CN115716731A - Low-shrinkage creep mechanism sandstone aggregate C55 concrete suitable for ultrahigh pumping - Google Patents
Low-shrinkage creep mechanism sandstone aggregate C55 concrete suitable for ultrahigh pumping Download PDFInfo
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- 239000004567 concrete Substances 0.000 title claims abstract description 95
- 238000005086 pumping Methods 0.000 title claims abstract description 34
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 49
- 239000004568 cement Substances 0.000 claims abstract description 46
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims abstract description 24
- 239000004576 sand Substances 0.000 claims abstract description 24
- 239000003638 chemical reducing agent Substances 0.000 claims abstract description 23
- 239000010881 fly ash Substances 0.000 claims abstract description 13
- 239000000843 powder Substances 0.000 claims abstract description 13
- 239000002893 slag Substances 0.000 claims abstract description 13
- 229910021487 silica fume Inorganic materials 0.000 claims abstract description 11
- 239000000203 mixture Substances 0.000 claims description 12
- 239000002245 particle Substances 0.000 claims description 8
- 239000011435 rock Substances 0.000 claims description 7
- 239000004594 Masterbatch (MB) Substances 0.000 claims description 6
- 239000010445 mica Substances 0.000 claims description 6
- 229910052618 mica group Inorganic materials 0.000 claims description 6
- 230000000979 retarding effect Effects 0.000 claims description 6
- 238000010521 absorption reaction Methods 0.000 claims description 5
- 238000012545 processing Methods 0.000 claims description 5
- 239000010754 BS 2869 Class F Substances 0.000 claims description 4
- 239000000126 substance Substances 0.000 claims description 4
- 239000002253 acid Substances 0.000 claims description 3
- 230000000740 bleeding effect Effects 0.000 claims description 3
- 229910004298 SiO 2 Inorganic materials 0.000 claims 1
- 238000010276 construction Methods 0.000 abstract description 14
- 239000004575 stone Substances 0.000 abstract description 14
- 230000036571 hydration Effects 0.000 abstract description 5
- 238000006703 hydration reaction Methods 0.000 abstract description 5
- 238000000034 method Methods 0.000 abstract description 4
- 229910052500 inorganic mineral Inorganic materials 0.000 abstract description 3
- 239000011707 mineral Substances 0.000 abstract description 3
- 239000002910 solid waste Substances 0.000 abstract description 3
- 239000004566 building material Substances 0.000 abstract description 2
- 238000012423 maintenance Methods 0.000 abstract description 2
- 238000012360 testing method Methods 0.000 description 16
- 238000001514 detection method Methods 0.000 description 10
- 239000000463 material Substances 0.000 description 7
- 238000013461 design Methods 0.000 description 5
- 229910000831 Steel Inorganic materials 0.000 description 4
- 238000009825 accumulation Methods 0.000 description 4
- 238000002474 experimental method Methods 0.000 description 4
- 238000005259 measurement Methods 0.000 description 4
- 239000011513 prestressed concrete Substances 0.000 description 4
- 239000010959 steel Substances 0.000 description 4
- 230000006835 compression Effects 0.000 description 3
- 238000007906 compression Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 239000003513 alkali Substances 0.000 description 2
- 238000005266 casting Methods 0.000 description 2
- 230000001186 cumulative effect Effects 0.000 description 2
- 230000003247 decreasing effect Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 230000005484 gravity Effects 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 239000002956 ash Substances 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 239000010883 coal ash Substances 0.000 description 1
- 238000007596 consolidation process Methods 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000005553 drilling Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000009415 formwork Methods 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
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- 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
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- Curing Cements, Concrete, And Artificial Stone (AREA)
Abstract
A low-shrinkage creep mechanism sandstone aggregate C55 concrete suitable for ultrahigh pumping belongs to the field of building materials. The method aims to solve the problems that natural gravel aggregate is lacked in the construction of mountainous areas with complex terrains, the mechanical property of the existing high-grade concrete is affected after the existing high-grade concrete is subjected to ultrahigh pumping, the maintenance difficulty is increased, the requirement on shrinkage and creep is high, and the pumping difficulty is high. The C55 concrete consists of cement, fly ash, slag powder, silica fume, fine aggregate, coarse aggregate, a water reducing agent and water. The mineral admixture in the invention is as high as 50%, not only realizes large mixing amount of solid waste, but also realizes low cement content and high grade, and simultaneously obviously reduces hydration heat. The high-grade concrete with low cement content is guaranteed by adopting machine-made sand and machine-made broken stones in 100 percent to completely replace natural gravel aggregate, the compressive strength of the concrete is generally higher than 65MPa through the optimal proportion, the concrete is suitable for ultrahigh pumping, and the problem of shrinkage and creep of the high-tower cement concrete is effectively solved. The C55 concrete is suitable for ultrahigh pumping.
