CN108164213B - Filling layer self-compacting concrete for anti-freezing and dynamic load coupling effect in severe cold area - Google Patents
Filling layer self-compacting concrete for anti-freezing and dynamic load coupling effect in severe cold area Download PDFInfo
- Publication number
- CN108164213B CN108164213B CN201711376516.6A CN201711376516A CN108164213B CN 108164213 B CN108164213 B CN 108164213B CN 201711376516 A CN201711376516 A CN 201711376516A CN 108164213 B CN108164213 B CN 108164213B
- Authority
- CN
- China
- Prior art keywords
- self
- compacting concrete
- concrete
- filling layer
- freezing
- 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.)
- Active
Links
Images
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
- C04B28/02—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 hydraulic cements other than calcium sulfates
- C04B28/04—Portland cements
-
- 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
- C04B2201/50—Mortars, concrete or artificial stone characterised by specific physical values for the mechanical strength
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Ceramic Engineering (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Inorganic Chemistry (AREA)
- Materials Engineering (AREA)
- Structural Engineering (AREA)
- Organic Chemistry (AREA)
- Curing Cements, Concrete, And Artificial Stone (AREA)
Abstract
The invention discloses filling layer self-compacting concrete for resisting freezing and dynamic load coupling action in severe cold areas. The filling layer self-compacting concrete is composed of ordinary portland cement, a composite mineral admixture, a deformation regulating component, a workability improving component, a durability guaranteeing component, water and a sandstone aggregate component, and the strength grade of 56d is C40. After the filling layer self-compacting concrete is subjected to freeze-thaw cycle for 300 times, the loss rate of the compressive strength is not more than 25%, the loss rate of the dynamic elastic modulus is not more than 40%, and the loss rate of the mass is not more than 2.3%; after the filling layer self-compacting concrete is subjected to freezing-bending-pulling load coupling action for 10 ten thousand times, the breaking strength loss rate of the filling layer self-compacting concrete is less than or equal to 10 percent. The self-compacting concrete has good capability of resisting freeze-thaw cycle and freezing-bending-pulling fatigue load coupling action when being used in a severe cold area under the action of freezing resistance and dynamic load, can effectively reduce the damage of freezing damage and load coupling action in the severe cold and freezing areas to concrete structures such as a high-speed railway filling layer and the like, improves the service life of a ballastless track structure, and has obvious technical and economic effects.
Description
Technical Field
The invention belongs to the technical field of civil engineering materials, and particularly relates to self-compacting concrete for a high-speed railway ballastless track filling layer under the conditions of freezing resistance and dynamic load action in severe cold areas.
Background
The development of the Chinese high-speed railway is rapid in nearly ten years, and as far as 2016, the total mileage of the high-speed railway reaches 2.2 kilometers, which accounts for 65% of the total mileage of the world, and the CRTS III plate type ballastless track structure with independent intellectual property rights has been gradually developed into the main track structure type of the Chinese high-speed railway, one of the remarkable characteristics is that self-compacting concrete is adopted as a filling layer material, the functions of supporting adjustment and limiting control are achieved, and the self-compacting concrete is of great importance to the smoothness and safety of the operation of the high-speed railway train [1 ]. The rapid development of the high-speed railway technology in China is wide, and the technology gradually extends to seasonal freezing and salt freezing areas such as northeast and northwest of China. In these areas, the average temperature can reach-20 ℃ in winter and last for months [2], and meanwhile, the high-speed railway of China has gradually gone out of China, especially Moka high-speed railway has been built in Russia, and the temperature in these areas is extremely low. Many critical concrete components of high speed railway tracks, such as self-compacting concrete filling layers, are subject to dynamic loading of trains and freezing in negative temperature environments, and such harsh environmental conditions will affect the durability of components of high speed railways, including self-compacting concrete filling layers. Therefore, it is necessary to develop self-compacting concrete with filling layer capable of resisting the coupling effect of negative temperature freezing and dynamic load of train.
At present, although a great deal of research is carried out on the frost resistance of concrete by a plurality of scholars at home and abroad, the freezing and thawing cycle effect has serious influence on the durability of the concrete; under freezing conditions, as water in concrete freezes to fill pores, the static mechanical property of the concrete material can be improved to a certain extent [3-6], but under the action of dynamic load and freeze-thaw cycle, the mechanical property of the concrete can be obviously degraded [7-12], and the degradation speed is higher than that under the action of single freeze-thaw cycle. Some researchers also try to improve the performance of the concrete against the damage of the freeze-thaw cycle by adopting methods of adding fibers, air entraining agents and the like [13-14], but the effect is still limited; particularly, the research on the durability of concrete under the coupling action of long-time freezing and dynamic load is not reported basically, and from the current practice in China, the concrete has obvious surface layer peeling damage in a short time under the freezing-dynamic load action (as shown in figure 1), and how to improve the durability of the concrete under the action of negative temperature freezing and dynamic load of trains in severe cold areas becomes a great challenge for the construction of high-speed railways in China.
