating assembly. The output end of a first hydraulic rod pushes a sliding rod to move, and then a connecting sleeve is driven to move, so that a first connecting block pushes a first connecting rod to move, the first connecting rod pushes a second connecting block to drive a smoothing plate to move, and the smoothing plate drives a first limiting block to slide in a limiting groove; and the flattening plate moves to make contact with the hole wall, the hole wall is flattened during rotation, and then the effect of preventing the hole wall from collapsing is achieved.

An adjustable screed board includes an outer member elongated along a longitudinal axis of the adjustable screed board. The outer member includes a leveling surface. The adjustable screed board also includes an inner member elongated along the longitudinal axis and coupled to the outer member for sliding movement, relative to the outer member, along the longitudinal axis. The inner member includes a leveling surface configured to remain flush with the leveling surface of the outer member during relative sliding movement of the inner and outer members. The leveling surfaces of the inner and outer members are oriented to cooperatively define a bottommost edge of the adjustable screed board along a working length.

The invention discloses a fabricated thermal insulation composite external wall panel, a preparation device and a preparation method thereof, and belongs to the technical field of composite wall panels. The fabricated thermal insulation composite external wall panel comprises a thermal insulation board, a reinforcing mesh is arranged outside the thermal insulation board and comprises a bottom mesh, a top mesh and a side mesh, the bottom mesh is located below the thermal insulation board, the top mesh is located above the thermal insulation board, the top mesh and the bottom mesh are fixedly connected through the side mesh, and the thermal insulation board is located in the reinforcing mesh defined by the bottom mesh, the side mesh and the top mesh; and a mortar layer is arranged outside the reinforcing mesh, convex blocks are arranged on one side of the mortar layer in the length direction and the width direction of the wallboard, and grooves matched with the convex blocks are formed in the other side of the mortar layer. By the adoption of the assembly type heat preservation composite external wall panel, the preparation device and the preparation method, the problems that an existing heat preservation composite external wall panel is heavy in weight, and a heat preservation layer is prone to damage can be solved, and the forming effect and the structural stability of the wall panel are improved through the preparation device and the preparation method.

The utility model relates to the technical field of heat preservation buildings, and provides an integrated energy-saving heat preservation building structure which comprises a non-dismantling formwork body, heat preservation nails penetrating through the non-dismantling formwork body are movably connected to one side of the non-dismantling formwork body at equal intervals, and a plastering mortar layer is fixedly connected to one side of the non-dismantling formwork body. One side of the plastering mortar layer is fixedly connected with a reinforcing frame, one side of the reinforcing frame is fixedly connected with a decorative face, one end of the non-dismantling formwork body is fixedly connected with a clamping plate, and the other end of the non-dismantling formwork body is provided with a clamping groove. The clamping plates slide in the clamping grooves, elastic deformation of the elastic pieces is utilized, the elastic pieces are made to be tightly attached to one sides of the clamping plates, then the fastening performance of sliding clamping of the clamping plates and the interiors of the reserved grooves is improved, quick and firm splicing and assembling between the non-dismantling formwork bodies are achieved, follow-up corresponding construction operation is facilitated, and the practicability of the non-dismantling formwork bodies is improved.

The utility model provides a concrete surface flatness control device, which relates to the field of concrete flatness control and comprises an adjusting control frame and a concrete pouring mold, the concrete pouring mold is attached to the end face of the inner side of the adjusting control frame, and the lower end of the adjusting control frame is connected with a discharging frame through an electric push rod. A slope leveling plate is welded to the lower surface of the discharging frame, a rotating rod is in shaft connection with the inner side cavity wall of the discharging frame, a scraping plate is fixed to the rod face of the rotating rod, a motor is connected to the left side end of the rotating rod, a discharging notch is formed in the front end face of the discharging frame, and a collecting frame is inserted into the front end face of the discharging notch. The rear side of the discharging frame is slidably connected with a light shield through an electric guide rail, and an optical fiber photoelectric sensor is installed on the inner wall of the upper end of the light shield. The concrete leveling device solves the problems that in the prior art, redundant concrete discharged by leveling of a leveling plate easily overflows the surface of the leveling plate and flows into the leveled concrete surface, and it is difficult to ensure that the flatness of the concrete surface meets the standard.

