Search

CN-122010505-A - High-performance concrete admixture based on building solid waste regenerated micro powder and preparation process thereof

CN122010505ACN 122010505 ACN122010505 ACN 122010505ACN-122010505-A

Abstract

The application belongs to the field of recycling of construction waste, and particularly provides a high-performance concrete admixture based on construction solid waste regenerated micro powder and a preparation process thereof, wherein the high-performance concrete admixture is prepared by mixing, by mass, 100-115 parts of broken stone, 70-75 parts of river sand, 21-28 parts of Portland cement, 16-17.5 parts of water, 7-14 parts of modified regenerated micro powder and 0.3-0.35 part of water reducer, the modified regenerated micro powder is prepared by adopting the construction solid waste regenerated micro powder and performing surface treatment by using a modifier, and the concrete 28d prepared by mixing the modified regenerated micro powder has the compressive strength of more than or equal to 42.8Mpa, the flexural strength of more than or equal to 5.1Mpa and good durability.

Inventors

  • SHI KAIYING
  • ZHAO CHENGWU
  • GAO JIAN
  • FAN XINGMIN
  • TIAN DELI
  • Liu Juejie
  • YANG YINGYING
  • WANG DANLIN
  • YANG QIUFANG
  • WANG WEIWEI
  • CHENG JUNJUN

Assignees

  • 麦琪新材料集团有限公司

Dates

Publication Date
20260512
Application Date
20260414

Claims (10)

  1. 1. The preparation process of the high-performance concrete admixture based on the construction solid waste regenerated micro powder is characterized by comprising the following raw materials, by mass, 100-115 parts of broken stone, 70-75 parts of river sand, 21-28 parts of Portland cement, 16-17.5 parts of water, 7-14 parts of modified regenerated micro powder and 0.3-0.35 part of water reducer; The modified regenerated micro powder is obtained by adopting the surface treatment of the construction solid waste regenerated micro powder by a modifying agent; the modifier is obtained by self-assembling phosphorylated chitosan and sulfonated cellulose, and the preparation steps comprise: And slowly dripping the phosphorylated chitosan water dilution solution into the sulfonated cellulose water dilution solution, stirring, then adjusting the pH value, continuously stirring, centrifuging, and washing and drying the precipitate to obtain the chitosan.
  2. 2. The preparation process of the high-performance concrete admixture based on the construction solid waste regenerated micro powder, which is disclosed in claim 1, is characterized in that the preparation method of the phosphorylated chitosan comprises the following steps: Mixing chitosan, urea and phosphoric acid with the mass concentration of 85%, heating to react, precipitating with absolute ethyl alcohol, washing and drying to obtain the phosphorylated chitosan.
  3. 3. The preparation process of the high-performance concrete admixture based on the construction solid waste regenerated micro powder is characterized in that the mass volume ratio of chitosan, urea and phosphoric acid with the mass concentration of 85% is (5-5.5) g (25-28) g (250-300) mL, the temperature rising reaction is that the temperature is raised to 115-122 ℃ and the constant temperature reaction is carried out for 3-4h.
  4. 4. The preparation process of the high-performance concrete admixture based on the construction solid waste regenerated micro powder, which is disclosed in claim 1, is characterized in that the preparation method of the sulfonated cellulose comprises the following steps: Taking microcrystalline cellulose, dispersing, stirring in a water bath, then adding sulfur trioxide pyridine, adjusting the pH value to be neutral, then carrying out suction filtration to collect precipitate, washing with absolute ethyl alcohol, and carrying out vacuum drying to obtain sulfonated cellulose.
  5. 5. The preparation process of the high-performance concrete admixture based on the construction solid waste regenerated micro powder, which is disclosed in claim 4, is characterized in that the mass ratio of microcrystalline cellulose to sulfur trioxide pyridine is (9.5-10.5) (10.2-11.7).
  6. 6. The preparation process of the high-performance concrete admixture based on the construction solid waste regenerated micro powder, which is disclosed in claim 1, is characterized in that the surface treatment adopts an impregnation method, a blending method or an impregnation-blending combination method.
  7. 7. The process for preparing the high-performance concrete admixture based on the construction solid waste regenerated micro powder according to claim 6, wherein the dipping method comprises the following steps: Preparing the modifier into a treatment liquid with the mass fraction of 0.25% -0.5%, mixing the treatment liquid with the building solid waste regenerated micro powder according to the solid-liquid ratio of 1:1, stirring the mixture for 30-60 minutes at 30+/-2 ℃, and drying, crushing and sieving the mixture after solid-liquid separation.
  8. 8. The process for preparing the high-performance concrete admixture based on the construction solid waste regenerated micro powder according to claim 6, wherein the blending method comprises the following steps: preparing the modifier into a treatment liquid with the mass fraction of 0.5%, spraying the treatment liquid into the building solid waste regenerated micro powder in a spraying mode, controlling the water content to be 15% -25%, aging for 2-4 hours, drying, grinding and sieving to obtain the modified building solid waste regenerated micro powder.
  9. 9. The preparation process of the high-performance concrete admixture based on the construction solid waste regenerated micro powder, which is disclosed in claim 6, is characterized in that the dipping-blending combination method comprises the following steps: Preparing a treating fluid with the mass fraction of 0.25% from the modifier, carrying out dipping treatment on the building solid waste regenerated micro powder for 20-30 minutes, controlling the water content of a filter cake to be 25% -35% after solid-liquid separation, adding the modifier dry powder to carry out strong mixing, and drying, grinding and sieving after ageing to obtain the modified solid waste regenerated micro powder.
  10. 10. A high-performance concrete admixture based on construction solid waste regenerated micro powder, which is characterized by being prepared by adopting the preparation process as claimed in any one of claims 1-9.

