CN115093196A - Early-strength magnesium phosphate cement mortar suitable for severe cold environment and preparation method thereof - Google Patents
Early-strength magnesium phosphate cement mortar suitable for severe cold environment and preparation method thereof Download PDFInfo
- Publication number
- CN115093196A CN115093196A CN202210903031.2A CN202210903031A CN115093196A CN 115093196 A CN115093196 A CN 115093196A CN 202210903031 A CN202210903031 A CN 202210903031A CN 115093196 A CN115093196 A CN 115093196A
- Authority
- CN
- China
- Prior art keywords
- cement mortar
- severe cold
- cold environment
- magnesium phosphate
- nano
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000011083 cement mortar Substances 0.000 title claims abstract description 48
- GVALZJMUIHGIMD-UHFFFAOYSA-H magnesium phosphate Chemical compound [Mg+2].[Mg+2].[Mg+2].[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O GVALZJMUIHGIMD-UHFFFAOYSA-H 0.000 title claims abstract description 38
- 239000004137 magnesium phosphate Substances 0.000 title claims abstract description 38
- 229960002261 magnesium phosphate Drugs 0.000 title claims abstract description 38
- 229910000157 magnesium phosphate Inorganic materials 0.000 title claims abstract description 38
- 235000010994 magnesium phosphates Nutrition 0.000 title claims abstract description 38
- 238000002360 preparation method Methods 0.000 title claims abstract description 11
- 239000000463 material Substances 0.000 claims abstract description 23
- 238000003756 stirring Methods 0.000 claims abstract description 23
- CPLXHLVBOLITMK-UHFFFAOYSA-N Magnesium oxide Chemical compound [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 claims description 58
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 40
- PNEYBMLMFCGWSK-UHFFFAOYSA-N Alumina Chemical compound [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims description 36
- 239000000395 magnesium oxide Substances 0.000 claims description 34
- 239000010881 fly ash Substances 0.000 claims description 28
- 239000004576 sand Substances 0.000 claims description 23
- DLYUQMMRRRQYAE-UHFFFAOYSA-N tetraphosphorus decaoxide Chemical compound O1P(O2)(=O)OP3(=O)OP1(=O)OP2(=O)O3 DLYUQMMRRRQYAE-UHFFFAOYSA-N 0.000 claims description 21
- LFVGISIMTYGQHF-UHFFFAOYSA-N ammonium dihydrogen phosphate Chemical compound [NH4+].OP(O)([O-])=O LFVGISIMTYGQHF-UHFFFAOYSA-N 0.000 claims description 17
- 229910000387 ammonium dihydrogen phosphate Inorganic materials 0.000 claims description 17
- 235000019837 monoammonium phosphate Nutrition 0.000 claims description 17
- AXZKOIWUVFPNLO-UHFFFAOYSA-N magnesium;oxygen(2-) Chemical compound [O-2].[Mg+2] AXZKOIWUVFPNLO-UHFFFAOYSA-N 0.000 claims description 16
- 239000011325 microbead Substances 0.000 claims description 16
- 239000005543 nano-size silicon particle Substances 0.000 claims description 14
- 229910052814 silicon oxide Inorganic materials 0.000 claims description 14
- 229910021538 borax Inorganic materials 0.000 claims description 13
- 239000004328 sodium tetraborate Substances 0.000 claims description 13
- 235000010339 sodium tetraborate Nutrition 0.000 claims description 13
- 230000002378 acidificating effect Effects 0.000 claims description 12
- 239000004570 mortar (masonry) Substances 0.000 claims description 12
- 229910052500 inorganic mineral Inorganic materials 0.000 claims description 11
- 239000011707 mineral Substances 0.000 claims description 11
- 229910019142 PO4 Inorganic materials 0.000 claims description 10
- 238000000034 method Methods 0.000 claims description 10
- 239000002086 nanomaterial Substances 0.000 claims description 10
- 239000010452 phosphate Substances 0.000 claims description 10
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 claims description 9
- 239000002245 particle Substances 0.000 claims description 3
- 229910001392 phosphorus oxide Inorganic materials 0.000 claims description 3
- VSAISIQCTGDGPU-UHFFFAOYSA-N tetraphosphorus hexaoxide Chemical compound O1P(O2)OP3OP1OP2O3 VSAISIQCTGDGPU-UHFFFAOYSA-N 0.000 claims description 3
- 238000005303 weighing Methods 0.000 claims description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 abstract description 25
- 238000006703 hydration reaction Methods 0.000 abstract description 12
- 239000004567 concrete Substances 0.000 abstract description 11
- 239000007788 liquid Substances 0.000 abstract description 11
- 230000036571 hydration Effects 0.000 abstract description 10
- 239000004568 cement Substances 0.000 description 18
- YWEUIGNSBFLMFL-UHFFFAOYSA-N diphosphonate Chemical compound O=P(=O)OP(=O)=O YWEUIGNSBFLMFL-UHFFFAOYSA-N 0.000 description 15
- 238000002156 mixing Methods 0.000 description 11
- 230000008439 repair process Effects 0.000 description 8
- 230000000052 comparative effect Effects 0.000 description 7
- 239000000203 mixture Substances 0.000 description 5
- 230000008569 process Effects 0.000 description 5
- 238000011161 development Methods 0.000 description 4
- 239000000843 powder Substances 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- 239000002253 acid Substances 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 229910000402 monopotassium phosphate Inorganic materials 0.000 description 3
- 235000019796 monopotassium phosphate Nutrition 0.000 description 3
- PJNZPQUBCPKICU-UHFFFAOYSA-N phosphoric acid;potassium Chemical compound [K].OP(O)(O)=O PJNZPQUBCPKICU-UHFFFAOYSA-N 0.000 description 3
