A self-stress connecting structure and construction method suitable for a fabricated road pavement panel

Abstract

The application discloses a self-stress connecting structure suitable for an assembled pavement slab and a construction method, and relates to the technical field of pavement construction. The self-stress connecting structure comprises a straight connecting structure and two curved connecting structures, and the connecting structures are all composed of an assembled prestressed slab, a self-stress efficiency device, a connecting joint, a self-stress reinforcing structure and a steel fiber expanded concrete structure. The straight connecting structure adopts a straight edge equal-width structure, and the curved connecting structures adopt two forms of a zigzag equal-width structure and a zigzag unequal-width structure. In addition, the application further discloses a construction method of the assembled prestressed slab, the self-stress efficiency device, the connecting joint, the self-stress reinforcing structure and the steel fiber expanded concrete structure. The self-stress connecting structure has the advantages of simple process, long service life, low maintenance cost and the like. The zigzag connecting structure solves the problem of difficulty in arranging prestressed reinforcing bars at a curved position of the assembled prestressed pavement.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pavement structure, in particular to a self-stress connecting structure suitable for assembled pavement slab and a construction method. BACKGROUND

[0002] The existing assembled concrete pavement adopts two kinds of connecting joint forms, one is ordinary reinforced concrete connecting joint, which is easy to crack under the double action of vehicle load and temperature stress, has joint work and poor durability; the other is prestressed concrete connecting joint, which has the problems of complex process, slurry pollution in on-site tensioning and grouting, high cost, whole replacement after single slab damage, and high maintenance cost, especially difficult to reinforce and easy to crack in curve design.

[0003] The self-stress connecting structure of the present application is generated by the chemical reaction of high-performance expanding agent, cement and water, the cement concrete expands, generates chemical energy, drives the longitudinal and transverse steel bars to stretch to both sides, thereby generating tensioning effect, the ordinary steel bars generate stress without mechanical tensioning, become self-stress steel bars, which have different effects from ordinary steel bars and are the same as the traditional mechanical tensioning steel strands. The conversion of chemical energy forms tensioning effect on the steel bars through the friction between the concrete and the steel bars, at the same time, the transverse steel bars of the connecting joint are welded on the self-stress enhancement plates on both sides, the concrete expansion pushes the self-stress enhancement plates to move outward, generates tensioning effect on the steel bars connected to the self-stress enhancement plates, the steel bars do not need to be mechanically tensioned to generate self-stress, and the longitudinal steel bars connected to the self-stress enhancement plates on both sides also generate greater self-stress. Due to the double tensioning of the steel bars and the added steel fibers, the connecting structure concrete generates bidirectional stress in the longitudinal and transverse directions, the self-stress of the longitudinal and transverse self-stress steel bars prevents the generation of transverse and longitudinal cracks in the connecting joint concrete, the self-stress of the steel fibers prevents the generation of micro cracks in the connecting joint concrete, and the slab blocks are connected to form an integral structure, which has simple process and strong bearing capacity.

[0004] The present application uses the same diameter steel bars with the same model, so that the stress generated by the self-stress steel bars in the longitudinal and transverse perpendicular sections has the same size and direction, which maximally eliminates the stress difference and reduces the generation of cracks. The self-stress enhancement plates make the efficiency of the conversion of chemical energy into mechanical energy higher; the present application has a wider application range, the precast slab edges at the curve are in a zigzag shape, the self-stress enhancement plates on both sides of the connecting joint are arc-shaped, and the connecting steel bars are arc-shaped and perpendicular to the precast slab edges, so that the connecting joint bears force uniformly and does not generate transverse shear force to cause damage to the slab end, which solves the problem of difficult reinforcement of the prestressed steel bars in the assembled prestressed pavement; the pavement structure connected by the present application can be cut and removed along the connecting joint when the single slab is damaged in use, the self-stress connecting structure is poured again after the installation of a new slab, which does not affect the working performance of other slab blocks, and has low maintenance cost SUMMARY

[0005] The technical problem solved by the present application is that ordinary concrete pavement connecting joints are prone to cracking, the construction process of the assembled prestressed connecting joint is complex, the grouting causes pollution, it is difficult to replace after damage, the maintenance cost is high, and the reinforcement of curved road sections is difficult to crack.

[0006] To solve the above technical problems, the present application provides a self-stress connecting structure suitable for an assembled pavement, characterized in that the connecting structure comprises a straight connecting structure and a curved connecting structure one and a curved connecting structure two.