Description
Technical Field
The invention belongs to the field of building materials; in particular to low-shrinkage creep mechanism sandstone aggregate C55 concrete suitable for ultrahigh pumping.
Background
Modern cable-stayed bridges can be traced back to the Stalon Sonde bridge built in Sweden in 1956, with a main span of 182.6m. The application of the cable-stayed bridge in the world is started from the 70 s of the 20 th century, cable-stayed bridge technology is unprecedentedly developed after the half century, and the cable-stayed bridge which has been built in the world and has a main span of more than 200m has more than 200 seats, wherein the span of more than 400m has more than 40 seats.
In the early days, most of cable-stayed bridges adopt a steel structure main beam, and a double box or a single box is matched with an orthotropic plate. In 1957, the first concrete cable-stayed bridge (taking concrete as a main beam) appears, but the span is only 17.5m +51.9m +17.53m. The bridge can be considered as a test bridge for a marakabo lake bridge built five years later. The modified marakawa lake bridge built in 1962 was the first modern concrete cable-stayed bridge. Taking the above as a starting point, the preface screen of the concrete cable-stayed bridge is uncovered. After the 70's of the 20's, prestressed concrete bridges were largely erected, such as the pludono (Bro-tonne) bridge erected in france in 1977, and the Luna cable-stayed bridge erected in spain. A plurality of steel cable-stayed bridges with the span of 300-600 m are repaired in Japan; in 1986, a concrete cable-stayed bridge with a span of 245m was also built, before which the span of the concrete cable-stayed bridge did not exceed 100m. The most extended concrete cable-stayed bridge in the world is the Skarnsund bridge in norway at present, and the main span is 530m.
China is the country where most concrete cable-stayed bridges are built. In 1975 and 1976, two test bridges, namely Chongqing Yunyang bridge and Xinwuqiao of Shanghai Songjiang, were respectively built, and the main spans of the bridges were 76m and 54m respectively. The first railway prestressed concrete cable-stayed bridge in China, namely the Honghe bridge (48m +96m + 48m), is built in Guangxi in 1980, and the cable-stayed bridge in China enters a rapid development stage. The erection of the great bridge (432 m main span, the largest rib plate type concrete cable-stayed bridge in the world) in the Yangtze river of the copper tomb in 1995 marks the design of the cable-stayed bridge in China to enter the lightweight era. The Jingzhou Changjiang bridge (500 m main span) built in 2002 is the largest rib plate type concrete cable-stayed bridge in the world; the Guangdong Jinma bridge (main bridge 233m + 283m) is the largest single-tower concrete cable-stayed bridge in the world.
Such as: the Nanmenxi grand bridge is located in the town of south Jia of Jian river county of Guizhou province, is a control project of a Guizhou Jianli expressway, is a double-tower double-cable-surface prestressed concrete cable-stayed bridge with the length of 2 multiplied by 30m + (160m +360m + 160m) +6 multiplied by 40m, and is 987.5m in bridge length, 360m in main span, a tower pier beam consolidation system, a cable tower is H-shaped, 244.5m/253.5m in height, a main girder is of a double-side box structure, the width of the bridge deck is 29.5m, and a steel strand stayed cable is adopted as the stayed cable.
In the mountainous area of Guizhou on the project, the construction condition is severe: the circuit is located the slope area of the former mountain region of Guizhou middle part mound to the transition of Hunan hills, and the topography is complicated, and relief is great, and the slope is steeper, basement rock breakage, and the level construction place that possesses the condition along the line is few, mostly is the mountain region, and is great to influence such as approaching site selection and construction, major structure construction, material transportation greatly, and main tower protection engineering volume is big.
High pier large span concrete cable-stayed bridge in valley area: the heights of two main towers of the Nanmenxi grand bridge are 244.5m and 253.5m respectively, the main bridge span is 360m, the bridge is a typical high-pier large-span concrete cable-stayed bridge, the bridge site area is positioned in a V-shaped valley, and the topographic conditions and the meteorological conditions are complex.
The safety risk is high: a Nanmenxi grand bridge with a main span (160 +, 360+, 160) m is a cable-stayed bridge with a main tower height of 253.5m, is a full-line control project, slopes of mountains on two sides are large, a construction site is narrow and small, material transportation is difficult, the main towers on two sides are protected, a construction period is abnormally short, a construction period risk is extremely high, and a safety risk is extremely high.