- 239000002002 slurry Substances 0.000 description 3
- 239000007787 solid Substances 0.000 description 3
- UEZVMMHDMIWARA-UHFFFAOYSA-N Metaphosphoric acid Chemical compound OP(=O)=O UEZVMMHDMIWARA-UHFFFAOYSA-N 0.000 description 2
- 230000009471 action Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 238000005336 cracking Methods 0.000 description 2
- 239000000428 dust Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 238000006386 neutralization reaction Methods 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 229910021487 silica fume Inorganic materials 0.000 description 2
- 239000000377 silicon dioxide Substances 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 239000011398 Portland cement Substances 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- -1 compound phosphate Chemical class 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000001934 delay Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 230000008014 freezing Effects 0.000 description 1
- 238000007710 freezing Methods 0.000 description 1
- 230000017525 heat dissipation Effects 0.000 description 1
- 238000005338 heat storage Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 230000000887 hydrating effect Effects 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000012466 permeate Substances 0.000 description 1
- 239000000376 reactant Substances 0.000 description 1
- 239000011150 reinforced concrete Substances 0.000 description 1
- 230000002787 reinforcement Effects 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B28/00—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements
- C04B28/34—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements containing cold phosphate binders
- C04B28/344—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements containing cold phosphate binders the phosphate binder being present in the starting composition solely as one or more phosphates
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B14/00—Use of inorganic materials as fillers, e.g. pigments, for mortars, concrete or artificial stone; Treatment of inorganic materials specially adapted to enhance their filling properties in mortars, concrete or artificial stone
- C04B14/02—Granular materials, e.g. microballoons
- C04B14/04—Silica-rich materials; Silicates
- C04B14/06—Quartz; Sand
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B14/00—Use of inorganic materials as fillers, e.g. pigments, for mortars, concrete or artificial stone; Treatment of inorganic materials specially adapted to enhance their filling properties in mortars, concrete or artificial stone
- C04B14/02—Granular materials, e.g. microballoons
- C04B14/30—Oxides other than silica
- C04B14/303—Alumina
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B18/00—Use of agglomerated or waste materials or refuse as fillers for mortars, concrete or artificial stone; Treatment of agglomerated or waste materials or refuse, specially adapted to enhance their filling properties in mortars, concrete or artificial stone
- C04B18/04—Waste materials; Refuse
- C04B18/06—Combustion residues, e.g. purification products of smoke, fumes or exhaust gases
- C04B18/08—Flue dust, i.e. fly ash
- C04B18/082—Cenospheres
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B22/00—Use of inorganic materials as active ingredients for mortars, concrete or artificial stone, e.g. accelerators, shrinkage compensating agents
- C04B22/002—Water
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B22/00—Use of inorganic materials as active ingredients for mortars, concrete or artificial stone, e.g. accelerators, shrinkage compensating agents
- C04B22/06—Oxides, Hydroxides
- C04B22/066—Magnesia; Magnesium hydroxide
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
- C04B2111/00008—Obtaining or using nanotechnology related materials
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
- C04B2111/72—Repairing or restoring existing buildings or building materials
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
- C04B2111/76—Use at unusual temperatures, e.g. sub-zero
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2201/00—Mortars, concrete or artificial stone characterised by specific physical values
- C04B2201/05—Materials having an early high strength, e.g. allowing fast demoulding or formless casting
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2201/00—Mortars, concrete or artificial stone characterised by specific physical values
- C04B2201/50—Mortars, concrete or artificial stone characterised by specific physical values for the mechanical strength
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W30/00—Technologies for solid waste management
- Y02W30/50—Reuse, recycling or recovery technologies
- Y02W30/91—Use of waste materials as fillers for mortars or concrete
Abstract
Early strength magnesium phosphate cement mortar suitable for severe cold environment and a preparation method thereof, and the magnesium phosphate cement mortar which can be used for stirring with ice and snow under the severe cold environment and still can generate higher early strength and the preparation method thereof. The invention aims to solve the technical problems that when a concrete structure repairing material is in a severe cold environment, the concrete structure repairing material is not hydrated or the hydration rate is slow, the hydration degree is low, and liquid water is difficult to obtain in field operation, and the like.
