A method for carbon dioxide strengthening of a recycled concrete aggregate comprises the following steps: (1) crushing and sieving waste concrete; (2) placing the sieved recycled concrete aggregate in a sealed container, controlling the relative humidity of 30-90% and the CO2 concentration of 5-90%, and carrying out carbonization treatment; and (3) making the treated recycled concrete aggregate particles into recycled mortar and concrete. Compared with mortar prepared from a recycled concrete aggregate without treatment, the mortar prepared from the obtained recycled concrete aggregate after CO2 strengthening treatment enables the mortar early strength to be improved by 20.1%-22.0% and the later strength to be improved by 12.1%-13.9%; the 28 d drying shrinkage value can be reduced by 7.8%-16.7%; and the 28 d water absorption rate can be reduced by 7.7%-13.3%.

Method for carbon dioxide strengthening of recycled concrete aggregate

The invention discloses a method for reinforcing recycled concrete fine aggregate by using carbon dioxide, which comprises the following steps: (1) calcium hydroxide solution or calcium salt calcification treatment: spreading recycled fine aggregate prepared from construction waste on a tray, spraying a calcium hydroxide or calcium salt solution, and stirring uniformly; (2) CO2 curing: putting the recycled fine aggregate subjected to calcium hydroxide solution or calcium salt calcification treatment in a closed carbonization box, and carrying out carbonization curing until the surface is completely carbonized; and (3) recycled mortar preparation: preparing recycled mortar with the substitution rate of 100% by using the treated recycled fine aggregate. Compared with the unreinforced recycled aggregate, the crushing value of the recycled fine aggregate prepared by the method is lowered by nearly 45%, and the water absorptivity is lowered by nearly 53%. Compared with the recycled mortar prepared from the unreinforced recycled aggregate, the consistency of the recycled mortar prepared by the method is enhanced by 42% or so, the 7d strength of the mortar is enhanced by 15-26%, and the 28d strength can be enhanced by 17-24%.

Method for reinforcing recycled concrete fine aggregate by using carbon dioxide

The invention belongs to the technical field of building materials, and provides a method for preparing building material products through processing industrial solid waste by hydration-carbonation coupling technique. The method comprises steps of uniformly mixing the industrial waste comprising at least one of calcium oxide, calcium hydroxide, dicalcium silicate, tricalcium silicate and tobermorite with alkaline excitation material and proper amount of water so as to prepare the blank of the building material product, wherein the industrial waste comprises steel slag, mineral waste residue, furnace slag, coal ash or coal gangue, the alkaline excitation material comprises carbide slag, lime, Portland cement or waste cement; maintaining for a period through hydration, then maintaining through carbonation so as to obtain the carbonate-based building material product. The coupling technique can effectively use the industrial solid wastes such as steel slag, mineral waste residue, furnace slag, coal ash, coal gangue, carbide slag and the like, so that emission of greenhouse gases is reduced, the greenhouse effect is relieved, furthermore, the method can be used for producing the building material products with good properties, effectively uses the waste and is environmentally friendly.

Method for preparing building material products through hydration-carbonation coupling technique

The invention discloses a lightweight brick produced by using papermaking sludge as a raw material and a preparation method thereof, and belongs to the fields of building materials and environmental friendliness. The papermaking sludge is used as the raw materials in the lightweight brick. The method comprises the following steps of: sequentially adding a base material, a cross linker and a foaming agent into a stirrer in a ratio, fully stirring the materials, mixing the materials uniformly, feeding the mixture into a brick making machine for molding, curing for 4 to 6 days in a curing room at normal temperature, and performing finishing treatment on the cured lightweight brick to obtain a finished product. The volume density of the prepared lightweight brick can reach 400 to 700kg/m ; because the lightweight brick is formed by cross linking and curing of cellulose, the lightweight brick has high strength and elasticity, and the seismic resistance and the bending resistance of the lightweight brick are further superior to those of a concrete lightweight brick; and the heat preservation performance of the lightweight brick is also superior to that of the concrete lightweight brick.