The pumping height reaches more than 250m, and the requirements on the concrete performance and pumping equipment are extremely high. The working performance of the ultra-high pump is ensured, and the mechanical performance of high grade is also ensured. However, because the construction environment is lack of natural aggregate, only artificial sandstone aggregate can be adopted, the mechanical property and the working property of high-grade concrete are difficult, the ultrahigh bridge tower main body cannot deform greatly, the influence of shrinkage and creep is avoided, and the series of problems are difficult to solve systematically by the existing materials and technologies.
Disclosure of Invention
The invention aims to solve the problems that natural sandstone aggregate is lacked in the construction of mountainous areas with complex terrain, the mechanical property of the existing high-grade concrete is influenced after ultrahigh pumping, the maintenance difficulty is increased, the requirement on shrinkage and creep is high, and the pumping difficulty is high, and provide the low-shrinkage creep mechanism sandstone aggregate C55 concrete suitable for ultrahigh pumping.
The low-shrinkage creep mechanism sandstone aggregate C55 concrete suitable for ultrahigh pumping has the volume weight of 2400-2500kg/m 3 (ii) a The composition comprises the following components in parts by weight: 225-275 parts of cement, 50-100 parts of fly ash, 100-150 parts of slag powder, 40-60 parts of silica fume, 700-800 parts of fine aggregate, 1000-1200 parts of coarse aggregate, 4-6 parts of water reducing agent and 140-170 parts of water.
Further, the cement is P.O42.5 cement, the specific surface area is 300-350 square meters per kilogram, the content of C2S is 35-40%, and the content of C3S is 40-50%.
Further, the fly ash is class F and class II, the specific surface area is 300-350 square meters per kilogram, and the water demand ratio is 100-105%.
Further, the grade of the slag powder is S105, the specific surface area is 300-350 square meters per kilogram, and the water demand ratio is 95-100%.
Further, siO in the silica fume 2 The content is 85-95%.
Further, the grain size of the fine aggregate is less than 4.75mm, the fine aggregate is machine-made sand, the compressive strength of the machine-made sand processing master batch rock is 100-350MPa, and the fineness modulus is 2.8-3.2; the fine aggregate comprises the following components in percentage by mass: 2-5% below 0.075mm, 2-5% below 0.075mm-0.15mm, 6-8% below 0.15mm-0.3mm, 19-21% below 0.3mm-0.6mm, 18-22% below 0.6mm-1.18mm, 28-32% below 1.18mm-2.36mm, and 18-22% below 2.36mm-4.75 mm.
Further, the fine aggregate has CL content of 0-0.01% and SO content 3 0 to 0.1 percent of mica, 0 to 0.5 percent of mica and 0 to 0.5 percent of light substances; the fine aggregate has a bulk density of 1600-1700g/cm 3 Apparent density of 2600-2800g/cm 3 The mud content is 0-0.2%, the firmness is 3-5%, the porosity is 35-40%, the crushing value is 12-20%, and the water absorption is 0.80-0.85%.
Further, the grain size of the coarse aggregate is 5-20mm machine-made crushed stone, and the compressive strength of the master batch rock processed by the machine-made crushed stone is 100-350MPa; wherein the mass ratio of the particle size of 5-10mm to the particle size of 10-20mm is (2.8-3.2) to (6.8-7.2); the bulk density of the coarse aggregate is 1300-1500g/cm 3 Apparent density of 2600-2800g/cm 3 Porosity of 40-45%, mud content of 0-0.2%, and needle sheet content of 0-5%.
Further, the water reducing agent is a high-performance retarding water reducing agent, the water reducing rate is 25-30%, and the bleeding rate ratio is 40-50%.
Further, the water reducing agent is a retarding polycarboxylic acid high-performance water reducing agent.
The invention has the advantages that:
the invention is suitable for ultra-high pumping low-shrinkage creep mechanism sandstone aggregate C55 concrete, the mineral admixture of the invention is up to 50 percent, not only realizes large solid waste doping amount, but also realizes low cement high grade, and obviously reduces hydration heat and effectively reduces shrinkage creep.
The invention improves the specific gravity (the sand rate is 40-43%) of the machine-made sand and the machine-made broken stone, and effectively improves the stacking model by strictly grading arrangement by utilizing the mechanical interlocking function of the machine-made sand aggregate, thereby not only ensuring the high-grade strength, but also obviously improving the shrinkage creep of the concrete.
According to the invention, the mechanical sand and the mechanical broken stone are adopted for 100 percent, natural sandstone aggregate is completely replaced, the high-grade mechanical requirement is met by adopting a large amount of fly ash and silica fume and combining slag powder and a water reducing agent, the problem of poor working performance of the mechanical sandstone aggregate is solved, the ideal slump (the slump is 170-200 mm) is obtained, and ultrahigh pumping is realized.