Description
Technical Field
The invention belongs to the technical field of cement mortar preparation, and particularly relates to early-strength magnesium phosphate cement mortar suitable for a severe cold environment and a preparation method thereof.
Background
In the long-term use process of the field concrete infrastructure engineering, cracking or partial damage sometimes occurs under the action of external loads or environmental factors. If these cracks or damage cannot be repaired in a timely manner, the geometry will continue to expand under the tip stress field. Meanwhile, harmful substances in the environment can also permeate into the structure through cracks or local damages, so that various performances of the concrete are continuously deteriorated, and the safety and the durability of the structure are further threatened. If the above-mentioned cracking or damage occurs in the cold region in winter and is not repaired in time, the deterioration of the concrete performance will be further aggravated by the freeze-thaw action. In addition, the width of cracks on the surface of a mass concrete structure often varies with ambient temperature. In winter in cold regions, cracks of reinforced concrete members of high reinforcement ratio or hyperstatic structure may expand to their maximum width in winter. From this point of view, winter repairs enable more effective filling of cracks or breaks. However, the common repair materials such as rapid hardening portland cement-based materials and sulphoaluminate cement-based materials are separated from heating mixing and heat storage maintenance measures in a low-temperature environment, and the repair materials are very slow in hydration speed and even not hydrated and cannot be used.
The magnesium phosphate cement consists of dead burned magnesium oxide (M), phosphate (P) and retarder (B), and is a quick-hardening and early-strength cementing material. The magnesium phosphate cement can be quickly hydrated and release a large amount of heat when being contacted with water, and can obtain higher strength within hours. The characteristics of large heat release and rapid strength development enable the magnesium phosphate cement to have the capability of hydrating and generating strength at negative temperature. However, in a severe cold environment, heat is dissipated very quickly, and the early strength development of the magnesium phosphate cement mortar is restricted. In addition, the common magnesium phosphate cement mortar needs to be mixed with liquid water, and when the magnesium phosphate cement mortar is used in field work in severe cold areas, the liquid water in the natural environment is always in an ice and snow state, and the liquid water is difficult to obtain.
Disclosure of Invention
The invention aims to solve the problems that a concrete structure repairing material is not hydrated or has low hydration rate and low hydration degree when being in a severe cold environment, liquid water is difficult to obtain during field operation and the like, and provides early strength magnesium phosphate cement mortar suitable for the severe cold environment and a preparation method thereof. The mortar has higher hydration heat, can melt ice and snow which replace mixed water, delays the freezing of solution in capillary holes in hardened slurry, can develop the strength which basically meets engineering requirements in a severe cold environment, and realizes the effective repair of cracks or damaged parts of a concrete structure.
In order to achieve the purpose, the technical scheme adopted by the invention is as follows:
the early strength magnesium phosphate cement mortar suitable for the severe cold environment consists of an alkaline component, an acidic component, an active mineral admixture, a nano material, a retarder, crushed ice/floating snow and sand; is suitable for the outdoor environment with the temperature of-15 ℃ to-10 ℃; the alkaline component consists of dead burned magnesium oxide (DBM) and light burned magnesium oxide (LBM); the acidic component consists of water-soluble phosphate (ammonium dihydrogen phosphate, ADP) and phosphorus oxide (phosphorus pentoxide P) 2 O 5 ) Forming; the active mineral admixture is fly ash micro-beads (FA); the nano material consists of nano silicon oxide (NS) and nano aluminum oxide (NA); the retarder is borax (B); the particle size of the crushed ice/floating snow (I) is less than 1 mm; the sand (S) is natural river sand with fineness modulus of 2.4.