A multifunctional spreading device comprising a main body, a conveying assembly and a screed assembly. The main body has a hopper including first and second lateral hopper walls and front and rear hopper walls, with a hopper outlet defined between lower ends of the hopper walls and a conveying assembly receiving cavity defined below the hopper outlet, between a first side wall and a second side wall each having a support structure projecting therefrom. The conveying assembly has an outer frame, sized and shaped to fit within the conveying assembly receiving cavity, with opposed frame walls each including an abutment member projecting therefrom and configured to abut onto the corresponding support structure to support the conveying assembly inside the conveying assembly receiving cavity. The screed assembly is mounted to the main body and extends laterally therefrom to engage and smooth aggregate material being discharged from the conveying assembly.

The invention provides a construction control system, method and equipment of an underwater leveling machine and the underwater leveling machine, and relates to the technical field of ocean engineering. The construction control system comprises a sensing subsystem used for obtaining the weight of stone in a hopper of the underwater leveling machine and the inclination angle of the hopper; the calculation subsystem is used for determining the stone mass based on the weight of the stone in the hopper and the inclination angle of the hopper and calculating the real-time material distribution mass flow rate based on the time sequence data of the stone mass; the current terrain elevation of the foundation bed is obtained to calculate the terrain residual error and the to-be-laid volume; and the control subsystem is used for generating a cloth control instruction through an optimization decision algorithm based on the real-time cloth mass flow rate, the terrain residual error, the to-be-laid volume and the predicted thickness distribution. According to the system, real-time working condition monitoring, dynamic flow calculation, terrain deviation analysis and predictive control strategies can be combined, closed-loop accurate control over the whole process from material conveying to bottom bed forming is achieved, and the control precision of underwater leveling construction is improved.

The invention relates to the technical field of concrete construction, in particular to a green low-carbon concrete construction operation device which comprises a vehicle body, a stirring tank is fixedly mounted on one side of the upper end of the vehicle body, a feeding cylinder is fixedly mounted on one side of the upper end of the stirring tank, and a feeding hopper is fixedly mounted at the upper end of the feeding cylinder. A first motor is started to drive a crushing roller and a rotating roller to rotate, the crushing roller crushes stones, the crushed stones fall at the upper end of an inclined plate, the rotating roller evenly throws the crushed stones to the upper end of a sieve plate, the stones are filtered, and the matched stone fragments fall into a stirring tank and are mixed with additives such as cement and sand to form concrete. Then a valve on the discharging pipe is opened, the vehicle body is pulled towards the concrete outlet side, the pressing cylinder rotates while moving up and down on the concrete, the surface of the concrete is vibrated to be flat, the concrete surface is leveled through the patter and the leveling plate, secondary leveling of workers is not needed, the labor intensity is reduced, and the efficiency is improved.

The invention belongs to the technical field of wallboard heat preservation, and particularly relates to an overhead floor slab heat preservation structure and a construction method thereof.The overhead floor slab heat preservation structure comprises a building wall and a heat preservation plate installed on the surface of the building wall, and the heat preservation plate is installed on the outer surface of the building wall in a pasted mode through a first mortar layer smeared on the surface; the bottoms of the heat preservation plates are inserted into the keels, the outer surfaces of the heat preservation plates are coated with outer mortar layers, net plates are arranged in the outer mortar layers in an interlayer mode, reinforcing pieces are arranged in four corner groove integration spaces at the splicing positions of the four adjacent heat preservation plates, and sleeves are movably inserted into the splicing positions of the four adjacent heat preservation plates. A groove rod is connected between the two reinforcing plates located in the same vertical line direction. According to the overhead floor heat preservation structure and the construction method thereof, the strength of the heat preservation plates can be improved, stripping and falling of one or more heat preservation plates can be avoided, the stability of the overall structure of an outer wall with the heat preservation plates is improved, and meanwhile wall skin of an outer heat preservation wall plate can be prevented from being stripped.

