High-performance repair mortar for hydraulic concrete and construction process thereofTechnical Field
The invention belongs to the technical field of hydraulic concrete repair, and particularly relates to hydraulic concrete high-performance repair mortar and a construction process thereof.
Background
Hydraulic concrete is often damaged by combined actions of freeze thawing cycle, water flow flushing and ice load, so that the function failure of the concrete structure is easily caused, and the normal operation of hydraulic engineering is influenced. In particular, the phenomenon of freeze thawing damage to the concrete frequently occurs at the positions of the water level change area, and concrete is generally degraded, and if the positions are to be repaired, the repair material must have higher impermeability, freezing resistance and anti-abrasion performance, and higher bonding strength, and in addition, a proper construction process must be selected, otherwise, secondary damage is extremely easy to occur, so that hydraulic concrete is completely abandoned before repair.
The application number CN 107935520A discloses a high-performance polymer repair mortar, which is mainly prepared from sulphoaluminate cement and ordinary silicate cement, has strong binding force with a concrete member after construction, does not crack or shrink after hardening, has high strength, good freeze-thawing resistance, salt-thawing resistance, fluoride ion permeability resistance and durability. However, the embodiment does not see the anti-freezing effect, has no anti-abrasion performance and is not suitable for repairing the hydraulic concrete overflow surface.
The application number CN 106242372A discloses an underwater epoxy repair mortar and a preparation method thereof, the method takes bisphenol A type epoxy resin and cashew shell oil modified phenolic amine curing agent as main materials, the underwater epoxy mortar can be rapidly cured and has higher bonding strength and acid and alkali corrosion resistance, the split tensile strength, the bonding strength and the breaking strength tested in the embodiment are higher, but the compressive strength is not high, the effects of freeze thawing resistance and anti-abrasion performance are not seen, the underwater epoxy repair mortar has high price from the component, the process is complex, and the method is suitable for small-area repair and plugging and is not suitable for large-area degraded repair of hydraulic concrete.
Based on the defects, the hydraulic concrete, particularly the overflow surface, is convenient and quick to repair, has strong bonding force with the concrete base surface after repair, and has good compression strength, freeze thawing resistance and anti-abrasion performance, so the hydraulic concrete is a problem to be solved by the invention.
The present invention has been made in view of this.
Disclosure of Invention
In order to solve the problems, how to repair hydraulic concrete, especially overflow surface, simply and quickly, and the adhesive force between the repaired hydraulic concrete and the concrete base surface is strong, the compressive strength, the freeze thawing resistance and the anti-abrasion performance are all good, the invention adopts the technical scheme that:
a construction process of hydraulic concrete high-performance repair mortar comprises the following process flows:
step S1, basal surface treatment: the base surface of the damaged concrete is treated, the loose and degraded part of the surface is chiseled to a hard layer, and the hard layer is washed by a high-pressure water gun;
step S2, preparing an interface treating agent: slowly adding 2-5 parts of rubber powder into 600-650 parts of stirring water to prepare the glue, continuously stirring, slowly adding 1000 parts of cement, 10-15 parts of polymer acrylic emulsion and 1-5 parts of hydroxypropyl methyl cellulose, and stirring to obtain slurry; the mixture is stirred in the process and is used up in half an hour;
step S3, coating an interface treating agent: after the basal surface is treated and no clear water exists, the prepared interface treating agent is coated on the basal surface by using a rolling brush or a row brush, and the coating is required to be uniform and no leakage point exists;
s4, preparing hydraulic concrete high-performance repair mortar: 1000 parts of cement, 150-200 parts of white cement, 1000-2000 parts of sand, 100-150 parts of polymer acrylic emulsion, 30-50 parts of silicon powder, 2-5 parts of rubber powder, 1-3 parts of nanoclay, 1-5 parts of hydroxypropyl methyl cellulose, 1-1.5 parts of basalt fiber, 10-15 parts of SKY air-entraining water reducer, 300-350 parts of mixing water, and placing into a stirrer, wherein forced stirring is adopted, and the stirred mortar is used up within 45 minutes;
step S5, repairing high-performance mortar: spreading the mixed mortar on the part to be repaired by using a spatula according to actual conditions, spreading the mortar continuously in the same direction as much as possible, compacting and leveling while spreading, compacting and exhausting at the joint, wherein the thickness of the planar coating is not more than 3cm, the thickness of the elevation coating is not more than 2cm, and layering and spreading are performed so as to avoid void; when the repairing area is too large, the construction joint or the staggered construction of the segments should be reserved, and each block of the repairing area should not exceed 10-15m2 Staggering the construction time to be not less than 24 hours;
step S6, maintenance: after the construction is finished, spraying or covering a straw curtain or a gunny bag and the like to keep moist after the surface is dried, wherein the maintenance temperature is not lower than 5 ℃; after 24 hours, the mixture is covered with plastic cloth and kept warm for 7 days.