Further, the cement mortar comprises 30-35% of alkaline component, 8.22-9.59% of acidic component, 2.71-3.16% of active mineral admixture, 0.29-0.35% of nano material, 1.5-1.75% of retarder, 5.9-6.9% of crushed ice/floating snow and 44-50% of sand according to mass percentage. The mass ratio of each component is as follows: (DBM + LBM + FA + NS + NA): (ADP + P) 2 O 5 )＝4；LBM/(DBM+LBM+FA+NS+NA)＝8％；P 2 O 5 /(ADP+P 2 O 5 )＝5％；(FA+NS+NA)：(DBM+FA+NS+NA)＝10％；(NS+NA)/(FA+NS+NA)＝10％；NS/NA＝2.3；B：(DBM+LBM)＝5％；I：(DBM+LBM+ADP+P 2 O 5 +FA+NS+NA+B)＝0.14；S：(DBM+LBM+ADP+P 2 O 5 +FA+NS+NA+B)＝1。
Further, the mass percentage of the heavy calcined magnesia to the total amount of the cement mortar is 27.4-31.9%, and the mass percentage of the light calcined magnesia to the total amount of the cement mortar is 2.6-3.1%.
Further, the ammonium dihydrogen phosphate accounts for 7.8-9.1% of the total amount of the cement mortar by mass, and the phosphorus pentoxide accounts for 0.42-0.49% of the total amount of the cement mortar by mass.
Further, the mass percent of the nano silicon oxide in the total amount of the cement mortar is 0.2-0.24%, and the mass percent of the nano aluminum oxide in the total amount of the cement mortar is 0.09-0.11%.
The preparation method of the early strength magnesium phosphate cement mortar suitable for the severe cold environment comprises the following steps:
the method comprises the following steps: respectively weighing heavy-burned magnesium oxide, light-burned magnesium oxide, ammonium dihydrogen phosphate, phosphorus pentoxide, fly ash microbeads, nano silicon oxide, nano aluminum oxide, borax, crushed ice/snow floes and river sand; wherein the phosphorus pentoxide is weighed by adopting a metal container;
step two: firstly, placing phosphorus pentoxide at the bottom of a stirring pot, then adding heavy-burned magnesium oxide, light-burned magnesium oxide, ammonium dihydrogen phosphate, fly ash microbeads, nano silicon oxide, nano aluminum oxide, borax and river sand into the stirring pot, and stirring at a low speed for 30-60 s; in the process, effective measures are taken to prevent powder from escaping, a stirrer motor is protected in the stirring process, and the escaping powder is prevented from entering the motor, for example, a dust cover is arranged outside the motor;
step three: adding crushed ice/floating snow into the uniformly mixed dry materials, and then continuously stirring at a low speed for 120-240 s until the materials are stirred into uniformly mixed mortar. The mortar can be used for repairing cracks or damaged parts of a concrete structure.
In the second step, the stirring speed of the low-speed stirring is 140 +/-5 r/min of rotation and 62 +/-5 r/min of revolution.
Compared with other cement-based materials with low-temperature environment application potential, the invention has the beneficial results that:
compared with other magnesium phosphate cement-based repair materials, the novel cement mortar is doped with light-burned magnesia and phosphorus pentoxide to replace part of heavy-burned magnesia and phosphate. The light calcined magnesia has higher chemical activity than the heavy calcined magnesia and generates acid-base neutralization reaction with acid (acid salt) to release a large amount of heat; dissolving phosphorus pentoxide in water to generate metaphosphoric acid, releasing a large amount of heat, and then carrying out acid-base neutralization reaction on the metaphosphoric acid and magnesium oxide to continuously release a large amount of heat. The chemical exotherms ensure the continuous hydration in a severe cold environment to a certain extent and are beneficial to the early strength development of the hardened cement paste.
Compared with other magnesium phosphate cement-based repair materials, the novel cement mortar is doped with fly ash microbeads (different from common fly ash). In a severe cold environment, the surface tension of the mixture is increased, so that the viscosity of the freshly mixed mortar is increased, and the ball bearing function of the fly ash microbeads can effectively reduce the viscosity of the freshly mixed mortar and improve the fluidity of the freshly mixed mortar. After the fluidity is improved, the water consumption for ensuring the fluidity of the mortar can be reduced, namely, the water-cement ratio of the mortar is reduced. The reduction of water consumption is equivalent to the increase of the concentration of reactants, the reaction process is accelerated, and the exothermic quantity of the reaction is increased.
