14 results about "Cementitious matrix" patented technology

The present invention relates to the technical field of concrete. Disclosed is a toughening design method for fiber-reinforced concrete. The method of the present invention changes the passive control characteristics of fibers on a concrete crack propagation process in conventional fiber-reinforced concrete. Starting from the origin of composite material design, firstly, an ultrahigh-ductility composite cementitious matrix is designed; and secondly, an aggregate is incorporated. On the basis of a specific combination of matrix and aggregate parameters, a composite material develops meso-scale multiple cracking and strain-hardening behaviors between aggregate particles during external loading. The fiber-reinforced concrete prepared by this method actively disperses brittle damage and failure within the material, and avoids unstable crack propagation caused by weak interfacial bonding between the aggregate and the matrix. Compared to conventional fiber-reinforced concrete design methods, the present invention more accurately establishes relationships between material compositions, microstructures and macroscopic mechanical response, and more efficiently enhances the toughness of the material.

The invention discloses self-repairing concrete based on modified carbon fibers and a preparation method thereof, and belongs to the technical field of building materials. An existing concrete crack repairing technology has two major problems that bonding between carbon fibers and a matrix is poor, and the repairing effect is limited; microbial self-repairing and nutrient adding can reduce the strength of the concrete. According to the solution provided by the invention, firstly, the surface of the carbon fiber is modified by an MICP method to form a stable three-dimensional calcium carbonate coating layer, so that the surface roughness is enhanced, the interface bonding capacity of the carbon fiber and a gelling matrix is greatly improved, and the carbon fiber is stably attached to an interface; then, the modified carbon fibers and concrete raw materials are accurately mixed according to a specific proportion, and the high-strength and good-crack-resistance self-repairing concrete is prepared. When cracks are generated, the carbon fibers limit crack propagation with high strength and high ductility, and surface microorganisms generate calcium carbonate through physiological reaction to fill the cracks; the strength, crack resistance and self-repairing capacity of a concrete structure are improved, the service life is prolonged, and the concrete is suitable for a hydraulic concrete structure in a complex environment and wide in application prospect.

The invention provides composite cementing material building floor sound insulation mortar and a preparation method thereof, and belongs to the technical field of novel building materials. Aiming at strong-alkalinity, high-humidity and intermittent impact coupling special environments such as hospitals and the like, a geopolymer precursor composed of metakaolin and blast furnace slag micro powder and an alkaline activator are introduced and interwoven with a cement hydration product to form an alkali-corrosion-resistant composite gel matrix; meanwhile, the composite corrosion inhibitor with the pH response release characteristic is adopted, and corrosion inhibition components are released during strong alkaline invasion to form a composite protective film; and regenerated elastic particles subjected to surface silanization treatment are selected as a damping filler. Under the synergistic effect of the three components, the mutually aggravated failure cycle of chemical erosion and mechanical impact is interrupted, so that the long-term sound insulation stability, mechanical durability and corrosion resistance of the sound insulation mortar in a severe environment are remarkably improved.

The present invention relates to methods for treating articles made of reinforced cementitious material, with the aim of protecting them and increasing their durability, which brings about both an improvement in the mechanical properties of the cementitious matrix and an improvement in the corrosion resistance of the steel bars.

Embodiments relate to use of graphite nanoplatelets (GnP) to enhance the mechanical and durability characteristics of cement that may be used as cement sheaths in wellbores of oil and gas wells. Generally, undesired permeability of cement is caused by diffusion of trapped oil and / or natural gas through the cementitious matrix of the cement, leading to material degradation of the cement. Methods disclosed involve using modified GnPs (having physically modified surfaces or chemically modified surfaces energies) to generate a cementitious nanocomposite with uniformly dispersed GnPs, which can effectively arrest the undesired diffusion mechanism. Modified GnPs can also increase the strength of interfacial adhesion (e.g., interfacial bonds and interfacial energies) between the GnP and the cement matrix (e.g., hydrations of the cement). Physical modification of GnP can involve non-covalent treatment techniques. Chemical modification of GnP can involve covalent treatment techniques.

