17 results about "Cementitious composite" patented technology

This invention discloses a method for fixing a seepage-proof transition section on an irregular rock slope in a mine landfill. A seepage-proof cementitious composite sprayed material is wet-sprayed onto the irregular rock slope (1-2), forming a seepage-proof cementitious composite sprayed material layer (2) on the surface of the seepage-proof transition section. A seepage-proof geomembrane (3) is laid from the regular rock slope (1-1), and then rubber pads (7) and thin steel plates (6) are laid on the geomembrane (3) from the inside out. Hollow grouting anchors (4) are self-drilled through the holes in the thin steel plates (6) and rubber pads (7), and the edges are trimmed with a seepage-proof sealing agent (8). This invention is applied to the reinforcement of seepage-proof transition sections on irregular rock slopes in mine landfills, overcoming the problem of easy damage during the fixing process of seepage-proof transition sections on irregular rock slopes, eliminating potential hazards, and improving the safety and reliability of the seepage-proof system. It not only has good economic benefits but also significant safety and environmental benefits.

The invention relates to the technical field of polyvinyl alcohol fiber surface modification, and particularly provides a method for preparing hyperbranched polyamide surface modified polyvinyl alcohol fibers through a one-step method and application of the hyperbranched polyamide surface modified polyvinyl alcohol fibers in cement-based materials. The surface modification method comprises the following raw material components: 1 part of polyvinyl alcohol fiber, 1-3 parts of 3, 5-diaminobenzoic acid, 0.1-0.3 part of 4-dimethylaminopyridine and 100 parts of N, N-dimethylformamide. The modification method comprises the following steps: mixing the raw materials, and keeping the constant temperature of 50-80 DEG C to react for 2-5 hours to obtain the surface-modified polyvinyl alcohol fiber. The application comprises the following steps: verifying the change of the interfacial strength between the fiber and the cement-based material before and after modification through a single fiber pull-out sample, and obtaining the change of the mechanical property parameters of the fiber before and after modification through a single fiber tensile test. Compared with unmodified polyvinyl alcohol fibers, the tensile strength and the elongation at break of the surface-modified polyvinyl alcohol fibers disclosed by the invention are respectively improved by 1.1-1.6 times and 1.4-2.2 times; the surface-modified polyvinyl alcohol fiber can enhance the interfacial strength with cement, and the interfacial strength can reach 3.7-6.3 times that of unmodified polyvinyl alcohol fiber; the method can be widely applied to the field of fiber reinforced cement-based composite materials, and has a wide application prospect.

Methods of additive manufacturing by spraying and automated spraying devices are provided. The device comprises a feed system and an automated spray head with at least one nozzle in communication with a first supply and a second supply to spray at least one stream comprising fibers and a sprayable cementitious material. A first nozzle may deliver the first sprayed stream comprising fibers, a second nozzle may deliver a second sprayed stream of first sprayable cementitious material, and a third nozzle may deliver a third sprayed stream of second sprayable cementitious material comprising carbon dioxide. The device forms a cementitious component on a target having a first region comprising a reinforced cementitious composite material. There is also a second distinct region comprising a carbonized cementitious material formed from the third sprayed stream comprising the second sprayable cementitious material comprising carbon dioxide.

The photocuring 3D printing cement-based composite material is prepared by the following steps: adding a stabilizer into deionized water, and stirring until the stabilizer is completely dissolved to obtain a stabilizer solution; adding an organic monomer, a cross-linking agent and a dispersing agent into the stabilizer solution, stirring until the materials are completely dissolved, then adding a photoinitiator, and performing ultrasonic dispersion to obtain an organic mixed solution; placing the mixed solution in a vacuum drying oven, and removing oxygen at room temperature; adding cement and a water reducing agent into the deoxygenated mixed solution, and uniformly stirring to obtain a precursor solution; the precursor solution is poured into a digital light treatment 3D printer material pool, the sliced three-dimensional model is printed, organic components in the precursor solution are subjected to a photopolymerization reaction, and a polymer template wrapped with cement particles is formed through 3D printing; and coating a film, and carrying out standard curing for 28 days, so that the cement particles are subjected to hydration reaction continuously, and finally, the set and hardened light-cured 3D printing cement-based composite material is obtained. And high-precision forming of a complex structure is achieved.

This invention belongs to the field of cement technology, specifically relating to a method for preparing molybdenum tailings cementitious composites using a microwave method. The specific steps of this method are as follows: Molybdenum tailings are ground together with other admixtures; water is added to the molybdenum tailings powder and stirred evenly to obtain a mixture; a microwave field is applied to the mixture and maintained for 10-40 minutes to obtain a composite material; the composite material is crushed and sieved to obtain the molybdenum tailings cementitious composite material prepared by the microwave method. This method uses molybdenum tailings as the main raw material, combined with natural minerals such as limestone and bauxite, to prepare a composite material with high activity. The operation is simple and does not require extensive new equipment or technology.