[0007] The straight connecting structure and the curved connecting structure both further comprise the following four parts:

[0008] An assembled prestressed plate is installed on a low friction isolation layer, and a connecting joint is left with a cross section perpendicular to the longitudinal self-stress reinforcement of the connecting structure;

[0009] A self-stress reinforcement device is fixed on both sides of the connecting joint of the assembled prestressed plate, and is composed of a self-stress reinforcement plate, a bolt for fixing the reinforcement plate, and a pressure spring;

[0010] A self-stress reinforcement structure is arranged in the connecting joint and is composed of longitudinal and transverse self-stress reinforcements, the longitudinal and transverse self-stress reinforcements are connected to the embedded connecting reinforcement of the assembled prestressed plate in the longitudinal direction and are connected to the self-stress reinforcement plate in the transverse direction, and the longitudinal and transverse self-stress reinforcements are symmetrically arranged and are configured with the same diameter and the same type;

[0011] A steel fiber expanded concrete structure is poured into the connecting joint, and the connecting joint is surrounded by the assembled prestressed plate and the self-stress reinforcement plate.

[0012] According to one specific embodiment of the present application, the connecting joint of the connecting structure further comprises a straight connecting joint, a curved connecting joint one, and a curved connecting joint two, wherein:

[0013] The straight connecting joint is an equal-width straight edge connecting joint, the curved connecting joint one is an equal-width zigzag connecting joint, and the curved connecting joint two is a non-equal-width zigzag connecting joint, and the prestressed plates on both sides of the curved connecting joint are provided with a stepped zigzag structure along the width direction, and the stepped directions are opposite.

[0014] According to another specific embodiment of the present application, the self-stress reinforcement device is used to limit the expansion amount of the expanded concrete, and comprises a self-stress reinforcement plate, a bolt, and a cylindrical pressure spring, wherein:

[0015] The self-stress reinforcement plate is divided into a straight self-stress reinforcement plate and a curved self-stress reinforcement plate, wherein the straight self-stress reinforcement plate is a straight plate, and the curved self-stress reinforcement plate is an arc-shaped plate.

[0016] According to still another specific embodiment of the present application, the self-stress steel bar structure comprises: longitudinal self-stress steel bars connected with the embedded connecting bars of the prestressed plate, transverse self-stress steel bars and stirrups connected with the self-stress reinforcing plate, wherein:

[0017] The longitudinal self-stress steel bars and the transverse self-stress steel bars are both double-layer steel bars symmetrically and uniformly arranged along the horizontal central axis, the straight connecting structure longitudinal self-stress steel bars are perpendicular to the end section of the prestressed plate, and the curved connecting structure longitudinal self-stress steel bars are consistent with the curved line of the curved section, and the longitudinal self-stress steel bars are arranged perpendicularly to the sawtooth surface of the prestressed plate at the position of the end of the prestressed plate.

[0018] According to still another specific embodiment of the present application, the steel fiber expanded concrete structure is formed by mixing milled steel fiber, high-performance expanding agent, high-efficiency water reducing agent, ordinary portland cement, limestone, medium sand and water according to a certain mixing ratio.

[0019] According to another specific embodiment of the present application, the prestressed plate has a thickness of 20cm-24cm and a compressive strength of 40Mpa-50Mpa, the straight prestressed plate is a rectangle with a longitudinal length of 3m-3.5m and a transverse width of 7.5m-7.8m, and the curved prestressed plate is a special-shaped plate with a sawtooth-shaped end.

[0020] According to still another specific embodiment of the present application, the connecting joint has the same depth as the thickness of the prestressed plate, the straight connecting joint and the curved connecting joint each have a width of 15cm-25cm, the curved connecting joint has a short side width of 15cm-25cm and a long side width arranged according to the matching of the curved radius.

[0021] According to still another specific embodiment of the present application, the self-stress reinforcing plate is a steel plate of model Q345q with a thickness of 3mm-5mm, a height equal to that of the prestressed plate and a length of the width of the connecting joint + an anchoring length of 10cm on each side, the self-stress reinforcing plate is anchored by a lengthened M20 bolt, a cylindrical pressure spring with a pressure of 20kN-30kN is arranged between the self-stress reinforcing plate and the nut, and the spring compression amount is 2cm.

[0022] According to another specific embodiment of the present application, the self-stress steel bar adopts HRB400 ribbed steel bars of the same model and diameter, and the reinforcement ratio is 0.5%-2%.

[0023] According to still another specific embodiment of the present application, the longitudinal stress design target value of the steel fiber reinforced concrete structure is 3-5 MPa, the compressive strength of the steel fiber reinforced concrete is 40-50 MPa, the flexural strength is 6-9 MPa, the content of the high-performance expansive agent is 10-12%, the volume ratio of the steel fiber content is 0.8-1.5%, the steel grade is ST52-3, the length is 32.0 mm±2 mm, the width is 2.6 mm±1.2 mm, the length-diameter ratio is 35-45, and the tensile strength is ≥700 N / mm 2 .

[0024] According to still another specific embodiment of the present application, the low-friction isolation layer comprises, from bottom to top, an oil-permeable layer, a high-strength high-density PVC engineering plate, and a plastic cloth.