Description

High-performance concrete admixture based on building solid waste regenerated micro powder and preparation process thereof Technical Field The application belongs to the technical field of recycling of construction waste, and particularly relates to a high-performance concrete admixture based on construction solid waste regenerated micro powder and a preparation process thereof. Background Concrete is used as an artificial building material with the largest dosage in the world today, and the basic composition of the concrete comprises cementing materials, coarse and fine aggregates, mixing water and additives. In the curing process of the concrete, cement and water are subjected to hydration reaction to generate hydration products such as hydrated calcium silicate gel, calcium hydroxide, ettringite and the like, and the products bond aggregate particles together to form a composite material system with higher strength and durability. With the rapid promotion of the urban process in China, the generation amount of building demolition waste rises year by year. The concrete is removed through multistage crushing, sieving and other processes, most of the concrete can be converted into recycled aggregate, but at the same time, the recycled micro powder of building solid waste with the grain size smaller than 75 microns is produced in the range of about 15-20%. Compared with natural aggregate concrete, the recycled aggregate has an old cement mortar layer attached to the surface, so that multiple interfaces are formed in the recycled aggregate concrete, namely a primary interface transition area between old cement mortar and natural aggregate, a secondary interface transition area between recycled aggregate and new cement mortar, and a microcrack and pore network in the old cement mortar, and the microstructure characteristics of high porosity and crystal orientation enable the interface transition area to be the weakest link in the recycled aggregate concrete, and the existing reinforcing method for the recycled aggregate is still concentrated in the methods of coating modification, carbonization treatment and the like, so that the cost is high and the lasting reinforcing effect is difficult to realize. Therefore, a high-performance concrete admixture based on the construction solid waste recycled micro powder for enhancing the use strength of recycled aggregate concrete and improving the use durability of the concrete and a preparation process thereof are needed to be searched. Disclosure of Invention Aiming at the problems, the application provides a high-performance concrete admixture based on the construction solid waste regenerated micro powder and a preparation process thereof in order to further strengthen the use strength of the regenerated aggregate concrete and improve the use durability of the concrete. The application firstly provides a preparation process of a high-performance concrete admixture based on construction solid waste regenerated micro powder, which is prepared by mixing the following raw materials, by mass, 100-115 parts of broken stone, 70-75 parts of river sand, 21-28 parts of silicate cement, 16-17.5 parts of water, 7-14 parts of modified regenerated micro powder and 0.3-0.35 part of water reducer; The modified regenerated micro powder is obtained by adopting the surface treatment of the construction solid waste regenerated micro powder by a modifying agent; the modifier is obtained by self-assembling phosphorylated chitosan and sulfonated cellulose, and the preparation steps comprise: And slowly dripping the phosphorylated chitosan water dilution solution into the sulfonated cellulose water dilution solution, stirring, then adjusting the pH value, continuously stirring, centrifuging, and washing and drying the precipitate to obtain the chitosan. Further, the preparation method of the phosphorylated chitosan comprises the following steps: Mixing chitosan, urea and phosphoric acid with the mass concentration of 85%, heating to react, and then precipitating by absolute ethyl alcohol, washing and drying to obtain phosphorylated chitosan; The mass volume ratio of the chitosan, the urea and the phosphoric acid with the mass concentration of 85 percent is (5-5.5) g (25-28) g (250-300) mL; The temperature-rising reaction is to raise the temperature to 115-122 ℃ and the constant temperature reaction is carried out for 3-4h. Further, the preparation method of the sulfonated cellulose comprises the following steps: taking microcrystalline cellulose, dispersing, stirring in a water bath, then adding sulfur trioxide pyridine, adjusting the pH value to be neutral, then carrying out suction filtration to collect precipitate, and then washing with absolute ethyl alcohol and carrying out vacuum drying to obtain sulfonated cellulose; The mass ratio of microcrystalline cellulose to sulfur trioxide pyridine is (9.5-10.5) (10.2-11.7). By adopting the technical scheme, in the high alkaline environment of