The invention also discloses a hydraulic concrete high-performance repair mortar, which comprises the following components in parts by mass:
1000 parts of cement, 150-200 parts of white cement, 1000-2000 parts of sand, 100-150 parts of polymer acrylic emulsion, 30-50 parts of silicon powder, 2-5 parts of instant rubber powder, 1-3 parts of nanoclay, 1-5 parts of hydroxypropyl methyl cellulose, 1-1.5 parts of basalt fiber, 10-15 parts of SKY air-entraining water reducer and 300-350 parts of mixing water.
As a preferred embodiment of the present invention, the cement is one of Portland cement p.O42.5 or p.O52.5 cement.
As a preferred embodiment of the present invention, the white cement is one of white Portland cement 42.5 or 52.5 cement; the color matching agent is used for mixing colors, so that the color of the repaired part is close to that of old concrete.
As a preferred embodiment of the present invention, the sand is one of natural sand or artificial sand; the specification is that the middle sand has the mud content not more than 3 percent.
As a preferred embodiment of the present invention, the polymer acrylic emulsion has a solids content of 55%; siO in the silicon powder2 The content is more than 85 percent, and the specific surface area is more than 15000m2 /kg。
As a preferred embodiment of the present invention, the rubber powder is one of 801-speed sol powder or 901-speed sol powder; the nano clay is white powder, and the average particle size of the particles is 1-100nm.
As a preferred embodiment of the present invention, the hydroxypropyl methylcellulose has a viscosity of 20 ten thousand or more.
As a preferred embodiment of the invention, the basalt fiber is one of a monofilament diameter of 13 μm and a length of 3mm or 6 mm.
As a preferred embodiment of the invention, the SKY air-entraining water reducer is an air-entraining water reducer with lignosulfonate as a water-reducing component.
Compared with the prior art, the invention has the following beneficial effects:
in order to realize the purpose of increasing the frost resistance of the hydraulic concrete repair mortar, the invention modifies the cement mortar by doping the polymer acrylic emulsion and the instant rubber powder, and forms a continuous film in the mortar, thereby playing a role in preventing seepage, further improving the frost resistance, improving the workability of the mortar, improving the bonding strength and the abrasion resistance, reducing shrinkage and improving the crack resistance. Meanwhile, the freezing resistance of the mortar is improved by adding the air-entraining water reducer. In order to realize the anti-abrasion performance of the repair mortar, the anti-abrasion performance is improved by doping silica powder and basalt fiber, meanwhile, the anti-freezing performance is also improved by doping silica powder, and the anti-cracking performance of the mortar is also improved by doping basalt fiber. The adhesive strength of the repair mortar is improved by adding hydroxypropyl methyl cellulose and instant rubber powder. The nano clay is doped to effectively inhibit the development of ultra-large pores in the concrete, reduce harmful pores and improve the impermeability and frost resistance of the concrete. The color of the repaired part is close to that of the old concrete after repairing by mixing white silicate cement, so that the appearance quality of the repaired concrete is improved.
The following describes the embodiments of the present invention in further detail with reference to the accompanying drawings.
Drawings
In the drawings:
FIG. 1 is a schematic diagram of the process flow of the present invention.
Detailed Description
For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions in the embodiments will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and the following embodiments are used to illustrate the present invention.
