16 results about "Flexural toughness" patented technology

The invention discloses a design method of a high-ductility cement-based composite material, which comprises the following steps: S1, carrying out mix proportion design by using Box-Behnken in a response surface method, and designing a three-factor three-response test, the three factors being a water-binder ratio, a sand-binder ratio and a fiber mixing amount; s2, mixing and proportioning the materials according to the three factors in S1, and preparing to obtain the high-ductility cement-based composite material, s3, maintaining the high-ductility cement-based composite material obtained in the S2, and testing the three-response mechanical properties in the S1, wherein the three responses are compressive strength Y1, breaking strength Y2 and equivalent bending toughness Y3; and S4, analyzing the influence of the interaction of the three factors in the S1 on the three responses in the S3, establishing a response surface model equation through variance analysis verification, and verifying and optimizing a result to obtain an optimal mix proportion. A Box-Behnke method in RSM is adopted to establish a regression model with the water-binder ratio, the sand-binder ratio and the fiber mixing amount as influence factors and the compressive strength, the breaking strength and the equivalent bending toughness as response values.

The invention belongs to the technical field of building materials, and particularly relates to an engineering gelling composite material and a preparation method and application thereof. The machine-made sand is used as the core aggregate, and the compactness of the engineering gel composite material is improved due to the good grading controllability and micro powder filling effect of the machine-made sand. Through the synergistic effect of the machine-made sand and the mixed fibers, the cost of the engineering gelling composite material is reduced, meanwhile, the excellent mechanical property and durability of the engineering gelling composite material are kept, the balance of the mechanical property and the durability is achieved, and the sustainability is high. Specifically, by controlling the mixing ratio of the raw materials, the engineering gelling composite material is excellent in mechanical property, and has excellent fluidity, high ductility, bending toughness, breaking strength and compressive strength; the mixed fibers form a multi-stage crack resistance mechanism, and the crack resistance of the engineering gelling composite material is enhanced by combining the grain composition advantage of the machine-made sand.

This application belongs to the field of ultra-high performance concrete (UHPC) technology, specifically providing a toughened and reinforced UHPC functional component and its preparation method. The preparation method of the toughened and reinforced UHPC functional component includes the following steps: a mixed slurry is prepared from a UHPC matrix and modified steel fibers, poured into a mold, allowed to stand, and then steam-cured after demolding. The preparation method of the modified steel fibers includes: first activating the steel fibers with a hydroperoxide solution, then modifying the activated steel fibers with aminosilane, and finally reacting the silanized steel fibers sequentially with acrylate and amine compounds. By constructing a high-density amino group and a large number of branched structures on the surface of the steel fibers, the bonding strength between the modified steel fibers and the UHPC matrix is ​​improved, and interfacial debonding is reduced, thereby improving the interfacial strength, flexural toughness, and impact resistance of the toughened and reinforced UHPC functional component.

The invention discloses an indoor test method for testing the rollability of an asphalt mixture, and relates to the field of road engineering. The method solves the problem that the cracking resistance and the damage resistance of the material in the curling process cannot be quantitatively and accurately evaluated in the prior art. According to the scheme, a standard test piece is prepared through a wheel rolling method; a rigid supporting surface with a preset curvature is formed through a flexible plate, a supporting hole array and an angle-adjustable rotating and sliding clamp by utilizing a special mold and a curvature adjusting and supporting system; fixing one end of the test piece on a rotary clamp and keeping tangent to the flexible plate, and pushing a walking roll shaft at a constant speed through a driving system to bend the test piece and finally fit the curved surface; synchronously acquiring a thrust-displacement curve, multi-point strain data and crack initiation time, and evaluating the bending toughness and the cracking resistance; the test piece is kept deformed after being completely attached, attenuation of maintenance force along with time is monitored, and the stress relaxation characteristic is evaluated. The device is used for testing the crimpability of the asphalt mixture.