In view of the above, the invention aims to research and develop the self-compacting concrete for the filling layer with excellent freezing and dynamic load resisting effects in the severe cold area aiming at the structural characteristics of the CRTSIII slab ballastless track of the high-speed railway and the service environmental conditions in the severe cold area on the basis of related researches.
Primary references
[1]Yuan Q,Long G,Liu Z,et al.Sealed-space-filling SCC:A special SCCapplied in high-speed rail of China[J].Construction&Building Materials,2016,124:167-176.
[2]Zhang X,Wang L,Zhang J.Mechanical behavior and chloridepenetration of high strength concrete under freeze-thaw attack[J].ColdRegions Science&Technology,2017.
[3] The research and application of the concrete in the ultralow temperature environment is summarized in (J) concrete, 2012(12) and 27-29.
[4] Jiangzhengwu, Lixiong, Zhang nan, high strength mortar strength development at ultra-low temperature [ J ] silicate academic, 2011,39(4):703-707.
[5]Montejo L A,Asce S M,Sloan J E,et al.Cyclic Response of ReinforcedConcrete Members at Low Temperatures[J].Journal of Cold Regions Engineering,2008,22(3):79-102.
[6]Xie J,Li X,Wu H.Experimental study on the axial-compressionperformance of concrete at cryogenic temperatures[J].Construction&BuildingMaterials,2014,72(72):380-388.
[7] Effect of Shinshi, freeze-thaw cycles on mechanical Properties of concrete [ J ] Prov. civil engineering, 1997(4):35-42.
[8] Zhang Shi Ping, Deng Ming, Tang Ming, research progress of concrete freeze-thaw cycle destruction [ J ] Proc of materials science and engineering, 2008(6): 990-.
[9]Li W,Sun W,Jiang J.Damage of concrete experiencing flexuralfatigue load and closed freeze/thaw cycles simultaneously[J].Construction&Building Materials,2011,25(5):2604-2610.
[10]Qiao Y,Sun W,Jiang J.Damage process of concrete subjected tocoupling fatigue load and freeze/thaw cycles[J].Construction&BuildingMaterials,2015,93:806-811.
[11] The research on concrete damage under the action of freeze-thaw cycle and fatigue load [ J ]. Proc. Changjiang academy of sciences, 2017.
[12]Gong F,Ueda T,Wang Y,et al.Mesoscale simulation of fatiguebehavior of concrete materials damaged by freeze-thaw cycles[J].Construction&Building Materials,2017,144:702-716.
[13]Jang J G,Kim H K,Kim T S,et al.Improved flexural fatigueresistance of PVA fiber-reinforced concrete subjected to freezing and thawingcycles[J].Construction&Building Materials,2014,59(59):129-135.
[14] The relation between the deterioration of the freezing and thawing durability of the concrete and the change of the pore structure [ J ]. Wuhan Ringji university school newspaper, 2002,24(12):14-17.
Disclosure of Invention
The invention aims to solve the technical problem of providing the self-compacting concrete for the filling layer, which has excellent freezing resistance and dynamic load coupling effect and meets the requirement of safe and stable operation of a high-speed railway train in a severe cold freezing area.
The invention relates to a filling layer self-compacting concrete for resisting freezing and dynamic load coupling action in severe cold areas,
the strength grade of the filling layer self-compacting concrete 56d is C40; and the 56d flexural strength is more than or equal to 6.0 MPa;
after the filling layer self-compacting concrete is subjected to freeze-thaw cycling for 300 times, the loss rate of the compressive strength is less than or equal to 25 percent, and preferably less than or equal to 22 percent; the loss rate of the dynamic elastic modulus is less than or equal to 30 percent, preferably less than or equal to 15 percent, and the loss rate of the mass is less than or equal to 3 percent, preferably less than or equal to 2.3 percent; when the freezing and thawing cycle is carried out for 300 times, the freezing temperature is-20 ℃;
after the self-compacting concrete of the filling layer is subjected to freezing fatigue test for 10 ten thousand times, the breaking strength loss rate of the self-compacting concrete of the filling layer is less than or equal to 10 percent.
The invention is used for resisting freezing and movement in severe cold areasThe filling layer self-compacting concrete with the load coupling effect has the advantages that the strength grade of 56 d-age-stage filling layer self-compacting concrete is C40, the expansion degree of a mixture is 600-660 mm, and T500The time is 4-8 s, the height difference of the J ring is less than 20mm, and the gas content is 5-9%.
