阅读说明：本技术 一种应变强化钢纤维及超高强韧耐蚀防腐uhpc材料 (Strain-strengthened steel fiber and ultrahigh-strength-toughness corrosion-resistant and corrosion-resistant UHPC material ) 是由 夏瑾 于 2021-10-15 设计创作，主要内容包括：本发明涉及一种应变强化钢纤维及超高强韧耐蚀防腐UHPC材料,该应变强化钢纤维包括钢纤维本体,所述钢纤维本体的外表面涂附有绝缘隔离层,该超高强韧耐蚀防腐UHPC材料采用上述应变强化钢纤维。本发明可以在搅拌时防止钢纤维结团或扎堆,从而提高UHPC材料的抗压强度和抗拉强度,进而提高UHPC材料的韧性和耐久性。(The invention relates to a strain-strengthened steel fiber and an ultrahigh-strength corrosion-resistant UHPC material. The invention can prevent steel fiber from caking or bunching during stirring, thereby improving the compressive strength and tensile strength of the UHPC material and further improving the toughness and durability of the UHPC material.)

1. The strain-strengthened steel fiber comprises a steel fiber body and is characterized in that: and an insulating isolation layer is coated on the outer surface of the steel fiber body.

2. The strain-strengthened steel fiber according to claim 1, wherein: the insulating isolation layer is a plastic layer or a resin layer.

3. A strain-strengthened steel fibre according to claim 1 or 2, characterized in that: the steel fiber body adopts copper-plated steel fiber or stainless steel fiber.

4. A strain-strengthened steel fibre according to claim 1 or 2, characterized in that: the cross section of the steel fiber body is rectangular, zigzag, circular or crescent; alternatively, the cross-sectional dimensions of the steel fibre body alternate along the length; or the whole steel fiber body is in a wave shape, a circle shape or a spiral shape.

5. An ultra-high strength and toughness corrosion-resistant and corrosion-resistant UHPC material is characterized in that: comprising a strain-strengthened steel fibre according to claim 1 or 2.

6. The UHPC material with ultra-high toughness, corrosion resistance and corrosion resistance as claimed in claim 5, wherein: the steel fiber body adopts copper-plated steel fiber or stainless steel fiber.

7. The UHPC material with ultra-high toughness, corrosion resistance and corrosion resistance as claimed in claim 5, wherein: the cross section of the steel fiber body is rectangular, zigzag, circular or crescent; alternatively, the cross-sectional dimensions of the steel fibre body alternate along the length; or the whole steel fiber body is in a wave shape, a circle shape or a spiral shape.

Technical Field

The invention relates to a strain-reinforced steel fiber and an ultra-high-strength, high-toughness, corrosion-resistant and corrosion-resistant UHPC material, belonging to the technical field of ultra-high-performance concrete materials.

Background

Ultra-High Performance Concrete (UHPC) is also called Reactive Powder Concrete (RPC), and is the most innovative cement-based engineering material in the last thirty years, and the Performance of the engineering material is greatly expanded. The ultra-high performance concrete (UHPC) refers to a cement-based composite material with the compressive strength of more than 150MPa, ultra-high toughness and ultra-long durability, and has wide application prospects in the fields of bridge engineering, building engineering, protection engineering and the like.

The main components of the UHPC are a cementing material such as silica fume and cement, a fine aggregate (the grain diameter is generally less than 0.5mm), a high-efficiency water reducing agent, steel fibers (generally, short steel fibers in a segment shape) and the like, and the improvement of the tensile strength of the UHPC, the improvement of the toughness after cracking and the like mainly depend on the doping of the steel fibers and the uniform distribution of the steel fibers in the cement-based composite material.

Because the steel fiber is generally packed in a box or a bag, the volume is compact, before the steel fiber is put into a mixer, the steel fiber is usually dispersed by a mechanical method (a steel fiber dispersing machine) or a manual method, or before the gelled material is put into the mixer, the steel fiber and the aggregate are required to be uniformly mixed in a dry mode. However, in the production practice of the applicant, the UHPC material is found that steel fibers can form lumps near the shaft of the stirrer during stirring, i.e. steel fiber lumps or bundles are formed during stirring, so that the steel fibers are difficult to disperse or the steel fibers and the aggregate are difficult to stir uniformly, and the construction quality is affected. After the steel fibers are agglomerated, the steel fibers are difficult to uniformly stir in the cement-based composite material, so that the compressive strength and the tensile strength of the UHPC are reduced, and the toughness and the durability of the UHPC are influenced.

Disclosure of Invention

The invention aims to provide a novel strain-strengthened steel fiber and a UHPC material using the same, which can prevent the steel fiber from caking or bunching when the UHPC material is stirred, thereby improving the compressive strength and tensile strength of the UHPC material and further improving the toughness and durability of the UHPC material.

To achieve the above objects, in one aspect, the present invention provides a strain-strengthened steel fiber including a steel fiber body having an insulating barrier layer applied to an outer surface thereof.

On the other hand, the invention also provides an ultra-high strength and toughness corrosion-resistant UHPC material which comprises the strain-strengthened steel fiber.

Preferably, the insulating isolation layer is a plastic layer or a resin layer.

The invention has the following beneficial effects:

1) the applicant has found that, through long-term research, in the UHPC material, static electricity is generated after steel fibers rub against gelled materials, fine aggregates and the like during stirring, so that a stirrer shaft adsorbs the steel fibers with static electricity to form a cluster near the stirrer shaft. According to the invention, the insulating isolation layer is coated on the outer surface of the steel fiber body, so that the electric insulation layer is formed outside the steel fiber body, and thus when the stirring is carried out by the stirrer, the steel fiber can not generate static electricity in the stirring process, so that the steel fiber can not be gathered near the shaft of the stirrer to be adsorbed and agglomerated, the phenomenon of agglomeration or bunching of the steel fiber in the stirring process is avoided, the steel fiber is uniformly dispersed in concrete, and the construction quality is improved.