[0025] According to another aspect of the present application, a construction method of a self-stress connecting structure suitable for a prefabricated pavement is also provided, which specifically comprises the following steps:

[0026] Mounting the prestressed plate: chiseling the side surface of the end part of the connecting joint of the prestressed plate, and hoisting the prestressed plate to a predetermined mounting position on the low-friction isolation layer;

[0027] Mounting the self-stress synergic plate: fixing the self-stress synergic plate on the prestressed plates on both sides of the connecting joint by means of bolts, the height of the self-stress synergic plate being flush with that of the prestressed plates, a pressure spring being arranged between the nut and the self-stress synergic plate, and high-grade mortar being used to seal the gap between the self-stress synergic plate and the low-friction isolation layer;

[0028] Binding the self-stress steel bars: binding the embedded connecting bars of the prestressed plate and the longitudinal self-stress steel bars, binding the stirrups and the transverse self-stress steel bars, and connecting the transverse self-stress steel bars and the self-stress synergic plate;

[0029] Mixing the steel fiber reinforced expansive concrete: placing the gravel, sand, cement and expansive agent into a mixer and stirring them uniformly, then adding water and water reducing agent, stirring again, and then adding the wetted steel fibers twice;

[0030] Pouring the steel fiber reinforced concrete: fully wetting the connecting joint with water, pouring the mixed steel fiber reinforced expansive concrete into the connecting joint, and vibrating and tamping the concrete in layers, with the proviso that the insertion type vibrating rod is prohibited, and the flat vibrator is used to vibrate and level the concrete after vibration, and the surface is manually finished;

[0031] Curing: covering curing cloth for curing, and the curing time is not less than 7 days, and preferably, the curing time is 10 days;

[0032] Self-stress synergic plate treatment: removing the pressure spring and the anchor bolt, and performing rust removal and rust-proof paint treatment on the self-stress synergic plate.

[0033] The beneficial effects of the present application are that the self-stress connecting structure of the present application is chemically reacted by high-performance expanding agent, cement and water, and the chemical energy is converted into mechanical energy to make the steel bar generate stress without traditional mechanical tensioning, and the setting of the self-stress synergistic plate can effectively improve the conversion efficiency of the chemical energy, and through the double tensioning of the self-stress steel bar and the added steel fiber, the longitudinal and transverse two-way stress of the connecting structure concrete is generated, the self-stress of the longitudinal and transverse self-stress steel bars prevents the generation of the transverse and longitudinal cracks of the connecting joint concrete, the self-stress of the steel fiber prevents the generation of the micro cracks of the connecting joint concrete, and the plate blocks are connected to form an integral structure, the process is simple, and the bearing capacity is strong.

[0034] The connected pavement structure of the present application can be cut and removed along the connecting structure when a single plate is damaged in use, and the self-stress connecting structure is recast after installing a new plate, and the working performance of other plate blocks is not affected, and the maintenance cost is low. Through adjusting the width of the connecting joint at the curve, setting the serrated plate edge, the arc-shaped self-stress synergistic plate, the arc-shaped steel bar and other designs, the problems of complex stress, difficult reinforcement and easy cracking of the curved prestressed pavement are solved, and the curved design and construction are facilitated. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 It is a straight connecting structure plane schematic diagram of the present application;

[0036] Figure 2 It is a first plane schematic diagram of the curved connecting structure of the present application;

[0037] Figure 3 It is a second plane schematic diagram of the curved connecting structure of the present application;

[0038] Figure 4 It is a self-stress synergistic plate schematic diagram.

[0039] In the figure: 1, transverse self-stress steel bar; 2, longitudinal self-stress steel bar; 3, stirrup; 4, prestressed plate; 5, straight connecting joint; 6, serrated structure; 7, self-stress synergistic plate; 8, bolt; 9, pressure spring; 10, steel fiber expanded concrete; 11, prestressed special-shaped plate; 12, arc-shaped longitudinal self-stress steel bar; 13, arc-shaped self-stress synergistic plate; 14, pre-buried connecting bar; 15, plastic cloth; 16, high-strength high-density PVC engineering plate; 17, oil permeable layer; 18, curved connecting joint one; 19, curved connecting joint two. EMBODIMENT

[0040] The following will be combined with the drawings of the embodiments of the present application to Figures 1-4For the sake of clearly and completely describing the technical solutions in the embodiments of the present application, all the directionality indications (such as up, down, left, right, front, back, etc.) in the present application are only used to explain the relative position relationship, movement condition, etc. between the components in a certain specific posture (as shown in the drawings), and if the specific posture changes, the directionality indications will also change accordingly.