The invention provides a basement large plate structure steel plate overlapping reinforcing structure and a construction method, and relates to the field of structural engineering.The basement large plate structure steel plate overlapping reinforcing structure comprises a large plate structure plate reinforcing structure which is connected to the lower portion of an original concrete plate and located in a large plate structure plate reinforcing area. The large plate structure plate reinforcing structure comprises a prefabricated newly-added concrete structure which is prefabricated and poured on the upper portion of a reinforcing steel plate, and a notch is reserved in the upper end of the prefabricated newly-added concrete structure; the reinforcing steel plate is arranged on the lower portion of the prefabricated newly-added concrete structure, and interface connection between the reinforcing steel plate and the prefabricated newly-added concrete structure is further achieved through the shear connector. The connecting steel bars are arranged on the reinforcing steel plates; the mortar layer is arranged on the upper surface of the convex part of the prefabricated newly-added concrete structure; the cast-in-place newly-added concrete is arranged at the notch; and the tensile steel bars are partially embedded in the original concrete slab and are partially embedded in the cast-in-place newly-added concrete. The original large plate structure can be reinforced conveniently, quickly, economically and reasonably, the bearing capacity of the structure is improved, and the durability of the structure is enhanced.

A slipform paver includes a slipform mold having a mold width extending transverse to a paving direction. At least one leveling beam is supported behind the slipform mould for engaging an upper surface of the formed unhardened concrete structure to level the upper surface, the at least one leveling beam being configured to oscillate transversely to the paving direction. At least one forward speed sensor is configured to provide a forward speed signal corresponding to a forward speed of the slipform paver in the paving direction. The controller is configured to receive the forward speed signal and generate a command signal to control the lateral oscillation frequencies of the at least one leveling beam such that a constant relationship is maintained between the forward speed lateral oscillation frequencies.

Machines, systems, and methods for pre-heating a screed plate (including maintaining the pre-heated screed plate) of a paving machine can comprise a screed assembly including the screed plate; and a thermal cover removably coupleable to or over a bottom working surface of the screed plate. The thermal cover can be movable between a first position where the thermal cover does not cover any portion of the bottom working surface of the screed plate and a second position where the thermal cover covers at least a portion of the bottom working surface of the screed plate.

The invention provides a waterproof connecting structure of an anti-floating anchor rod node, and belongs to the technical field of anti-floating anchor rod construction of constructional engineering. The structure comprises an anti-floating anchor rod, a waterproof connecting assembly, a polymer cement waterproof mortar layer and a fine aggregate concrete protection layer. The lower end of the anti-floating anchor rod is anchored in the concrete anchoring body of the basement structure layer, and the upper end penetrates through the anchoring plate through hole; the waterproof connecting assembly is composed of an anchoring plate and a pre-buried support, the lower end of the pre-buried support is pre-buried in the concrete anchoring body, and the anchoring plate is fixed between the supports. The concrete cushion layer and the anchoring body are sealed through polyurethane sealant, and a waterproof mortar layer, a self-adhesion waterproof roll and a reinforced fine aggregate concrete protection layer are sequentially laid on the concrete cushion layer and the anchoring body to form a totally-closed waterproof system. Through the design of multi-layer collaborative protection and the rigid support, the problems that a traditional joint is prone to leakage, and an anchoring plate displaces are solved, the horizontal displacement resisting capacity is improved, the construction efficiency is improved, and the structure is suitable for anti-floating projects such as basements and basement and has high waterproofness, structural stability and economical efficiency.

The invention discloses a fabricated ultra-low-energy-consumption overhanging type closed balcony system and a construction method thereof. The construction method comprises the following steps that firstly, a prefabricated bottom plate is constructed; and secondly, first joint bars and second joint bars are arranged in the vertical hole channels of the prefabricated bottom plate. And step 3, surveying and setting out. And 4, the outer hanging plate and the side hanging plate are installed. Fifthly, second horizontal plugging materials are arranged on the inner sides of the tops of the transverse prefabricated plates and the longitudinal prefabricated plates, and the inner sides of the second horizontal plugging materials are filled with second waterproof mortar layers; second horizontal sealing rods are arranged on the outer sides of the tops of the transverse prefabricated plates and the longitudinal prefabricated plates. And sixthly, an upper-layer prefabricated bottom plate is installed. And seventhly, the second step to the sixth step are repeated till construction of the upper-layer prefabricated bottom plate on the top of the topmost balcony is completed, and grouting materials are poured into the vertical hole channels in the top of the topmost balcony till construction is completed. According to the method, the technical problems that many problems still exist in traditional closed balcony type selection, material selection, installation and connection, air tightness treatment and the like, the construction progress is slow, and a mature practice system is lacked are solved.