Compared with other magnesium phosphate cement-based repair materials, the nano-scale fly ash is formed by replacing 10% of fly ash with nano-silica and nano-alumina according to the proportion of silica to alumina in the fly ash micro-beads. The activity of the fly ash is improved while the micro-composition of the fly ash is optimized, so that the fly ash can participate in the hydration reaction of magnesium phosphate cement to a certain extent in a severe cold environment.
Compared with other magnesium phosphate cement-based repair materials, the novel cement mortar disclosed by the invention can replace liquid mixing water with solid ice and snow, and solves the problem of acquiring and storing field liquid water in a severe cold environment.
Compared with other cement-based materials with low-temperature environment application potential, the novel cement mortar disclosed by the invention has shorter setting time and higher early strength in a severe cold environment, and can quickly recover the bearing capacity and the environment resistance of the repaired part of the concrete structure.
Detailed Description
The technical solutions of the present invention are further described below with reference to the following examples, but the present invention is not limited thereto, and any modifications or equivalent substitutions may be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.
The existing magnesium phosphate cement-based patching material consists of basic components of dead burned magnesium oxide, phosphate, a retarder and mixing water, but under a severe cold environment, the magnesium phosphate cement only containing the basic components has very fast heat dissipation, and the early strength development of the magnesium phosphate cement mortar is restricted. Therefore, the light burned magnesia and the phosphorus pentoxide are doped on the basis of the existing magnesium phosphate cement-based patching material to replace part of the heavy burned magnesia and the phosphate, so that the hydration heat of the reaction is greatly improved, the continuous hydration of the magnesium phosphate mortar in a severe cold environment is ensured, and the early strength of the hardened cement slurry is ensured. And secondly, the fluidity of the fly ash can be improved after the fly ash micro-beads are doped, 10% of fly ash is replaced by the nano silicon oxide and the nano aluminum oxide to form the nano fly ash, the activity of the fly ash is improved while the micro-scale composition of the fly ash is optimized, and the fly ash can participate in the hydration reaction of the magnesium phosphate cement to a certain extent in a severe cold environment. And finally, solid ice and snow are adopted to replace liquid mixing water, so that the problem of acquiring and storing field liquid water in a severe cold environment is solved.
Example 1:
the early strength magnesium phosphate cement mortar suitable for mixing ice and snow in severe cold environment is prepared by mixing an alkaline component, an acidic component, an active mineral admixture, a nano material, a retarder, crushed ice/floating snow (solid water) and river sand, and is suitable for outdoor environment at the temperature of-15 to-10 ℃. The alkaline component consists of dead burned magnesium oxide (DBM) and light burned magnesium oxide (LBM); the acidic component is composed of water-soluble phosphate (ammonium dihydrogen phosphate, ADP) and phosphorus oxide (phosphorus pentoxide)，P 2 O 5 ) Composition is carried out; the active mineral admixture is fly ash micro-beads (FA); the nano material consists of nano silicon oxide (NS) and nano aluminum oxide (NA); the retarder is borax (B); the crushed ice/floating snow (I) with the particle size of less than 1mm and the like are adopted to completely replace liquid mixing water; the sand (S) is natural river sand with fineness modulus of 2.4.
Further, the cement mortar consists of 32.89% of alkaline component, 9.01% of acidic component, 2.97% of active mineral admixture, 0.33% of nano material, 1.6% of retarder, 6.5% of crushed ice/floating snow and 46.7% of sand in percentage by mass. The mass ratio of each component is as follows: (DBM + LBM + FA + NS + NA): (ADP + P) 2 O 5 )＝4；LBM/(DBM+LBM+FA+NS+NA)＝8％；P 2 O 5 /(ADP+P 2 O 5 )＝5％；(FA+NS+NA)：(DBM+FA+NS+NA)＝10％；(NS+NA)/(FA+NS+NA)＝10％；NS/NA＝2.3；B：(DBM+LBM)＝5％；I：(DBM+LBM+ADP+P 2 O 5 +FA+NS+NA+B)＝0.14；S：(DBM+LBM+ADP+P 2 O 5 +FA+NS+NA+B)＝1。
The preparation method of the early strength magnesium phosphate cement mortar suitable for ice and snow mixing in severe cold environment is completed according to the following steps:
firstly, weighing heavy-burned magnesium oxide, light-burned magnesium oxide, ammonium dihydrogen phosphate, phosphorus pentoxide, fly ash microbeads, nano silicon oxide, nano aluminum oxide, borax, crushed ice/snow floes and river sand respectively. Wherein the phosphorus pentoxide is weighed by adopting a metal container.