A construction process of hydraulic concrete high-performance repair mortar comprises the following process flows:
step S1, basal surface treatment: the base surface of the damaged concrete is treated, the loose and degraded part of the surface is chiseled to a hard layer, and the hard layer is washed by a high-pressure water gun;
step S2, preparing an interface treating agent: slowly adding 2-5 parts of rubber powder into 600-650 parts of stirring water to prepare the glue, continuously stirring, slowly adding 1000 parts of cement, 10-15 parts of polymer acrylic emulsion and 1-5 parts of hydroxypropyl methyl cellulose, and stirring to obtain slurry; the mixture is stirred in the process and is used up in half an hour;
step S3, coating an interface treating agent: after the basal surface is treated and no clear water exists, the prepared interface treating agent is coated on the basal surface by using a rolling brush or a row brush, and the coating is required to be uniform and no leakage point exists;
s4, preparing hydraulic concrete high-performance repair mortar: 1000 parts of cement, 150-200 parts of white cement, 1000-2000 parts of sand, 100-150 parts of polymer acrylic emulsion, 30-50 parts of silicon powder, 2-5 parts of rubber powder, 1-3 parts of nanoclay, 1-5 parts of hydroxypropyl methyl cellulose, 1-1.5 parts of basalt fiber, 10-15 parts of SKY air-entraining water reducer, 300-350 parts of mixing water, and placing into a stirrer, wherein forced stirring is adopted, and the stirred mortar is used up within 45 minutes;
step S5, repairing high-performance mortar: spreading the mixed mortar on the part to be repaired by using a spatula according to actual conditions, spreading the mortar continuously in the same direction as much as possible, compacting and leveling while spreading, compacting and exhausting at the joint, wherein the thickness of the planar coating is not more than 3cm, the thickness of the elevation coating is not more than 2cm, and layering and spreading are performed so as to avoid void; when the repairing area is too large, the construction joint or the staggered construction of the segments should be reserved, and each block of the repairing area should not exceed 10-15m2 Staggering the construction time to be not less than 24 hours;
step S6, maintenance: after the construction is finished, spraying or covering a straw curtain or a gunny bag and the like to keep moist after the surface is dried, wherein the maintenance temperature is not lower than 5 ℃; after 24 hours, the mixture is covered with plastic cloth and kept warm for 7 days.
The invention also discloses a hydraulic concrete high-performance repair mortar, which comprises the following components in parts by mass:
1000 parts of cement, 150-200 parts of white cement, 1000-2000 parts of sand, 100-150 parts of polymer acrylic emulsion, 30-50 parts of silicon powder, 2-5 parts of instant rubber powder, 1-3 parts of nanoclay, 1-5 parts of hydroxypropyl methyl cellulose, 1-1.5 parts of basalt fiber, 10-15 parts of SKY air-entraining water reducer and 300-350 parts of mixing water.
Further, the cement is one of ordinary Portland cement P.O42.5 or P.O52.5 cement; the white cement is one of white Portland cement 42.5 or 52.5 cement; the color matching is used for matching colors, so that the color of the repaired part is close to that of old concrete; the sand is one of natural sand or artificial sand; the specification is that the middle sand has the mud content not more than 3 percent; the solid content of the polymer acrylic emulsion is 55%; siO in silicon powder2 The content is more than 85 percent, and the specific surface area is more than 15000m2 /kg; the rubber powder is 801 quick sol powder or 901 quick solOne of the powders; the nano clay is white powder, and the average particle size of the particles is 1-100nm; hydroxypropyl methylcellulose is 20 ten thousand viscosity or more; basalt fiber is one of monofilament diameter 13 μm and length 3mm or 6 mm; the SKY air-entraining water reducer is an air-entraining water reducer taking lignosulfonate as a water-reducing component.
Example 1:
adding 2 parts of 801 rubber powder into 600 parts of stirring water slowly to prepare the glue, continuing stirring, adding 1000 parts of P.O42.5 cement, 10 parts of polymer acrylic emulsion and 1 part of hydroxypropyl methyl cellulose slowly, stirring into slurry, preparing an interface treating agent, treating a concrete base surface, and smearing the treated concrete base surface on a base surface. Meanwhile, 1000 parts of P.O42.5 cement, 150 parts of white cement, 1000 parts of natural sand, 100 parts of polymer acrylic emulsion, 30 parts of silicon powder, 2 parts of 801 rubber powder, 1 part of nanoclay, 1 part of hydroxypropyl methyl cellulose, 1 part of basalt fiber, 10 parts of SKY type air entraining water reducer, and 300 parts of mixed water are put into a stirrer to prepare the high-performance repair mortar by forced stirring. The repairing process is to prepare compressive strength, splitting tensile strength, frost resistance and abrasion resistance test pieces by sampling, and test the samples after 28 days, wherein the frost resistance test adopts a quick freezing method, and the abrasion resistance test adopts an underwater steel ball method. The results are shown in Table 1.
