CN111764210B - Method for determining shrinkage joint space of low-reinforcement-ratio continuous reinforced concrete pavement - Google Patents
Method for determining shrinkage joint space of low-reinforcement-ratio continuous reinforced concrete pavement Download PDFInfo
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Abstract
The invention discloses a method for determining the distance between the contraction joints of a low-reinforcement-ratio continuous reinforced concrete pavement, which comprises the following steps: determining design parameters of the low-reinforcement-ratio continuous reinforced concrete pavement; calculating the plate thickness of the low-reinforcement-ratio continuous reinforced concrete pavement according to the determined design parameters; determining the traffic load grade of the low-reinforcement-ratio continuous reinforced concrete pavement, and preliminarily simulating the reinforcement ratio of the low-reinforcement-ratio continuous reinforced concrete pavement according to the traffic load grade; according to the preliminary reinforcement ratio, selecting reinforcement parameters in the low-reinforcement-ratio continuous reinforced concrete pavement, and then determining the actual reinforcement ratio of the low-reinforcement-ratio continuous reinforced concrete pavement according to the selected reinforcement parameters; and calculating the transverse contraction joint spacing of the low-reinforcement-ratio continuous reinforced concrete pavement according to the actual reinforcement ratio of the low-reinforcement-ratio continuous reinforced concrete pavement. The shrinkage joint spacing of the continuous reinforced concrete pavement with low reinforcement ratio can be rapidly and accurately determined.
Description
Technical Field
The invention relates to the technical field of road engineering, in particular to a method for determining the distance between contraction joints of a low-reinforcement-ratio continuous reinforced concrete pavement.
Background
The continuous reinforced concrete pavement is a cement concrete pavement which is characterized in that longitudinal continuous reinforcing steel bars and transverse reinforcing steel bars are arranged in a surface layer, and shrinkage joints are not transversely arranged. The continuous reinforced concrete pavement can be free of transverse contraction joints because the structure is internally provided with enough longitudinal steel bars, the longitudinal reinforcement ratio is usually as high as 0.6-1.0%, the shrinkage cracking of the concrete is limited through the bonding effect between the longitudinal steel bars and the concrete, and the transverse shrinkage cracks are dispersed into a plurality of micro cracks with certain intervals, so that the aim of not cutting the contraction joints is fulfilled. The reinforced concrete pavement is a cement concrete pavement with longitudinal and transverse reinforcing steel bars or reinforcing mesh arranged in a surface layer and provided with joints, the longitudinal reinforcing steel bars in the structure are usually discontinuous, the reinforcement ratio is much lower than that of a continuous reinforced concrete pavement, the longitudinal reinforcement ratio is usually 0.1-0.2%, and because of the constraint effect of the longitudinal discontinuous reinforcing steel bars, compared with a common concrete pavement, the longitudinal reinforcing steel bars are required to be provided with contraction joints at 4-6 m, the reinforced concrete pavement is provided with the transverse contraction joints at 6-15 m in the length direction, and the contraction joint distance is increased.
The continuous reinforced concrete pavement generally requires that the width of a crack gap at the embedding depth of a longitudinal steel bar is not more than 0.5mm, the average distance of transverse cracks is not more than 1.8m, the crack gap is too small, the impact damage is easy to cause, the wide cracks can be generated when the crack gap is too large, and the wide cracks can cause rainwater infiltration and steel bar corrosion. In reality, due to the diversity of materials, the variability of construction, the uncertainty of load and the experience of a design method, unreasonable crack forms such as short-distance wide cracks often appear on the continuous reinforced concrete pavement, and researches show that 90% of breaking diseases occur at crack dense positions of 30-60 cm, so that pre-cutting seams are performed after the continuous reinforced concrete pavement is finished for some projects, active control on the cracks is hoped to be performed, but the pre-cutting seam interval is difficult to determine, and no theoretical support exists. Although the transverse contraction joint space of the reinforced concrete pavement is increased, smooth round steel bar dowel bars of the front steel bar support are required to be arranged between the transverse contraction joints, the construction is complex, the period is long, and the joint cutting workload is still large. Based on the problems, the low-reinforcement-ratio continuous reinforced concrete pavement with the reinforcement ratio between the continuous reinforced concrete pavement and the reinforced concrete pavement, the longitudinal reinforcements which are continuous and replace dowel bars and the large-interval transverse contraction joints is designed, the problems of two pavement structures can be effectively solved, the using amount of the reinforcements can be reduced, the joint cutting is reduced, the construction is simple and convenient, the engineering investment is saved, and the contraction joint interval is determined to be a core technical problem.