The invention relates to the technical field of building materials, and particularly discloses ultra-high performance concrete containing coarse aggregate, a preparation method of the ultra-high performance concrete and a method for testing the abrasion resistance of the ultra-high performance concrete, the ultra-high performance concrete containing the coarse aggregate comprises cement, a mineral admixture, fine aggregate, steel fiber, the coarse aggregate, an additive and water, and the coarse aggregate is pretreated through cationic emulsified asphalt. The coarse aggregate ultra-high performance concrete is subjected to molding preparation, demolding maintenance, vacuum water saturation and other processes to obtain an original test piece for testing the abrasion resistance, two sub test pieces are obtained after radial cutting, and the mass of the test pieces before and after abrasion is weighed to obtain the abrasion resistance strength. According to the testing method, the abrasion resistance of the surface mortar layer and the abrasion resistance of the internal aggregate layer in the same test piece can be compared, and the abrasion resistance of the ultra-high performance concrete containing the coarse aggregate can be evaluated more comprehensively and objectively. The coarse-aggregate ultra-high-performance concrete has excellent mechanical properties, the abrasion resistance is enhanced, the use amount of a cementing material can be effectively reduced, and the production cost is reduced.

The present invention relates to a rotating device for integration in a substrate, preferably in a building floor element, more particularly in a screed floor, having at least three support units, which can be arranged individually in the circumference of the substrate within a circular area about an axis of rotation, a rotating plate which extends at least over the circular area and has a room side and a bearing side opposite the room side, a rotary bearing unit, and at least one drive apparatus, wherein the rotating plate is rotatably mounted in the axis of rotation and the at least three support units support the rotating plate in a rotationally movable manner in the orientation of the axis of rotation in a vertical axis on the bearing side, and wherein the drive apparatus is configured to set the rotating plate in rotation about the axis of rotation.

The invention provides a parameterization construction method of a recycled concrete three-dimensional mesoscopic numerical model. The parameterization construction method comprises the following steps: 1) calculating the particle number and the particle size of recycled concrete aggregate and the thickness of an old mortar layer; 2) constructing a geometric model of the recycled concrete three-dimensional random spherical aggregate test piece; (3) constructing a geometric model of the recycled concrete three-dimensional random convex polyhedral aggregate test piece; (4) carrying out unstructured grid division; and 5) construction of a recycled concrete projection network model. According to the method, the problem that the geometric space structure of the recycled concrete is complex is solved, and the established geometric model can truly reflect the actual grading, content and shape of the aggregate in the recycled concrete; according to the unstructured mesh generation method aligned with the interface, the problems that mesh generation is difficult, and modeling is difficult due to the fact that an interface transition area is too thin are solved, and the generated mesh model has extremely high unit quality.

The utility model discloses a water stop structure suitable for an upper gate room of a high gate with a deep and thick covering layer in the technical field of engineering water stop, which comprises a plurality of gate plates, a structural seam is arranged between two adjacent gate plates, the structural seam is communicated with a water stop cavity, and a water stop device is filled in the water stop cavity. The water stop device comprises a first mortar layer, a flexible filler layer and a second mortar layer which are sequentially filled in the structural joint from top to bottom, a copper sheet water stop assembly and a water stop belt assembly are arranged on the flexible filler layer in a penetrating mode at intervals, the overall structure is large in flexibility effect, the function of adapting to large uneven deformation between adjacent gate sections can be achieved, damage is not prone to occurring, and the service life of the water stop device is prolonged. Therefore, safe operation of the water gate structure is guaranteed.

A concrete working tool may include a pivot bearing attached to a first attachment bracket, a second attachment bracket and a screed board attached to the first attachment bracket and the second attachment bracket. The pivot bearing may be attached to the first attachment bracket by a hinge and the second attachment bracket may include a swivel with a handle attachment attached thereto. A kit for making a concrete working tool may include the pivot bearing and first attachment bracket and the second attachment bracket. In one application the pivot bearing may be attached to a pivot pin that was movable along a support rail so the concrete working tool can be used between a form and a wall or form work.

