LT6806B - Composite module for pedestrian and bicycle traffic zones and its building method - Google Patents

Abstract

The object of the invention is to create the asphalt-concrete composite modules (slabs) for the installation of shoulders, pedestrian and bicycle paths, characterized by specific requirements for dimensions, convenient and quick installation or replacement, durability, skid resistance, traffic comfort and low cost. Asphalt-concrete composite module (slab) consisting of a 65 mm in thickness cement- concrete module (slab) made of ordinary concrete with a compressive strength class of C30/37- C40/50 with the addition of both 0.6-1.1 kg/m³ of micro-fibres (e.g. 0.8 kg/m³) and 3-5 kg/m³ of macro-fibres (e.g. 4 kg/m³), layer (2), constructed on a conventional base course (unbound base course, base course bound with hydraulic or bituminous binders) (3), ensuring a static deformation modulus of at least 100 MPa and a compaction coefficient of at least 100%, differing in constructed an anti-slip layer of asphalt mixture on the cement concrete module (slab) (1), asphalt-concrete composite modules (slabs) are available in 4 sizes, the joints between the modules (slabs) are filled with seals.

Description

The invention belongs to the field of construction industry, more precisely to asphalt-concrete composite modules (slabs) used in pedestrian and bicycle traffic areas (footpaths, sidewalks, pedestrian and bicycle paths, bicycle paths), which have specific requirements for size and thickness, increased durability, slipperiness reducing road safety and comfort. Also, reduce the need for maintenance of the building and the cost of maintenance.

It is known that in order to ensure the safe movement of vulnerable road users, it is very important to have pedestrian and bicycle traffic areas with the right parameters. Proper drainage of surface (rain) water and pavements that ensure sufficient adhesion and slip resistance significantly reduce the risk of accidents with severe consequences.

The surface of footpaths, squares, parks and other public spaces must be solid, stable, non-slip when wet, and rainwater must not accumulate on it (see Order No. D1-653 of the Minister of Environment of the Republic of Lithuania of 4 November 2019 “On Construction Technical Technical Regulation STR 2.03.01: 2019 “Accessibility of Structures” approved by the Technical Regulation STR 2.03.01: 2019 “Availability of Structures”). The choice of pavement types and materials must ensure that they have sufficient and long-term wheel adhesion to the pavement, as well as sufficient long-term slip resistance. It should also be taken into account that pedestrian areas or paths, especially in front of shop windows or on ramps, should have the necessary slip resistance (see Order No. V-71 of 21 February 2014 of the Director of the Lithuanian Road Administration under the Ministry of Transport and Communications Approval of the UN Road Pavement Construction Regulations for Road Pavement Structures from Blocks and Slabs ”approved Road Construction Regulations for Road Pavement Construction from Blocks and Slabs (UN PADS 14).

There are known cement concrete slabs for paving streets, roads, highways and highways, when a cement concrete mixture is poured on a installed and prepared base and a pavement is formed. The width of the cement concrete slab is selected according to the standard or average distance between the wheels of the front or rear axle of the truck, whichever is smaller. And the length of the cement concrete slab is chosen according to the smallest distance between the front and rear axles of the truck. In this way, the width and length of the cement concrete slab can be from 0.50 m to 3.50 m. The thickness of the cement concrete slab is selected according to the deformation modulus determined by the compressive strength of the cement concrete mix, traffic loads, base quality and soil type. These cement concrete slabs can be formed on a conventional substrate - unbound mixture, cement or bituminous binder-bound mixture (see WO 2007/042338 A1, publ. 2007-04-19).

The coating formed from these cement concrete slabs is resistant to heavy transport loads, as the cement concrete slab will always be affected by the load on one wheel of the truck or only one chassis. However, the installation of this type of coating is a slow process, as cement concrete slabs are formed on an installed and prepared base by pouring and compacting the cement concrete mix. In addition, the repair of such a cement-concrete slab coating is not possible by replacing a damaged cement-concrete slab, so its repair requires timely traffic restrictions and technological processes and materials.

There are known prefabricated cement concrete slabs for paving, which can be used for quick and convenient construction, repair and maintenance, and which are durable and cost-effective. Prefabricated cement concrete slabs, each of which is adapted to the width of the road, can be easily transported to the construction site and using lifting equipment mounted on each part of the slab. Also, each cement concrete slab is fitted with inserts to firmly connect the slab blocks. Waterproofing elements that prevent water from penetrating the substrate are installed between the continuously connected adjacent panels. Therefore, the road surface made of cement concrete slabs can be easily repaired or replaced in a cost-effective way. Also, the road surface can be improved and a smooth surface can be achieved (see US 6688808 B2, publ. 2004-02-10).