Disclosure of Invention
The invention aims to solve the technical problem that the method for determining the contraction joint spacing of the low-reinforcement-ratio continuous reinforced concrete pavement can quickly and accurately determine the contraction joint spacing of the low-reinforcement-ratio continuous reinforced concrete pavement aiming at the defects in the prior art.
The technical scheme adopted by the invention for solving the technical problems is as follows:
a method for determining the distance between the contraction joints of a low-reinforcement-ratio continuous reinforced concrete pavement comprises the following steps:
1) determining design parameters of the low-reinforcement-ratio continuous reinforced concrete pavement;
2) calculating the plate thickness of the low-reinforcement-ratio continuous reinforced concrete pavement according to the determined design parameters;
3) determining the traffic load grade of the low-reinforcement-ratio continuous reinforced concrete pavement, and preliminarily simulating the reinforcement ratio of the low-reinforcement-ratio continuous reinforced concrete pavement according to the traffic load grade;
4) according to the pre-planned reinforcement ratio, selecting reinforcement parameters in the low-reinforcement-ratio continuous reinforced concrete pavement, wherein the reinforcement parameters comprise the type, the diameter and the spacing of reinforcements, and determining the actual reinforcement ratio of the low-reinforcement-ratio continuous reinforced concrete pavement according to the selected reinforcement parameters;
5) and calculating the transverse contraction joint spacing of the low-reinforcement-ratio continuous reinforced concrete pavement according to the actual reinforcement ratio of the low-reinforcement-ratio continuous reinforced concrete pavement.
According to the technical scheme, in the step 1), the design parameters comprise road grade, design reference period, safety grade, design axle load, heaviest axle load, accumulated axle load acting times, traffic load grade, comprehensive resilience modulus of the top surface of the roadbed, standard value of bending tensile strength of cement concrete, material parameters, maximum temperature gradient and plate width.
According to the technical scheme, in the step 3), the low-reinforcement-ratio continuous reinforced concrete pavement is suitable for roads above a medium traffic load level, the suitable reinforcement ratio range is 0.2-0.6%, wherein the reinforcement ratio at the medium traffic load level is preferably 0.2-0.3%, the reinforcement ratio at a heavy traffic load level is preferably 0.3-0.4%, the reinforcement ratio at an extra-heavy traffic load level is preferably 0.4-0.5%, and the reinforcement ratio at the extreme-heavy traffic load level is preferably 0.5-0.6%.
According to the technical scheme, in the step 4), the type of the steel bar is HRB400 hot-rolled ribbed steel bar, the diameter is 14 mm-20 mm, and the spacing is 150 mm-350 mm.
According to the technical scheme, in the step 5), the contraction joint interval L is
Rho is the reinforcement rate of the low reinforcement rate continuous reinforced concrete pavement; [ sigma ]s]-allowable stress of the steel reinforcement; k is a radical ofcConsidering a comprehensive coefficient influenced by factors such as theoretical and actual differences, construction variation level, material parameter variation level and the like; mu.s0The dynamic friction coefficient of the surface layer and the base layer of the low-reinforcement-ratio continuous reinforced concrete pavement; gamma-the gravity of the concrete.
According to the technical scheme, the allowable stress of the steel bar is
[σs]＝ksfsy；
Wherein k iss-the allowable stress reduction factor of the steel reinforcement; f. ofsy-the yield strength of the steel reinforcement.
According to the technical scheme, the allowable stress reduction coefficient k of the steel bars75 to 85 percent;
the dynamic friction coefficient of the surface layer and the base layer of the low-reinforcement-ratio continuous reinforced concrete pavement is 1.5-8.9;
the concrete is taken as the heavy load of 24kN/m3。
According to the technical scheme, the comprehensive coefficient
Wherein,
-theoretical and actual difference coefficients;
-construction variation level coefficient;
-coefficient of variation level of material parameter.