[0041] As shown in the drawings, the present embodiment provides a self-stress connecting structure, which specifically comprises a prestressed plate (4) (11), a self-stress enhancing device fixed on both sides of a connecting joint (5) (18) (19) of the prestressed plate (4) (11) to limit the expansion amount of the expansive concrete, a self-stress connecting structure composed of longitudinal self-stress steel bars (2) connected with the longitudinal embedded connecting bars (14) of the prestressed plate and transverse self-stress steel bars (1) connected with the self-stress enhancing plate (7) (13), a connecting joint (5) (18) (19) surrounded by the prestressed plate (4) (11) and the self-stress enhancing plate (7) (13), and a steel fiber expansive concrete structure (10) poured into the connecting joint (5) (18) (19). Figures 1-3 As shown in the drawings, the connecting joint comprises a straight connecting joint (5), a curved connecting joint one (18) and a curved connecting joint two (19). The straight connecting joint (5) is located between the prestressed plates (4) of the straight path and is an equal-width connecting joint; the curved connecting joint one (18) is located between the prestressed special-shaped plates (11) of the curved path and is an equal-width connecting joint; and the curved connecting joint two (19) is located between the prestressed special-shaped plates (11) and is an unequal-width connecting joint. The prestressed plates on both sides of the straight connecting joint (5) are straight edges along the width direction, and the prestressed special-shaped plates (11) on both sides of the curved connecting joint one (18) and the curved connecting joint two (19) are provided with stepped sawtooth structures (6) along the width direction, the stepped directions are opposite, the sawtooth structures (6) are arranged to make the steel fiber expansive concrete structure (10) form a vertical pressure on the prestressed special-shaped plates (11), the distance between the opposite sawtooth surfaces of the curved connecting joint one (18) is the same (in this example, the same means approximately the same, that is, the distance difference between the opposite sawtooth surfaces is very small), the distance between the opposite prestressed special-shaped plates (11) of the curved connecting joint two (19) gradually increases from the inside to the outside, and the whole presents a fan structure.

[0042] Figures 1-3 As shown in the drawings, the connecting joint comprises a straight connecting joint (5), a curved connecting joint one (18) and a curved connecting joint two (19). The straight connecting joint (5) is located between the prestressed plates (4) of the straight path and is an equal-width connecting joint; the curved connecting joint one (18) is located between the prestressed special-shaped plates (11) of the curved path and is an equal-width connecting joint; and the curved connecting joint two (19) is located between the prestressed special-shaped plates (11) and is an unequal-width connecting joint. The prestressed plates on both sides of the straight connecting joint (5) are straight edges along the width direction, and the prestressed special-shaped plates (11) on both sides of the curved connecting joint one (18) and the curved connecting joint two (19) are provided with stepped sawtooth structures (6) along the width direction, the stepped directions are opposite, the sawtooth structures (6) are arranged to make the steel fiber expansive concrete structure (10) form a vertical pressure on the prestressed special-shaped plates (11), the distance between the opposite sawtooth surfaces of the curved connecting joint one (18) is the same (in this example, the same means approximately the same, that is, the distance difference between the opposite sawtooth surfaces is very small), the distance between the opposite prestressed special-shaped plates (11) of the curved connecting joint two (19) gradually increases from the inside to the outside, and the whole presents a fan structure.

[0043] As shown in the drawings, the connecting joint comprises a straight connecting joint (5), a curved connecting joint one (18) and a curved connecting joint two (19). The straight connecting joint (5) is located between the prestressed plates (4) of the straight path and is an equal-width connecting joint; the curved connecting joint one (18) is located between the prestressed special-shaped plates (11) of the curved path and is an equal-width connecting joint; and the curved connecting joint two (19) is located between the prestressed special-shaped plates (11) and is an unequal-width connecting joint. The prestressed plates on both sides of the straight connecting joint (5) are straight edges along the width direction, and the prestressed special-shaped plates (11) on both sides of the curved connecting joint one (18) and the curved connecting joint two (19) are provided with stepped sawtooth structures (6) along the width direction, the stepped directions are opposite, the sawtooth structures (6) are arranged to make the steel fiber expansive concrete structure (10) form a vertical pressure on the prestressed special-shaped plates (11), the distance between the opposite sawtooth surfaces of the curved connecting joint one (18) is the same (in this example, the same means approximately the same, that is, the distance difference between the opposite sawtooth surfaces is very small), the distance between the opposite prestressed special-shaped plates (11) of the curved connecting joint two (19) gradually increases from the inside to the outside, and the whole presents a fan structure. Figures 1-3 ​As shown, the self-stress intensifier device includes a self-stress intensifier plate (7) (13), a bolt (8), and a cylindrical pressure spring (9). The straight self-stress intensifier plate (7) is in a linear shape, and the curved self-stress intensifier plate (13) is in an arc shape with the same curvature as the curve of the curved section. The self-stress intensifier plate (7) (13) has an anchor length of 10 cm longer than each side of the connecting joint, and the self-stress intensifier plate (7) (13) is fixed to the side of the prestressed plate (4) (11) by the bolt (8) of M20. The cylindrical pressure spring (9) is arranged between the self-stress intensifier plate (7) (13) and the nut, and the arrangement of the pressure spring (9) enables the self-stress intensifier device to move with the expansion of the steel fiber reinforced concrete structure (10) within a certain range and limits the expansion of the steel fiber reinforced concrete structure (10).