According to the invention, through series orthogonal experiments and optimized design, the optimal proportion is obtained, the high-grade concrete with low cement content is ensured to be prepared by adopting machine-made sand and machine-made broken stone to replace natural sandstone aggregate in 100%, the compressive strength of the concrete is generally higher than 65MPa, the concrete is suitable for ultrahigh pumping, and the problem of shrinkage and creep of high-tower cement concrete is effectively solved.
The cement, the fly ash and the slag powder have lower specific surface area, so that the heat release rate is well adjusted, the heat release is integrally reduced, and the hydration heat is reduced, the shrinkage and creep of high-grade concrete are solved and the strength of the high-grade concrete is guaranteed by adjusting the amount of C2S and C3S.
According to the invention, the optimal gradation of the machine-made sand is optimally designed through a compact accumulation model and an orthogonal experiment, particularly, the gradation of 5-10mm and 10-20mm is controlled, so that the strength and the elastic modulus of the machine-made sand are ensured, particularly, the accumulation density, the porosity and the water absorption rate are strictly controlled, the strength of the concrete is improved, the shrinkage and creep of high-grade concrete are remarkably reduced, the working performance of the concrete is ensured, and the ultrahigh pumping smooth construction is realized.
The low-shrinkage creep mechanism sandstone aggregate C55 concrete is suitable for ultrahigh pumping.
Drawings
FIG. 1 is an index graph of measured properties of P.O42.5 cement in the examples;
FIG. 2 is a test report of fly ash in the examples;
FIG. 3 is a graph of various performance indexes of the fine aggregate in the examples;
FIG. 4 is a graph showing the results of modulus detection of fineness of fine aggregates in examples;
FIG. 5 is a graph showing the results of coarse aggregate testing in the examples;
FIG. 6 is a diagram showing the results of the component detection of coarse and fine aggregates in the examples;
FIG. 7 is a diagram showing the detection results of the water reducing agent in the examples;
FIG. 8 is a diagram showing the detection results of river water in the example;
FIG. 9 is a graph showing the results of testing the strength of concrete at a mixing ratio over time in the examples;
FIG. 10 is a graph of intensity versus water-cement ratio for the examples;
FIG. 11 is a drawing of a real object of the Nanmenxi grand bridge in the example;
FIG. 12 is a test record chart of the design of the engineering project cement concrete mix proportion in the example;
FIG. 13 is a graph showing cumulative screen residue in the example;
FIG. 14 is a plot of laboratory mix intensity in the examples;
FIG. 15 is a graph of the intensity versus water-cement ratio for the examples;
FIG. 16 is a graph showing the test results of the compressive strength of cement concrete in the highway project 1 in the example;
FIG. 17 is a graph showing the results of testing the compressive strength of cement concrete for highway project 2 in the examples;
FIG. 18 is a graph showing the results of testing the consistency of the cement concrete mixture in the examples;
FIG. 19 is a graph showing the results of measurement of apparent density of cement concrete in examples;
FIG. 20 is a graph showing the results of measuring the setting time of the cement concrete mixture in the examples;
FIG. 21 is a graph showing the results of measurement of the compression modulus of elasticity of cement concrete in examples.
Detailed Description
The technical solution of the present invention is not limited to the embodiments listed below, and includes any combination of the embodiments.
The first specific implementation way is as follows: the embodiment is suitable for ultra-high pumping low-shrinkage creep mechanism sandstone aggregate C55 concrete, and the volume weight of the concrete is 2400-2500kg/m 3 (ii) a The composition comprises the following components in parts by weight: 225-275 parts of cement, 50-100 parts of fly ash, 100-150 parts of slag powder, 40-60 parts of silica fume, 700-800 parts of fine aggregate, 1000-1200 parts of coarse aggregate, 4-6 parts of water reducing agent and 140-170 parts of water.
In the present embodiment, the water reducing agent is a commercially available product.
The second embodiment is as follows: different from the specific embodiment, in the embodiment, the cement is p.o42.5 cement, the specific surface area is 300 to 350 square meters per kilogram, the content of C2S is 35 to 40%, and the content of C3S is 40 to 50%. Other steps and parameters are the same as those in the first embodiment.
The third concrete implementation mode: different from the first or second specific embodiment, in the embodiment, the coal ash is class F class ii, the specific surface area is 300 to 350 square meters per kilogram, and the water demand ratio is 100 to 105%. Other steps and parameters are the same as those in the first or second embodiment.