The present invention relates to a jig for evaluating the tensile properties of a fabric-reinforced cementitious matrix (FRCM) composite and, more specifically, to a jig for evaluating the tensile properties of an FRCM composite, the jig being capable of improving the accuracy of tensile property evaluation by preventing the FRCM composite from slipping that may occur during the tensile property evaluation of the FRCM composite.

This invention discloses a thermal insulation, sound insulation, and fireproof material and its preparation method, belonging to the field of building materials technology. The material, by mass percentage, comprises: 25-45% inorganic cementitious matrix, 15-28% MOF-confined aerogel low thermal conductivity composite, 8-15% piezoelectric-damping sound-absorbing microspheres, 5-12% supramolecular flame-retardant system, 1-4% reinforcing fiber, 0.5-2.5% foam stabilizing crosslinking agent, and deionized water. This invention reduces gaseous heat conduction and inhibits alkaline corrosion by confining UiO-66-NH2 within the mesopores of hydrophobic silica aerogel and forming a fluorinated alkali-resistant shell on the outer surface; constructs a damping-piezoelectric composite energy-dissipating structure using barium titanate nanowires / polyurethane urea microspheres containing dynamic disulfide bonds; and utilizes the MXene-POSS-MPP supramolecular flame-retardant system to promote the formation of a Ti-O-Si-P ceramic barrier at high temperatures. The resulting material is lightweight, heat-insulating, sound-insulating, fire-resistant, and mechanically stable, making it suitable for applications such as prefabricated buildings, equipment thermal and sound insulation, and protection of new energy batteries.

This invention provides a method for evaluating the bond strength between reinforcing fibers and early-age cementitious matrix, relating to the field of cementitious material testing technology. The method includes: step S1, mixing raw materials; step S2, curing samples to a specified age; step S3, testing penetration pressure or penetration resistance values; step S4, calculating the average value, standard deviation, and mean deviation rate; and step S5, determining the degree of fiber dispersion. This method is simple to prepare samples and convenient to test. It can be used for screening reinforcing fibers in cementitious material research and preparation processes, and as a supplementary explanation for the improved tensile strength, toughness, and other properties of fiber-reinforced cementitious materials.

The invention relates to the technical field of soft soil treatment, and discloses a curing agent for coastal soft soil and a manufacturing process of the curing agent. The process comprises the following steps: carrying out coarse and fine grading pretreatment on the furnace bottom slag, carrying out acid activation treatment on the zeolite powder, carrying out surface modification treatment on the basalt fiber, preparing a component A delayed coagulation curing agent, preparing a component B coagulation accelerating curing agent, and compounding the two components in proportion for use. The curing speed can be adjusted within 15-90 minutes by compounding the component A and the component B according to different mass proportions, and a double-phase structure of a rigid framework and a gelling matrix is formed by the surface modified basalt fibers and graded furnace bottom slag coarse particles. The rheological property of slurry is adjusted through selective ion adsorption of acid activated zeolite powder and molecular chain extension of hydroxypropyl methyl cellulose, and the technical problems that a coastal soft soil curing agent is large in brittleness, poor in construction adaptability, non-adjustable in curing speed and low in synergistic utilization rate of various solid wastes are solved.

The invention provides a method for simultaneously preparing pull-out samples of single fibers in cement matrixes with different thicknesses and application of the pull-out samples. The sample preparation mold comprises a bottom plate, a back plate, a baffle plate, a sample separation module and a thick bottom regulator which are fixedly connected through screws and mortise and tenon joint structures. The back plate and the sample separation module are composed of an upper part and a lower part; grooves for determining fiber positions are formed in the upper surfaces of the lower back plate and the bottom plate; the cement base body is placed in a groove formed by the back plate, the baffle plate and the sample separation module; the thickness of the fiber embedded in the cement matrix can be achieved by rotating the thickness adjuster to move the lower sample separation module. The invention provides a casting and stripping method of a single-fiber pull-out sample based on the mold and a testing method of the single-fiber pull-out sample, and the casting and stripping method and the testing method are applied to measuring the critical length of single-fiber pull-out. Through integrated mold design, pulling-out samples of fibers in cement-based materials with different thicknesses can be prepared at the same time, and the critical length that the fibers are pulled out of a matrix without breakage is further obtained. The method can fundamentally ensure that all contrast samples have high consistency in material composition, maintenance history and interface microstructure, so that the matrix thickness is used as a unique independent variable for accurate research, the test efficiency is remarkably improved, and the method is widely applied to the field of fiber reinforced cement-based materials.

