RU2379406C2 - Building method and prefabricated pavement structure - Google Patents

Abstract

FIELD: building.

SUBSTANCE: in building method for prefabricated pavements, involving placement of prestressed right-angled or square reinforced-concrete slabs on a ground, sand or other base, fastening of the slabs together in one or two mutually perpendicular directions by means of through armature in openings to be tensed thereafter, sealing of joints between the slabs with an air-tight material, paving of the concrete base with asphalt or poured asphalt concrete. The slabs are fastened by packing five to twenty slabs with steel ropes thereafter to be tensed at the effort 5 to 30 "те" per each rope. Herewith between end faces of the slabs, the ropes are covered with resilient members. The steel ropes are placed in the through openings, while their ends having been fixed are anchored within fastening cavities of the slabs last in the packages with concreting the cavities. In the prefabricated pavement structure, the steel ropes are located in the through openings at the distance 0.7-2 m from each other at length of the packing openings 15 to 60 metres, with concreting the fastening cavities for the anchors and ends of the steel ropes. The slab joint dimensions are 15 to 40 mm.

EFFECT: higher maintainability of the pavement.

3 dwg, 2 cl

Description

The invention relates to the field of road construction, mainly to structures and methods for the construction of prefabricated road surfaces of roads, airfield strips and their entrances, car parks and other heavily loaded road surfaces.

There are various methods of building prefabricated pavements, including a method of building a prefabricated pavement by connecting reinforced concrete slabs containing continuously closed prestressed longitudinal and transverse strand reinforcement wound in the form of beams around the perimeter and edges of the slab on the internal anchors (see, for example, USSR copyright certificate No. 1813823, class E01C 5/10, 1989). The connection of the plates with each other with the formation of a continuous pavement is carried out in a known manner by additionally connecting the internal anchors using bolts with nuts and washers, which avoids the welding operation during installation of the coating.

However, the complexity of the design of the known coating, as well as insufficient strength and reliability of the connection only with bolts larger than the dimensional plates between them reduces the effectiveness of the known method.

In another known method, slabs for prefabricated paving are made directly at the construction site, for which cement-concrete mixture is placed in the side formwork, and after compaction, metal anchor elements are embedded in it, followed by laying on the surface of the hardened concrete layer of hot molded asphalt, and after forming each plate a separation layer is laid on it, and the formation of a continuous coating is carried out by molding each subsequent plate on a separation peeling of the underlying plate (see, for example, USSR copyright certificate No. 1700124, class E01C 5/06, 1989).

The known method allows to exclude the use of steam for heat and moisture treatment of the package of plates due to the warming of the cement concrete mixture with hot heat when laying asphalt concrete, to reduce the formation of microcracks in cement concrete under a layer of cast asphalt. However, this method, in its implementation, is time-consuming, and the resulting paved road surface is characterized by a large number of seams (joints) between the plates, which to some extent worsens the evenness of the coatings.

Various structural solutions of prefabricated pavements are also known. So, for example, in the known construction of a precast road pavement (see, for example, USSR author's certificate No. 1520173, class E01C 5/20, 1987) of a precast pavement, longitudinal and transverse flexible strips of sand-impermeable material are laid on a sand base, flat elastic elements located between flexible strips, and precast concrete slabs. Flexible strips are located under the longitudinal and transverse seams of the coating, and flat elastic elements can be provided along their perimeter with anchor rods directed perpendicular to the plane of the elastic elements.

In this case, the anchor rods directed downwards are buried in the sand base, and directed upwards are located in the planes of the longitudinal and transverse seams of the coating and are rigidly connected to the butt and assembly-butt elements of the plates. When there is a moving load on the cover plate, the edges and corners of the plate at which the highest stresses appear tend to bend down and penetrate the base. This is prevented by flat elastic elements that distribute the load transmitted to the base over a large area occupied by these elements. Thus, there is a decrease in specific pressure on the sandy base. However, the known design does not sufficiently transfer the load from one plate to another, which leads to uneven settlement and displacement of the plates relative to each other, deterioration of the evenness of the coating.

In another known construction of the pavement, including the subgrade, on which an additional layer of the base is made of soil reinforced with a binder, and on top of the additional layer the blocks of the main layer of the road surface are staggered (see, for example, USSR author's certificate No. 1807152, cl. E01C 5/06, 1990). Moreover, the connection of the blocks with each other is carried out in a known design due to protrusions in the form of a dovetail, but if necessary, the blocks are combined using special, for example, metal rods, passed through the transverse and longitudinal channels.

On the upper layer of blocks, which can be stacked in several layers, a coating is made of cold asphalt mix, compacted by known methods. The described design of the pavement improves the strength and operational reliability of the roadway. Its disadvantage is the need for strict observance of the accuracy of manufacturing and stacking blocks, which is associated with increased complexity of these operations, which reduces the efficiency of the known design.