As a preferred scheme, the filling layer self-compacting concrete for resisting freezing and dynamic load coupling action in severe cold areas is prepared from the following raw materials in each cubic concrete:
340 Kg of cement, preferably 350 Kg;
110-130Kg of composite mineral admixture, preferably 120 Kg;
42-46Kg, preferably 45Kg of deformation regulating component;
5-7Kg of workability improving component, preferably 6 Kg;
4-6Kg of durability ensuring component, preferably 5 Kg;
170 Kg of water, preferably 175 Kg;
830-870Kg of river sand, preferably 850 Kg;
800-830Kg of limestone; preferably 810 kg;
the composite mineral admixture is prepared by compounding I-grade low-calcium fly ash, S95 slag powder and metakaolin;
the deformation regulating component consists of a type II expanding agent and a polyoxyethylene alkyl ether shrinkage reducing agent;
the workability improving component consists of a carboxylic acid high-efficiency water reducing agent, carboxymethyl cellulose and calcium montmorillonite;
the durability guaranteeing component is formed by combining lignin, rubber particles, an air entraining agent and nano siliceous powder.
The filling layer self-compacting concrete adopting the technical scheme is based on 3 requirements of workability, deformability, durability and the like of a filling layer self-compacting concrete mixture, an integral theory method is applied, the angles of optimized compatibility of raw materials, improvement of resistance of an internal micro-structure and the like are included, test results are combined, research and development characteristic components are optimized, and an aggregate phase, a slurry phase and an aggregate-slurry interface transition region phase of the concrete are designed by means of a self-compacting forming process technology, so that the guarantee of the performance of the anti-freezing and dynamic load coupling action of the concrete is realized, and the filling layer self-compacting concrete is suitable for the anti-freezing and dynamic load action of the filling layer self-compacting concrete in severe cold areas.
As a preferred scheme, the filling layer self-compacting concrete for resisting the coupling effect of freezing and dynamic load in severe cold areas comprises a slurry system and an aggregate system, wherein the volume ratio of slurry to aggregate in the single-component concrete is 0.37: 0.40 is preferably 0.38: 0.62, the slurry consists of cement, a composite mineral admixture, a deformation regulating component, a workability improving component, a durability guaranteeing component and water; the aggregate system consists of river sand and limestone.
As a preferable scheme, the invention relates to a filling layer self-compacting concrete for resisting the coupling effect of freezing and dynamic load in severe cold areas,
the cement is P.O 42.5.5 ordinary portland cement;
the river sand is II-zone graded river sand with fineness modulus of 2.5-3.0;
the particle size of the limestone is 5-16 mm.
Preferably, the composite mineral admixture comprises I-grade low-calcium fly ash, S95 slag powder and 1000-sand 1200-mesh metakaolin according to the mass ratio of 40:40: 20.
As a preferred scheme, the filling layer self-compacting concrete for resisting freezing and dynamic load coupling action in severe cold areas comprises a deformation regulating component and a polyoxyethylene alkyl ether shrinkage reducing agent according to a mass ratio of 98: 2.
As a preferred scheme, the filling layer self-compacting concrete for resisting the coupling effect of freezing and dynamic load in severe cold areas comprises a workability improving component, a powder type carboxylic acid high-efficiency water reducing agent with the water reducing rate of 35%, carboxymethyl cellulose and calcium-based montmorillonite in a mass ratio of 50:10: 40.
As a preferred scheme, the filling layer self-compacting concrete for resisting freezing and dynamic load coupling action in severe cold regions comprises lignin, 100-mesh and 120-mesh waste rubber particles, an air entraining agent and nano-siliceous powder according to a mass ratio of 10:60:1: 30.
The application method of the invention comprises the following steps: weighing the raw materials according to the proportion, putting dry materials such as river sand, limestone macadam, cement, composite mineral admixture, deformation regulation component, workability improvement component, durability guarantee component and the like into a forced mixer, pre-mixing for 30 seconds, then adding liquid components such as water and the like, continuously stirring for about 150 seconds, taking the mixture out of the mixer, checking the self-compactness of the mixture (including slump expansion, T500 time, J-ring height difference and the like), confirming that the mixture meets corresponding performances, then forming corresponding performance test pieces and carrying out corresponding application practices.
The invention is based on the deep knowledge of the damage and deterioration mechanism of the concrete material under the conditions of freezing and dynamic load, the analysis of the mutual relationship principle of the composition, the structure and the performance of the concrete material, the combination of the action and the mutual relationship of various organic and inorganic components in a special system of self-compacting concrete, by adjusting the mixing amount of the admixture and the additive and adopting the self-compacting molding process instead of the traditional mechanical vibration compacting process, so that all the components are uniformly distributed in the system to form a framework supporting system consisting of limestone and sand, a filling system of hardened slurry and a stress buffering system of micro-nano closed pores, the composition and the micro-pore structure of the self-compacting concrete are optimized, thereby obtaining the filling layer self-compacting concrete with excellent construction workability, higher mechanical strength, excellent anti-freezing and dynamic load Europe effect, and forming the invention. Therefore, the scientific basis of the invention is sufficient.
