Low-temperature ultrahigh-toughness concrete repairing material as well as use method and application thereof

Abstract

The invention provides a low-temperature ultrahigh-toughness concrete repairing material as well as a use method and application thereof, and belongs to the technical field of concrete materials. The low-temperature ultrahigh-toughness concrete repairing material is prepared from the following components in parts by mass: 5-13 parts of Portland cement; 32 to 45 parts of sulphoaluminate cement clinker; 3-8 parts of silica fume; 40 to 50 parts of graded sand; 1-3 parts of an anti-freezing agent; 0.1 to 0.3 part of a coagulation accelerator; 0.1 to 0.3 part of a retarder; 0.3 to 0.8 part of a water reducing agent; and 2-8 parts of fiber. The low-temperature ultrahigh-toughness concrete repairing material which is suitable for a low-temperature environment, high in early strength, stable in later strength development, good in toughness and convenient to produce and use is prepared by adopting a method of combining synthetic fibers and steel fibers and compounding multifunctional and various components.

Description

Technical Field

[0001] The present invention relates to the technical field of concrete materials, and in particular to a low-temperature ultra-high toughness concrete repair material and a use method and application thereof. Background Art

[0002] As an important auxiliary structure of the bridge, the expansion joint can adapt to the deformation caused by temperature and humidity changes, concrete shrinkage and creep, bridge pier settlement and beam end rotation, and ensure the smoothness of the bridge deck and driving comfort. However, the expansion joint is also a weak link in the bridge structure. Due to the increase in traffic volume and the shortcomings of the existing expansion joint device in design, construction and maintenance, the expansion joints of highway bridges are damaged prematurely. The damage of the expansion joint will not only seriously affect the traffic safety, but also cause additional impact loads on the bridge and road surface. It will also greatly increase the maintenance cost of the bridge and reduce the economic and social benefits. The traditional anchoring area concrete is mainly repaired with high-strength grouting materials, high-toughness epoxy concrete and other materials. The early strength of these materials is unstable, and the construction time for the maintenance or replacement of the expansion joint is too long, which seriously interferes with road traffic. In addition, the traditional anchoring area concrete material also lacks sufficient toughness, has a short fatigue life under repeated vehicle impact loads, and has poor durability under complex environmental loads, which greatly shortens the service life of the expansion joint. Moreover, in the northern winter environment, the strength of ordinary concrete repair materials develops slowly between -5 degrees and 5 degrees and may even be frostbitten.

[0003] In response to the above problems, it is necessary to develop ultra-high toughness concrete repair materials with high early strength and good durability in low temperature environments to achieve rapid opening of highways, and to improve driving comfort while improving the working performance of the bridge deck structure system. Summary of the invention

[0004] The purpose of the present invention is to provide a low-temperature ultra-high toughness concrete repair material and its use method and application, which are used to solve the technical problems of existing cement concrete repair materials in low-temperature environments, such as slow strength development or even frostbite, poor concrete toughness and easy breakage, and severe later strength shrinkage.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The present invention provides a low-temperature ultra-high toughness concrete repair material, which is composed of the following components in parts by mass:

[0007]

[0008]

[0009] Furthermore, the Al2O3 content in the sulphoaluminate cement clinker is 30-38%, the CaO content is 38-45%, and the residue on a 0.08 mm sieve is less than 8%.

[0010] Furthermore, the content of SO2 in the silica ash is ≥92%.

[0011] Furthermore, the graded sand comprises 10-20 mesh quartz sand, 40-70 mesh quartz sand and 80-120 mesh quartz sand, and the mass ratio of the 10-20 mesh quartz sand, 40-70 mesh quartz sand and 80-120 mesh quartz sand is 4-6:2-5:1-2.

[0012] Furthermore, the antifreeze comprises sodium thiosulfate, alum and calcium nitrate, and the mass ratio of the sodium thiosulfate, alum and calcium nitrate is 20-40:20-40:30-50.

[0013] Furthermore, the coagulant comprises calcium formate and lithium carbonate, and the mass ratio of the calcium formate to the lithium carbonate is 1-3:1-3.

[0014] Furthermore, the retarder comprises tartaric acid; the effective content is greater than 99%; the water reducer comprises a powdered polycarboxylic acid water reducer, and the water reduction efficiency is greater than 25%.

[0015] Furthermore, the fibers include polyoxymethylene synthetic fibers and steel fibers, and the volume ratio of the polyoxymethylene synthetic fibers to the steel fibers is 10-30:70-90.

[0016] The present invention also provides a method for using the low-temperature ultra-high toughness concrete repair material, which can be used by mixing the low-temperature ultra-high toughness concrete repair material and water in a solid-liquid ratio of 100:13-15.

[0017] The invention also provides an application of a low-temperature ultra-high toughness concrete repair material in a building repair project.

[0018] Beneficial effects of the present invention:

[0019] The present invention adopts a method of combining synthetic fibers with steel fibers and compounding multifunctional and multi-type components to formulate a low-temperature ultra-high toughness concrete repair material that is suitable for low-temperature environments, has high early strength, stable later strength development, good toughness, and is easy to produce and use.