2) The components made of UHPC materials are degraded in performance mainly due to sulfuric acid corrosion, chloride ion corrosion, circulating thawing, alkali silicate reaction and steel fiber corrosion caused by the alkali silicate reaction, the friction force of the rusted steel fibers is increased, and the steel fibers are easy to be bundled in the stirring process. In all these cases of rust, the penetration of water (water permeability) plays a crucial role. That is, the durability of UHPC members is mainly dependent on the invasion/permeation rate of water, and the reinforcement of steel fibers improves crack resistance of concrete, increases the surface roughness of cracks, and thus significantly reduces the water permeability of concrete. The invention coats an insulating isolation layer on the outer surface of the steel fiber body, plays a role in protecting the steel fiber body, solves the problem that the steel fiber is easy to rust in the prior art, further reduces the water permeability of concrete, prolongs the service life of the UHPC member, namely the UHPC member adopting the scheme of the invention is corrosion-resistant and heavy-corrosion-resistant, and is especially suitable for severe environments.

3) Generally, the higher the strength of the concrete, the poorer the fire resistance, because it is too dense, and the steam pore pressure after high temperature is released everywhere, resulting in the bursting of the concrete member. According to the invention, the outer surface of the steel fiber body is coated with the insulating isolation layer, so that the fire resistance of the UHPC is obviously improved, and no matter the insulating isolation layer adopts a plastic layer or a resin layer, when a fire disaster occurs, the insulating isolation layer can be melted after a certain temperature is exceeded, so that a channel and a space for releasing and transmitting internal pressure are formed inside a component made of the UHPC, the UHPC component is prevented from bursting due to internal high pressure, and the fire resistance of the UHPC is improved; and the steel fiber is responsible for maintaining the strength after high temperature, so that the UHPC component after high temperature can still maintain certain strength, and unnecessary casualties and property loss caused by rapid collapse are avoided.

4) The composite steel fiber (the steel fiber body and the insulating isolation layer) has high elastic modulus and does not settle, the problem that the appearance of the exterior wall decorative plate is seriously influenced by corrosion when a steel fiber UHPC material (which is anticorrosive through the insulating isolation layer) is applied to the exterior wall decorative plate is solved, the problems of ageing, poor mechanical property and low tensile strength (because the tensile strength of a steel fiber monofilament is greater than that of an organic fiber) of the organic fiber UHPC material are solved, and the problem of high organic fiber mixing amount in the exterior wall decorative plate is solved.

Detailed Description

Example one

The embodiment relates to a strain-strengthened steel fiber, which comprises a steel fiber body, wherein an insulating isolation layer is coated on the outer surface of the steel fiber body. Preferably, the insulating isolation layer is preferably a plastic layer or a resin layer. During implementation, the insulating isolation layer can be coated on the outer surface of the steel fiber body in a plastic coating or spraying manner, which is the prior art and is not described in detail.

Preferably, the steel fiber body is made of copper-plated steel fibers or stainless steel fibers. The copper-plated steel fiber has the characteristics of strong compression resistance, tensile resistance and crack resistance, and the stainless steel fiber has the characteristics of short process flow, low price, high strength and toughness.

In order to increase the interfacial bonding strength between the steel fiber and the cementing material in the UHPC material, various shaped steel fiber bodies are usually selected, for example, the cross section of the steel fiber body is rectangular, zigzag, circular or crescent; the cross-sectional dimensions of the steel fiber body alternate along the length; the steel fiber body is in a wave shape, a circle shape or a spiral shape and the like.

Example two

The UHPC material is an ultrahigh-strength cement-based material with high strength, high toughness and low porosity. The basic preparation principle is as follows: by increasing the fineness and activity of the components, coarse aggregate is not used, and defects (pores and microcracks) in the material are minimized, so that ultrahigh strength and high durability are obtained. The UHPC can be named as an engineering material with the best durability, the mechanical property of the UHPC with proper reinforcement is close to that of a steel structure, and meanwhile, the UHPC has excellent wear resistance and anti-explosion performance. Therefore, UHPC is particularly suitable for use in large span bridges, blast resistant structures and thin walled structures, and in highly abrasive, highly corrosive environments.

The embodiment relates to an ultra-high strength and toughness corrosion-resistant and corrosion-resistant UHPC material which comprises a gelled material, fine aggregate, an ultra-high efficiency water reducing agent and steel fiber, wherein the steel fiber in the first embodiment is adopted as the steel fiber. The UHPC material can obtain the optimal grain composition, the steel fiber size and the doping amount through calculation based on a grain compact packing theory, a cement hydration theory, a random fiber intersection theory and the like, so that the inside of concrete achieves extremely high compactness, extremely fine pore diameter and a continuous steel fiber net which is mutually staggered.

In this embodiment, the diameter of the steel fiber body is 0.3mm, the thickness of the insulating isolation layer is 0.1mm, and the volume weight (weight of the object in unit volume) of the raw steel fiber is 7.85KG/m³The volume weight of the existing steel fiber and the insulating isolation layer is 3.0 KG/m³About 2.35 KG/m close to common concrete³The volume weight is left and right, so that the UHPC material is easier to uniformly disperse in the wet stirring process, the fiber can not sink, and the strength is more controllable and guaranteed.

The present invention is not limited to the specific technical solutions described in the above embodiments, and other embodiments may be made in the present invention in addition to the above embodiments. It will be understood by those skilled in the art that various changes, substitutions of equivalents, and alterations can be made without departing from the spirit and scope of the invention.