In the process of researching and developing the filling layer self-compacting concrete for resisting freezing and dynamic load in severe cold areas, a large amount of experimental research work is carried out, and the filling layer self-compacting concrete with target performance is finally obtained by adjusting different key components. The concrete filling layer self-compacting concrete for resisting freezing and dynamic load in severe cold regions has the advantages that the concrete filling layer self-compacting concrete for resisting freezing and dynamic load in severe cold regions has the best raw material composition, therefore, the invention has sufficient experimental research foundation and basis, good effectiveness and feasibility, effectively ensures the obvious improvement of the anti-freezing and dynamic load coupling performance of the self-compacting concrete of the filling layer.
In order to solve the technical problems, the self-compacting concrete for the filling layer provided by the invention is characterized in that: the cement mortar is composed of P.O 42.5.5 ordinary portland cement, a composite mineral admixture, a deformation regulation component, a workability improving component, a durability guaranteeing component, mixing water, II-zone graded river sand with fineness modulus of 2.5-3.0, limestone gravel with particle size of 5-16 mm and the like. The material dosage in each cubic concrete is 350kg of cement, 120kg of composite mineral admixture, 45kg of deformation regulating component, 6kg of workability improving component, 5kg of durability guaranteeing component, 175kg of mixing water, 850kg of river sand and 810kg of limestone macadam. The self-compacting concrete strength grade of the filling layer is C40(56d age), the expansion degree of the mixture is (630 +/-30) mm, and T500The time is (6 +/-2) s, the height difference of the J-ring is less than 20mm, and the gas content is (7 +/-2)%.
The invention has the advantages and positive effects that:
1. the filling layer self-compacting concrete provided by the invention has excellent performance of resisting freeze-thaw cycle, freezing and dynamic load while meeting the requirements of working performance and basic mechanical performance of a mixture, ensures the service safety of the high-speed railway plate-type ballastless track filling layer in severe cold and seasonal freezing areas, and prolongs the service life of the self-compacting filling layer.
2. The self-compacting concrete of the filling layer provided by the invention adopts a self-compacting forming process, has the characteristics of simple construction process, convenience in operation, high reliability, greenness, economy and good comprehensive benefit.
In conclusion, the self-compacting concrete can obviously improve the performance of the anti-freezing and dynamic load coupling effect of the concrete, can well meet the performance requirements of a high-speed railway filling layer in service in severe cold and frozen areas, and has good technical and economic effects.
Drawings
FIG. 1 is a photograph of concrete deterioration under ice-train dynamic load for 4 years.
FIG. 2 is a photograph of (a) slump expansion and (b) a J-ring test of a self-compacting concrete mix in a pack prepared in accordance with the examples.
FIG. 3 is a photograph and a schematic illustration of fatigue loading of concrete prepared according to an embodiment under freezing conditions.
FIG. 4 is a schematic view of the loading regime for the concrete frost fatigue prepared in accordance with the preferred embodiment.
FIG. 5 is a graph showing the bending stress-strain curves of the NC concrete prepared in the comparative example under normal temperature (20 ℃), freezing (-20 ℃) and freezing fatigue conditions (note: the strain is positive in tension and negative in compression).
FIG. 6 is a plot of the flexural stress-strain resistance of the comparative concrete SCC1 under normal temperature (20 ℃), freezing (-20 ℃) and freezing fatigue conditions (note: the strain is positive in tension and negative in compression).
FIG. 7 is a plot of the flexural stress-strain resistance of the comparative concrete SCC2 under normal temperature (20 ℃), freezing (-20 ℃) and freezing fatigue conditions (note: the strain is positive in tension and negative in compression).
FIG. 8 is a plot of the flexural stress-strain resistance of SCC3 concrete prepared in accordance with the present invention under normal temperature (20 ℃), freezing (-20 ℃) and freezing fatigue conditions (note: the strain is positive in tension and negative in compression).
FIG. 9 is a stress-strain curve of NC concrete prepared in comparative example after freeze-thaw cycling.
FIG. 10 is a stress-strain curve of SCC1 concrete prepared in the comparative example after freeze-thaw cycling.
FIG. 11 is a stress-strain curve of SCC2 concrete prepared in the comparative example after freeze-thaw cycling.
FIG. 12 is a stress-strain curve of SCC3 concrete prepared in accordance with an embodiment of the present invention after freeze-thaw cycling.
Fig. 13 is a graph showing the dynamic elastic modulus loss rate of each grade of concrete obtained in the embodiment of the present invention after freeze-thaw cycles.