Lightweight brick produced by using papermaking sludge as raw material and preparation method thereof

The invention discloses a preparation method for a bottom mud brick. Riverway bottom mud serves as a raw material, the riverway bottom mud, plant straws, waste glass powder and a binding agent are mixed in proportion, and the preparation method comprises the following steps that: steel slag is added for evenly mixing; a moisture content is adjusted to be 20-40%, even stirring and beating homogenizing are carried out, and a brick making die is used for pressing and compression molding; the moisture content is adjusted to be 1-5% in a dried mode; and the bottom mud brick is made through high-temperature calcination of a muffle furnace. The bottom mud brick prepared by the method is high in strength, good in water permeability, multiple in hole, less in energy dissipation, less in heavy metal dissolution and low in biotoxicity. The preparation method utilizes bottom mud of heavy-polluted riverways, therefore, solidification of heavy metals in polluted bottom mud is achieved, damage of the bottom mud to environment is reduced, and simultaneously, resource recycling of the bottom mud is achieved.

Preparation method for bottom mud brick

The invention relates to a recycled aggregate made by pre-adding water to carbonated curing wastes for forming balls which absorb carbon dioxide gas in industrial waste gas, which belongs to the building material technique field. The recycled aggregate is made by adopting the following processes of: utilizing steel slag or cement containing carbonization compositions as a raw material, adding water for even mixture, and implementing the granulation for spheroidizing so as to make the recycled aggregate under the curing of carbonization gas; and the carbonization compositions include one or more than one of calcium oxide, calcium hydroxide, dicalcium silicate, tricalcium silicate, hydrated calcium silicate, hydrated calcium aluminate, hydrated calcium ferrite, ettringite, magnesium hydroxide and magnesium oxide, and the carbonization compositions have a weight percentage of no less than 30 percent in materials. The recycled aggregate has the main point that: the accelerated carbonization technique is utilized to treat industrial wastes such as steel slag, sludge and waste concrete, solidify and store carbon dioxide of greenhouse gas, and make the recycled aggregate. The pollution problem of wastes such as steel slag and waste gas is released; meanwhile, the light recycled aggregate with excellent performance is prepared.

Regeneration aggregate made of carbonized maintaining castoff

The invention belongs to the technical field of environmental protection, and relates to a method for preparing a building material by using industrial wastes (paper making sludge, different steel slag, furnace cinders, waste concrete) as main raw materials and applying an accelerated carbonation technology, in particular to the method for producing the building material by using the paper making sludge. The method comprises the following steps: according to the weight ratio of between 1 to 0.5 and 1 to 4, mixing the paper making sludge with a carbonized material; adding water into the mixture and mixing the mixture evenly; pressing the mixture into a semi-finished product of the building material; and preparing the semi-finished product of the building material into a finished product of the building material under the curing of accelerated carbonation. The method effectively makes use of the industrial wastes such as the paper making sludge, reduces the emission of the greenhouse gas of carbon dioxide, and prepares the building material with excellent performance and beautiful appearance. The method has the advantages of favorability for waste recycling, environmental protection, energy conservation, and low cost.

Method for producing architectural materials by using paper making sludge

The invention belongs to the technical field of building materials and relates to an enhancer for the building materials which are prepared by taking wastes (including different types of steel slag, furnace slag, smelting slag, sludge, red sludge, incineration ash and waste cement, and the like) as main materials for absorbing CO2 waste gas, in particular to the enhancer for the building materials which are prepared by the carbonation curing wastes and using steel slag and cement as the main materials for absorbing the CO2 gas. The enhancer contains more than 50 percent by weight of easily carbonized ingredients, and the easily carbonized ingredients are one or more of calcium hydroxide, calcium oxide, portland cement or waste concrete. The enhancer of the invention plays the roles of strengthening and improving the carbonation rate, improves the strength of the building materials which are prepared by carbonation and curing and the CO2 absorption rate and shortens the production cycle.

Strengthening agent for construction material prepared by carbonizing curing waste

The invention belongs to the technical field of a constructional material, and relates to an excitant used for carbonizing and curing offal prepared constructional materials. The excitant comprises not less than 50 percent of excitable components by weight which are one or more than one of NaHCO3, soluble glass, plaster, Ca(HCO3)2, NaCl and Na2CO3. The excitant has the advantages that when offal prepared constructional materials are carbonized and cured, the excitant can promote carbonization in carbonization materials through the excitable components by adding the excitant of proper amount, thus increasing the carbonization ratio and reducing the discharged carbon dioxide as a greenhouse gas to great extent, preparing products for carbonizing and curing constructional materials having good performance, and reducing the production cycle with good economic benefit.

Liang Ding

Papers

Regeneration aggregate made of carbonized maintaining castoff

Method for producing architectural materials by using paper making sludge

Strengthening agent for construction material prepared by carbonizing curing waste

Excitant for preparing construction material by carbonized curing wastes