The coating formed from these cement concrete slabs has sufficient resistance to heavy transport loads, but such cement concrete slabs have a higher bearing capacity than a bicycle and / or footpath or pavement, making the installation of these cement concrete slabs inefficient for such buildings.

Also, cement concrete slabs are known for the rapid installation of road pavement and their subsequent rapid maintenance and repair. These cement concrete slabs are 3-5 m wide and 25-35 cm thick, therefore, in order not to deform during the installation of the road surface or its replacement during repairs, a reinforcement network is installed in the lower part of the slab at a distance of 5 cm from the lower surface. Also, each cement concrete slab is fitted with inserts that protrude 20-50 cm from the surface on the sides of the cement concrete slab and are designed to firmly connect the slab blocks (see CN203514143U, publ. 2014-04-02).

Cement concrete slabs of this type are not suitable for light load traffic areas, such as footpaths, sidewalks, bicycle paths.

There is a known high-strength cement-concrete mix for the installation of road pavements that are particularly resistant to high static and dynamic loads. This strength of the cement concrete mix is achieved by the addition of metal fibers that strengthen the carcass and provide resistance to crack formation (see US6080234A, publ. 2000-06-27 and US6887309B2, publ. 2005-05-03).

Cement concrete mix with metal fibers has good mechanical properties, as well as good resistance to static and dynamic loads, but metal fibers make it difficult to ensure the required surface texture and adhesion of the cement concrete slab.

The closest are cement concrete modules (slabs), which are made of a conventional cement concrete mix with micro and macro fibers, and are without inserts and are not interconnected, installed on a conventional base - unbound mix, cement and / or bituminous binder mix (see LT 6720 , publ. 2020-03-25).

The prototype has specific requirements for size and thickness, convenient and quick installation on a conventional base, convenient and quick replacement (in case of repair), different surface texture and slip resistance are possible, as well as durability and low cost. However, the texture of these modules is not deep. During rain, the surface (rain) water entering the pedestrian and bicycle traffic areas from the cement concrete modules (slabs) forms a water film, therefore the paths installed from these modules may not be sufficiently resistant to slipping, and there is a risk of vulnerable road users slipping and injuring themselves. In addition, the joints of cement concrete modules (slabs) of traffic area coverings are usually not sealed, therefore the joints become contaminated with foreign substances and vegetation takes place during the warm season. In addition, the gaps (seams) in the pavement reduce the comfort of vulnerable road users.

Conventional cement concrete pavement is smooth and slippery, especially in adverse weather conditions, precipitation, when the surface (rain) water on the pavement surface reduces the slip resistance of the pavement. To increase slip resistance in pedestrian areas with concrete pavements, surface roughening is often performed using mechanical means such as the broom method (see Frederick R. Steiner, Kent Butler, Planning and Urban Design Standards, Student Edition, American Planning Association, 2006). This increases the adhesion characteristics, but the surface texture of the concrete surface obtained in this way does not ensure sufficient surface (rain) water leakage, therefore a layer of water is formed on the surface of such a coating, which reduces the slip resistance.

It is known that the surface texture of an asphalt pavement is directly related to slip resistance. Small unevenness of the asphalt mix aggregate particles prevents the formation of a continuous water film, which increases the slip resistance of the pavement (see Malal Kane, Ignacio Artamendi, Tom Scarpas, “Long-term skid resistance of asphalt surfacings: Correlation between Wehner-Schulze friction values and the mineralogical composition of the aggregate ”, Wear 303 (2013) 235-243). The texture depth of the asphalt pavement is greater than that of the concrete pavement. The surface of asphalt pavements has grooves through which surface (rain) water drains from the pavements, therefore, in the presence of rain of normal intensity, no water layer is formed on the tracks.

In addition, the asphalt pavement is more resilient than the concrete pavement, making the asphalt pavement paths more comfortable for both pedestrians and cyclists to move around.

