30results about How to "Increase cracking load" patented technology

The invention relates to a concrete structure reinforcing method, a self-anchored prestress assembly and an assembled tensioning assembly. The concrete structure reinforcing method comprises the following steps including: an anchor seat installation step: an anchor seat is fixed on a concrete structure, wherein the anchor seat is pasted by adopting a pouring method, and fastening elements are chemically buried; a prestress cable manufacturing and installation step: a prestress cable is manufactured and is arranged in the assembled tensioning assembly; a prestress tensioning step: the prestress tensioning step includes a single prestress cable pre-tensioning sub step and a whole prestress cable tensioning sub step, so that the single prestress cables can be sequentially tensioned, and all of the prestress cables can be subsequently tensioned integrally; and a mortar spraying reinforcing step: the mortar spraying is at least carried out on regions covered by the prestress cables of the concrete structure, so that the reinforcement on the concrete structure is realized. The invention aims at providing the method of obviously improving the bearing force of the concrete structure.

The invention discloses a pressure bearing pipe damage repair process. The process is performed by the following steps: a carbon fiber fabric (4), a repair agent, adhesive, a torque spanner (15) and a tensioning device (1) are prepared; the damage positioning is performed for a pressure bearing pipe (5), and an obstacle is removed; a foreign matter at a damage part is removed, and an area to be repaired is determined; after the repair agent is coated on the area to be repaired, the adhesive is coated; the carbon fiber fabric (4) is bonded on the adhesive, and the left and right ends of the carbon fiber fabric (4) are tightened by the tensioning device (1); the torque spanner (15) is clamped on a shaft head (10), and is wrenched to enable a finger of a dial (16) to reach preset torsion; all locking screws (3) are tightened, and the prestress of the carbon fiber fabric (4) is constant; the adhesive is uniformly coated on the surface of the carbon fiber fabric (4); and after the adhesive reaches the stated condensation period, the tensioning device (1) is disassembled to finish one-time repair process.

The invention discloses a negative bending moment area UHPC treatment steel-concrete composite structure and a preparation method thereof. An UHPC bridge deck slab is adopted within a segment length of a steel-concrete composite structure negative bending moment area; and a top flange of an adjacent steel girder is welded (bolted) to a pier top. For a steel-concrete simply supported bridge deck continuous composite structural beam, the negative bending moment area UHPC treatment steel-concrete composite structure has the advantages that the cracking load of the negative bending moment area composite beam can be obviously increased; and due to smaller fracture interval, the development of a concrete crack can be obviously suppressed; and the excellent anti-cracking performance can effectively solve the cracking problem of the negative bending moment area.

The present invention relates to building member and its construction process and is especially composite arched structure of fiber reinforced plastic and concrete. The present invention proposes one kind of arced structure with laminated fiber reinforced plastic adhered to the surface of concrete and its construction process. The construction process includes forming concrete arch, milling surface with grinding wheel to eliminate floated surface mortar and roughen the surface, smearing epoxy resin-cement putty to flat the surface, painting primer with structural glue, coating with fiber fabric, soaking the fiber fabric with resin adhesive, covering with polyester film, extruding with scraper the excessive resin adhesive, curing and taking down the polyester film. The composite arched structure is corrosion resistant and durable, and has doubled bearing capacity and simple construction.

The invention relates to a post-tensioning retard-bonded co-tensioning prestress concrete composite beam and design and construction methods thereof. The post-tensioning retard-bonded co-tensioning prestress concrete composite beam is a novel prestressed composite beam for applying bonded prestress and retard-bonded prestress to a precast beam and the composite beam through pre-tensioning method and post-tensioning method processes in stages in order to meet the construction and use demands. Compared with a traditional prestress composite beam, the post-tensioning retard-bonded prestress technology is adopted in the post-tensioning retard-bonded co-tensioning prestress concrete composite beam, the characteristics of high prefabrication degree, convenient and fast construction and the likeof a lower composite structure are achieved, and the anti-crack and anti-bending properties of a member can be further improved. Configuration of prestressed tendons is relatively more flexible, and the post-tensioning retard-bonded prestress tendons have the good anti-corrosion property, so that the post-tensioning retard-bonded co-tensioning prestress concrete composite beam is especially suitable for structures which have the high-property requirements such as the large span and the heavy load and have the high requirements for deformation control, bearing capacity and the weather-proof property, and the superiority of the fabricated structures can also be embodied while the design requirements are met.