This application provides a multi-level scale sisal cellulose fiber reinforced cement-based composite material and its preparation method. The composite material comprises cement, standard sand, and multi-level scale sisal cellulose fibers, wherein the amount of multi-level scale sisal cellulose fibers incorporated is 0.01%–0.3% of the cement mass, and the diameter of the multi-level scale sisal cellulose fibers is in the nanometer scale and the length is in the micrometer scale. This application optimizes existing cement-based material curing methods and significantly improves the mechanical strength and durability of cement-based materials.

The invention relates to a combined experiment method for improving ECC performance test success probability, and belongs to the technical field of civil engineering material test and design. Aiming at the problems of low trial and error efficiency, large discreteness of experimental results and the like in the research and development of the existing high-strength and ultrahigh-ductility engineering cementitious composites (ECC), the invention provides a closed-loop experimental system based on the combination of micromechanics matching screening and macroscopic accurate verification. The method mainly comprises two stages: in a screening stage (step 1), respectively through a pure matrix three-point bending experiment and a single fiber bundle drawing experiment, acquiring matrix fracture toughness and interface bonding strength parameters, verifying an energy matching relationship according to a micromechanics criterion, if the energy matching relationship is not matched, feeding back and guiding fiber modification or matrix adjustment, and if the energy matching relationship is not matched, feeding back and guiding the interface bonding strength parameters; reverse design and pre-screening of the mix proportion are realized; in the verification stage (step 2), a special dumbbell test piece designed with a specific long scale distance (80mm effective observation area) is adopted to perform a uniaxial tensile test on the all-component material meeting the matching requirement, and end damage interference is avoided. By applying the method, the research and development period can be shortened by 40% or above, the high-performance ECC with the compressive strength larger than 135 MPa, the tensile strength larger than 10.0 MPa and the tensile strain capacity of 10%-12% is successfully guided, prepared and verified, and the test success rate and the data authenticity are remarkably improved.

The present invention refers to a Daytime Radiative Cooling Cementitious composite includingan OPC binder in the form of grains, with an amount of Fe2O3 lower than 0.05% by weight with respect to the total weight of the OPC binder, wherein the grain size is below 25 μm,water, wherein the weight ratio between water and the OPC binder is between 0.2 to 0.6,an addition in a proportion between 0.1% and 50% by weight with respect to the weight of the OPC binderand wherein the resulting DRCCC has a pore size below 6 μm as defined by mercury intrusion porosimetry, that can optionally comprise micropatterns, and to its use in the construction industry, such as building construction, in civil works such as reservoirs, bridges, dams and sewers, in solar cell technology or in urban architectural design.

The present application belongs to the technical field of engineering cement-based composite materials, and particularly relates to a self-healing cement-based composite material and a preparation method thereof. Raw material composition of the self-healing cement-based composite material comprises Portland cement, fly ash, slag powder, water reducing agent, fiber, SAP and capsule type additive. The capsule type additive comprises an inner core and a silica coating shell layer, and the inner core comprises a silane modified ethylene-acrylic ester-GMA terpolymer and a sodium carbonate activator. The self-healing cement-based composite material of the present application can effectively limit cracking through fiber reinforcement ductility, and further realizes good synergistic self-healing performance through SAP and the capsule type additive. The self-healing cement-based composite material has the advantages of low cost, stable performance and easy industrialization.

This invention provides an auxiliary component for fireproof and flame-retardant indoor soundproof walls based on inorganic cementitious composite materials, relating to the field of fireproof and flame-retardant board technology. It includes: a wear-resistant fire-retardant board and a sound-insulating fireproof board. The wear-resistant fire-retardant board is composed of the following components by weight: 40-60 parts ceramic fiber, 5-10 parts aluminate cement clinker, and 10-15 parts silica powder. The sound-insulating fireproof board is composed of the following components by weight: 25-30 parts ceramic fiber, 15-20 parts potassium feldspar powder, 5-10 parts aluminate cement clinker, 15-20 parts expanded perlite, and 5-10 parts porous diatomaceous earth. The core materials of the wear-resistant fire-retardant board and the sound-insulating fireproof board in this invention are inorganic substrates such as ceramic fiber and potassium feldspar, possessing a Class A long-lasting flame-retardant effect, and also exhibiting excellent characteristics such as wear resistance, high temperature resistance, aging resistance, and sound insulation. This solves the problem that most components do not use high-efficiency inorganic substrates, resulting in overall performance that does not meet ideal standards.

This invention relates to a method, apparatus, equipment, and storage medium for preparing cement-based composite materials. The method includes: retrieving a process parameter package from a database based on initial parameters; generating control signals for an ultrasonic device, a CO2 gas supply device, and a stirring device based on the process parameter package; sending the ultrasonic device control signal to the ultrasonic device, the CO2 gas supply device control signal to the CO2 gas supply device, and the stirring device control signal to the stirring device, so that the ultrasonic device, the CO2 gas supply device, and the stirring device operate on materials within the same reactor. This disclosure achieves carbon fixation during cement slurry mixing, rapidly improves the early strength of the cement-based material system, facilitates subsequent rapid demolding, curing, and practical application, reduces energy consumption, and is green and low-carbon.