[0044] It should be noted that the connecting joint is provided with self-stress intensifier devices on both sides in the transverse direction, which are composed of a self-stress intensifier plate (7) (also referred to as a self-stress expansion limiting plate), a bolt (8), and a pressure spring (9). If there is no self-stress intensifier device, the tension of the steel bar caused by the expansion of the concrete is only generated by the frictional force between the concrete and the steel bar, the efficiency of the conversion of chemical energy into mechanical energy is low, and the generated self-stress is small. After the self-stress intensifier device is arranged, firstly, the tension of the steel bar caused by the expansion of the concrete is generated by the frictional force between the concrete and the steel bar, secondly, the steel bar is welded to the self-stress intensifier plate, the expansion of the concrete pushes the self-stress intensifier plate, and the outward movement of the self-stress intensifier plate also generates tension on the connected steel bar, thus the efficiency of the conversion of chemical energy into mechanical energy is enhanced, and the generated self-stress is large.

[0045] The connecting joint is provided with self-stress intensifier devices on both sides in the transverse direction, which are composed of a self-stress intensifier plate (7) (also referred to as a self-stress expansion limiting plate), a bolt (8), and a pressure spring (9). If there is no self-stress intensifier device, the tension of the steel bar caused by the expansion of the concrete is only generated by the frictional force between the concrete and the steel bar, the efficiency of the conversion of chemical energy into mechanical energy is low, and the generated self-stress is small. After the self-stress intensifier device is arranged, firstly, the tension of the steel bar caused by the expansion of the concrete is generated by the frictional force between the concrete and the steel bar, secondly, the steel bar is welded to the self-stress intensifier plate, the expansion of the concrete pushes the self-stress intensifier plate, and the outward movement of the self-stress intensifier plate also generates tension on the connected steel bar, thus the efficiency of the conversion of chemical energy into mechanical energy is enhanced, and the generated self-stress is large.

[0046] The pressure spring (9) is arranged on the outside of the self-stress intensifier plate and has a certain pressure on the intensifier plate. The pressure value is between 0.5 KN and 1 KN. When the pressure is less than 0.5 KN, the concrete of the connecting structure is easy to leak mortar between the intensifier plate and the prestressed plate during vibration. When the pressure is greater than 1 KN, the outward movement of the intensifier plate is hindered, and the efficiency of the conversion of chemical energy into self-stress is affected.

[0047] Meanwhile, for the curved section connecting structure I and the curved section connecting structure II, the edge of the prestressed plate is in a zigzag shape, the intensifier plates on both sides are arc-shaped plates with the same radius as the curve, and the steel bars are arc-shaped and perpendicular to the cross section of the prestressed plate with the same radius as the curve. Such design enables the prestressed plate to enhance the self-stress of the steel bar and concentrate the self-stress of the steel bar, and does not generate transverse shear force.

[0048] As shown in FIG. 1, the connecting structure is composed of a connecting joint (1), a straight section (2), a curved section (3), a prestressed plate (4), a self-stress intensifier plate (5), a steel bar (6), and a steel fiber reinforced concrete structure (10). Figures 1-3As shown, the self-stress steel structure includes: longitudinal self-stress steel bars (2) connected with the pre-stressed plate (4) (11) embedded connecting bars (14), transverse self-stress steel bars (1) and stirrups (3) connected with the self-stress reinforcing plate (7) (13). The longitudinal self-stress steel bars (2) and the transverse self-stress steel bars (1) are both provided with double-layer steel bars, which are uniformly arranged along the horizontal central axis symmetrically. The straight connection structure longitudinal self-stress steel bars (2) are perpendicular to the end section of the pre-stressed plate (4); the curved longitudinal self-stress steel bars (12) of the curved connection structure are consistent with the curvature of the curved line, and the curved longitudinal self-stress steel bars (12) are perpendicular to the sawtooth surface at the end position of the pre-stressed special-shaped plate (11).

[0049] It should be noted that the self-stress steel structure is all symmetrically arranged by steel bars of the same diameter and the same type. The purpose of this design is to make the stress size and direction of the self-stress steel bars in the longitudinal and transverse vertical sections consistent. If the diameters are different and not symmetrically arranged, stress differences may exist in the longitudinal and transverse directions, and cracks may be generated.

[0050] As shown in Figure 4 The low-friction isolation layer is sequentially composed of an oil-permeable layer (17), a high-strength high-density PVC engineering plate (16) and a plastic cloth (15) from bottom to top, and the oil-permeable layer is an emulsified asphalt layer.