The fourth concrete implementation mode: unlike one of the first to third specific embodiments, in this embodiment, the slag powder has a grade of S105, a specific surface area of from 300 to 350 square meters per square gram, and a water demand ratio of from 95 to 100%. Other steps and parameters are the same as those in one of the first to third embodiments.
The fifth concrete implementation mode: in this embodiment, the difference between the first embodiment and the fourth embodiment is that SiO in the silica fume 2 The content is 85-95%. Other steps and parameters are the same as in one of the first to fourth embodiments.
The sixth specific implementation mode: the difference between the embodiment and one of the first to the fifth embodiments is that the grain size of the fine aggregate is less than 4.75mm, the fine aggregate is machine-made sand, the compressive strength of the machine-made sand processing master batch rock is 100-350MPa, and the fineness modulus is 2.8-3.2; the fine aggregate comprises the following components in percentage by mass: 2-5% below 0.075mm, 2-5% below 0.075mm-0.15mm, 6-8% below 0.15mm-0.3mm, 19-21% below 0.3mm-0.6mm, 18-22% below 0.6mm-1.18mm, 28-32% below 1.18mm-2.36mm, and 18-22% below 2.36mm-4.75 mm. Other steps and parameters are the same as in one of the first to fifth embodiments.
The seventh concrete implementation mode: this embodiment is different from any one of the first to sixth embodiments in that the fine aggregate has a CL content of 0 to 0.01%, and SO 3 0 to 0.1 percent of mica, 0 to 0.5 percent of mica and 0 to 0.5 percent of light substances; the fine aggregate has a bulk density of 1600-1700g/cm 3 The apparent density is 2600-2800g/cm 3 0-0.2% of mud content, 3-5% of firmness and poresThe percentage is 35-40%, the crushing value is 12-20%, and the water absorption is 0.80-0.85%. Other steps and parameters are the same as those in one of the first to sixth embodiments.
The specific implementation mode is eight: the difference between the embodiment and one of the first to seventh embodiments is that the coarse aggregate has a grain size of 5-20mm machine-made broken stone, and the compression strength of the machine-made broken stone processing master batch rock is 100-350MPa; wherein the mass ratio of the particle size of 5-10mm to the particle size of 10-20mm is (2.8-3.2) to (6.8-7.2); the coarse aggregate has a bulk density of 1300-1500g/cm 3 The apparent density is 2600-2800g/cm 3 Porosity of 40-45%, mud content of 0-0.2%, and needle sheet content of 0-5%. Other steps and parameters are the same as those in one of the first to seventh embodiments.
The specific implementation method nine: the difference between the first embodiment and the eighth embodiment is that the water reducing agent is a high-performance retarding water reducing agent, the water reducing rate is 25-30%, and the bleeding rate ratio is 40-50%. Other steps and parameters are the same as those in one to eight of the embodiments.
The specific implementation mode is ten: the difference between this embodiment and the ninth embodiment is that the water reducing agent is a retarding polycarboxylic acid high-performance water reducing agent. Other steps and parameters are the same as those in the ninth embodiment.
The beneficial effects of the present invention are demonstrated by the following examples:
example 1:
the low-shrinkage creep mechanism sandstone aggregate C55 concrete suitable for ultrahigh pumping has the volume weight of 2455kg/m 3 (ii) a The composition comprises the following components in parts by weight: 250 parts of cement, 75 parts of fly ash, 125 parts of slag powder, 50 parts of silica fume, 740 parts of fine aggregate, 1065 parts of coarse aggregate, 5 parts of water reducing agent and 145 parts of water.
In the C55 concrete of the present example, the water cement ratio was 0.29 and the sand ratio was 41%.
In the present example, p.o42.5 cement, jinguifang and tai cement co., ltd, was used as the cement, and various measured performance indexes are shown in fig. 1.
In the embodiment, the fly ash is class F II ash of Guizhou Guidong thermal power plant; the test report is shown in FIG. 2:
in this embodiment, the grade of the slag powder is S105, the specific surface area is 300 to 350 square meters per kilogram, and the water demand ratio is 95 to 100%.
SiO in silica fume in this example 2 The content is 85-95%.
In the embodiment, the fine aggregate is prepared from machine-made sand of Riping Xinkun stone Co., ltd, which is less than 4.75 mm; the screening result is medium sand, and various performance indexes are shown in figure 3; the results of the fineness modulus detection of the fine aggregate are shown in fig. 4.
In the embodiment, the coarse aggregate is crushed into stones of 5-20mm by a mechanism of Riping Xinkun stone Limited company; wherein the mixing proportion of the crushed stones is 5-10mm and 10-20mm, and is 3; the results are shown in FIG. 5.