The present invention relates to concrete compositions and methods of making a concrete composition having self-healing properties, including a cementitious matrix impregnated with a plurality of biofibers, wherein the biofibers comprise: a polymer fiber core comprising one or more polymers selected from the group consisting of polyester, polyethylene, polypropylene, polyvinyl alcohol, polyamide, aramid, polyacrylonitirile, cellulose, polyurethane, and combinations thereof; a crosslinked hydrogel layer coating on the polymer fiber core, wherein the hydrogel layer comprises endospores, one or more cross-linked anionic polymers, and a (co)polymer shell encapsulating the hydrogel layer, wherein the shell has one or more layers which may be the same or different, and each of the one or more layers is formed with a (co)polymer selected from the group consisting of nitrocellulose (NITR), epoxy resin (ER), polymethyl methacrylate(PMMA), polyvinylidene fluoride (PVDF), cyanoacrylate adhesive (CYA), polystyrene (PS), polylactic acid (PLA), and combinations thereof.

The invention relates to the technical field of cement gelling materials, and discloses a composite gelling material and a preparation method thereof.The composite gelling material is prepared from cement, gypsum powder, mineral powder, steel slag powder, fly ash superfine powder, sulfonate styrene-butadiene latex and water according to the proportion of (32-45) g: (1.5-2.3) g: (22-36) g: (9-20) g: (18-35) g: (5-18) g: (30-38) g; a large number of hydrophilic sodium sulfonate groups are introduced into the styrene butadiene rubber, so that the dispersity of the styrene butadiene rubber in water is improved, aggregation of the styrene butadiene rubber in latex is reduced, and sulfonate styrene butadiene rubber in the latex forms a continuous, compact and uniformly dispersed viscoelastic polymer film in a cementing material matrix, so that a good cementing effect is achieved; the compactness and the integrity of a cementing matrix are improved, and the compressive strength and the breaking strength of the cementing material are improved.

The invention discloses a multi-source tailing solid waste-based road base material and a preparation method thereof, and belongs to the technical field of road engineering materials. The material is prepared by taking industrial solid wastes such as gold tailings and iron ore tailings as main raw materials and adding an alkaline activator, a gelling matrix material, an additive, modified montmorillonite, an anti-cracking material and the like. The modified montmorillonite is modified by adopting a composite pillared agent and a chelating agent, through ion exchange and chelation, the curing effect on heavy metal ions is remarkably improved, and the leaching toxicity is reduced. Meanwhile, the material has good freeze-thaw stability, and the influence of frost heaving stress on the structure is effectively reduced. Compared with the prior art, efficient utilization of industrial solid waste is achieved, the production cost is reduced, dependence on natural materials is reduced, and remarkable environmental protection and economic benefits are achieved.

The invention provides a nucleation threshold control and delayed hydration method for a cementing material system, which comprises the following steps of: firstly, adding a common-resistance nucleation inhibition composition and water into a cementing matrix, and mixing, so as to effectively inhibit the formation and growth of crystal nucleus and improve the critical nucleation supersaturation of a cementing material; then dropwise adding a regulating solution into the material and monitoring the ion activity of the solution in real time so as to ensure that an ion activity path is always in a controllable state, and controlling the addition amount of the regulating solution in combination with a PID closed-loop control algorithm, so that the critical nucleation super-saturation degree of the system is maintained in a preset super-saturation window until the target time is reached; by changing the solution environment or introducing external induction factors, a system is promoted to quickly break through a preset supersaturation window, accurate triggering of the nucleation process is achieved, the hydration process can be remarkably delayed, the normal reaction rate of the cementing material can be quickly recovered after triggering, and the stability of the cementing material is improved. And higher flexibility and reliability are provided for engineering application.