[0051] It should be noted that, as shown in the above Figures 1-4 As shown in the above

[0052] 1. The content of the high-efficiency expanding agent is 8%-14%

[0053] If the content of the expanding agent is less than 8%, the chemical energy and the expansion amount generated by the dry shrinkage and the temperature shrinkage of the connecting structure concrete are small, the self-stress generated by the longitudinal and transverse steel bars is small, and the self-stress generated by the connecting structure is too small to reduce the load stress of the structure.

[0054] The content of the expanding agent has a great influence on the strength of the connecting structure concrete. If the content of the expanding agent is greater than 14%, the strength is reduced, and the strength requirement of the road concrete cannot be met.

[0055] Considering the influence of the content of the expanding agent on the size of the steel bar self-stress and the strength of the concrete, the content of the expanding agent is more appropriate between 8%-14%, and the optimal content is between 10%-12%.

[0056] 2. The reinforcement ratio of the self-stress steel bar is 0.5%-2%

[0057] The reinforcement ratio less than 0.5% is too little to generate enough self stress, and the reinforcement ratio more than 2% is too much to generate enough self stress, so the optimal reinforcement ratio is 0.5%-2%.

[0058] Meanwhile, the application also provides a construction method of the self stress connecting structure, which comprises the following steps:

[0059] S1: installation of the prestressed plate (4): preparing the prestressed plate (4), roughening the part of the prestressed plate close to the connecting joint (5), and hoisting the prestressed plate (4) to the predetermined installation position on the low friction resistance isolation layer by using a crane.

[0060] S2: installation of the self stress reinforcement plate (7): fixing the self stress reinforcement plate (7) on the prestressed plates (4) on both sides of the connecting joint (5) by using bolts (8), and the height of the self stress reinforcement plate (7) is flush with the prestressed plate (4), the pressure spring (9) is arranged between the nut and the self stress reinforcement plate (7), and the gap between the self stress reinforcement plate (7) and the low friction resistance isolation layer is sealed by using high-grade mortar.

[0061] S3: binding of the self stress steel reinforcement: binding the self stress steel reinforcement structure between the adjacent prestressed plates (4), connecting the embedded connecting reinforcement (14) of the prestressed plate (4) with the longitudinal self stress steel reinforcement (2), the single side connecting length is not less than 10 times the diameter, connecting the binding stirrup (3) with the transverse self stress steel reinforcement (1), and connecting the transverse self stress steel reinforcement (1) with the self stress reinforcement plate (7). The transverse self stress steel reinforcement (1) and the longitudinal self stress steel reinforcement (2) are symmetrically arranged on the elevation and are not less than two layers.

[0062] S4: mixing of the steel fiber expansive concrete structure (10): firstly, wetting the steel fiber in a bucket, and the wetting water is deducted from the total water quantity, then putting the gravel, sand, cement and expansive agent into a mixer, adding water and water reducing agent after uniform stirring, and adding the wetted steel fiber into the mixer again.

[0063] The materials used by the steel fiber expansive concrete structure (10);

[0064] S5: pouring: wetting the connecting joint (5) by using clean water, pouring the mixed steel fiber expansive concrete structure (10), and vibrating in layers, and the insertion type vibration is prohibited, and the flat vibrator is used for vibrating and flattening after the vibration, and finally the surface is manually collected to avoid the exposure of the steel fiber.

[0065] S6: curing: curing by covering curing cloth, and the curing time is not less than 7 days.

[0066] S7: Self-stress enhancement plate (7) processing: remove the pressure spring (9), and rust removal and rust prevention paint treatment are carried out on the self-stress enhancement plate (7).

[0067] The bending channel connecting structure and the straight channel connecting structure have the same construction steps.

[0068] In the current traditional prestressed structure, the prestress is generated by mechanical tensioning of longitudinal and transverse steel strands, steel wire strands or fine rolled threaded steel through a jack by using the pre-tensioning method or post-tensioning method, and the prestress is generated by mechanical energy; the reinforcement of ordinary reinforced cement concrete only plays a framework role in the prefabrication process and has no stress. The self-stress in the application is generated by chemical energy conversion to make the reinforcement and steel fibers generate tensile stress: the chemical reaction of high-performance expansive agent, cement and water causes the expansion of cement concrete, generates chemical energy, and drives the longitudinal and transverse reinforcement to expand to both sides (longitudinal 2 and transverse 1), thereby generating tensioning effect. The ordinary reinforcement generates stress without mechanical tensioning and becomes self-stress reinforcement, which has the same effect as the traditional mechanical tensioning steel strand. Therefore, the application is different from the traditional prestress in that the reinforcement generates tensile stress without mechanical tensioning, and is different from the ordinary reinforced cement concrete in that the reinforcement has tensile stress during the curing process. Similarly, the chemical energy of the expansion of cement concrete can also generate a certain self-stress of the steel fibers distributed therein. Figure 1

[0069] The reinforcement and steel fibers are doubly tensioned, the longitudinal and transverse self-stress reinforcement generates transverse and longitudinal self-stress in the connecting structure, the self-stress is compressive stress, thereby reducing the tensile stress generated by the load, increasing the load-carrying capacity of the connecting structure, reducing the cracks of the connecting structure in use, and preventing the corrosion of water to the reinforcement.

