7results about How to "High yield stress" patented technology

Provided is a technique for a steel sheet having a TS of 780 MPa or more and less than 1180 MPa, high YS, and excellent press formability of the inside and the ends of the steel sheet. A steel sheet in which a base steel sheet has a prescribed component composition and a Vickers hardness of 84% or less with respect to a position 1 / 4 of the sheet thickness from the surface of the base steel sheet, and which has a surface soft layer satisfying the following formula (1), the structure in the surface soft layer being within a specific range, and the structure in the position 1 / 4 of the sheet thickness of the base steel sheet being within a specific range, and a tensile strength of 780 MPa or more but less than 1180 MPa. 20 < = X < = 120-3800 * [Sb]-1900 * [Sn]... (1) (In formula (1), X is the thickness ([mu] m) of the soft surface layer, and [Sb] and [Sn] are respectively the contents (mass%) of Sb and Sn in the steel.

The application discloses a high-flow-state self-compacting grouting dry-mixed mortar and a preparation method thereof, and belongs to the technical field of building materials. The mortar comprises, in parts by weight, cementing material 350-450 parts, modified spherical steel slag sand microbeads 500-600 parts, water reducing agent 4-8 parts, plastic expansion agent 0.1-0.5 parts and defoaming agent 0.1-0.5 parts. The alkali-responsive ionized modified warm rubber is pre-anchored on the surface of the spherical steel slag sand through a chemical bond, the ball rolling effect during mixing is fully played, the anti-segregation effect during the standing period is fully played, and the automatic triggering under the alkali condition is realized. The application solves the problems that the flowability and the anti-segregation property of the existing grouting mortar are difficult to be considered, the anti-segregation agent is directly mixed to easily cause a large loss of the flowability, and the dispersion is uneven. The obtained mortar has an initial flowability of greater than or equal to 325 mm, a bleeding rate of zero and a 28d compressive strength of greater than or equal to 85 MPa.

This invention discloses a low-carbon, high-density shotcrete admixture, its preparation method, and its application, relating to the field of concrete admixtures in building materials. The admixture comprises the following components by mass percentage: 53-73% rheological component, 15-25% thickening component, 10-18% early-strength component, and 0.5-4% setting regulator component. The rheological component includes manganese slag powder and silica fume, and the thickening component is tailings powder loaded with nano-modified cellulose ether. This invention increases the cohesiveness of shotcrete and improves the slurry encapsulation of concrete through the thickening component, increases the yield stress of concrete through the rheological component, and synergistically improves the adhesion and rapid hardening performance of the material after spraying by combining with the early-strength component, thereby reducing the rebound rate. Furthermore, the nanoparticles loaded on organic matter hydrate in the pores, directionally filling harmful pores, effectively improving the density and strength of shotcrete, achieving low-carbon, low-rebound, and high-density shotcrete.

An underwater anti-dispersion ultra-high performance concrete based on reversible network design, its preparation method, and its application. The ultra-high performance concrete comprises cementitious materials, water, polycarboxylate superplasticizer, and a synergistic anti-dispersion composite admixture; wherein the composite admixture consists of a main agent and auxiliary agents. The main agent and auxiliary agents are used to construct a three-dimensional reversible network structure with significant thixotropic properties in situ within the slurry, endowing the slurry with intelligent rheological properties of "shear thinning—static thickening": the yield stress reaches 50–320 Pa at rest to resist underwater erosion, and the plastic viscosity is maintained at 2–8 mPa·s during shearing to ensure pumpability. This invention effectively solves the problem of balancing rheological properties and anti-dispersion properties in ultra-high performance concrete systems, and is particularly suitable for the repair and reinforcement of underwater piers, pile foundations, and tunnel linings.

The invention relates to the technical field of building materials, and discloses a novel anti-dispersion grouting material capable of adjusting setting time under a flowing water condition. The invention relates to a quick hardening iron aluminate cement mortar which is prepared from the following raw materials: quick hardening iron aluminate cement, silica fume, superfine fly ash, a modified inorganic thixotropic stabilizer, a composite setting time regulator, polycarboxylate superplasticizer powder, hydroxyethyl methyl cellulose, an organic silicon defoaming agent and the like. The dispersion resistance of the slurry in a flowing water environment is improved; the hydration rate is regulated by utilizing the synergistic effect of the boric acid powder and the trisodium citrate dehydrate powder, so that the technical problem that the setting time of the quick-hardening cement is difficult to control is solved; and in cooperation with the micro-grading filling effect of the mineral admixture, the high fluidity, high flowing water retention rate and high early strength of the slurry under the low water-binder ratio are achieved, and the slurry is suitable for grouting reinforcement in the complex underground flowing water environment.

This invention discloses an adaptive balancing lifting device for aircraft door assembly and disassembly, belonging to the field of lifting device technology. It includes a lifting frame, lifting components, and a clamping assembly. The clamping assembly is equipped with a flexible component containing magnetofluid and a corresponding excitation component, which can adapt to the curved surface of the door and actively harden to provide reliable clamping. The lifting device also integrates a multi-degree-of-freedom angle adjustment component and a vision-feedback-based active balancing system. Before handling, the clamping angle can be adjusted to align the door using the longitudinal and lateral adjustment components. During handling, a vision camera detects the door's attitude in real time, and the control system drives independent lifting components on both sides for dynamic leveling. Micro-vibrations are absorbed by adjusting the magnetofluid state, achieving adaptive flexible gripping, precise attitude adjustment, and stable anti-sway handling of irregular doors, significantly improving the safety, accuracy, and efficiency of assembly and disassembly operations.

The present application relates to a kind of carbonization 3D printing concrete mix design method and carbonization 3D printing concrete.The present application is introduced into carbon dioxide to cement-based printing slurry, controls its amount of introduction, while introducing carbon dioxide into cement-based printing slurry, according to the content of carbonation reaction product CaCO3, and the ratio of calcite and aragonite in the required concrete mixture, the amount of magnesium chloride is calculated, magnesium chloride and carbon dioxide are added into cement-based printing slurry at the same time, fully react, finally 3D printing concrete material is prepared.The present application improves the thixotropy of material by the addition of magnesium chloride, the generation of aragonite type calcium carbonate, the constructability of cement slurry is stronger, at the same time, the orientation of nanoscale aragonite fiber is arranged according to the printing direction, has excellent reinforcing and toughening effect, and the bending strength, bending strength and compressive strength are improved.