5results about How to "Improve flexural toughness" patented technology

The application provides a 1700MPa-grade hot forming steel with high cold bending performance and a preparation method and application thereof. A surface layer of the hot forming steel has soft ferrite structure, a subsurface layer has mixed structure of soft ferrite and martensite, and a core layer has carbon-poor martensite structure. The preparation method comprises any one or a combination of at least two of the following conditions: (A) the coiling temperature after hot rolling is 650-700 DEG C; (B) the pickling speed is less than or equal to 150 m / min; (C) the temperature of continuous annealing is 780-830 DEG C; (D) the atmosphere in the furnace is a mixture of nitrogen and hydrogen; (E) the dew point temperature is-35 DEG C to-17 DEG C. Through fine component design and process integration, the application successfully solves the contradiction between material strength and toughness, realizes double guarantee of high strength and high toughness, simultaneously meets the light weight requirement, and improves the competitiveness of existing products.

The present application relates to the technical field of fiber reinforced geopolymer, and particularly discloses a fiber reinforced geopolymer and a drainage pipeline prepared from the same. The fiber reinforced geopolymer comprises mineral powder, fly ash, quartz sand, alkali activator, fiber, latex powder and rubber powder. The mineral powder and the fly ash are sequentially added, stirred at low speed, and mixed uniformly. While stirring, the fiber is slowly added and dry-stirred, then the quartz sand and the rubber powder are added, and water is added to stir uniformly. The latex powder is dissolved in water after being added, forms a coating layer to wrap the surface of the fiber or the geopolymer raw material, changes the interface characteristics of the fiber and the geopolymer matrix, slows down the occurrence of the polymerization reaction, makes the mechanical properties of the EGC material decrease, improves the interface bonding between the fiber and the geopolymer matrix, forms a structure of the synergistic effect of the fiber-latex powder-geopolymer matrix, increases the fracture energy of the fiber reinforced geopolymer, and improves the bending toughness of the fiber reinforced geopolymer.

The utility model discloses a widening structure for new and old bridges with large height difference, which relates to the field of widening transformation of old bridges and comprises a first bridge body and a second bridge body. The first bridge body embedded steel bars and the second bridge body embedded steel bars are embedded in the tops of the first bridge body and the second bridge body respectively; the first bridge floor cast-in-place layer and the second bridge floor cast-in-place layer are both poured at the top ends of the first bridge body and the second bridge body; the anchoring steel bars are embedded in the top of the second bridge body and located at the bottoms of the second bridge body embedded steel bars, the lightweight concrete precast blocks are arranged at the top end of the second bridge body, and the outer sides of the lightweight concrete precast blocks are matched with the second bridge body embedded steel bars and the anchoring steel bars correspondingly. The lightweight concrete leveling layer is reasonable and reliable in structure, the lightweight concrete precast blocks are adopted to replace a traditional concrete leveling layer, the weight is reduced by 30%-50%, the dead load of the newly-added leveling layer is controlled within 15% of the live load of an original bridge, and the influence on the original bridge structure is remarkably reduced.

This invention discloses a high-toughness crack-resistant concrete and its preparation method, relating to the field of building materials technology. The high-toughness crack-resistant concrete includes cementitious materials, aggregates, water, admixtures, and reinforcing components. The reinforcing components include a multi-scale hybrid fiber system and a time-compensated shrinkage system. The multi-scale hybrid fiber system includes micro-scale high-modulus fibers and macro-scale crack-resistant fibers. The micro-scale high-modulus fibers are used to inhibit the initiation of cracks in the concrete matrix and induce crack refinement. In this invention, by setting up a multi-scale hybrid fiber system and utilizing the synergistic effect of micro-scale high-modulus fibers and macro-scale crack-resistant fibers, the entire process of concrete cracking is controlled. Due to their small diameter and large specific surface area, the micro-scale high-modulus fibers can be uniformly distributed in the concrete matrix, effectively inhibiting crack initiation and inducing crack refinement after crack formation.

The present application relates to the technical field of building materials, and in particular to a concrete material based on modified coral microcrystalline composite fiber and a preparation method thereof. The concrete material based on modified coral microcrystalline composite fiber comprises cementitious materials, coarse aggregate, fine aggregate, modified coral microcrystalline composite fiber, water reducing agent and mixing water. The modified coral microcrystalline composite fiber is prepared by wet spinning with modified coral microcrystalline and polyvinyl alcohol as raw materials. The modified coral microcrystalline is aragonite type calcium carbonate microcrystalline modified by a silane coupling agent. By adding the modified coral microcrystalline composite fiber to the concrete base material, the industry pain point of traditional fibers that are not toughened and not enhanced in compressive resistance is solved. The 28d splitting tensile strength, bending toughness and compressive strength of the prepared concrete material are simultaneously improved, and a comprehensive breakthrough in the mechanical properties of concrete is achieved.