Table 1 example 1 test results
Example 2:
3 parts of 801 rubber powder is slowly added into 620 parts of stirred water to prepare the glue, stirring is continued, 1000 parts of P.O42.5 cement and 12 parts of polymer acrylic emulsion are slowly added, 3 parts of hydroxypropyl methyl cellulose are stirred into slurry, an interface treating agent is prepared, and the surface of the concrete is coated on a base surface after being treated. Meanwhile, 1000 parts of P.O42.5 cement, 170 parts of white cement, 1500 parts of natural sand, 120 parts of polymer acrylic emulsion, 40 parts of silicon powder, 4 parts of 801 rubber powder, 2 parts of nanoclay, 3 parts of hydroxypropyl methyl cellulose, 1.2 parts of basalt fiber, 12 parts of SKY type air entraining water reducer, and 320 parts of mixed water are put into a stirrer to prepare the high-performance repair mortar by forced stirring. The repairing process is to prepare compressive strength, splitting tensile strength, frost resistance and abrasion resistance test pieces by sampling, and test the samples after 28 days, wherein the frost resistance test adopts a quick freezing method, and the abrasion resistance test adopts an underwater steel ball method. The results are shown in Table 2.
Table 2 example 2 test results
Example 3:
slowly adding 5 parts of 801 rubber powder into 650 parts of stirred water to prepare the glue, continuously stirring, slowly adding 1000 parts of P.O42.5 cement, 15 parts of polymer acrylic emulsion and 5 parts of hydroxypropyl methyl cellulose, stirring into slurry, preparing an interface treating agent, treating a concrete base surface, and smearing the treated concrete base surface on a base surface. Meanwhile, 1000 parts of P.O42.5 cement, 200 parts of white cement, 2000 parts of sand, 150 parts of polymer acrylic emulsion, 50 parts of silicon powder, 5 parts of 801 rubber powder, 3 parts of nanoclay, 5 parts of hydroxypropyl methyl cellulose, 1.5 parts of basalt fiber, 15 parts of SKY type air entraining water reducer, and 350 parts of mixed water are put into a stirrer to prepare the high-performance repair mortar by forced stirring. The repairing process is to prepare compressive strength, splitting tensile strength, frost resistance and abrasion resistance test pieces by sampling, and test the samples after 28 days, wherein the frost resistance test adopts a quick freezing method, and the abrasion resistance test adopts an underwater steel ball method. The results are shown in Table 3.
Table 3 example 3 test results
The embodiment shows that the hydraulic concrete high-performance repair mortar provided by the invention has higher early strength and 28-day-age strength, and the material consumption can be increased or decreased according to actual conditions during application; the freezing resistance cycle is more than 300 times, so that the hydraulic engineering requirement is met; the anti-abrasion strength is better, and the performance is better than that of the original engineering common concrete; the splitting tensile strength is more than 2.0MPa, which indicates that the bonding strength is also better, and the bonding requirement of new and old interfaces of concrete is met.
In order to realize the purpose of increasing the frost resistance of the hydraulic concrete repair mortar, the cement mortar is modified by doping the polymer acrylic emulsion and the instant rubber powder, and a continuous film is formed in the mortar, so that the cement mortar has the effects of preventing seepage, further improving the frost resistance, improving the mortar workability, improving the bonding strength and the abrasion resistance, reducing shrinkage and improving the crack resistance. Meanwhile, the freezing resistance of the mortar is improved by adding the air-entraining water reducer. In order to realize the anti-abrasion performance of the repair mortar, the anti-abrasion performance is improved by doping silica powder and basalt fiber, meanwhile, the anti-freezing performance is also improved by doping silica powder, and the anti-cracking performance of the mortar is also improved by doping basalt fiber. The adhesive strength of the repair mortar is improved by adding hydroxypropyl methyl cellulose and instant rubber powder. The nano clay is doped to effectively inhibit the development of ultra-large pores in the concrete, reduce harmful pores and improve the impermeability and frost resistance of the concrete. The color of the repaired part is close to that of the old concrete after repairing by mixing white silicate cement, so that the appearance quality of the repaired concrete is improved.