The invention provides a toughening design and a preparation method of ductile matrix concrete, the concrete comprises a ductile matrix and aggregate, and the ductile matrix is selected from a rubber modified fiber reinforced composite material. According to the invention, the fiber reinforced composite material is used as a concrete matrix and is subjected to fracture mechanical modification by adopting rubber, so that a ductile matrix with saturated multi-seam cracking and high-limit tensile strain is obtained. The ductile matrix can cooperate with aggregate to improve the mechanical and physical properties of concrete and effectively disperse microscopic damage under the action of external load, so that the concrete has higher bending toughness and good tensile strength to improve the structural safety and durability. The design idea and method of traditional rubber concrete are fundamentally changed, and the application value of rubber in high-performance building materials can be improved. The method for preparing the concrete is easy and convenient to operate, large-scale production can be achieved by means of existing concrete stirring and production equipment, and the application value is high.

The utility model relates to the technical field of building construction, in particular to a PVA fiber concrete carborundum floor. Comprising a base layer, a cushion layer is arranged on the base layer, a graded gravel layer is arranged between the base layer and the cushion layer, a reinforcing layer is fixedly arranged on the cushion layer, a carborundum wear-resistant layer is arranged on the reinforcing layer, the cushion layer is a concrete layer, and the reinforcing layer is a PVA fiber concrete layer. A certain deformation space is reserved for expansion of soil of the base layer through the graded gravel layer laid between the base layer and the cushion layer, the working conditions of the base layer and a soil base are improved, meanwhile, the PVA fiber concrete layer is adopted, the breaking strength and bending toughness of a reinforcing layer are improved, and the service life of the carborundum ground is prolonged.

The utility model relates to the technical field of concrete test block manufacturing, in particular to a sprayed concrete circular plate bending toughness test block forming device which comprises a machine frame and a forming demoulding mechanism detachably connected in the machine frame, the forming demoulding mechanism comprises a reciprocating motion component, a support and a mould ring, the support comprises a circular cage body, and the mould ring is arranged in the cage body. A rotating shaft is arranged at the circumferential end of the cage body, a bearing is arranged on the rack, and the rotating shaft is connected into the bearing; a bottom plate and a fixing plate are arranged at the two ends of the cage body respectively, the reciprocating motion component comprises an electric push rod, the fixed end of the electric push rod is fixed to the fixing plate, a groove is formed in the side, away from the electric push rod, of the bottom plate, a through hole is coaxially formed in the groove, a push plate is arranged at the groove, the free end of the electric push rod penetrates through the through hole to be connected with the push plate, and the shape and size of the push plate are consistent with those of the groove; the mold ring is annular and detachably connected to the face, away from the cage body, of the bottom plate. By implementing the scheme, the test block demolding effect and the operation efficiency are improved.

The present application relates to a kind of thermal shrinkage type fiber reinforced 3D printing concrete and its preparation method, the present application will be added to concrete thermal shrinkage type fiber, its length will change after heating, by the shrinkage stress of thermal shrinkage type fiber uniformly distributed in concrete to concrete prestressed, to improve the density of concrete, thermal shrinkage type fiber uniformly dispersed in concrete to the self-stress of three-dimensional tightness that concrete matrix is applied, can heal the gel hole and microcrack formed in early hydration, help to form more dense microstructure, realize the enhancement and toughening of concrete structure, to increase the bearing capacity and crack resistance of 3D printing concrete, compared with the 3D printing concrete without adding fiber and the 3D printing concrete mixed with ordinary synthetic fiber, the 3D printing concrete mixed with thermal shrinkage type fiber and simultaneously using heat curing, its compressive strength, flexural strength and flexural toughness significantly improve.