Closest to the proposed design and method of construction of prefabricated pavement are the constructive solution and method of construction of prefabricated pavement, given in the book of V. Mogilevich and others. Prefabricated road surfaces. - M .: Higher. School, 1072, p. 59-71).

The known construction includes an earthen, sand or other base, prestressed rectangular or square reinforced concrete slabs bonded to each other, seams filled with sealed material, and a soft topcoat of concrete slabs made of asphalt or cast asphalt. When installing such a coating design, prestressed concrete slabs are laid on a prepared base, then the slabs are connected to each other by prestressed steel reinforcement, passed through the slots through the through voids - channels, and laid on asphalt or asphalt concrete concrete slabs interconnected.

In the implementation of the known technical solution, small-sized concrete and reinforced concrete slabs are connected to each other, for which through fittings are provided through the channels provided in the slabs, through reinforcement is then tensioned and injected through channels with high-strength cement mortar. The resulting road surfaces are characterized by increased strength and, above all, fracture toughness, since the concrete slabs in such a coating work with their full cross section. Due to this, the thickness of concrete slabs can be significantly smaller, which can significantly reduce the consumption of concrete for their manufacture.

However, the excessive rigidity of the known prefabricated pavement, especially affecting alternating ever-increasing mobile loads, leads to a gradual destruction of the pavement, and the installation of the pavement itself, including pulling the ropes through a long (when laying and simultaneously pulling down a slab package with a length of, for example, over 20 m) coverage is associated with great difficulty.

The purpose of the proposed technical solution is to increase the operational characteristics and durability of the road surface, accelerate construction work, minimize the volume and material consumption of works on the basis of the road surface.

This goal is achieved by the fact that in the method of constructing a precast pavement, including laying prestressed rectangular or square reinforced concrete slabs on an earthen, sand or other base, fastening the slabs to each other in one or two mutually perpendicular directions using through fittings in the channels with subsequent by tensioning, sealing joints between slabs with hermetic material, covering a concrete base with asphalt or cast asphalt concrete, fastening reinforced concrete slabs they are pulled together in packages containing from 5 to 20 plates by steel ropes, followed by tension with a force of 5 to 30 ton-force per rope, while elastic elements are put on the ropes between the ends of the plates, steel ropes are placed in through channels located in the middle part slabs, and the ends of the ropes after tension are fixed with anchors in the fastening cavities of the extreme in the packs of plates with monolithic cavities with concrete, and in the design of the proposed prefabricated paving, including earthen, sand or other foundation, preliminary o strained rectangular or square plates bonded to each other, as well as seams filled with sealed material, and a soft top coating of concrete slabs made of asphalt or cast asphalt concrete, steel ropes are located in through channels in the internal volume of the plates at a distance of 0.7-2.0 m from each other (along the axes), the length of the tightening and prestressing steel ropes is selected in the range from 15 to 60 m; monolithic fastening cavities for anchors and ends of steel ropes are made rectangular or square with a ratio of width to length, selected in the range from 1: 1 to 1: 4 of the thickness of the plates until monolithic with concrete open upwards and bounded below by the lower surface of the through channels, and the elastic elements are made preferably made of rubber in the form of cylinders or parallelepipeds with a cross-sectional area of 4 to 20 cross-sectional areas of the through channels and a length of 0.3 to 1.0 plate thickness, and the size of the joints between the plates selected in the range from 15 to 40 mm.

Given in the claimed technical solution, the design parameters and the method of construction of the precast pavement achieve this goal. Outside the specified parameters, the goal is not achieved.

The essence of the proposed technical solution is as follows. By tightening the slabs into the pavement instead of reinforcement with high-strength steel ropes, it is possible to quickly install high-strength and durable pavement in the conditions of a construction site on almost the simplest basis - a compacted subgrade or sand. At the same time, the tightening of the ropes with a force of 5 to 30 tf for each rope allows you to connect large-sized plates with each other in packets of 15 to 60 m in length, and the placement of elastic, preferably rubber elements on steel ropes between the plates from the end faces allows you to effectively extinguish periodic alternating loads on the roadway, thus increasing the reliability and durability of the precast road surface. The use of fixing voids on the upper surface of the slabs in the packages for pulling steel ropes and fastening them with fixing anchors greatly facilitates the process of tightening the plates in packages while ensuring high-quality tension and fixing of steel ropes with anchors with monolithic concrete cavities.

All this provides an increase in the operational characteristics and durability of the road surface, acceleration of road construction while minimizing the volume of work performed.

The design of the precast pavement is shown in figures 1-3. Figure 1 shows a fragment of a precast road surface for roads (plan view); figure 2 is a fragment of a wide two-dimensional area, for example, airfield cover or parking (plan view); figure 3 - mounting anchor.