According to the technical scheme, the theoretical and actual difference coefficient
0.05 to 0.25;
coefficient of construction variation
The concrete pavement can be 0.18 when being horizontal, 0.26 when being horizontal, 0.36 when being horizontal, and the higher the road grade is, the lower the variation level is;
coefficient of variation level of material parameter
The concrete pavement can be 0.05 when being horizontal, 0.10 when being horizontal, 0.15 when being horizontal, and the higher the road grade is, the lower the variation level is.
According to the technical scheme, the low-reinforcement-ratio continuous reinforced concrete pavement comprises a subbase layer, a base layer, a buffer layer and a low-reinforcement-ratio continuous reinforced concrete surface layer which are sequentially paved from bottom to top; the low-reinforcement-ratio continuous reinforcement concrete surface layer is internally provided with single-layer continuous reinforcement or double-layer continuous reinforcement, and the concrete surface layer is provided with a transverse contraction joint at intervals of a certain distance L.
The invention has the following beneficial effects:
the method not only solves the problem that the existing specification does not have a mode for determining the distance between the contraction joints of the low-reinforcement-rate continuous reinforced concrete pavement, but also fills the blank of the existing specification on the design of the low-reinforcement-rate continuous reinforced concrete pavement; the calculation formula of the shrinkage joint spacing of the continuous reinforced concrete pavement with the low reinforcement ratio can be used for guiding design, can effectively solve the problems that unreasonable cracks often appear on the continuous reinforced concrete pavement and a dowel bar of the reinforced concrete pavement is complex in arrangement and has more cutting joints, and has great engineering practical value; the method has simple steps and clear formula, fully considers various internal and external factors, can quickly and accurately determine the contraction joint spacing of the continuous reinforced concrete pavement with low reinforcement ratio, and has higher calculation precision.
Drawings
FIG. 1 is a flow chart of a method for determining the distance between the contraction joints of a low-reinforcement-ratio continuous reinforced concrete pavement in the embodiment of the invention;
FIG. 2 is a schematic longitudinal cross-sectional view of a low-reinforcement-ratio continuous-reinforced concrete pavement structure according to an embodiment of the present invention;
in the figure, 1-underlayer, 2-base layer, 3-buffer layer, 4-continuous reinforced concrete surface layer with low reinforcement ratio, 5-transverse steel bar, 6-longitudinal steel bar and 7-transverse contraction joint.
Detailed Description
The present invention will be described in detail below with reference to the accompanying drawings and examples.
Referring to fig. 1 to 2, a method for determining a gap between two joints of a low-reinforcement-ratio continuous-reinforcement concrete pavement according to an embodiment of the present invention includes the following steps:
1) determining design parameters of the low-reinforcement-ratio continuous reinforced concrete pavement;
2) calculating the plate thickness of the low-reinforcement-ratio continuous reinforced concrete pavement according to the determined design parameters;
3) determining the traffic load grade of the low-reinforcement-ratio continuous reinforced concrete pavement, and preliminarily simulating the reinforcement ratio of the low-reinforcement-ratio continuous reinforced concrete pavement according to the traffic load grade;
4) according to the pre-planned reinforcement ratio, selecting reinforcement parameters in the low-reinforcement-ratio continuous reinforced concrete pavement, wherein the reinforcement parameters comprise the type, the diameter and the spacing of reinforcements, and determining the actual reinforcement ratio of the low-reinforcement-ratio continuous reinforced concrete pavement according to the selected reinforcement parameters;
5) calculating the transverse contraction joint spacing of the low-reinforcement-ratio continuous reinforced concrete pavement according to the actual reinforcement ratio of the low-reinforcement-ratio continuous reinforced concrete pavement; according to the principle that the low-reinforcement-ratio continuous reinforcement is mainly used for resisting the tensile force generated when the shrinkage of a concrete surface layer is hindered, the frictional resistance of the bottom of the layer is considered to be equal to the tensile force of two ends of a concrete slab, and the tensile force is completely acted on longitudinal steel bars.
Further, in the step 1), the design parameters include road grade, design reference period, safety grade, design axle load, heaviest axle load, accumulated axle load acting times, traffic load grade, comprehensive resilience modulus of the top surface of the roadbed, standard value of the bending tensile strength of the cement concrete, material parameters, maximum temperature gradient and plate width.