Fig. 14 is a graph showing the mass loss rate of each grade of concrete obtained in the embodiment of the present invention after freeze-thaw cycles.
Detailed Description
The following examples are intended to illustrate the invention without further limiting it.
In the examples of the invention and the comparative examples:
the composite mineral admixture is composed of I-grade low-calcium fly ash, S95 slag powder and 1000-one 1200-mesh metakaolin according to the mass ratio of 40:40: 20;
the deformation regulating component consists of a type II expanding agent and a polyoxyethylene alkyl ether shrinkage reducing agent according to the mass ratio of 98: 2;
the workability improving component is composed of a carboxylic acid high-efficiency water reducing agent with the water reducing rate of 35%, carboxymethyl cellulose and calcium-based montmorillonite according to the proportion of 50:10: 40;
the durability guaranteeing component consists of lignin, 100-plus-120-mesh waste rubber particles, an air entraining agent and nano silicon powder according to the mass ratio of 10:60:1: 30;
the filling layer self-compacting concrete consists of a slurry system and an aggregate system, and the volume ratio of slurry to aggregate in the single-side concrete is 0.38: 0.62, the slurry body is composed of cement, composite mineral admixture, deformation regulating component, workability improving component, durability guaranteeing component and mixing water; the aggregate system consists of high-quality river sand in a II area and 5-16 mm continuous graded high-quality limestone macadam.
The raw materials used in the examples and the comparative examples are prepared according to the components set in the table 1; NC and SCC1 are adopted; SCC2, SCC3, wherein NC is plain concrete, SCC1 is No. 1 conventional self-compacting concrete, SCC2 is No. 2 conventional self-compacting concrete doped with a swelling agent, SCC3 is the pack layer self-compacting concrete developed in the examples of the present invention, and SCC4 and SCC5 are two sets of comparative examples of the pack layer concrete.
TABLE 1 examples of the mix ratios of different concretes (unit: kg/m)3)
As shown in table 1, in this embodiment, component parameters of each concrete sample are selected according to a design strength grade of C40, NC common concrete is normal pump concrete, a design slump is 130 ± 20mm, SCC1 is traditional self-compacting concrete which does not consider requirements of expansion deformation and freezing resistance and achieves a filling performance of class I, SCC2 is self-compacting concrete which considers expansion deformation but does not consider the freezing resistance and achieves a filling performance of class I, three groups of SCC3 to SCC5 are designed based on the requirements of filling performance design and considers requirements of vertical expansion deformation and freezing resistance, wherein SCC3 is an optimal proportion, the material consumption in each cubic concrete is 350kg of cement, 120kg of composite mineral admixture, 45kg of deformation regulating component, 6kg of workability improving component, 5kg of durability ensuring component, (170 + 180) kg of mixing water, 860kg of river sand and 810kg of limestone, SCC4 and SCC5 are comparative examples, taking into account the effect on performance of the rubber, aggregate amount, and changes in the key component materials. The self-compacting concrete strength grade of the filling layer is C40(56d age), the expansion degree of the mixture is (630 +/-30) mm, and T500The time is (6 +/-2) s, the height difference of the J-ring is less than 20mm, and the gas content is (7 +/-2)%.
The preparation method comprises the following steps: each numbered sample was prepared for raw material and other preparation work in an amount of 30L.
Putting dry materials such as river sand, limestone macadam, cement, a composite mineral admixture, a deformation regulation component, a workability improvement component and a durability guarantee component into a forced mixer, pre-mixing for 30 seconds, adding liquid components such as water and a water reducing agent, continuously stirring for about 150 seconds, taking the uniformly stirred mixture out of the mixer, testing the working performance (including self-compactness) of the mixture, and forming a test piece with a corresponding size after the working performance requirement is met. And (3) standing and maintaining the molded test piece for 24 hours under the standard environmental condition, then removing the mold, moving the test piece into a standard maintenance room, maintaining the test piece to 28d or 56d under the indoor standard environment, and testing indexes such as the compressive strength, the flexural strength and the like of the concrete at normal temperature (20 ℃). The test results are shown in table 2. And (3) freezing the corresponding test piece for 3d by water saturation, taking out the test piece to test the mechanical properties of the test piece after freezing-thawing cycle and freezing fatigue under freezing and dynamic loads, wherein the test results are shown in Table 3. Photographs of the self-compacting concrete mixtures of the pack are shown in FIG. 2, and photographs ((a), (b)) and a schematic (c) of fatigue loading of each concrete under freezing conditions are shown in FIG. 3. The loading system of the concrete freezing fatigue is shown in figure 3, the bending stress strain curves of the concrete under the conditions of normal temperature (20 ℃), freezing (-20 ℃) and freezing fatigue are shown in figures 5-8, the dynamic elastic modulus loss rate of the concrete after different freezing and thawing cycle times is shown in figures 9-12, and the mass loss rate of the concrete after different freezing and thawing cycle times is shown in figure 13.