The invention relates to a construction method of a waterproof structure for a crack between a masonry structure outer wall and a frame beam, which comprises the following steps of: (1) constructing a concrete frame structure, fixing an embedded section of a waterproof thin plate on a beam steel bar by welding and binding during frame beam construction, arranging a square wood box to be tightly attached to the waterproof thin plate, and then pouring frame beam concrete; (2) constructing a firstly-built part of the outer wall masonry structure, and building a later-built part after the firstly-built part settles, shrinks and stabilizes; (3) removing a square wood box preset in the frame beam, and stripping and exposing the waterproof thin plate at the embedded section; (4) covering a crack area between the outer wall and the frame beam with a waterproof thin plate extension section, wherein the waterproof thin plate extension section is connected with the waterproof thin plate of the embedded section through screws; (5) the grooves in the waterproof thin plate section area are blocked through grouting materials; and (6) a net hanging mortar layer and an outer wall decoration layer are sequentially constructed according to construction procedures. The water leakage problem of the outer wall settlement crack can be effectively prevented, and the waterproof performance and durability of a building are improved.

The utility model relates to the technical field of house repairing, in particular to a waterproof layer structure for repairing an old house, which comprises a base surface layer and a concrete mortar layer, and a waterproof layer is arranged between the base surface layer and the concrete mortar layer. The waterproof layer comprises a cement-based permeable crystallization self-healing coating layer, an asphalt waterproof coating layer is arranged on the cement-based permeable crystallization self-healing coating layer, and a gridding cloth layer is arranged on the asphalt waterproof coating layer. The utility model has the characteristics that the structure is simpler and more reasonable, blistering and peeling can be better avoided, the waterproof effect can be improved, and moisture overflow can be avoided.

The invention provides an asphalt concrete paver, and relates to the technical field of pavers. The paver comprises a vehicle body, a first driving mechanism, a paving mechanism, a first connecting mechanism and a discharging mechanism, the vehicle body comprises a hopper. The first driving mechanism comprises a supporting frame and a driving lead screw which is arranged in the supporting frame in a penetrating mode and driven by a first motor to rotate. The paving mechanism comprises an ironing plate connected with the driving screw rod; the first connecting mechanism comprises a connecting plate connected to a rod body of the driving screw rod, and the other end of the connecting plate is connected with the ironing plate; the discharging mechanism is arranged at the bottom of the car hopper and comprises a first rotating shaft and a plurality of blades, the first rotating shaft penetrates through the discharging channel in the direction perpendicular to the bottom of the car hopper, the blades surround the first rotating shaft and are located in the discharging channel, and one end of the first rotating shaft is connected with the driving lead screw through a linkage structure; and the driving screw rod is used for driving the ironing plate to move and driving the first rotating shaft to rotate through self rotation, so that the paving uniformity and the discharging speed uniformity can be synchronously improved.

A road finishing machine comprises a screed for producing a paving layer from a paving material, a material bunker for receiving the paving material, a longitudinal conveying device configured to transport the paving material from the material bunker toward the screed, and a transverse distributor auger configured to distribute the paving material transported by the longitudinal conveying device transversely in front of the screed. The transverse distributor auger is mounted in front of a screed basic body of the screed within a transverse distributor channel, which is formed at least in sections by channel plates supported at a chassis of the road finishing machine, and by pre-scrapers attached laterally of a screed basic body of the screed. The road finishing machine further includes at least one suction device with at least one intake line which is configured to suck off aerosols forming during the transverse distribution of the paving material.

The utility model discloses a rock wool calcium chloride hexahydrate-based high-temperature-resistant energy-storage thermal-insulation wallboard, which relates to the technical field of thermal-insulation wallboards and comprises a building block, masonry layers are arranged on the surfaces of two sides of the building block, and a first thermal-insulation mortar layer and a second thermal-insulation mortar layer are respectively arranged on the surfaces of two sides of the building block. A first anti-crack layer is arranged on the outer surface of the first thermal insulation mortar layer, a second anti-crack layer is arranged on the outer surface of the second thermal insulation mortar layer, a first modification layer is arranged on the outer surface of the first anti-crack layer, and a second modification layer is arranged on the outer surface of the second anti-crack layer. The occurrence time of indoor peak temperature is delayed, and indoor temperature fluctuation is reduced.