Secondly, placing phosphorus pentoxide at the bottom of a stirring pot, adding heavy-burned magnesia, light-burned magnesia, ammonium dihydrogen phosphate, fly ash microbeads, nano silicon oxide, nano aluminum oxide, borax and river sand into the stirring pot, and stirring at a low speed for 30-60 s. In the process, effective measures are taken to prevent powder from escaping, a stirrer motor is protected in the stirring process, and the escaping powder is prevented from entering the motor, for example, a dust cover is arranged outside the motor.
Thirdly, adding crushed ice/floating snow into the uniformly mixed dry materials, and then continuing stirring at a low speed for 120-240 s until the materials are stirred into uniformly mixed mortar. The mortar can be used for repairing cracks or damaged parts of a concrete structure.
Comparative example 1:
this comparative example differs from example 1 in that: the cement mortar is prepared by mixing dead burned magnesium oxide, ammonium dihydrogen phosphate, a retarder, mixing water and river sand. Wherein the mass fraction of the dead burned magnesia is 36.4 percent; the mass fraction of ammonium dihydrogen phosphate is 9.1%; the mass fraction of borax is 1.8%; the mass fraction of the mixed water is 7.2 percent; the mass fraction of the river sand is 45.5 percent. The other steps were the same as in example 1.
Comparative example 2:
this comparative example differs from example 1 in that: in the first step, 10% of dead-burned magnesia is replaced by active mineral admixture with more siliceous substances, such as silica fume. The total mass fraction of the alkaline components is 32.89 percent, wherein the heavy-burned magnesia accounts for 29.99 percent, and the light-burned magnesia accounts for 2.9 percent; the total mass fraction of the acidic components is 9.01 percent, wherein, the ammonium dihydrogen phosphate accounts for 8.55 percent, and the phosphorus pentoxide accounts for 0.46 percent; the mass fraction of the silica fume is 3.3 percent; the mass fraction of borax is 1.6%; the mass fraction of the mixed water is 6.5 percent; the mass fraction of the river sand is 46.7 percent. The other steps are the same as in example 1.
Comparative example 3:
this comparative example differs from example 1 in that: and the crushed ice/floating snow in the step one is replaced by half of water and half of crushed ice/floating snow. The total mass fraction of the alkaline components is 32.89 percent, wherein the heavy-burned magnesia accounts for 29.99 percent, and the light-burned magnesia accounts for 2.9 percent; the total mass fraction of the acidic components is 9.01 percent, wherein, the ammonium dihydrogen phosphate accounts for 8.55 percent, and the phosphorus pentoxide accounts for 0.46 percent; the mass fraction of the fly ash micro-beads is 2.97 percent; the weight fraction of the nano silicon oxide is 0.23 percent, and the weight fraction of the nano aluminum oxide is 0.1 percent; the mass fraction of borax is 1.6%; the mass fraction of crushed ice/floating snow is 3.25 percent, and the mass fraction of the mixing water is 3.25 percent; the mass fraction of the river sand is 46.7 percent. And D, adding crushed ice/snow into the uniformly mixed dry material obtained in the step two, then continuously stirring, adding water after uniformly stirring, and continuously stirring until slurry with certain fluidity is obtained. The other steps are the same as in example 1.
Comparative example 4:
and the acidic component in the first step is a compound phosphate, namely ammonium dihydrogen phosphate and potassium dihydrogen phosphate are doped in a compound manner, wherein the total amount of the phosphate is (0.7 ammonium dihydrogen phosphate +0.3 potassium dihydrogen phosphate). Namely, the total mass fraction of the alkaline components is 32.89 percent, wherein the dead burned magnesia accounts for 29.99 percent, and the light burned magnesia accounts for 2.9 percent; the total mass fraction of the acid components is 9.01 percent, wherein, the ammonium dihydrogen phosphate accounts for 4.275 percent, the potassium dihydrogen phosphate accounts for 4.275 percent, and the phosphorus pentoxide accounts for 0.46 percent; the mass fraction of the fly ash micro-beads is 2.97%; the weight fraction of the nano silicon oxide is 0.23 percent, and the weight fraction of the nano aluminum oxide is 0.1 percent; the mass fraction of borax is 1.6%; the mass fraction of crushed ice/floating snow is 6.5%; the mass fraction of the river sand is 46.7 percent. The other steps are the same as in example 1.