The design of the prefabricated pavement includes an earthen, sand or other base (not shown), prestressed rectangular or square reinforced concrete slabs 1, laid end to end to each other and fastened with steel ropes 2 from 15 to 60 m long. The ropes are stretched through the through channels 3 located in the internal volume of the plates, in their middle part, at a distance of 0.7-2.0 m (along the axes) from each other. Mounting cavities 4 of rectangular or square shape with a ratio of the width to the length of each cavity, selected in the range from 1: 1 to 1: 4 of the thickness of the plates, are placed in the upper part of the plates. Mounting cavities 4 are intended for pulling steel ropes and securing the ends of the ropes with anchors after tensioning the ropes. Prior to monolithic concrete, the cavities 4 are open upward and bounded below by the lower surface of the through channels 3. Between the ends of the plates 1 on the steel ropes 2 are elastic, preferably rubber elements 5 in the form of cylinders or parallelepipeds with a cross-sectional area of 4 to 20 transverse cross-sections of through channels and lengths from 0.3 to 1.0 plate thickness. Between the plates 1, after tensioning the steel ropes, a gap of 6 to 15 mm is provided.

The proposed method using the claimed design of a precast pavement is as follows. On a prepared earthen, sand or other base along the roadway lay prestressed rectangular or square reinforced concrete slabs 1 in an amount of from 5 to 20 pcs. on each package so that the through channels 3 in the plates are placed coaxially to each other. Then, steel ropes 2 are pulled through the through channels, at the same time putting elastic elements 5 on the ropes between the plates from the ends of the plates, and the plates 1 are pulled together with steel ropes 2, followed by jacking the ropes with a pulling force of 5 to 30 tf for each rope. In this case, gaps are left between the plates after tensioning - seams 6 with a size of 15 to 40 mm. High-quality laying of the ropes in the through channels 4 is provided by adjusting the position of the steel ropes in the mounting cavities 4, where the ends of the ropes are fastened together with fixing anchors (Fig. 3) after the ropes are tensioned. After tightening the reinforced concrete slabs with steel ropes into packages, fixing the ends of the ropes in the fastening cavities of the extreme in the packages of plates and monolithic these cavities, the joints-gaps between the plates are sealed with a sealed material. Asphalt or asphalt concrete is laid on concrete slabs stacked in bags.

The inventive design and method of construction of prefabricated pavement allows in a short time: a link of workers of 10-12 people, provided with the necessary equipment, can lay 3-4 blocks of slabs 50-60 m long with a total length of about 200-220 meters per worker day, and within one month to lay 4-5 kilometers of the roadway.

The advantages of the invention are:

- acceleration of the construction of roads, airfield strips, sites and other coatings;

- factory industrial production of high quality plates;

- the possibility of year-round manufacturing of slabs and the construction of prefabricated pavings;

- the possibility of laying precast concrete cover on a simplified base: earthen, gravel or sand embankment;

- Effective construction of high-quality pavings on soft and frozen soils;

- reuse (if necessary) of the same structures;

- the opening of traffic immediately after completion of the construction of the pavement;

- reducing the complexity of the work;

- the possibility of using mechanization and industrialization of the construction of prefabricated road surfaces.

Claims (2)

1. The method of construction of prefabricated pavements, including laying prestressed rectangular or square reinforced concrete slabs on an earthen, sand or other base, fastening the slabs to each other in one or two mutually perpendicular directions using through fittings in the channels with its subsequent tension, sealing the joints between slabs with hermetic material, covering a concrete base with asphalt or cast asphalt, characterized in that the reinforced concrete slabs are fastened together by pulling together in packages containing from 5 to 20 plates, with steel ropes, followed by tension with a force of 5 to 30 ton-force per rope, while elastic elements are put on the ropes between the ends of the plates, steel ropes are placed in through channels located in the middle of the plates, and the ends of the ropes after tensioning are fixed with anchors in the fastening cavities of the extreme in packs of plates with monolithic cavities with concrete. 2. The design of the precast road surface, including earthen, sand or other base, pre-stressed rectangular or square plates bonded to each other; seams filled with sealed material and a soft top coating of concrete slabs made of asphalt or cast asphalt, characterized in that the steel ropes are located in the through channels in the internal volume of the slabs at a distance of 0.7-2.0 m from each other (along the axes), the length of the tightening and prestressing steel ropes is selected in the range from 15 to 60 m; monolithic fastening cavities for anchors and ends of steel ropes are made rectangular or square with a ratio of width to length selected in the range from 1: 1 to 1: 4 of the thickness of the plates, until monolithic with concrete open upwards and bounded below by the lower surface of the through channels, the elastic elements are made preferably made of rubber in the form of cylinders or parallelepipeds with a cross-sectional area of 4 to 20 cross-sectional areas of the through channels and a length of 0.3 to 1.0 thickness of the plates, and the size of the joints between the plates E is selected from 15 to 40 mm.

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