The detection results of the coarse and fine aggregate components in this example are shown in FIG. 6.
In the embodiment, the water reducer adopts a high-performance water reducer retarding type of Guizhou Kaixiang new material Co., ltd, and the detection result is shown in FIG. 7.
In this example, river water was used as water, and the results of the measurement are shown in FIG. 8.
In the embodiment, a constant water content method is adopted during concrete molding, the water-cement ratio reference mixing ratios of the other two mixing ratios are respectively increased and decreased by 0.05, the sand rate (the ratio of coarse and fine aggregates) is adapted by increasing 1% and decreasing 1%, and the detection result of the time strength of the concrete mixing ratio is shown in figure 9. The intensity versus water-cement ratio curve is shown in FIG. 10.
According to the concrete trial mixing working performance and the 28d indoor test result, the optimal mixing ratio of the C55 concrete is shown in the table 1:
TABLE 1
The construction and construction are carried out in series of projects by adopting the proportion, and the Nanmenxi grand bridge is taken as an example for discussion:
the south Mengxi grand bridge of Guizhou Jian Li expressway is located in the south California of Jianhe county of southeast autonomous State of Guizhou province, the starting and ending mileage K34+815.0K35+802.5 spans across south Mengxi of the clear water Yangxi, and the distance of about 27 kilometers from the dam of the three-plate xi power station is a control project of the Jianli expressway;
the bridge is shown in FIG. 11 as a whole object, the full length of the bridge is 987.5m, and the hole span is arranged to be 2 × 30m + (160 +360+ 160) m +6 × 40m. The main bridge is 160+360+160m double-tower double-cable-plane prestressed concrete cable-stayed bridge, the full bridge has 152 steel strand stay cables, the main beam adopts a double-side box section, the full width of the bridge deck is 29.5m, the height of the beam is 3.0m, the length of a standard segment is 9.0m, the height of a 3# main tower is 244.5m, the height of a 4# main tower is 253.5m, the size of a main tower bearing platform is 35m multiplied by 29m multiplied by 6.5m, and 30 pile foundations with the diameter of 2.8m are arranged below the main bridge. Adopting rotary drilling hole-forming and manual hole-forming processes according to geological conditions on the pile foundation; the main tower is constructed by adopting a hydraulic creeping formwork, and the sectional casting height is 6m; the main beam is constructed by adopting a front supporting point hanging basket, and the weight of the maximum hanging casting section is about 630t.
Detection of harmful substances, concrete mixing proportion Cl < - > content, alkali content and SO 3 The contents are as follows:
cl content 0.168kg/m in total 3 The weight of the cementing material is 500kg/m 3 Accounting for 0.03 percent of the total amount of the cementing material.
The total alkali content is 2.05kg/m 3 Less than 2.1kg/m 3 。
SO 3 The total content is 10.722kg/m 3 The weight of the cementing material is 500kg/m 3 Accounting for 2.14 percent of the total amount of the cementing material.
The engineering project cement concrete mix proportion design test detection record is shown in figure 12. The cumulative sieve excess is shown in FIG. 13. The laboratory mix intensity is shown in figure 14. The intensity vs. water-cement ratio curve is shown in FIG. 15. The test result of the compressive strength of the cement concrete for the highway project 1 is shown in figure 16. The test result of the compressive strength of the cement concrete for the highway item 2 is shown in figure 17. The results of the consistency test of the cement concrete mixture are shown in FIG. 18. The measurement result of the apparent density of the cement concrete is shown in FIG. 19. The result of measuring the setting time of the cement concrete mixture is shown in FIG. 20. The test results of the compression elastic modulus of the cement concrete are shown in figure 21.
And (4) engineering summary:
1. due to the application of scientific and technological achievements in the engineering, the concrete mineral admixture is up to 50%, the cement consumption is greatly reduced, the cost is greatly reduced, and the carbon emission is also obviously reduced.
2. The adoption of solid waste with large mixing amount, machine-made sand and machine-made broken stone realizes low cement grade and high grade, obviously reduces hydration heat and effectively reduces shrinkage and creep.
3. The specific gravity of the machine-made sand and the machine-made gravel is improved, the mechanical interlocking effect of the machine-made gravel aggregate is utilized, the strength of the high-grade concrete is ensured, and the shrinkage and creep of the concrete are obviously improved.
4. The mechanical requirement of high-grade concrete is met by replacing natural sandstone aggregates with 100% machine-made sand and machine-made broken stones, and the fly ash, the silica fume, the slag powder and the water reducing agent are adopted, so that the problem of poor working performance of the machine-made sandstone aggregates is solved, ideal slump is obtained, and ultrahigh pumping is realized.