The compressive strength after hardening of the magnesium phosphate cement mortar prepared in each of the above embodiments was measured according to method for testing the strength of cement mortar (ISO method) (GB/T17671-2021), and the results are shown in Table 1.
The 1d and 28d compressive strengths of example 1 were 25.1MPa and 36.9MPa, respectively, by performing strength tests on each case. The traffic can be opened after one day of construction at the temperature of between 15 ℃ below zero and 10 ℃ below zero. Compared with the common magnesium phosphate cement mortar, the early strength is higher. Replacement of fly ash microbeads and nanomaterials with aluminum activated mineral admixtures on the basis of example 1 resulted in a decrease in setting time and fluidity, as well as a decrease in 1d and 28d compressive strength. When half water and half crushed ice/snow are adopted for stirring, although the early strength can be slightly improved, the 28d compressive strength has no great difference, but the problem of acquiring and storing the field liquid water in a severe cold environment can be better solved by adopting full crushed ice/snow mixture. The adoption of the two kinds of phosphate for the remixing can cause the reduction of hydration heat of the magnesium phosphate cement mortar, and further can reduce the early strength of the hardened magnesium phosphate cement mortar.
Claims (7)
1. The utility model provides an early strong magnesium phosphate cement mortar suitable for severe cold environment which characterized in that: the cement mortar consists of an alkaline component, an acidic component, an active mineral admixture, a nano material, a retarder, crushed ice/floating snow and sand; the alkaline component consists of dead-burned magnesia and light-burned magnesia; the acidic component consists of water-soluble phosphate and phosphorus oxide; the active mineral admixture is fly ash microbeads; the nano material consists of nano silicon oxide and nano aluminum oxide; the retarder is borax; the particle size of the crushed ice/floating snow is less than 1 mm; the sand is natural river sand with fineness modulus of 2.4.
2. The early strength magnesium phosphate cement mortar suitable for severe cold environment according to claim 1, characterized in that: the cement mortar comprises, by mass, 30-35% of an alkaline component, 8.22-9.59% of an acidic component, 2.71-3.16% of an active mineral admixture, 0.29-0.35% of a nano material, 1.5-1.75% of a retarder, 5.9-6.9% of crushed ice/floating snow and 44-50% of sand.
3. The early strength magnesium phosphate cement mortar suitable for severe cold environment according to claim 1 or 2, wherein: the weight percentage of the heavy calcined magnesia to the total amount of the cement mortar is 27.4-31.9%, and the weight percentage of the light calcined magnesia to the total amount of the cement mortar is 2.6-3.1%.
4. The early strength magnesium phosphate cement mortar suitable for severe cold environment according to claim 1 or 2, wherein: the ammonium dihydrogen phosphate accounts for 7.8-9.1% of the total mass of the cement mortar, and the phosphorus pentoxide accounts for 0.42-0.49% of the total mass of the cement mortar.
5. The early strength magnesium phosphate cement mortar suitable for severe cold environment according to claim 1 or 2, wherein: the mass percentage of the nano silicon oxide in the total amount of the cement mortar is 0.2-0.24%, and the mass percentage of the nano aluminum oxide in the total amount of the cement mortar is 0.09-0.11%.
6. The preparation method of the early strength magnesium phosphate cement mortar suitable for severe cold environment as claimed in any one of claims 1 to 5, which is characterized by comprising the following steps: the method comprises the following steps:
the method comprises the following steps: respectively weighing heavy-burned magnesium oxide, light-burned magnesium oxide, ammonium dihydrogen phosphate, phosphorus pentoxide, fly ash microbeads, nano silicon oxide, nano aluminum oxide, borax, crushed ice/snow floes and river sand;
step two: firstly, placing phosphorus pentoxide at the bottom of a stirring pot, then adding heavy-burned magnesia, light-burned magnesia, ammonium dihydrogen phosphate, fly ash microbeads, nano silicon oxide, nano aluminum oxide, borax and river sand into the stirring pot, and stirring at a low speed for 30-60 s;
step three: adding crushed ice/floating snow into the uniformly mixed dry materials, and then continuing stirring at a low speed for 120-240 s until the materials are stirred into uniformly mixed mortar.