The object of the invention is to provide asphalt-concrete composite modules (slabs) for the installation of footpaths, sidewalks, footpaths and bicycle paths, bicycle path pavements with specific requirements for size and thickness, convenient and quick installation on a conventional base - unbound base layer, hydraulic or bituminous binder-bonded base layer - convenient and fast replacement (in case of repair), durability, slip resistance, comfortable in traffic and low cost. The aim of the invention is achieved by implementing the project “Modular Coatings” financed from the European Regional Development Fund (project No. 01.2.2-LMT-K-718-01-0044) according to the grant agreement with the Lithuanian Science Council (LMTLT).

This goal is achieved by producing 4 sizes of asphalt-concrete composite modules (slabs), the dimensions of which are selected according to the requirements for pedestrian and bicycle traffic areas to ensure functionality:

asphalt-concrete composite module (slab) width - 500 mm, length - 1000 mm and thickness - 80 mm;

asphalt-concrete composite module (slab) width - 1000 mm, length - 1000 mm and thickness - 80 mm;

asphalt-concrete composite module (slab) width - 1200 mm, length - 1000 mm and thickness - 80 mm;

asphalt-concrete composite module (slab) width - 1800 mm, length - 1000 mm and thickness - 80 mm;

Also, the goal is achieved by using cement-concrete modules (slabs) in asphalt-concrete composite modules (slabs) (see LT 6720, publ. 2020-0325), which are without inserts and are not interconnected, are installed on a non-bonded base. layer, hydraulically or bituminously bound substrate, the bearing capacity of which, determined in accordance with the requirements of the standard LST 1360-5, is: deformation modulus E _v2 > 100 MPa, and / or the degree of compaction determined in accordance with the standards LST 1360.6 and LST EN 1360-2 requirements is D _Pr ž 100%. Cement concrete modules (slabs) weigh 150-300 kg, depending on the cement concrete mix used, therefore they are installed and, if necessary, replaced (in case of repair) using vacuum or compression hoists, ie no additional metal loops are required. These cement concrete modules (slabs) must be made of a regular mixture of cement concrete with micro and macro fibers. Conventional cement concrete is manufactured in accordance with the relevant technical documents and / or standards with a compressive strength class of C30 / 37 to C40 / 50. Typically, the compressive strength of such a cement concrete mix is from 35 MPa to 55

MPa and a bending strength of 4 MPa to 6 MPa. ^{0.6-1.1 kg / m 3 of} micro-fibers (eg 0.8 kg / m ³ ) and 3-5 kg / m ^{3 of} macro-fibers (eg 4 kg / m ³ ) are added to the normal cement concrete mix. . The mechanical properties of such a mixture of cement concrete with micro and macro fibers must meet the requirements given in Table 1:

table

Feature Standard Value required Compressive strength after 7 days, MPa LST EN 12690-3 > 30.0 Bending strength at 7 days, MPa LSTEN 12690-5 ž3.5 Compressive strength after 28 days, MPa LSTEN 12690-3 > 45.0 Bending strength at 28 days, MPa LSTEN 12690-5 > 5.0

Also, the goal is achieved by installing a 15 mm thick layer of asphalt mixture on the manufactured modules at the factory. The composition of the asphalt mix (see LT 6724, publ. 10/04/2020) includes a mixture of aggregates from fractionated crushed stone and mineral powder, an adhesion improver, cellulose fiber and polymer-modified bitumen in a weight ratio of components of:

2-5 mm granite chippings fraction - 75,0 to 86,0, 0-2 mm granite chippings -7.0-14.0, mineral powder - 1,0 to 5,0, adhesion promoter - 0,01 -0,03, cellulose fiber - 0,30 to 0,60, bitumen - 5.0-6.5.

The object is also achieved in that the particle size distribution of said mixture of fillers in% by weight is:

spread through a 0.063 mm sieve - 3,0 to 8,0, spread through a 0.125 mm sieve -4.0-9.0, spill through a 0.250 mm sieve -5.0-10.0, spill through a 0.5 mm sieve -6.0-12.0, spill through a 1.0 mm sieve -7.0-13.0, spill through a 2.0 mm sieve -11.0-18.0, spread through a 5.6 mm sieve -85.0-100.0,

spread through a 8.0 mm sieve -100.0.

These asphalt mixtures have good mechanical and performance properties.

Also, the goal is achieved by sealing the joints formed between the asphalt-concrete composite modules (slabs) with seals (bitumen, silicone or epoxy based). In this way, the edge of the asphalt pavement is stabilized and the joints of the slabs are protected from contamination by foreign materials, preventing plant vegetation in the joints. The maintenance of such traffic areas will be easier. In addition, sealing the joint gaps will make the pavement smoother, the edges of the modules (panels) will be safer, and pedestrian and cyclist traffic will be more comfortable. Paths made of asphalt-concrete composite modules (slabs) are superior to conventional paved asphalt pavement paths in that their installation and maintenance is easier to implement, i. it is not necessary to frame the curbs of the trail, it can be installed even in cold weather.