5. Through series orthogonal experiments and optimized design, the optimal proportion is obtained, 100% of high-grade concrete with low cement content is prepared by adopting machine-made sandstone aggregates instead of natural sandstone aggregates, the compressive strength of the concrete is generally higher than 65MPa, the concrete is suitable for ultrahigh pumping, and the problem of shrinkage and creep of high-tower cement concrete is effectively solved.
6. The cement, the fly ash and the slag powder have lower specific surface area, so that the heat release rate is well adjusted, the heat release is integrally reduced, and the hydration heat is reduced through the amount of C2S and C3S, so that the shrinkage and creep of high-grade concrete are solved, and the strength of the high-grade concrete is guaranteed.
7. The strength and the elastic modulus of the machine-made sand are ensured by optimally designing the optimal gradation of the machine-made sand, and particularly, the strength of the concrete is improved and the shrinkage creep of high-grade concrete is remarkably reduced by strictly controlling the bulk density, the porosity and the water absorption.
8. Through a compact accumulation model and an orthogonal experiment, the optimal gradation of the mechanical broken stone is optimally designed, and particularly through controlling the gradation, the accumulation density, the porosity and the needle sheet content of 5-10mm and 10-20mm, the shrinkage creep of high-grade concrete is improved, the working performance of the concrete is ensured, and the ultrahigh pumping smooth construction is realized.
Although the present invention has been described in detail with reference to the preferred embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the true spirit and scope of the present invention.
Claims (10)
1. The low-shrinkage creep mechanism sandstone aggregate C55 concrete suitable for ultrahigh pumping is characterized in that the volume weight of the concrete is 2400-2500kg/m 3 (ii) a The composition comprises the following components in parts by weight: 225-275 parts of cement, 50-100 parts of fly ash, 100-150 parts of slag powder, 40-60 parts of silica fume, 700-800 parts of fine aggregate, 1000-1200 parts of coarse aggregate, 4-6 parts of water reducing agent and 140-170 parts of water.
2. The low-shrinkage creep mechanism sandstone aggregate C55 concrete suitable for ultrahigh pumping according to claim 1, wherein the cement is P.O42.5 cement, the specific surface area is 300-350 square meters per kilogram, the content of C2S is 35-40%, and the content of C3S is 40-50%.
3. The low shrinkage creep mechanism sandstone aggregate C55 concrete suitable for ultrahigh pumping according to claim 1, wherein the fly ash is class F and class II, the specific surface area is 300 to 350 square meters per kilogram, and the water demand ratio is 100 to 105 percent.
4. The low-shrinkage creep mechanism sandstone aggregate C55 concrete suitable for ultrahigh pumping according to claim 1, wherein the grade of the slag powder is S105, the specific surface area is 300-350 square meters per kilogram, and the water consumption ratio is 95-100%.
5. The low shrinkage creep mechanism sandstone aggregate C55 concrete suitable for ultra-high pumping according to claim 1, wherein the SiO in the silica fume is SiO 2 The content is 85-95%.
6. The low shrinkage creep mechanism sandstone aggregate C55 concrete suitable for ultrahigh pumping according to claim 1, wherein the fine aggregate has a particle size of 4.75mm or less, the fine aggregate is machine-made sand, the compressive strength of the machine-made sand processing master batch rock is 100-350MPa, and the fineness modulus is 2.8-3.2; the fine aggregate comprises the following components in percentage by mass: 2-5% below 0.075mm, 2-5% below 0.075mm-0.15mm, 6-8% below 0.15mm-0.3mm, 19-21% below 0.3mm-0.6mm, 18-22% below 0.6mm-1.18mm, 28-32% below 1.18mm-2.36mm, and 18-22% below 2.36mm-4.75 mm.
7. The low shrinkage creep mechanism sandstone aggregate C55 concrete suitable for ultrahigh pumping according to claim 1, wherein the fine aggregate has CL content of 0-0.01%, SO 3 0 to 0.1 percent of mica, 0 to 0.5 percent of mica and 0 to 0.5 percent of light substances; the fine aggregate has a bulk density of 1600-1700g/cm 3 Apparent density of 2600-2800g/cm 3 The mud content is 0-0.2%, the firmness is 3-5%, the porosity is 35-40%, the crushing value is 12-20%, and the water absorption is 0.80-0.85%.