Cement pores are filled with modified butyl rubber powder, surface activated rubber particles form a skeleton structure, the modified butyl rubber powder and the surface activated rubber particles are grafted through maleic anhydride and form a chemical bond bridge with a silane coupling agent, a two-stage damping system is constructed, and the high-damping flame-retardant pavement cementing composite material is prepared. Therefore, the vibration and noise reduction performance of the composite material can be effectively improved. The intumescent flame retardant forms a compact carbon layer at high temperature, oxygen and heat transfer are effectively isolated, the flame retardance of the material is effectively improved, and the problem that a single component is prone to failure is solved through the compound design. And the ethylene glycol antifreeze agent can greatly improve the flexibility and crack resistance of the composite material under a low-temperature condition, so that the use requirements in cold regions are met. The application of the waste rubber particles subjected to surface activation treatment not only improves the interfacial compatibility of the material and a cement matrix, but also realizes efficient cyclic utilization of resources, and has excellent economic and environmental benefits.

The application belongs to the technical field of mine engineering materials, and particularly relates to a cementitious material composite targeted activator for consolidating tailings and a preparation method thereof. The cementitious material composite targeted activator for consolidating tailings comprises the following raw materials in parts by weight: 10-30 parts of an alkaline excitation source, 5-10 parts of a core-shell structure agent, 20-50 parts of a nanocrystal seed, 4-10 parts of an organic template agent, and 1-5 parts of a heavy metal solidification agent. The composite targeted activator realizes targeted activation through multi-component cooperation, is suitable for tailings with different properties, and has excellent performance such as compressive strength and heavy metal solidification rate. The composite targeted activator not only significantly improves the utilization rate of industrial solid waste, but also is environmentally friendly and economical, and is suitable for mine tailings filling engineering.

The embodiment of the invention discloses a non-toxic and harmless inorganic double-liquid grouting material with good durability and a preparation method thereof. The material comprises a high-performance cement-based gelling composite material and a cement setting adjusting material, the high-performance cement-based cementitious composite material comprises the following components in percentage by mass: 80-85% of ordinary Portland cement, 5-10% of a mineral admixture and 5-10% of limestone powder, the cement setting adjusting material composite material comprises the following components in percentage by mass: 65%-75% of a flash setting component, 5%-10% of a setting adjusting component and 15%-25% of a reinforcing component. According to the invention, a series of problems of too fast gelation time, large slurry viscosity, large pumping resistance, low early strength, influence on water quality due to high content of soluble alkali metal, poor water resistance of a stone body, easy corrosion by sulfate and the like of a traditional cement-water glass double-liquid grouting material can be solved, and the cement-water glass double-liquid grouting material has good popularization and application values.

This invention discloses a method for evaluating the interfacial reinforcement of ultra-high performance concrete using limestone powder as a substitute for silica fume, belonging to the technical field of cementitious composite material mix design and performance evaluation. The invention first establishes a reference cementitious material matrix system containing silica fume and sets up gradient substitution groups for silica fume using limestone powder. The strength of specimens with different substitution ratios is pre-screened based on the 28-day matrix compressive strength, selecting representative substitution groups. The 100-hour cumulative heat release, 28-day total porosity, peak pull-out load of a single steel fiber, and pull-out work of a single fiber are measured for the representative substitution groups. Hydration response coefficient, pore structure compactness coefficient, peak bearing capacity coefficient, and energy dissipation coefficient are constructed, and a coupled determination method of interfacial reinforcement index (IEI) and strength constraint coefficient (Kc) is established. Based on IEI and Kc, candidate reinforcement groups, optimal substitution groups, and corresponding substitution ratios are output. This invention can be used for the rapid screening and quantitative design of low-silica fume ultra-high performance concrete cementitious systems.

This invention provides a design method for reinforcing masonry structures with high-ductility cement-based composite materials based on toughness, comprising the following steps: assessing the seismic toughness level of the existing masonry structure to determine the seismic toughness improvement target; preliminarily determining the design parameters of the high-ductility cement-based composite material surface layer based on the seismic toughness improvement target; assessing the seismic toughness level of the reinforced masonry structure to confirm whether the seismic toughness improvement target is met, and obtaining the design parameters of the high-ductility cement-based composite material surface layer that meet the seismic toughness improvement target based on the confirmation result. The beneficial effects of this invention are: this invention organically combines the quantification of seismic toughness with the reinforcement design scheme, and uses a new high-performance material to establish a reinforcement design method for existing masonry structures to improve the seismic toughness level of existing masonry structures. Therefore, this invention not only considers the improvement of the seismic performance of existing masonry structures, but also the optimization of structural repair time and repair costs.

This invention relates to a shrinkage stress relief device for concrete towers and its construction method. The device includes a filler and circumferential reinforcement. The filler is provided at the circumferential joint of the tower sections. The filler is made of a high-ductility fiber-reinforced cementitious composite material. The filler is connected to the tower sections through internal circumferential reinforcement. The device is obtained by first casting the filler and binding the circumferential reinforcement, and then casting the tower sections after installing the device. Compared with the prior art, this invention can prevent unnecessary shrinkage damage to the concrete tower sections during the production process and prevent the tower sections from cracking due to shrinkage stress.