Further, in the step 3), the low-reinforcement-ratio continuous reinforced concrete pavement is suitable for roads above the medium traffic load level, and the suitable reinforcement ratio range is 0.2% -0.6%, wherein the reinforcement ratio at the medium traffic load level is preferably 0.2% -0.3%, the reinforcement ratio at the heavy traffic load level is preferably 0.3% -0.4%, the reinforcement ratio at the extra-heavy traffic load level is preferably 0.4% -0.5%, and the reinforcement ratio at the extremely-heavy traffic load level is preferably 0.5% -0.6%.
Further, in the step 4), the type of the steel bar is HRB400 hot rolled ribbed steel bar, the diameter is 14 mm-20 mm, and the spacing is 150 mm-350 mm.
Further, in the step 5), the contraction joint interval L is
Rho is the reinforcement ratio of the low reinforcement ratio continuous reinforced concrete pavement,%; [ sigma ]s]-allowable stress of the bars, MPa; k is a radical ofcConsidering a comprehensive coefficient influenced by factors such as theoretical and actual differences, construction variation level, material parameter variation level and the like; mu.s0The dynamic friction coefficient of the surface layer and the base layer of the low-reinforcement-ratio continuous reinforced concrete pavement; gamma-mixtureSevere of the concrete, kN/m3。
Further, allowable stress [ sigma ] of the reinforcing bars]Is composed of
[σs]＝ksfsy；
Wherein k iss-the allowable stress reduction factor of the steel reinforcement; f. ofsy-yield strength of the steel bar, MPa.
Further, the allowable stress reduction coefficient k of the steel barsGenerally 75-85%, and the representative value can be 80%;
dynamic friction coefficient mu of low-reinforcement-rate continuous reinforced concrete pavement surface layer and base layer0Generally 1.5-8.9, considering that multiple relative sliding can be generated between the surface layer and the base layer due to temperature rise and fall, so that the dynamic friction coefficient is small, and the representative value can be 1.8;
the heavy gamma of the concrete can be 24kN/m3。
Further, the integrated coefficient
Wherein,
-theoretical and actual difference coefficients;
-construction variation level coefficient;
-coefficient of variation level of material parameter.
Further, the theoretical and actual difference coefficients
Generally 0.05 to 0.25, and the representative value thereof may be 0.15;
coefficient of construction variation
The concrete pavement can be 0.18 when being horizontal, 0.26 when being horizontal, 0.36 when being horizontal, and the higher the road grade is, the lower the variation level is;
coefficient of variation level of material parameter
The concrete pavement can be 0.05 when being horizontal, 0.10 when being horizontal, 0.15 when being horizontal, and the higher the road grade is, the lower the variation level is.
The level one represents that the variation level grade is low, the level two represents that the variation level grade is medium, the level three represents that the variation level grade is high, different road grades correspond to different variation levels, the variation level grade of a high-speed road and a first-level road is low, the variation level grade of a second-level road is not more than the medium, and the variation level grade of a third-level road can be high.
Furthermore, the low-reinforcement-ratio continuous reinforced concrete pavement comprises an underlayer, a base layer, a buffer layer and a low-reinforcement-ratio continuous reinforced concrete surface layer which are sequentially paved from bottom to top; the low-reinforcement-ratio continuous reinforcement concrete surface layer is internally provided with single-layer continuous reinforcement or double-layer continuous reinforcement, and the concrete surface layer is provided with a transverse contraction joint at intervals of a certain distance L.
Further, the single-layer continuous reinforcement includes a plurality of continuous longitudinal reinforcing bars 6 and transverse reinforcing bars 5, and the longitudinal reinforcing bars 6 are arranged above the transverse reinforcing bars 5.
Further, the double-layer continuous reinforcing steel bars comprise upper-layer continuous reinforcing steel bars and lower-layer continuous reinforcing steel bars; the upper continuous steel bar comprises a plurality of continuous longitudinal steel bars 6 and transverse steel bars 5, and in the upper continuous steel bar, the longitudinal steel bars 6 are arranged above the transverse steel bars 5; the lower continuous reinforcement includes continuous longitudinal reinforcements 6 and transverse reinforcements 5, and in the lower continuous reinforcement, the transverse reinforcements 5 are arranged above the longitudinal reinforcements 6.