8. The low-shrinkage creep mechanism gravel aggregate C55 concrete suitable for ultra-high pumping according to claim 1, characterized in that the coarse aggregate has a particle size of 5-20mm mechanism gravel, and the compressive strength of the mechanism gravel processing master batch rock is 100-350MPa; wherein the mass ratio of the particle size of 5-10mm to the particle size of 10-20mm is (2.8-3.2) to (6.8-7.2); the bulk density of the coarse aggregate is 1300-1500g/cm 3 The apparent density is 2600-2800g/cm 3 Porosity of 40-45%, mud content of 0-0.2%, and needle-shaped content of 0-5%.
9. The low-shrinkage creep mechanism sandstone aggregate C55 concrete suitable for ultra-high pumping according to claim 1, wherein the water reducing agent is a high-performance retarding water reducing agent, the water reducing rate is 25-30%, and the bleeding rate ratio is 40-50%.
10. The low shrinkage creep mechanism sand aggregate C55 concrete suitable for ultra-high pumping according to claim 1, characterized in that the water reducer is a set-retarding polycarboxylic acid high performance water reducer.
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Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH1192200A (en) * | 1997-09-18 | 1999-04-06 | Hazama Gumi Ltd | Low-shrinking concrete composition |
| CN104628343A (en) * | 2015-02-13 | 2015-05-20 | 福州大学 | Low-compression creep and high-performance recycled concrete |
| CN108147746A (en) * | 2017-12-29 | 2018-06-12 | 中建西部建设贵州有限公司 | A kind of Machine-made Sand C120 super high strength concretes for being easy to super high-rise pumping |
| CN109369097A (en) * | 2018-11-08 | 2019-02-22 | 中国核工业华兴建设有限公司 | A kind of low cracking resistance mass concrete of high performance of creeping of lower shrinkage |
| CN111302733A (en) * | 2020-03-13 | 2020-06-19 | 中铁大桥科学研究院有限公司 | Low-shrinkage creep wet joint ultra-high-strength concrete material and preparation method thereof |
| CN111393105A (en) * | 2020-03-25 | 2020-07-10 | 中建西部建设西南有限公司 | Full-machine-made sand high-strength super-high-rise pumping concrete and production method and application thereof |
| CA3115734A1 (en) * | 2019-01-08 | 2020-07-16 | Sika Technology Ag | Cementitious compositions with accelerated curing at low temperatures |
| CN111798931A (en) * | 2020-06-17 | 2020-10-20 | 中国铁道科学研究院集团有限公司铁道建筑研究所 | Machine-made gravel aggregate prestressed concrete mix proportion design method based on deformation control |
| CN112979248A (en) * | 2021-03-30 | 2021-06-18 | 佛山市交通科技有限公司 | Sandstone crushed stone C60 low-creep concrete for bridge engineering |
| CN115298148A (en) * | 2020-03-17 | 2022-11-04 | 陶氏东丽株式会社 | Cement composition and cured product thereof |
-
2022
- 2022-11-14 CN CN202211419293.8A patent/CN115716731B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH1192200A (en) * | 1997-09-18 | 1999-04-06 | Hazama Gumi Ltd | Low-shrinking concrete composition |
| CN104628343A (en) * | 2015-02-13 | 2015-05-20 | 福州大学 | Low-compression creep and high-performance recycled concrete |
| CN108147746A (en) * | 2017-12-29 | 2018-06-12 | 中建西部建设贵州有限公司 | A kind of Machine-made Sand C120 super high strength concretes for being easy to super high-rise pumping |
| CN109369097A (en) * | 2018-11-08 | 2019-02-22 | 中国核工业华兴建设有限公司 | A kind of low cracking resistance mass concrete of high performance of creeping of lower shrinkage |
| CA3115734A1 (en) * | 2019-01-08 | 2020-07-16 | Sika Technology Ag | Cementitious compositions with accelerated curing at low temperatures |
| CN111302733A (en) * | 2020-03-13 | 2020-06-19 | 中铁大桥科学研究院有限公司 | Low-shrinkage creep wet joint ultra-high-strength concrete material and preparation method thereof |
| CN115298148A (en) * | 2020-03-17 | 2022-11-04 | 陶氏东丽株式会社 | Cement composition and cured product thereof |
| CN111393105A (en) * | 2020-03-25 | 2020-07-10 | 中建西部建设西南有限公司 | Full-machine-made sand high-strength super-high-rise pumping concrete and production method and application thereof |
| CN111798931A (en) * | 2020-06-17 | 2020-10-20 | 中国铁道科学研究院集团有限公司铁道建筑研究所 | Machine-made gravel aggregate prestressed concrete mix proportion design method based on deformation control |
| CN112979248A (en) * | 2021-03-30 | 2021-06-18 | 佛山市交通科技有限公司 | Sandstone crushed stone C60 low-creep concrete for bridge engineering |
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