7. The preparation method of the early strength magnesium phosphate cement mortar suitable for severe cold environment according to claim 6, which is characterized in that: in the second step, the stirring speed of the low-speed stirring is 140 +/-5 r/min of rotation and 62 +/-5 r/min of revolution.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210903031.2A CN115093196A (en) | 2022-07-28 | 2022-07-28 | Early-strength magnesium phosphate cement mortar suitable for severe cold environment and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210903031.2A CN115093196A (en) | 2022-07-28 | 2022-07-28 | Early-strength magnesium phosphate cement mortar suitable for severe cold environment and preparation method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115093196A true CN115093196A (en) | 2022-09-23 |
Family
ID=83300604
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210903031.2A Pending CN115093196A (en) | 2022-07-28 | 2022-07-28 | Early-strength magnesium phosphate cement mortar suitable for severe cold environment and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115093196A (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4436555A (en) * | 1982-09-23 | 1984-03-13 | The United States Of America As Represented By The United States Department Of Energy | Magnesium phosphate glass cements with ceramic-type properties |
| CN111056815A (en) * | 2019-11-28 | 2020-04-24 | 广州市北二环交通科技有限公司 | Slow-setting high-toughness magnesium phosphate cement road rapid repair material |
-
2022
- 2022-07-28 CN CN202210903031.2A patent/CN115093196A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4436555A (en) * | 1982-09-23 | 1984-03-13 | The United States Of America As Represented By The United States Department Of Energy | Magnesium phosphate glass cements with ceramic-type properties |
| CN111056815A (en) * | 2019-11-28 | 2020-04-24 | 广州市北二环交通科技有限公司 | Slow-setting high-toughness magnesium phosphate cement road rapid repair material |
Non-Patent Citations (1)
| Title |
|---|
| 李俊萌等: "《严寒环境抢修抢建用磷酸镁水泥混凝土的制备与力学性能研究》", 《中国优秀硕士学位论文全文数据库 工程科技Ⅰ辑》 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US11008251B2 (en) | Underwater non-dispersible quick-setting and rapid-hardening cement-based composite material and preparation method and application thereof | |
| JP7362083B2 (en) | 3D printing concrete of coastal irregular structure, processing process and application | |
| CN103803918A (en) | Porcelain powder waste mixed cement-based tiny-expansion crack repairing mortar and using method thereof | |
| Vikas et al. | Setting time, workability and strength properties of alkali activated fly ash and slag based geopolymer concrete activated with high silica modulus water glass | |
| CN109942238A (en) | A kind of preparation method of quick setting and rapid hardening coal gangue alkaline excitation fast repairing material | |
| CN102976672A (en) | Low-carbon high-performance concrete auxiliary cementing material | |
| CN101698576B (en) | Method for preparing slag-activated metakaolin cementitious materials | |
| CN108424073A (en) | A kind of high abrasion high-strength concrete and preparation method thereof | |
| CN108328977B (en) | Concrete repairing material | |
| JP7036315B2 (en) | Geopolymer for crack repair or cross-section repair of concrete | |
| CN110698133A (en) | High-titanium heavy slag sand ultrahigh-performance concrete and preparation method thereof | |
| CN105016671A (en) | Superfluid self-compacting concrete and preparing method thereof | |
| CN110041002A (en) | A kind of levigate rice hull ash base composite blend and its application | |
| CN114853394A (en) | High-ductility geopolymer composite material and preparation method thereof | |
| CN110498630B (en) | Concrete composite additive, preparation method thereof and concrete | |
| CN102295447B (en) | Quick-hardening early-strength structure reinforcement material based on aluminate cement and steel slag | |
| Li et al. | Effect of fly ash on the rheological properties of potassium magnesium phosphate cement paste | |
| CN107746233A (en) | A kind of mortar for building and its production method | |
| CN102211918B (en) | Rapid structural strengthening material taking steel slag as aggregate | |
| CN115594450B (en) | Geopolymer ceramsite lightweight concrete and preparation method thereof | |
| CN115093196A (en) | Early-strength magnesium phosphate cement mortar suitable for severe cold environment and preparation method thereof | |
| Long | Optimizing mixtures of alkali aluminosilicate cement based on ternary by-products | |
| CN112777983A (en) | Concrete rapid repairing material and preparation method thereof | |
| GB2563904A (en) | Non-calcined cementitious compositions, non-calcined concrete compositions, non-calcined concrete and preparation methods thereof | |
| CN111302744A (en) | Self-repairing high-abrasion-resistance concrete with impact and abrasion resistance and preparation method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20220923 |