Table 2 blend Properties and Standard cured 56d Strength results for each of the above concrete samples
As can be seen from the results in Table 2, the prepared NC plain concrete meets the requirements of design slump and design compressive strength grade, but the vertical expansion rate obtained by the test is negative due to no doped expansion component, namely, the concrete is shown to shrink. SCC1 also meets the mix workability and compressive strength requirements required by the design, but its vertical expansion is also negative, with air contents of only 4.5%. SCC2 satisfies the mix performance and the compressive strength requirement of design, and vertical expansion rate is 0.9%, and the gas content reaches 5.6%. The mixture performance and the compressive strength of the SCC3 filling layer sample both meet the design requirements, especially the flexural strength reaches 6.5MPa, which is higher than other groups, and the vertical expansion rate is 0.7%, and the gas content is 7.2%. And the SCC4 group has lower vertical expansion rate and lower breaking strength due to lower mixing amount of the expansion components, higher sand content and the like, and the SCC5 group has smaller workability improving components, larger water consumption and more expansion components, larger expansion degree and larger vertical expansion rate, and is difficult to meet the requirement of the pouring construction quality of the filling layer.
Table 3 Performance results after freeze-thaw cycling and freeze fatigue of each of the above concretes
The performance results obtained from the tests of table 3 show that: the NC, SCC1 and SCC2 groups have the compressive strength loss rate of more than 25 percent after being subjected to 300 times of freeze-thaw cycles, have large mass loss rate and cannot meet the performance of resisting 300 times of freeze-thaw cycles, the compressive strength loss rate and the dynamic modulus loss rate of two groups of samples of SCC4 and SCC5 after being subjected to 300 times of freeze-thaw cycles are also large, particularly the breaking strength loss rate after being subjected to 10 ten thousand times of freeze-load coupling is also more than 10 percent, the self-compacting concrete adopting the mix proportion of SCC3 has the strength loss rate, the dynamic modulus loss rate and the mass loss rate after being subjected to 10 ten thousand times of freeze fatigue and is obviously better than that of common concrete and other self-compacting concrete, and simultaneously, the compressive strength and the breaking strength of the self-compacting concrete of the filling layer can reach 40MPa and 6.5MPa from the measured 56-day compressive strength, the strength requirement of the self-compacting concrete of the high-speed railway ballastless track filling layer is met, and meanwhile, the performance requirement of the high-speed railway filling layer in service in severe cold and frozen areas can be well met.
Claims (9)
1. A self-compacting concrete of a filling layer for resisting the coupling action of freezing and dynamic load in severe cold areas is characterized in that;
the strength grade of the filling layer self-compacting concrete 56d is C40; and the 56d flexural strength is more than or equal to 6.0 MPa;
after the filling layer self-compacting concrete is subjected to freeze thawing cycle for 300 times, the loss rate of the compressive strength is less than or equal to 25%, the loss rate of the dynamic elastic modulus is less than or equal to 30%, and the loss rate of the mass is less than or equal to 3.0%; when the freezing and thawing cycle is carried out for 300 times, the freezing temperature is-20 ℃, and the time of the freezing and thawing cycle period is 3 hours;
after the self-compacting concrete of the filling layer is subjected to a freezing fatigue test for 10 ten thousand times, the breaking strength loss rate of the self-compacting concrete of the filling layer is less than or equal to 10 percent;
the raw materials used by each cubic concrete are as follows:
340 Kg of ordinary portland cement;
110-130Kg of composite mineral admixture;
42-46Kg of deformation regulating component;
5-7Kg of workability improving component;
4-6Kg of durability ensuring component;
170 Kg of water;
830-870Kg of river sand;
800-830Kg of limestone;
the composite mineral admixture is prepared by compounding I-grade low-calcium fly ash, S95 slag powder and metakaolin;
the deformation regulating component consists of a type II expanding agent and a polyoxyethylene alkyl ether shrinkage reducing agent;
the workability improving component consists of a carboxylic acid high-efficiency water reducing agent, carboxymethyl cellulose and calcium montmorillonite;
the durability guaranteeing component is formed by combining lignin, rubber particles, an air entraining agent and nano siliceous powder.
2. The self-compacting concrete for the pack layer with freezing resistance and dynamic load coupling effect in the severe cold area according to claim 1, wherein the self-compacting concrete comprises a concrete core and a concrete core; the strength grade of the filling layer self-compacting concrete 56d age is C40, the expansion degree of the mixture is 600-660 mm, and T500The time is 4-8 s, the height difference of the J ring is less than 20mm, and the gas content is 5-9%.