The invention relates to a post-tensioning unbonded co-tensioning prestressed concrete composite beam and design and construction methods thereof. The post-tensioning unbonded co-tensioning prestressed concrete composite beam is a novel prestressed composite beam for applying bonded and unbonded prestress to a precast beam and the composite beam in stages by adopting a pre-tensioning method and apost-tensioning method in order to meet the construction and use demands. Compared with a traditional prestressed composite beam, the post-tensioning unbonded prestressed technology is adopted in thepost-tensioning unbonded co-tensioning prestressed concrete composite beam, the characteristics of high prefabricated degree, convenient and fast construction and the like of a lower composite structure are upheld, the unique advantages are also possessed, thus the anti-crack and anti-bending properties of a member can be improved, the structure demands at different stages are met through batchedtensioning, the integrity and the anti-seismic property of the structure can be enhanced by cooperating with the design of fabricated integrated prestress joint connection, thus the post-tensioning unbonded co-tensioning prestressed concrete composite beam is especially suitable for structures which have the high-property requirements such as the large span and the heavy load and have the high requirements for deformation control, and bearing capacity, and the superiority of the fabricated structure can also be embodied while the design requirements are met.

The invention relates to a post-tensioning retard-bonded prestress concrete composite beam and design and construction methods thereof. A layer of top longitudinal bars is arranged at the top of the composite beam, a layer of bottom longitudinal bars is arranged at the bottom of the composite beam; the composite beam is further provided with a plurality of stirrups, a plurality of post-tensioningretard-bonded prestress bars are further arranged on the lower part of the composite beam, and the two ends of the post-tensioning retard-bonded prestress bars extend out of the composite beam and arefixedly provided with anchorage devices and clamps correspondingly. The post-tensioning retard-bonded prestress concrete composite beam adopts a post-tensioning retard-bonded prestress technology, the characteristics that a lower composite structure is high in prefabricating degree and fast and convenient to construct are accorded, and the anti-cracking and anti-bending performance of componentscan also be improved. The post-tensioning prestress can be applied to the post-tensioning retard-bonded prestress concrete composite beam after whole construction, post-tensioning unbounded prestresstendons also have good anti-corrosion performance, thus the post-tensioning retard-bonded prestress concrete composite beam is particularly suitable for structures with the high requirements for deformation control, bearing capacity and weather resistance and with the high-performance requirements for the large span and the heavy load, and the superiority of the fabricated structure can also be reflected while the design requirements are met.

The invention provides a method for reinforcing a box girder by pre-stress shear-resistance. Anchorage blocks are correspondingly installed on both sides of a web plate of a box chamber of the box girder up and down, a shear-resistance bar is temporarily fixed between the two anchorage blocks; a precast open type electromagnetic heating coil is used for wrapping the periphery of the shear-resistance bar, and the electromagnetic heating coil is connected with a heating main machine; and a high-frequency magnetic field generated by variable-frequency power supply enables the shear-resistance barto carry out self-heating rapidly, a temperature control device controls the electromagnetic heating temperature, a displacement meter controls the elongation of the shear-resistance bar, and at thesame time, two ends of the shear-resistance bar are anchored by an anchorage, so that the disposal of the pre-stress shear-resistance reinforcement box girder is achieved. According to the method forreinforcing box girder by pre-stress shear-resistance, the initiative is strong, the cracking load of the web plate of the box girder is effectively improved, and the shear-resistance bearing capacityof the web plate is improved; and through the novel construction process, large tensile equipment is not required, the operation is simple, easy control is achieved, the accuracy is high, the safetyis high, and the construction efficiency is greatly improved.