[0020] The invention can meet the requirements for early strength of quick-repair concrete in low-temperature environment. It can be prepared into quick-repair concrete by mixing it with fiber at a water-to-material ratio of 13% to 15%. The 1h flexural and compressive strengths of concrete materials repaired with the repair material of the invention can reach 4.7MPa and 25.9MPa respectively; the 2h flexural and compressive strengths can reach 6.2MPa and 42.4MPa respectively; the 28-day flexural and compressive strengths can reach 8.6MPa and 67.6MPa respectively.

[0021] The repair material of the present invention has a slight expansion performance in the early stage and a small shrinkage in the later stage, and the 28d shrinkage rate is ≤150×10 -6 The quick-repair concrete prepared by the present invention has strong bonding strength with old concrete, which can generally reach 85% of the overall shear strength of concrete; the quick-repair concrete prepared by the present invention has good durability, its antifreeze grade can reach F250, and the wear per unit area is <1.3kg / m 2 The quick-repair concrete prepared by the present invention has good toughness, and its equivalent bending toughness is 4-6 times that of ordinary concrete. DETAILED DESCRIPTION

[0022] The present invention provides a low-temperature ultra-high toughness concrete repair material, which is composed of the following components in parts by mass:

[0023]

[0024] In the present invention, the content of the silicate cement is preferably 8 to 12 parts by mass, more preferably 9 to 11 parts, and more preferably 10 parts. The 28d compressive strength of the silicate cement is greater than 60 MPa.

[0025] In the present invention, the content of the sulphoaluminate cement clinker is preferably 32 to 40 parts by mass, and more preferably 36 to 38 parts by mass.

[0026] In the present invention, the content of the silica fume is preferably 4 to 7 parts by mass, and more preferably 5 to 6 parts by mass.

[0027] In the present invention, the content of the graded sand is preferably 40 to 48 parts by mass, and more preferably 42 to 46 parts by mass.

[0028] In the present invention, the content of the antifreeze agent is preferably 1 to 2 parts by mass, and more preferably 2 parts by mass.

[0029] In the present invention, the content of the coagulant is preferably 0.2 to 0.3 parts by mass, and more preferably 0.2 parts.

[0030] In the present invention, the content of the retarder is preferably 0.2 to 0.3 parts by mass, and more preferably 0.2 parts.

[0031] In the present invention, the content of the water reducing agent is preferably 0.4 to 0.7 parts by mass, and more preferably 0.5 to 0.6 parts by mass.

[0032] In the present invention, the content of the fiber is preferably 3 to 6 parts by mass, and more preferably 4 to 5 parts by mass.

[0033] In the present invention, the Al2O3 content in the sulphoaluminate cement clinker is 30-38%, preferably 32-36%, and more preferably 33-35%; the CaO content is 38-45%, preferably 39-44%, and more preferably 40-42%; and the residue on the 0.08 mm sieve is less than 8%.

[0034] In the present invention, the content of SO2 in the silica ash is ≥92%, preferably ≥93%.

[0035] In the present invention, the graded sand comprises 10-20 mesh quartz sand, 40-70 mesh quartz sand and 80-120 mesh quartz sand, and the mass ratio of the 10-20 mesh quartz sand, 40-70 mesh quartz sand and 80-120 mesh quartz sand is 4-6:2-5:1-2, preferably 5:3:2.

[0036] In the present invention, the antifreeze comprises sodium thiosulfate, alum and calcium nitrate, and the mass ratio of the sodium thiosulfate, alum and calcium nitrate is 20-40:20-40:30-50, preferably 25-35:25-35:35-45, and more preferably 30:30:40.

[0037] In the present invention, the coagulant comprises calcium formate and lithium carbonate, and the mass ratio of calcium formate to lithium carbonate is 1-3:1-3, preferably 1:1.

[0038] In the present invention, the retarder is preferably tartaric acid, with an effective content of >99%;

[0039] The water reducing agent comprises a powdered polycarboxylate water reducing agent, and the water reducing efficiency is greater than 25%.

[0040] In the present invention, the fibers include polyoxymethylene synthetic fibers and steel fibers, and the volume ratio of the polyoxymethylene synthetic fibers to the steel fibers is 10-30:70-90, preferably 20:80.

[0041] The present invention also provides a method for using the low-temperature ultra-high toughness concrete repair material, which can be used by mixing the low-temperature ultra-high toughness concrete repair material and water in a solid-liquid ratio of 100:13-15, preferably 100:14.

[0042] The present invention also provides an application of a low-temperature ultra-high toughness concrete repair material in a building repair project, which is preferably used for the rapid repair construction of municipal road expansion joints, cement concrete pavements, bridge decks, municipal construction, airport runways, parking lots, ports, docks and other projects under low temperature environments.

[0043] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0044] The components of Examples 1 to 3 are shown in Table 1 below.