The concept of asphalt-concrete composite modules (slabs) for the installation of pavements for bicycles and / or footpaths and sidewalks presented in the invention is illustrated by an example.

example of asphalt-concrete composite module (slab) fig. shows an asphalt-concrete composite module (slab) according to the invention.

The developed asphalt-concrete composite modules (slabs) have good mechanical and operational characteristics, durability and low cost.

The present invention can be applied to the pavement of bicycle and / or footpaths and sidewalks and other traffic areas where heavy traffic does not occur.

It should be understood that many specific details are set forth in order to provide a complete and understandable description of an exemplary embodiment of the invention. However, it will be clear to a person skilled in the art that the detail of the examples of implementation of the invention does not limit the implementation of the invention, which can be implemented without such specific instructions. Well-known methods, procedures, and ingredients have not been described in detail to avoid misleading examples of the practice of the invention.

Claims (7)

DEFINITION OF THE INVENTION An asphalt-concrete composite module (slab) consisting of a 65 mm cement-concrete module (slab) layer (2) made of conventional C30 / 37-C40 / 50 compressive strength class cement concrete with the addition of 0.6-1.1 kg / m ^{3 of} micro-fibers (eg 0.8 kg / m ³ ) and 3-5 kg / m ^{3 of} macro-fibers (eg 4 kg / m ³ ) mounted on a conventional substrate (unbound substrate, hydraulic or bituminous binder-bonded base) layer (3), ensuring a static deformation modulus of at least 100 MPa and a compaction coefficient of at least 100%, characterized in that a layer of asphalt mixture (1) reducing the slipperiness is installed on the cement concrete module (slab), asphalt -concrete composite modules (slabs) are available in 4 sizes, the joints between the modules (slabs) are filled with sealants. 2. The layer of asphalt mixture according to claim 1, characterized in that its thickness is 15 mm. 3. The asphalt mixture according to claim 1, characterized in that it comprises an adhesion promoter, a cellulose fiber and a polymer-modified bitumen, a mixture of aggregates from fractionated crushed stone and mineral powder consisting of a fraction of 2-5 mm granite crushed stone, and 0-2 mm granite chippings and mineral powder, the ratio of the components in% by weight is: 2-5 mm granite chippings fraction - 75,0 to 86,0, 0-2 mm granite chippings -7.0-14.0, mineral powder - 1,0 to 5,0, adhesion promoter -0.001-0.03, cellulose fiber - 0,300 to 0,60, bitumen - 5.0-6.5. 4. The asphalt mixture according to claim 1, characterized in that the particle size distribution of said aggregate mixture is% by weight: spread through a 0.063 mm sieve - 3,0 to 8,0, spread through a 0.125 mm sieve -4.0-9.0, spill through a 0.250 mm sieve -5.0-10.0, spill through a 0.5 mm sieve -6.0-12.0, spill through a 1.0 mm sieve -7.0-13.0, spill through a 2.0 mm sieve -11.0-18.0, spills through 5.6 mm sieve - 85.0-100.0, spills through 8.0 mm sieve -100.0. 5. Asphalt-concrete composite module (slab) according to claims 1, 2, 3 and 4, characterized in that four sizes of modules are produced: asphalt-concrete composite module (slab) width - 500 mm, length - 1000 mm and thickness - 80 mm; asphalt-concrete composite module (slab) width - 1000 mm, length - 1000 mm and thickness - 80 mm; asphalt-concrete composite module (slab) width - 1200 mm, length - 1000 mm and thickness - 80 mm; asphalt-concrete composite module (slab) width - 1800 mm, length - 1000 mm and thickness - 80 mm. Pavement of footpaths, sidewalks, footpaths and cycle paths, cycle paths comprising an asphalt-concrete composite module (slab) according to claims 1, 2, 3, 4 and 5. 7. Pavement of sidewalks, sidewalks, pedestrian and bicycle paths, bicycle paths according to claim 6, characterized in that the asphalt-concrete composite modules (slabs) are without inserts and they (they) are not interconnected, and the joints are filled with sealant (bitumen, silicone or epoxy based).