The present invention relates to the field of high-altitude infrastructure projects, and discloses a high-toughness frost-resistant concrete block for high-altitude infrastructure projects and a preparation method thereof. The preparation method of the concrete block comprises: preparing modified rubber basalt fiber and modified basalt ore sand; after cement and water reducer are fully mixed, mixing water is added and continuously mixed until an obvious adhesive state is obtained, then river sand and modified basalt ore sand are added and mixed to obtain mortar, thickener is added to the mortar to adjust the mortar consistency, and then modified rubber basalt fiber is added to the mortar and mixed evenly to obtain concrete slurry; the concrete slurry is formed to obtain high-toughness frost-resistant concrete blocks for high-altitude infrastructure projects. The present invention carries out orthogonal experimental design and analysis and mix ratio optimization, and obtains the optimal mix ratio of concrete with the best flexural strength and flexural toughness index, further improving the toughness of the concrete blocks.

The invention discloses high-ductility concrete based on composite modified rubber powder and a preparation method of the high-ductility concrete. A production raw material formula comprises the following components in parts by mass: 910-1050 parts of a cementing material, 370-400 parts of river sand, 400-430 parts of composite modified filler, 13-20 parts of fibers, 5-6 parts of a water reducing agent, 0.8-1.0 part of a thickening agent and 2-6 parts of a defoaming agent, the composite modified filler is composed of calcined clay, oyster shell powder and composite modified waste rubber powder according to the mass ratio of 0.8: (0.1-0.15): (0.05-0.1). The high-ductility concrete has the advantages that (1) experiments show that the mechanical property of the concrete can be remarkably improved, and the obtained high-ductility concrete has high compressive strength (greater than or equal to 67 MPa), high bending toughness (greater than or equal to 790 kJ / m), high tensile strength (greater than or equal to 5.6 MPa) and high ductility (greater than or equal to 7.7%); 2) resource utilization of solid wastes such as the waste rubber powder and the oyster shells is realized, and the development direction of green building materials is met.

The application discloses high-ductility concrete based on composite modified rubber powder and a preparation method thereof, and production raw material formula includes the following component in the mass fraction ratio: cementing material 910-1050 parts, river sand 370-400 parts, composite modified filler 400-430 parts, fiber 13-20 parts, water reducing agent 5-6 parts, thickening agent 0.8-1.0 parts, and defoaming agent 2-6 parts; the composite modified filler is composed of calcined clay, oyster shell powder and composite modified waste rubber powder in the mass ratio of 0.8:0.1-0.15:0.05-0.1. The application has the following advantages: 1) experiments show that the application can significantly improve the mechanical properties of concrete, and the obtained high-ductility concrete has high compressive strength (>=67MPa), high flexural toughness (>=790kJ / m³), high tensile strength (>=5.6MPa) and high elongation rate (>=7.7%); and 2) the application realizes the resource utilization of waste rubber powder, oyster shell and other solid wastes, and conforms to the development direction of green building materials.

The present invention provides a dust-suppressed, low-rebound sprayed ultra-high performance concrete, and a preparation method and construction method thereof. The raw materials include silicate cement, fly ash beads, nano-mineral additives, quartz sand, functional porous lightweight aggregate, conductive aggregate, steel fiber, water reducer and mixing water. The purpose of using sodium alginate solution to pre-wet the porous lightweight aggregate is to adjust the rheological properties of the freshly mixed ultra-high performance concrete and reduce the rebound rate; through the selection and proportioning of raw materials, the later strength and flexural toughness of the sprayed concrete can be improved, the rebound rate can be reduced, and the dust concentration in the working environment can be reduced. The purpose of applying voltage at both ends of the working surface during the spraying construction process is to charge the sprayed ultra-high performance concrete, produce an adsorption effect on dust, and reduce the dust concentration in the working environment. The present invention can solve the current problems of low late strength, relatively poor toughness, poor durability, high rebound rate during construction, and harsh working environment of sprayed concrete.