Further, in the continuous reinforcement of individual layer and the continuous reinforcement of double-deck, a plurality of continuous longitudinal reinforcement 6 arrange in same height side by side, extend along road length direction, and a plurality of transverse reinforcement 5 arrange in proper order along road length direction.
Furthermore, the depth of the transverse contraction joint is not more than 4cm, and the width is 5-10 mm; according to the continuous reinforced concrete pavement structure with low reinforcement ratio, the transverse contraction joint is filled with polyurethane or high-viscosity high-elasticity modified asphalt.
In one embodiment of the present invention, referring to fig. 1, the present invention comprises the steps of:
step one, the design parameter value of the low-reinforcement-ratio continuous reinforced concrete pavement is as follows:
a low-reinforcement-rate continuous reinforced concrete pavement is combined with a certain level of highway, a design reference period is 30 years, the safety level is one level, the design axle load is 100kN, the maximum axle load is 180kN, the accumulated axle load action times are 1700 ten thousand times, the heavy traffic load level, the comprehensive resilience modulus of the top surface of a road bed is 100MPa, the standard value of the bending tensile strength of cement concrete is 5.0MPa, the elastic modulus of the cement concrete is 31000MPa, the Poisson ratio is 0.15, the thickness of a cement stabilized macadam base layer is 0.36m, the elastic modulus is 2000MPa, the Poisson ratio is 0.20, the thickness of a graded macadam subbase layer is 0.15m, the elastic modulus is 250MPa, the Poisson ratio is 0.35, the maximum temperature gradient is 92 ℃/m, and the plate width is 4 m.
Step two, calculating the plate thickness of the low-reinforcement-ratio continuous reinforced concrete pavement:
calculating the plate thickness of the low-reinforcement-ratio continuous reinforced concrete pavement by a calculation method provided by the current design Specification for road cement concrete pavement (JTG D40-2011) to be 0.24 m;
step three, setting the reinforcement ratio of the low reinforcement ratio continuous reinforced concrete pavement:
according to the heavy traffic load grade of the low-reinforcement-ratio continuous reinforced concrete pavement, the reinforcement ratio of the preliminary low-reinforcement-ratio continuous reinforced concrete pavement is 0.35%;
step four, determining the actual reinforcement ratio:
according to the pre-designed reinforcement ratio of 0.35 percent and the plate thickness of the low-reinforcement-ratio continuous reinforced concrete pavement of 0.24m, HRB400 longitudinal reinforcements are selected, the diameter is 18mm, the spacing is 300mm, and the actual reinforcement ratio is 0.37 percent;
step five, calculating the transverse contraction joint spacing of the continuous reinforced concrete pavement with the low reinforcement ratio:
[σs]＝ksfsy；
in the formula: l-transverse contraction joint spacing, m, of the low-reinforcement-ratio continuous reinforced concrete pavement; rho-reinforcement ratio of low reinforcement ratio continuous reinforced concrete pavement,%; [ sigma ]s]-allowable stress of the bars, MPa; k is a radical ofs-the allowable stress reduction factor of the steel reinforcement; f. ofsy-yield strength of the steel reinforcement, MPa; k is a radical ofcConsidering a comprehensive coefficient influenced by factors such as theoretical and actual differences, construction variation level, material parameter variation level and the like;
-theoretical and actual difference coefficients;
-construction variation level coefficient;
-coefficient of variation level of material parameter; mu.s0The dynamic friction coefficient of the surface layer and the base layer of the low-reinforcement-ratio continuous reinforced concrete pavement; gamma-concrete Severe, kN/m3；
The allowable stress reduction coefficient of the steel bar is 80 percent;
the coefficient of difference between the theoretical coefficient and the actual coefficient is 0.15;
constructing a variation level coefficient, namely taking 0.18 at a time according to the level;
the coefficient of variation level of the material parameter is 0.05 according to the first level;
the dynamic friction coefficient of the surface layer and the base layer of the low-reinforcement-ratio continuous reinforced concrete pavement is 1.8;
the weight of the concrete is 24kN/m3；
The transverse contraction joint spacing of the low-reinforcement-ratio continuous reinforced concrete pavement is 39.72m, and the transverse contraction joint can be arranged according to 35m after the completion of the simplification, so that the transverse contraction joint spacing is greatly increased compared with that of the reinforced concrete pavement.