3. The self-compacting concrete for the pack layer with freezing resistance and dynamic load coupling effect in the severe cold area according to claim 1, wherein the self-compacting concrete comprises a concrete core and a concrete core;
the raw materials used by each cubic concrete are as follows:
350kg of ordinary portland cement;
120kg of composite mineral admixture;
45kg of deformation regulating component;
the workability improving component is 6 kg;
5kg of durability ensuring component;
175kg of water;
850kg of river sand;
810kg of limestone;
the composite mineral admixture is prepared by compounding I-grade low-calcium fly ash, S95 slag powder and metakaolin;
the deformation regulating component consists of a type II expanding agent and a polyoxyethylene alkyl ether shrinkage reducing agent;
the workability improving component consists of a carboxylic acid high-efficiency water reducing agent, carboxymethyl cellulose and calcium montmorillonite;
the durability guaranteeing component is formed by combining lignin, rubber particles, an air entraining agent and nano siliceous powder.
4. The self-compacting concrete for the pack layer with freezing resistance and dynamic load coupling effect in the severe cold area according to claim 1, wherein the self-compacting concrete comprises a concrete core and a concrete core;
the filling layer self-compacting concrete consists of a slurry system and an aggregate system, wherein the volume ratio of slurry to aggregate in the single-component concrete is 0.37-0.40: 0.63-0.60, wherein the slurry body is composed of cement, a composite mineral admixture, a deformation regulating component, a workability improving component, a durability guaranteeing component and water; the aggregate system consists of river sand and limestone.
5. The self-compacting concrete for the filling layer with the coupling effect of freezing resistance and dynamic load in severe cold areas according to any one of claims 1 to 4, wherein the self-compacting concrete is a self-compacting concrete for the filling layer;
the cement is PO 42.5 ordinary portland cement;
the river sand is the river sand of II-zone gradation with fineness modulus of 2.5-3.0;
the particle size of the limestone is 5-16 mm.
6. The self-compacting concrete for the pack layer with anti-freezing and dynamic load coupling effect in the severe cold area according to any one of claims 1-4, wherein: the composite mineral admixture is composed of I-grade low-calcium fly ash, S95 slag powder and 1000-sand 1200-mesh metakaolin according to the mass ratio of 40:40: 20.
7. The self-compacting concrete for the filling layer with the coupling effect of freezing resistance and dynamic load in severe cold areas according to any one of claims 1 to 4, wherein the self-compacting concrete is a self-compacting concrete for the filling layer; the deformation regulating component consists of a II type expanding agent and a polyoxyethylene alkyl ether shrinkage reducing agent according to the mass ratio of 98: 2.
8. The self-compacting concrete for the filling layer with the coupling effect of freezing resistance and dynamic load in severe cold areas according to any one of claims 1 to 4, wherein the self-compacting concrete is a self-compacting concrete for the filling layer; the workability improving component comprises a powdery carboxylic acid high-efficiency water reducing agent with the water reducing rate of 35%, carboxymethyl cellulose and calcium-based montmorillonite in a mass ratio of 50:10: 40.
9. The self-compacting concrete for the filling layer with the coupling effect of freezing resistance and dynamic load in severe cold areas according to any one of claims 1 to 4, wherein the self-compacting concrete is a self-compacting concrete for the filling layer; the durability guaranteeing component comprises lignin, 100-sand 120-mesh waste rubber particles, an air entraining agent and nano silicon powder according to the mass ratio of 10:60:1: 30.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711376516.6A CN108164213B (en) | 2017-12-19 | 2017-12-19 | Filling layer self-compacting concrete for anti-freezing and dynamic load coupling effect in severe cold area |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711376516.6A CN108164213B (en) | 2017-12-19 | 2017-12-19 | Filling layer self-compacting concrete for anti-freezing and dynamic load coupling effect in severe cold area |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108164213A CN108164213A (en) | 2018-06-15 |
| CN108164213B true CN108164213B (en) | 2020-11-03 |
Family
ID=62522566
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201711376516.6A Active CN108164213B (en) | 2017-12-19 | 2017-12-19 | Filling layer self-compacting concrete for anti-freezing and dynamic load coupling effect in severe cold area |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108164213B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108896746B (en) * | 2018-07-06 | 2021-03-02 | 中南大学 | Quantitative detection device and method for defects of self-compacting concrete filling layer of ballastless track |
| CN109293301B (en) * | 2018-09-25 | 2021-06-01 | 李鹏宇 | Anti-freezing concrete |