[0070] The steel fibers are uniformly distributed in the connecting structure, and due to the expansion of the cement concrete, self-stress in various directions is generated, the micro-cracks of the connecting structure in various directions due to dry shrinkage and temperature shrinkage are reduced, and the corrosion of water to the reinforcement and steel fibers is reduced.

[0071] The generation of the two self-stresses simultaneously increases the load stress resistance of the connecting structure and the durability of the structure.

[0072] In summary, compared with the ordinary concrete connecting joint and the prestressed concrete connecting joint, the self-stress connecting structure of the application has the following advantages:

[0073] 1. The connecting structure uses steel fiber expanded concrete, and the tensile strength is relatively high. Due to the existence of self-stress, the tensile stress will not exceed the ultimate tensile stress of the concrete, and no cracks will occur during operation, the durability is high, and the service life is long.

[0074] ​2. The self-stress synergic device is arranged to effectively improve the efficiency of converting chemical energy into mechanical energy to make the steel bar produce self-stress;

[0075] 3. The bend connecting structure one and the bend connecting structure two make the left and right widths of the connecting structure freely changeable, the prestressed pavement can be used on the bend by adjusting the width of the connecting structure, and the problems of complex stress, difficult reinforcement and easy cracking of the prestressed pavement on the bend are solved;

[0076] 4. The self-stress connecting structure is used to connect the prestressed plates, in the process of pavement operation, only the damaged prestressed plate is replaced, the replacement is relatively simple, the stress of other plates is not affected, the maintenance is facilitated, and the maintenance cost is low;

[0077] 5. The tensioning and grouting is not performed on site, the process is simple, the cost is low, there is no slurry pollution, and the application is green and environmentally friendly.

[0078] Although the example embodiments and their advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the application as defined by the appended claims. For example, it will be readily apparent to those of ordinary skill in the art that the order of the process steps can be changed while remaining within the scope of the present application.

[0079] In addition, the scope of the application is not limited to a specific embodiment of the processes, mechanisms, articles of manufacture, compositions of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure herein, processes, mechanisms, articles of manufacture, compositions of matter, means, methods or steps existing or later developed that perform substantially the same function or achieve substantially the same result as corresponding embodiments described herein can be utilized according to the present application. Accordingly, the appended claims are intended to cover all such processes, mechanisms, articles of manufacture, compositions of matter, means, methods and steps.

Claims

1. A self-stressing connection structure suitable for use in a modular pavement, characterized in that: The connecting structure comprises a straight connecting structure and a curved connecting structure one and two. The straight connecting structure and the curved connecting structure further comprise the following four parts: The prefabricated prestressed slab is installed on the low friction isolation layer, and has a connecting joint and a cross section perpendicular to the longitudinal self-stress steel bars of the connecting structure; The self-stress reinforcing device is fixed on both sides of the connecting joint of the prefabricated prestressed slab, and is composed of a self-stress reinforcing plate, bolts for fixing the self-stress reinforcing plate and pressure springs; The self-stress steel bar structure is arranged in the connecting joint and is composed of longitudinal and transverse self-stress steel bars, the longitudinal and transverse self-stress steel bars are connected with the embedded connecting steel bars of the prefabricated prestressed slab in the longitudinal direction and are connected with the self-stress reinforcing plate in the transverse direction, the longitudinal and transverse self-stress steel bars are symmetrically arranged and are configured with the same diameter and the same type; The steel fiber reinforced concrete structure is poured in the connecting joint and is surrounded by the prefabricated prestressed slab and the self-stress reinforcing plate.

2. The self-stressing connection of claim 1, wherein, The connecting joint of the connecting structure further comprises a straight connecting joint, a curved connecting joint one and a curved connecting joint two. The straight connecting joint is an equal-width straight edge connecting joint, the curved connecting joint one is an equal-width sawtooth connecting joint, the curved connecting joint two is an unequal-width sawtooth connecting joint, and the prestressed slabs on both sides of the curved connecting joint are provided with a stepped sawtooth structure along the width direction, and the step directions are opposite.

3. The self-stressing connection of claim 1, wherein, The self-stress reinforcing device is used for limiting the expansion amount of the expanded concrete and comprises a self-stress reinforcing plate, bolts and cylindrical pressure springs. The self-stress reinforcing plate is divided into a straight self-stress reinforcing plate and a curved self-stress reinforcing plate, the straight self-stress reinforcing plate is a straight plate, and the curved self-stress reinforcing plate is an arc-shaped plate.