[0045] Table 1 Component content (unit: part)

[0046] Components Example 1 Example 2 Example 3 Ordinary Portland Cement 10 10 7 Sulphoaluminate cement clinker 30 34 38 Silica Fume 4 4 6 Graded sand 49.8 43.6 37.9 antifreeze 1.5 1.5 2 Coagulant 0.2 0.3 0.3 Retarder 0.1 0.1 0.2 Water reducing agent 0.4 0.5 0.6 fiber 4 6 8

[0047] Among them, the content of Al2O3 in sulphoaluminate cement clinker is 38%, and the content of CaO is 45%; the content of SO2 in silica fume is ≥92%; in the graded sand: the mass ratio of 10-20 mesh quartz sand, 40-70 mesh quartz sand and 80-120 mesh quartz sand is 5:3:2; the mass ratio of sodium thiosulfate, alum and calcium nitrate in the antifreeze is 3:3:4; the mass ratio of calcium formate and lithium carbonate in the accelerator is 1:1; the retarder is tartaric acid, and the effective content is greater than 99%; the water reducer is a powdered polycarboxylic acid water reducer, and the water reduction efficiency is greater than 25%; the mass ratio of polyoxymethylene synthetic fiber and steel fiber in the fiber is 20:80.

[0048] The low-temperature ultra-high toughness concrete repair material of the present invention can be obtained by uniformly mixing the above components in proportion. After the above prepared repair material and water are uniformly mixed according to the solid-liquid ratio of 100:14, the mixed material is cured and its performance is tested. The test environment is -5 degrees for the first 7 days, and then transferred to the standard 20 degrees curing temperature for 21 days. The performance test results are shown in Table 2 below.

[0049] Table 2 Performance test results

[0050]

[0051] It can be seen from the above embodiments that the present invention provides a low-temperature ultra-high toughness concrete repair material and its use method and application. From the test results in Table 2 above, it can be seen that the 1h flexural and compressive strengths can reach 4.7MPa and 25.9MPa respectively; the 2h flexural and compressive strengths can reach 6.2MPa and 42.4MPa respectively; the 28-day flexural and compressive strengths can reach 8.6MPa and 67.6MPa respectively. The repair material of the present invention has micro-expansion performance in the early stage and small shrinkage in the later stage. The 28d shrinkage rate is ≤150×10 -6The quick-repair concrete prepared by the present invention has strong bonding strength with old concrete, which can generally reach 85% of the overall shear strength of concrete; the quick-repair concrete prepared by the present invention has good durability, its antifreeze grade can reach F250, and the wear per unit area is <1.3kg / m 2 The quick-repair concrete prepared by the present invention has good toughness, and its equivalent bending toughness is 4-6 times that of ordinary concrete.

[0052] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A low-temperature ultra-high toughness concrete repair material, characterized in that: It is composed of the following components in parts by weight:

2. The low-temperature ultra-high toughness concrete repair material according to claim 1, characterized in that: The Al2O3 content in the sulphoaluminate cement clinker is 30-38%, the CaO content is 38-45%, and the residue on a 0.08 mm sieve is less than 8%.

3. The low-temperature ultra-high toughness concrete repair material according to claim 1 or 2, characterized in that: The content of SO2 in the silica ash is ≥92%.

4. The low-temperature ultra-high toughness concrete repair material according to claim 3, characterized in that: The graded sand comprises 10-20 mesh quartz sand, 40-70 mesh quartz sand and 80-120 mesh quartz sand, and the mass ratio of the 10-20 mesh quartz sand, 40-70 mesh quartz sand and 80-120 mesh quartz sand is 4-6:2-5:1-2.

5. The low temperature ultra-high toughness concrete repair material according to claim 1, 2 or 4, characterized in that: The antifreeze agent comprises sodium thiosulfate, alum and calcium nitrate, and the mass ratio of the sodium thiosulfate, alum and calcium nitrate is 20-40:20-40:30-50.

6. The low-temperature ultra-high toughness concrete repair material according to claim 5, characterized in that: The coagulant comprises calcium formate and lithium carbonate, and the mass ratio of the calcium formate to the lithium carbonate is 1-3:1-3.

7. The low-temperature ultra-high toughness concrete repair material according to claim 6, characterized in that: The retarder comprises tartaric acid, and the effective content thereof is greater than 99%; the water reducer comprises a powdered polycarboxylic acid water reducer, and the water reduction efficiency thereof is greater than 25%.

8. The low temperature ultra-high toughness concrete repair material according to claim 1, 6 or 7, characterized in that: The fibers include polyoxymethylene synthetic fibers and steel fibers, and the mass ratio of the polyoxymethylene synthetic fibers to the steel fibers is 10-30:70-90.

9. The method for using the low-temperature ultra-high toughness concrete repair material according to any one of claims 1 to 8, characterized in that: Mix the low-temperature ultra-high toughness concrete repair material and water in a solid-liquid ratio of 100:13-15 and it can be used.

10. Use of the low-temperature ultra-high toughness concrete repair material according to any one of claims 1 to 8 in building repair projects.

Images