The utility model discloses an unmanned material pushing and uniformizing vehicle which comprises an AGV chassis, a supporting frame is arranged on the upper side of the AGV chassis, a material uniformizing box is arranged on the inner wall of the supporting frame through a lead screw, an upper cover is arranged at the top of the material uniformizing box, a feeding port and a stirring mechanism are arranged on the upper cover, a material pushing channel is arranged at the lower end of the material uniformizing box, and a spiral extrusion mechanism is arranged in the material pushing channel. The material uniformizing box is arranged on the upper side of the AGV chassis through the supporting frame and the lead screw, so that unmanned material uniformizing treatment can be achieved, the material uniformizing box is arranged on the upper side of the AGV chassis through the supporting frame and the lead screw, the material uniformizing efficiency is improved, the material uniformizing efficiency is improved, and the material uniformizing efficiency is improved. And the material uniformizing box and the discharging opening can be driven to be adjusted in a lifting mode through the lead screw, so that the requirements for pushing and feeding of materials at different heights can be met, and the material uniformizing efficiency can be improved.

Aspects of the disclosure are directed to systems, and apparatuses, and methods for a screed system for a road paver that includes tamper bar subsystem including a screed plate, the tamper bar subsystem, and a tamper bar drive subsystem. The screed plate has a first paving surface with a first pattern for contacting a paving material. The tamper bar subsystem is positioned forward of the screed plate in a paving direction of the screed system and includes a tamper plate and a tamper bar. The tamper plate has a second paving surface with a second pattern for contacting the paving material. The tamper bar drive subsystem is coupled to the tamper bar and configured to selectively move the tamper bar between a first position and a second position in a direction non-parallel to the paving direction of the screed system.

The utility model relates to a fabricated wall structure, which belongs to the technical field of prefabricated walls and comprises an ALC (autoclaved lightweight concrete) light partition batten, a door, a door side plate, a door lintel plate, a U-shaped clamp and a structural beam / plate. The ALC light partition wall battens are mutually spliced, the door edge plates are fixed to the left side and the right side of the door, and the door lintel plate is arranged above the door. The splicing positions of the upper ends of the ALC light partition wall battens, the door head plate and the door lintel plate are connected in a clamped mode through U-shaped clamps. A fastener is arranged on the U-shaped clamp and is connected between a top plate of the U-shaped clamp and the structural beam / plate; a mortar layer is arranged between the ALC light partition wall and a structural beam / plate at the top of the ALC light partition wall, and mortar used in the mortar layer contains an AEA expanding agent; the two adjacent ALC light partition wall battens are fixed through the U-shaped clamps, the flatness and the structural stability of the ALC light partition wall battens can be improved, the inverted-U-shaped clamps and the structural beams are fixed through the fasteners, the structural stability of an inner wall is further improved, the square tube steel columns / concrete constructional columns and the structural wall columns are arranged between the ALC light partition wall battens, and the structural wall columns are arranged between the square tube steel columns / concrete constructional columns and the structural wall columns. And the wall body structure can be further reinforced.

This invention provides an asphalt finisher that can precisely adjust the width of the screed by extending and retracting the screed extension cylinder at an appropriate extension and retraction speed. [Solution] The asphalt finisher 100 is equipped with a screed 3 that spreads and levels the paving material PV while moving in the laying direction. The asphalt finisher 100 includes a screed extension cylinder 26, a switching valve 34, a screed position sensor 51C, and a controller 50. The controller 50 calculates the target trajectory of the side frame 32 where the side frame 32 is located, and calculates the extension and retraction speed of the screed extension cylinder 26 based on the deviation between the target trajectory of the side frame and the current position of the side frame 32 detected by the screed position sensor 51C. The controller 50 then controls the screed extension and retraction cylinder 26 by switching the switching valve 34 on and off based on the extension and retraction speed.