Although a certain amount of longitudinal continuous steel bars are arranged on the low-reinforcement-ratio continuous reinforced concrete surface layer 4, the reinforcement ratio of the low-reinforcement-ratio continuous reinforced concrete surface layer is not enough to completely control the development of the transverse contraction joint, so that the transverse contraction joints 7 still need to be arranged at certain intervals, and the higher the reinforcement ratio is, the larger the contraction joint interval is, and the corresponding relationship between the reinforcement ratio and the transverse contraction joint is shown in table 1.
The invention aims to improve the problems of a continuous reinforced concrete pavement and a reinforced concrete pavement and develops a method for determining the gap between the contraction joints of the continuous reinforced concrete pavement with low reinforcement ratio.
The purpose of the reinforcement of the low reinforcement ratio continuous reinforced concrete pavement is to lengthen the distance between the contraction joints, simultaneously keep the two sides of the cracks to be closely contacted when the concrete is contracted or warped and cracked, and do not expand the cracks, but the reinforcement can not eliminate the cracks and reduce the load stress, so the low reinforcement ratio continuous reinforced concrete pavement adopts the same plate thickness as the common concrete pavement. After the thickness of the selected plate is calculated, how to determine the transverse contraction joint spacing matched with the reinforcement ratio is the core of the design of the low-reinforcement-ratio continuous reinforced concrete pavement. If the transverse contraction joint distance is too short, the joint cutting workload is increased, meanwhile, the contraction joint is a weak land belt, and the quality hidden danger is increased due to too many joints; if the transverse contraction joint distance is too long, although the joint seam is reduced, the control action of the steel bar is insufficient, random and irregular cracks with larger width can be generated between the two contraction joints, and the quality hidden trouble also exists.
The above description is only a preferred embodiment of the present invention, and certainly should not be taken as limiting the scope of the invention, which is defined by the claims and their equivalents.
Claims (9)
1. A method for determining the distance between the contraction joints of a low-reinforcement-ratio continuous reinforced concrete pavement is characterized by comprising the following steps of:
1) determining design parameters of the low-reinforcement-ratio continuous reinforced concrete pavement;
2) calculating the plate thickness of the low-reinforcement-ratio continuous reinforced concrete pavement according to the determined design parameters;
3) determining the traffic load grade of the low-reinforcement-ratio continuous reinforced concrete pavement, and preliminarily simulating the reinforcement ratio of the low-reinforcement-ratio continuous reinforced concrete pavement according to the traffic load grade;
4) according to the pre-planned reinforcement ratio, selecting reinforcement parameters in the low-reinforcement-ratio continuous reinforced concrete pavement, wherein the reinforcement parameters comprise the type, the diameter and the spacing of reinforcements, and determining the actual reinforcement ratio of the low-reinforcement-ratio continuous reinforced concrete pavement according to the selected reinforcement parameters;
5) calculating the transverse contraction joint spacing of the low-reinforcement-ratio continuous reinforced concrete pavement according to the actual reinforcement ratio of the low-reinforcement-ratio continuous reinforced concrete pavement;
the low-reinforcement-ratio continuous reinforced concrete pavement comprises a subbase layer, a base layer, a buffer layer and a low-reinforcement-ratio continuous reinforced concrete surface layer which are sequentially paved from bottom to top; a single-layer continuous reinforcement or a double-layer continuous reinforcement is arranged in the low reinforcement ratio continuous reinforcement concrete surface layer, and a transverse contraction joint is arranged on the concrete surface layer at intervals of a certain distance L;
in the step 3), the low-reinforcement-ratio continuous reinforced concrete pavement is suitable for roads with a medium traffic load grade or above, and the suitable reinforcement ratio range is 0.2% -0.6%.