| CN109704620B (en) * | 2019-02-15 | 2021-04-09 | 华电西藏能源有限公司大古水电分公司 | Concrete admixture suitable for cold and dry environment and preparation method and application thereof |
| CN115947577B (en) * | 2023-02-14 | 2023-11-14 | 南通市建设混凝土有限公司 | Self-compacting anti-freezing concrete and preparation process thereof |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102390967A (en) * | 2011-08-11 | 2012-03-28 | 中铁八局集团第四工程有限公司 | Self-compacting concrete for rapid transit railway III-type plate ballastless tracks and preparation method of self-compacting concrete |
| CN102503309B (en) * | 2011-11-07 | 2013-07-03 | 西南交通大学 | Self-compacting concrete mixture for plate-type ballastless track of railway |
| CN104030644B (en) * | 2014-06-09 | 2016-04-27 | 中国铁道科学研究院铁道建筑研究所 | A kind of polymer cement mortar for high-speed railway plate type ballastless track filling bed |
-
2017
- 2017-12-19 CN CN201711376516.6A patent/CN108164213B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102390967A (en) * | 2011-08-11 | 2012-03-28 | 中铁八局集团第四工程有限公司 | Self-compacting concrete for rapid transit railway III-type plate ballastless tracks and preparation method of self-compacting concrete |
| CN102503309B (en) * | 2011-11-07 | 2013-07-03 | 西南交通大学 | Self-compacting concrete mixture for plate-type ballastless track of railway |
| CN104030644B (en) * | 2014-06-09 | 2016-04-27 | 中国铁道科学研究院铁道建筑研究所 | A kind of polymer cement mortar for high-speed railway plate type ballastless track filling bed |
Non-Patent Citations (2)
| Title |
|---|
| Damage behaviors of self-compacting concrete and prediction model under coupling effect of salt freeze-thaw and flexural load;Jun Tian等;《Construction and Building Materials》;20160615;全文 * |
| 疲劳荷载和冻融循环耦合作用下路面混凝土微裂缝扩展行为;郭寅川;《交通运输工程学报》;20161015;全文 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN108164213A (en) | 2018-06-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108164213B (en) | Filling layer self-compacting concrete for anti-freezing and dynamic load coupling effect in severe cold area | |
| Murali et al. | Low-velocity impact response of novel prepacked expanded clay aggregate fibrous concrete produced with carbon nano tube, glass fiber mesh and steel fiber | |
| CN110395955A (en) | A kind of impervious freeze thawing resistance self-compacting concrete and preparation method thereof | |
| Lu et al. | Experimental investigation on the mechanical properties and pore structure deterioration of fiber-reinforced concrete in different freeze-thaw media | |
| CN109928703A (en) | A kind of cracking resistance frost-resistant concrete for railway deck waterproof protective layer | |
| Xu et al. | Combined effect of isobutyltriethoxysilane and silica fume on the performance of natural hydraulic lime-based mortars | |
| Xia et al. | Damage characteristics of hybrid fiber reinforced concrete under the freeze-thaw cycles and compound-salt attack | |
| Kumar et al. | Influence of lightweight aggregates and supplementary cementitious materials on the properties of lightweight aggregate concretes | |
| Dolatabad et al. | Effects of perlite, leca, and scoria as lightweight aggregates on properties of fresh and hard self-compacting concretes | |
| Zhang et al. | Microscopic reinforcement mechanism of shotcrete performance regulated by nanomaterial admixtures | |
| Ma et al. | Effects of curing temperature on mechanical properties and pore size distribution of cement clay modified by metakaolin and basalt fiber | |
| Guler et al. | The coupling effect of silica fume and basalt fibers on workability and residual strength capacities of traditional concrete before and after freeze–thaw cycles | |
| JP6130767B2 (en) | Mortar or concrete composition with improved frost resistance using blast furnace slag fine aggregate, molded product formed by molding the same, and method for producing molded product | |
| Wen-yu et al. | Study on reactive powder concrete used in the sidewalk system of the Qinghai-Tibet railway bridge | |
| Cai et al. | Effect of low temperature on mechanical properties of concrete with different strength grade | |
| Tian et al. | Application of foamed concrete in road engineering | |
| Fan et al. | Experimental research on the freeze-thaw resistance of basalt fiber reinforced concrete | |
| Hussein | Production of Lightweight Concrete by Using Polystyrene (Cork) Waste | |
| Ramli et al. | Comparative study between flowable high strength mortar and flowing high strength concrete | |
| Liu et al. | Mechanical properties, permeability and freeze-thaw durability of low sand rate pervious concrete | |
| Pan et al. | Preparation and properties of ultra-high performance lightweight concrete | |
| Wu et al. | Investigation on thermal insulation and mechanical strength of lightweight aggregate concrete and porous mortar in cold regions | |
| Hu et al. | Freezing and thawing resistance of cement asphalt mortar | |
| Ramanjaneyulu et al. | Experimental investigations on lightweight self-compacting concrete produced with sintered fly ash aggregate | |
| Pei-Wei et al. | Effect of fly ash on deformation of roller-compacted concrete |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |