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CN-118184395-B - Low-shrinkage light high-alkali-excitation foam concrete and preparation method and application thereof

CN118184395BCN 118184395 BCN118184395 BCN 118184395BCN-118184395-B

Abstract

The invention discloses a low-shrinkage light high-alkali excited foam concrete and a preparation method and application thereof. The foam concrete comprises, by weight, 30-80 parts of slag powder, 40-120 parts of mineral admixture, 2-15 parts of porous filler, 5-20 parts of sodium-potassium sodium silicate, 0.5-10 parts of foaming agent and 0.5-5 parts of shrinkage inhibitor. The shrinkage-resistant agent is prepared by placing water-absorbent resin in a saturated shrinkage-reducing agent solution, then preserving heat under a heating condition to enable the water-absorbent resin to reach a saturated state, and then separating out the water-absorbent resin and draining liquid to obtain the shrinkage-resistant agent. The invention not only reduces the self-shrinkage degree of the alkali-activated foam concrete and overcomes the shrinkage cracking problem in the service process of the foam concrete, but also increases the compressive strength of the alkali-activated foam concrete.

Inventors

  • JIANG DONGBING
  • SU YANLI
  • ZHAO PIQI
  • LIANG CHEN
  • YU ZHENGYU
  • ZHAO HONGBO

Assignees

  • 济南大学

Dates

Publication Date
20260512
Application Date
20240402

Claims (17)

  1. 1. The low-shrinkage light high-alkali-activated foam concrete is characterized by comprising, by weight, 30-80 parts of slag powder, 40-120 parts of mineral admixture, 2-15 parts of porous filler, 5-20 parts of sodium-potassium sodium silicate, 0.5-10 parts of foaming agent and 0.5-5 parts of shrinkage inhibitor, wherein the shrinkage inhibitor is prepared by the following steps: The method comprises the steps of placing water-absorbent resin in a saturated shrinkage reducing agent solution, then preserving heat under a heating condition, enabling the water-absorbent resin to reach a saturated state, separating out water-absorbent resin and draining liquid to obtain the shrinkage resisting agent, wherein the water-absorbent resin comprises at least one polymer or copolymer of acrylic acid, acrylamide and carboxymethyl cellulose, the saturated shrinkage reducing agent solution is saturated liquid formed by dissolving any one of polyether and polyol into water, the foaming agent is formed by compounding a component A, a component B, silicone resin polyether emulsion and water, the component A comprises at least one of fatty alcohol polyoxyethylene ether sodium sulfate, sodium dodecyl sulfate and alpha-alkenyl sodium sulfonate, and the component B comprises at least one of starch ether and cellulose ether.
  2. 2. The low-shrinkage light-weight high-alkali activated foam concrete according to claim 1, wherein the water-absorbent resin is an acrylamide resin.
  3. 3. The low-shrinkage light high-alkali activated foam concrete according to claim 1, wherein the heating temperature is 50-85 ℃ and the heat preservation time is 0.5-1 h.
  4. 4. The low shrinkage light weight high alkali activated foam concrete of claim 1, wherein the polyether comprises a polymer or copolymer of at least one of an oxyvinyl ether, an alkyl ether alkylene oxide, and a vinyl methyl ether.
  5. 5. The low shrinkage light weight high alkali activated foam concrete of claim 1, wherein the polyol comprises a polymer or copolymer of at least one of ethylene glycol, alkylene oxide glycol.
  6. 6. The low shrinkage light weight high alkali activated foam concrete of claim 1, wherein the mineral admixture comprises at least one of fly ash, kaolin, metakaolin.
  7. 7. The low-shrinkage light high-alkali activated foam concrete of claim 1, wherein the fineness range of the mineral admixture is 40-200 mesh.
  8. 8. The low-shrinkage light-weight high-alkali activated foam concrete according to claim 1, wherein the porous filler comprises at least one of ceramsite, expanded perlite and expanded vermiculite.
  9. 9. The low-shrinkage light high-alkali activated foam concrete of claim 1, wherein the porous filler has a particle size of 30-200 μm.
  10. 10. The low-shrinkage light high-alkali activated foam concrete according to claim 1, wherein the sodium-potassium water glass is compounded by liquid sodium silicate or liquid potassium silicate, potassium hydroxide or sodium hydroxide and water.
  11. 11. The low-shrinkage light high-alkali activated foam concrete according to claim 10, wherein the proportion of the liquid sodium silicate or the liquid potassium silicate, the potassium hydroxide or the sodium hydroxide and the water is 20-80 parts by weight, 10-35 parts by weight and 10-25 parts by weight.
  12. 12. The low-shrinkage light high-alkali activated foam concrete of claim 10, wherein the mass fraction of the liquid sodium silicate or the liquid potassium silicate is 30-40%.
  13. 13. The low-shrinkage light-weight high-alkali-activated foam concrete according to any one of claims 1 to 12, wherein the proportion of the component A, the component B, the silicone polyether emulsion and the water is 1 to 5 parts by weight, 0.02 to 0.05 parts by weight, 0.2 to 1 part by weight and 50 to 85 parts by weight.
  14. 14. The method for preparing the low-shrinkage light high-alkali activated foam concrete according to any one of claims 1 to 13, which is characterized by comprising the following steps: (1) Uniformly mixing the slag powder, the mineral admixture and the porous filler to form dry powder for standby; (2) Adding the dry powder into sodium-potassium water glass, uniformly stirring, then adding the shrinkage resistance agent, and uniformly stirring to obtain slurry for later use; (3) And uniformly mixing the foaming agent with the slurry after foaming to obtain the alkali-activated foam concrete.
  15. 15. The preparation method of the low-shrinkage light high-alkali activated foam concrete is characterized in that in the step (2), the dry powder is added into sodium-potassium sodium silicate and then stirred for 1-5 min, and the slurry is obtained after the shrinkage resistance agent is added and then stirring is continued for 1-3 min.
  16. 16. The method for preparing the low-shrinkage light high-alkali-activated foam concrete according to claim 14 or 15, wherein in the step (3), the foaming method is that the foaming agent is stirred for 1-2 min at the speed of 300-1000 rpm.
  17. 17. The method for preparing the low-shrinkage light high-alkali-activated foam concrete according to claim 14 or 15, wherein in the step (3), the foaming agent after foaming is mixed with the slurry and stirred for 1-3 min.

Description

Low-shrinkage light high-alkali-excitation foam concrete and preparation method and application thereof Technical Field The invention relates to the technical field of foam concrete, in particular to low-shrinkage light high-alkali excited foam concrete and a preparation method and application thereof. Background The novel cementing material of alkali-activated foam concrete has the advantages of rapid hardening, good heat preservation performance, high strength, environment friendliness, low carbon, and the like. These advantages result from the high specific surface area and reactivity of their amorphous gels, which promote rapid setting and development of strength. However, this rapid curing reaction also results in rapid consumption of free water, which in turn poses a series of challenges. With the consumption of free water, the relative humidity inside the concrete is reduced, and various stresses (such as capillary pressure, interlayer water migration pressure, separation pressure and the like) which are dominant with the change of the internal humidity are accumulated, so that the alkali-activated foam concrete has poor volume stability, is easy to crack and has reduced strength. Because the foam concrete is porous, the characteristic also limits the performance of the alkali-activated foam concrete in practical application. The current solution mainly comprises the addition of internal curing materials, fillers and the like in alkali-activated foam concrete. Wherein, the curing amount of the internal curing material is limited, and the shrinkage reducing effect on the alkali-activated material is not obvious. Although the filler can play a certain framework role to inhibit shrinkage, the low gelation activity and the high roughness of the filler have a degradation effect on the interface between the foam and the alkali-activated cementing material, and influence the volume weight and the compression resistance of the alkali-activated foam concrete. Disclosure of Invention Aiming at the problems, the invention provides the low-shrinkage light high-alkali-activated foam concrete and the preparation method and application thereof, which not only lighten the self-shrinkage degree of the alkali-activated foam concrete and overcome the shrinkage cracking problem in the service process of the foam concrete, but also increase the compressive strength of the alkali-activated foam concrete. Specifically, the invention discloses a technical scheme shown as follows. The invention discloses low-shrinkage light high-alkali excited foam concrete which comprises, by weight, 30-80 parts of slag powder, 40-120 parts of mineral admixture, 2-15 parts of porous filler, 5-20 parts of sodium-potassium sodium silicate, 0.5-10 parts of foaming agent and 0.5-5 parts of shrinkage resistance agent. The shrinkage-resistant agent is prepared by placing water-absorbent resin in a saturated shrinkage-reducing agent solution, then preserving heat under a heating condition to enable the water-absorbent resin to reach a saturated state, and then separating out the water-absorbent resin and draining liquid to obtain the shrinkage-resistant agent. Further, the water absorbent resin includes a polymer or copolymer of at least one of acrylic acid, acrylamide, carboxymethyl cellulose, and the like. Preferably, the hydrophilic group (-NH 2) of the acrylamide resin is not affected by calcium ions, so that the complexing with calcium ions in the foam concrete can be prevented better. This is because calcium ions change the internal three-dimensional network structure of the resin by forming coordination bonds with carboxyl and hydroxyl groups in the super absorbent resin, so that the three-dimensional network structure is prematurely shrunk and collapsed, and the saturated shrinkage reducing agent solution therein is prematurely released. Optionally, the heating temperature is 50-85 ℃, and the heat preservation time is 0.5-1 h. Further, the saturated shrinkage reducing agent solution is a saturated liquid formed by dissolving any one of polyether, polyol, and the like into water. Optionally, the polyether comprises a polymer or copolymer of at least one of an oxyvinyl ether, an alkyl ether alkylene oxide, vinyl methyl ether, and the like. The polyol includes a polymer or copolymer of at least one of ethylene glycol, alkylene oxide glycol, and the like. Further, the mineral admixture includes, but is not limited to, at least one of fly ash, kaolin, metakaolin, and the like. Optionally, the fineness range of the mineral admixture is 40-200 meshes. Further, the porous filler includes, but is not limited to, at least one of ceramsite, expanded perlite, expanded vermiculite, and the like. Optionally, the particle size of the porous filler is 30-200 um. Further, the sodium-potassium water glass is formed by compounding liquid sodium silicate or liquid potassium silicate, potassium hydroxide or sodium hydroxide and water. Optionally, the proportio