2. The method for determining the shrinkage joint spacing of the low-reinforcement-ratio continuous reinforced concrete pavement according to claim 1, wherein in the step 1), the design parameters comprise a road grade, a design reference period, a safety grade, a design axle load, a heaviest axle load, an accumulated axle load action time, a traffic load grade, a comprehensive resilience modulus of a top surface of a road bed, a standard bending-tensile strength value of cement concrete, material parameters, a maximum temperature gradient and a plate width.
3. The method for determining the contraction joint spacing of the low-reinforcement-ratio continuous reinforced concrete pavement according to claim 1, wherein in the roads above the medium traffic load grade, the reinforcement ratio of the medium traffic load grade is preferably 0.2-0.3%, the reinforcement ratio of the heavy traffic load grade is preferably 0.3-0.4%, the reinforcement ratio of the extra-heavy traffic load grade is preferably 0.4-0.5%, and the reinforcement ratio of the extreme-heavy traffic load grade is preferably 0.5-0.6%.
4. The method for determining the shrinkage cavity spacing of the low-reinforcement-ratio continuous reinforced concrete pavement according to claim 1, wherein in the step 4), the type of the steel bars is HRB400 hot-rolled ribbed steel bars, the diameter is 14 mm-20 mm, and the spacing is 150 mm-350 mm.
5. The method for determining the gap between the contraction joints of the low-reinforcement-ratio continuous reinforced concrete pavement as claimed in claim 1, wherein in the step 5), the gap between the contraction joints L is
Rho is the reinforcement rate of the low reinforcement rate continuous reinforced concrete pavement; [ sigma ]s]-allowable stress of the steel reinforcement; k is a radical ofcConsidering a comprehensive coefficient influenced by factors such as theoretical and actual differences, construction variation level, material parameter variation level and the like; mu.s0The dynamic friction coefficient of the surface layer and the base layer of the low-reinforcement-ratio continuous reinforced concrete pavement; gamma-the gravity of the concrete.
6. The method for determining the shrinkage joint spacing of a low-reinforcement-ratio continuous-reinforced concrete pavement according to claim 5, wherein the allowable stress of the steel reinforcement is [ sigma ]s]＝ksfsy；
Wherein k iss-the allowable stress reduction factor of the steel reinforcement; f. ofsy-the yield strength of the steel reinforcement.
7. The method for determining the distance between the contraction joints of the low-reinforcement-ratio continuous reinforced concrete pavement according to claim 6, wherein the allowable stress reduction coefficient k of the steel reinforcement iss75 to 85 percent;
dynamic friction coefficient mu of low-reinforcement-rate continuous reinforced concrete pavement surface layer and base layer01.5 to 8.9;
the weight gamma of the concrete is 24kN/m3。
8. The method for determining the distance between the contraction joints of a low-reinforcement-ratio continuous reinforced concrete pavement according to claim 5, wherein the comprehensive coefficient
Wherein,
-theoretical and actual difference coefficients;
-construction variation level coefficient;
variation of material parametersThe horizontal coefficient.
9. The method for determining the distance between the contraction joints of a low-reinforcement-ratio continuous reinforced concrete pavement according to claim 8, wherein the theoretical and actual difference coefficients
0.05 to 0.25;
coefficient of construction variation
The concrete pavement can be 0.18 when being horizontal, 0.26 when being horizontal, 0.36 when being horizontal, and the higher the road grade is, the lower the variation level is;
coefficient of variation level of material parameter
The concrete pavement can be 0.05 when being horizontal, 0.10 when being horizontal, 0.15 when being horizontal, and the higher the road grade is, the lower the variation level is.
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| CN104988823B (en) * | 2015-05-22 | 2017-03-08 | 长沙理工大学 | A kind of cement concrete pavement structure that continuity reinforcement(bar) is set |
| CN108004869B (en) * | 2017-11-21 | 2020-04-07 | 华南理工大学 | Method for designing basalt fiber bar continuous reinforcement cement concrete pavement |
| CN108978392A (en) * | 2018-06-27 | 2018-12-11 | 武汉华中科大土木工程检测中心 | A kind of big spacing seam arrangement of reinforcement cement concrete pavement structure and method of construction |
| CN110468648B (en) * | 2019-07-05 | 2021-07-27 | 武汉市政工程设计研究院有限责任公司 | Large-spacing joint reinforced concrete pavement structure design method and system |
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