This invention belongs to the technical fields of infrastructure construction, urban renewal, seismic reinforcement, and infrastructure improvement in cold regions, and discloses a low-fiber-content, high-toughness self-prestressed concrete. It achieves the dual goals of high toughness and crack-free service life in low-fiber-content concrete by controlling the volume deformation of a highly efficient expansion component. This invention controls the mass fraction (25 parts / 2000 parts - 45 parts / 2000 parts) and particle size (1 μm - 80 μm) of the highly efficient expansion component, and cures it with water for at least 3 days. The volume of the expanded highly efficient expansion component accounts for 2.5% - 4.5% of the total volume; thus, an equivalent flexural toughness of not less than 160 kJ / m is achieved with a low fiber volume content. 3 It achieves the goal of low cost and high toughness with a flexural strength of not less than 12 MPa. It has broad prospects in infrastructure construction, urban renewal, hydraulic structures, seismic reinforcement, and especially in upgrading infrastructure in cold regions.

The application provides a preparation of a foamed concrete foaming agent and application in a fiber-reinforced foamed concrete vacuum insulation board. The core material of the insulation board is composed of a foamed concrete matrix and glass fiber reinforced material uniformly distributed therein, and is externally wrapped with a heat-shrinkable film and an airproof wrapping bag. The insulation board has excellent thermal insulation performance, mechanical properties and flame retardant properties. The preparation process comprises the following steps: firstly, a foaming agent is prepared by compounding surfactants (including cocamide propyl betaine and sodium dodecyl sulfate) and foam stabilizers (nano calcium aluminate particles and polyvinyl alcohol). Water, cement, fly ash, the foaming agent and glass fiber are mixed to prepare a foamed concrete slurry; the glass fiber reinforced material is added and uniformly stirred; the mixture is poured into a mold for molding; the foamed concrete insulation board prepared by using the foaming agent has significantly improved tensile strength, compressive strength and bending toughness. The insulation board of the application not only has the characteristics of light weight and high strength, but also significantly improves the flame retardant performance, and can be widely applied in the fields of building exterior wall insulation, roof heat insulation and the like.

The invention discloses a preparation method of a cement-based composite material with a multistage bionic toughening structure, which comprises the following steps: mixing and stirring a water-based polymer diluent, cement, a thickening agent and deionized water to obtain a water-based polymer modified cement paste, and carrying out bidirectional freezing by using an ice template method to promote the uniform distribution of a water-based polymer in a cement layer, so as to obtain the water-based composite material with the multistage bionic toughening structure. The preparation method comprises the following steps: preparing a modified cement blank with directional pores and a layered structure, de-molding and curing, terminating hydration of the blank, drying and curing polymer particles to form a pomelo peel-like porous structure, immersing in an oily epoxy resin solution, and fully filling interlayer pores with the oily epoxy resin solution by adopting a vacuum negative pressure method to obtain the pomelo peel-like modified cement. And after the resin is cured, a pearl layer brick-mud structure is formed. The pearl layer brick-mud structure and the pomelo peel porous structure are fused, the composite material has low density (about 1.56 g / cm < 3 >) and high mechanical property through the multi-stage bionic structure, the bending strength reaches 35.2 MPa, the bending toughness is improved by 2576% compared with cement paste, and the compressive strength is improved by 82%.

The application discloses a kind of composite biomimetic tenacious aluminate cement-based materials and preparation method thereof, the aluminate cement-based material is formed by arranging and hot-pressing several semi-dry particles, the structure of the arrangement includes a layer of a layer by a particle size particle paving, a layer by b particle size particle paving is paved on the a layer, a layer by c particle size particle paving is paved on the b layer, wherein a particle size, b particle size and c particle size are all different;The components of the semi-dry particles include, by weight fraction, 500 parts of cement, 80 parts of water, 0-30 parts of PVA, 0-5 parts of glycerol, 0-60 parts of Fe3O4.The method prepares semi-dry particles by adjusting the mix proportion of cement material and re-arranges hot-pressing to form gradient "brick-mud" structure, simple operation, controllable cost, easy to realize, the tensile strength and flexural toughness of the obtained cement-based board material are greatly improved compared with the control group, and the high-strength and high-toughness cement-based material can cover a wider range of applications.