The invention provides internal centralized transverse prestress restraint masonry and a prestress applying method thereof. The internal centralized transverse prestress restraint masonry comprises house masonry provided with concrete structural columns and concrete horizontal ring beams. Unbonded prestressing tendons are arranged in reinforcement cages of the concrete horizontal ring beams, applyprestress at the tension ends and are anchored by prestressed anchorage devices. The prestress applying method of the internal centralized transverse prestress restraint masonry comprises the steps that the unbonded prestressing tendons are arranged, concrete of the horizontal ring beams is poured, and the unbonded prestressing tendons are tensioned. A prestress transmitting route of the transverse prestress restraint masonry is clear, and the action mechanism is facilitated to be clear. The cracking load, the ultimate deformation capability and the energy dissipation capability of a house masonry wall are improved significantly, when damaged, the house masonry wall cracks but is not scattered, and thus good integrity and good collapse resistance are maintained.

The invention relates to a post-tensioned unbonded prestressed concrete composite beam and a construction method thereof. According to the post-tensioned unbonded prestressed concrete composite beam,post-tensioned unbonded prestress is applied to a whole beam after the composite beam is composited and formed to meet the use requirement. Compared with a traditional composite beam, post-tensioned unbonded prestressed technology is adopted, the characteristics of a lower composite structure, such as high prefabricated fabricated degree and convenient construction are inherited, the crack resistance and bending resistance of the elements are improved. Due to ability to apply post-tensioned prestress after overall construction, the post-tensioned unbonded prestressed concrete composite beam isespecially suitable for structures with high performance requirements such as large span and heavy load which require high deformation control and bearing capacity, and can further embody the advantages of fabricated structures while meeting the design requirements.

The invention relates to a post-tensioned bonded co-tensioned prestressed concrete composite beam and a design and construction method thereof. The composite beam is a novel prestressed composite beamwhich applies bonded prestress to a prefabricated beam and the composite beam by adopting a pretensioning method and a post-tensioning method in stages in order to meet construction and use requirements. Compared with a traditional prestressed composite beam, post-tensioned bonded prestressed technology is adopted, the characteristics of the lower composite structure such as high prefabrication and fabricating degree and convenient construction are inherited, unique advantages are achieved, the crack resistance and bending resistance of elements can be improved, the structural requirements ofdifferent stages are met by batch tensioning, and the integrity and seismic resistance of the structure can be enhanced by matching with the design of fabricated integral prestressed joint connection. The post-tensioned bonded co-tensioned prestressed concrete composite beam is especially suitable for structures with high performance requirements such as large span and heavy load which require high deformation control and bearing capacity, and can further embody the advantages of the fabricated structure while meeting the design requirements.

A double prestressed beam mainly comprises a prefabricated part and a cast-in-place part. Wherein the prefabricated part is manufactured in a factory and comprises profile steel, prestressed tendons, longitudinal bars, stirrups, shear bolts, H-shaped perforated steel plate connecting pieces and prefabricated concrete. In the manufacturing process, a vertical load is firstly applied to the profile steel to enable the profile steel to be bent and deformed to a certain degree, then prefabricated part concrete is poured and cured, when the concrete reaches certain strength, unloading is conducted, auxiliary profile steel is dismantled, and the profile steel on the lower portion contracts to apply first prestress to the concrete; however, deformation of the profile steel on the lower portion cannot be completely recovered due to constraint of the concrete, the profile steel still bends to a certain degree, at the moment, the prestressed tendons are tensioned to completely recover the deformation, and second prestress is applied to the concrete due to the action of the prestressed tendons. According to the method, the double prestressing force is applied to the concrete in sequence only by changing the construction process, and the cracking load and the durability in the use stage are greatly improved.

The invention discloses a dry quenching coke tank and a production method thereof. The dry quenching coke tank comprises a coke tank body, the coke tank body comprises a tank body, a refractory fiberfelt and grids; the tank body is formed by laying and splicing lining plate precast blocks; the refractory fiber felt is arranged on the outer surface of the tank body; and the grids are coated on theouter surface of the refractory fiber felt in a stretching state. The grids are tensioned, and prestress is applied to the coke tank, so that the stress is uniformly transferred to a refractory working layer, the tensile stress generated by coke on the side wall of the coke tank is counteracted, the defect that the lining is easy to crack and peel off is avoided, and the service life of the coketank can be effectively prolonged.