4. The self-stressing connection of claim 1, wherein, The self-stress steel bar structure comprises longitudinal self-stress steel bars connected with embedded connecting steel bars of a prestressed slab, transverse self-stress steel bars connected with a self-stress reinforcing plate and stirrups. The longitudinal and transverse self-stress steel bars are double-layer steel bars symmetrically and uniformly arranged along the horizontal central axis, the longitudinal self-stress steel bars of the straight connecting structure are perpendicular to the end cross section of the prestressed slab, and the longitudinal self-stress steel bars of the curved connecting structure are consistent with the curved line of the curved connecting structure, and the longitudinal self-stress steel bars are arranged perpendicularly to the sawtooth surface of the prestressed slab at the end position of the prestressed slab.

5. The self-stressing connection of claim 1, wherein, The steel fiber reinforced concrete structure is composed of milled steel fibers, high-performance expanding agent, high-efficiency water reducing agent, ordinary portland cement, limestone, medium sand and water.

6. The self-stressing connection of claim 1, wherein, The prestressed slab has a thickness of 20-24 cm and a compressive strength of 40-50 Mpa, the straight prestressed slab is a rectangular plate with a longitudinal length of 3-3.5 m and a transverse width of 7.5-7.8 m, and the curved prestressed slab is a special-shaped plate with a sawtooth-shaped end.

7. The self-stressing connection structure according to claim 1 or 2, wherein The depth of the connecting joint is the same as the thickness of the prestressed slab, the width of the straight connecting joint and the curved connecting joint one is 15-25 cm, and the width of the curved connecting joint two is 15-25 cm in the short side and is arranged according to the matching of the curved radius in the long side.

8. The self-stressing connection structure according to claim 1 or 3, wherein The self-stress reinforcement plate is a steel plate of model Q345q, with a thickness of 3mm-5mm, a height equal to that of the prestressed plate, and a length of the joint width+10cm on both sides of the anchoring length, the self-stress reinforcement plate is anchored by the lengthened M20 bolt, the cylindrical pressure spring with a pressure of 20kN-30kN is arranged between the self-stress reinforcement plate and the nut, and the spring compression amount is 2cm.

9. The self-stressing connection structure according to claim 1 or 4, wherein The self-stress steel bar adopts the HRB400 ribbed steel bar with the same model and diameter, and the reinforcement ratio is 0.5%-2%.

10. The self-stressing connection structure according to claim 1 or 5, wherein The longitudinal stress design target value of the steel fiber expanded concrete structure is 3-5 MPa, the compressive strength of the steel fiber concrete is 40-50 MPa, the flexural strength is 6-9 MPa, the high-performance expansive agent content is 10-12%, the steel fiber content is 0.8-1.5% in volume ratio, the steel grade is ST52-3, the length is 32.0 mm±2 mm, the width is 2.6 mm±1.2 mm, the length-diameter ratio is 35-45, and the tensile strength is greater than or equal to 700 N / mm 2 .

11. The self-stressing connection structure according to claim 1 or 2, wherein The low-friction isolation layer comprises, from bottom to top, an oil-permeable layer, a high-strength high-density PVC engineering plate, and a plastic cloth.

12. A construction method of the self-stress connecting structure suitable for the assembled pavement according to claim 1 or 2, and specifically comprising the following steps: installing the prestressed plate: the prestressed plate is chiseled on the side surface of the joint end, and the prestressed plate is hoisted to the predetermined installation position on the low-friction isolation layer; installing the self-stress reinforcement plate: the self-stress reinforcement plate is fixed on the prestressed plates on both sides of the joint by the bolt, the height of the self-stress reinforcement plate is flush with the prestressed plate, the pressure spring is arranged between the nut and the self-stress reinforcement plate, and the gap between the self-stress reinforcement plate and the low-friction isolation layer is sealed by the high-grade mortar; binding the self-stress steel bar: the longitudinal self-stress steel bar is bound to the embedded connecting bar of the prestressed plate, the transverse self-stress steel bar is bound to the stirrup, and the transverse self-stress steel bar is connected to the self-stress reinforcement plate; mixing the steel fiber expanded concrete: the gravel, sand, cement, and expanding agent are uniformly stirred in the mixer, then the water and the water reducing agent are added, and the steel fiber is added again after being uniformly stirred twice; pouring the steel fiber concrete: the joint is fully moistened with water, the mixed steel fiber expanded concrete is poured and vibrated layer by layer, the insertion type vibration is prohibited, the flat vibrator is used for vibration and leveling after vibration, and the surface is manually collected; curing: curing cloth is covered for curing, and the curing time is not less than 7 days; self-stress reinforcement plate treatment: the pressure spring and the anchoring bolt are removed, and the self-stress reinforcement plate is treated by rust removal and rust prevention paint.

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