Large formats (road surface)
A covering for traffic areas in road and path construction is referred to as large format . According to the information sheet on large formats, large formats are standardized paving stones or slabs with an edge length of 400 mm and a minimum thickness of 12 cm. The total length of the large formats is a maximum of 1250 mm within the scope of the FGSV information sheet. DIN 18318 can be used as the contractual basis for the installation, as it does not contain any length restrictions on the building materials to be used. However, specific requirements for the installation and to the construction products in should bid document are listed. In addition to the set of standards, the Betonverband Straße, Landschaft, Garten e. V. published a leaflet on the correct dimensioning and processing of large-format elements made of concrete.
Large formats are also installed with component lengths over 1250 mm as surface fasteners. These elements can have component lengths of up to 3 m and should be statically verified according to Westergaard. The permissible load classes differ from the large formats up to 1250 mm in length.
Large-format elements were already used in ancient times as surface reinforcement and in recent decades have gained increasing importance in inner-city areas with increased design requirements. In Germany, large formats are often used in the course of redesigning and redesigning pedestrian zones and other representative areas in municipal and private areas.
Traffic areas with large formats differ due to the larger dimensions of paving slabs and paving according to ZTV Pflaster-Stb. Large formats for road and path construction are made from natural stone, concrete or a combination of both materials - so-called multi-layer panels.
history
Large formats made of natural stone were already used in Mesopotamia in ancient times , especially on representative areas and processional streets. Nebuchadnezzar had around 600 BC Lay limestone slabs in the format 105/105/34 at the Ishtar Gate in Babylon . Each of these panels had a signature on the underside with the name Nebuchadnezzar II. On both sides of these large formats were sidewalks with brecciated panels 66/66/20.
In the Roman Empire, large-format elements were also used. The driving surface, u. a. Pavimentum (Latin for "screed") often consisted of approximately 60 × 60 cm and 25 cm thick basalt stone slabs. Other formats and materials from Roman road construction have also come down to us. In the 5th century AD, the 550 m long Arcadiusstraße (Hafenstraße) with marble slabs in the format 100/60 was built in Ephesus . In Roman forums, natural stone slab formats were used alongside screed. Where there were no quarries nearby, bricks in the formats 70/70 and more often 55/55/4 were used on the sidewalks.
In German cities, large-format granite slabs were used in sidewalk areas. These natural stones, also known as crust slabs, had a flat top, while the curved underside was roughly hewn. The shape of the underside gave the panels a high level of stability. In Berlin, from the 19th century, such plates were exchanged for field stones to make them easier to walk on. The granite slabs laid in the middle of the sidewalks were mostly framed by paving stones on both sides.
Grosse Strasse, as part of the Nazi party rally grounds in Nuremberg, was largely completed with large granite formats in 1939 according to plans by Albert Speer and renovated from 1991–1995. The edge length of the large formats used is 1.20 m. Component thicknesses of 10 cm or 12 cm were used.
In the GDR, the Taucha plate gained extensive importance from around 1970 . The Tauchaer plate was usually made with a standard size of 120/120 cm in 10 cm thickness and structurally reinforced for transport. The laying was carried out directly on a cement stabilization , which roughly corresponded to an HGT (hydraulically bound base course). The area of application of the large formats was both high-quality surface paving and industrial areas.
In western Germany, large-format elements were used much less frequently for paving in the 1970s. One of the projects that has been preserved is the town hall square in Veitshöchheim. The town hall square was laid in 1972 with large formats made of concrete in the format 100/100 and 7 cm thick. Due to the expected exposure to frost and de-icing salt, the concrete slabs were manufactured in concrete quality B 600. According to today's standards, this corresponds to a compressive strength class between C50 / 60 and C55 / 67.
Large formats with a modern definition, i.e. with a component thickness matched to the load, were first used in 1993 at Ulm Münsterplatz on the basis of extensive scientific load tests. Large-format multi-layer panels with the “Rosa Dante” surface in various square formats up to an edge length of 60 cm with a component thickness of 16 cm were used at Ulm Münsterplatz. The large formats at Münsterplatz were laid cross-joint with 8 mm joint width on a 20 cm thick drain concrete base layer with geotextile. In the area of the northern Münsterplatz and Kramgasse there are multilayer boards in the format 60/40/16. In 2004, granite slabs were laid on around 200 m² in the extension area from Münsterplatz to Neue Straße.
Building products
Large formats can be concrete blocks according to DIN EN 1338, concrete slabs according to DIN EN 1339 or natural stone slabs according to DIN EN 1341. Multi-layer panels are not subject to any standard. Due to the higher requirements of this construction method, specific features should be taken into account in the requirements for the construction products.
Large formats made of concrete (machine production)
Large-format elements made of concrete (according to DIN EN 1338 or DIN EN 1339) should be manufactured with increased requirements for dimensional accuracy. The permissible deviations from the length, width and height should be a maximum of ± 2 mm. Due to the high dimensional requirements and indispensable manufacturing tolerances, large formats made of concrete should be calibrated - i.e. sanded to height. Regardless of the standard on which the component is based, a characteristic minimum flexural strength of 5 MPa should be used. Large-format elements made of concrete can be manufactured with molded-on anti-movement devices and profiling on the underside to ensure positional stability.
Large formats made of concrete (hand-made)
Large-format elements (according to DIN EN 13198) with component lengths of up to 4 m are usually poured into precisely fitting formwork with C 30/37 or C 35/45 concrete. Large formats by hand should be produced with increased requirements for dimensional accuracy and concrete quality. The permissible deviations from the length, width and height should be a maximum of ± 3 mm. The permissible frost and thaw resistance (slap test) should be limited to 500 g / m² (medium). This usually requires the addition of concrete admixtures. Regardless of the compressive strength, hand-made large formats should have a characteristic minimum flexural strength of at least 5 MPa. These elements are dimensioned using the finite element method or a dimensioning according to Westergaard. The permissible expansion capacity of the concrete of 0.1 mm / m must not be exceeded - reinforcement inserts should only be used constructively to limit cracks for shrinkage cracks. Large-format hand-made elements can be manufactured with molded anti-slip devices and roughening on the underside to ensure positional stability.
Large formats made of natural stone
Large-format elements made of natural stone (according to DIN EN 1341) should be manufactured with increased demands on dimensional accuracy. The permissible deviations from the length, width and height should be a maximum of ± 2 mm. In addition, a static calculation should be carried out for large formats made of natural stone due to the different material strengths. Sawn side surfaces and, if necessary, smooth undersides are to be roughened, as cut, smooth surfaces are very relevant to damage due to inadequate power transmission with the bedding and joint material. With regard to the material properties (weather resistance, water absorption and color behavior), reliable tests must be carried out in advance. Natural stones usually have a good ecological balance, but adequate social standards are not always guaranteed.
Multilayer panels
Multi-layer panels are composite elements in which surface-processed natural stone panels in thicknesses of 2 cm to 4 cm are applied to a concrete base. The connection is usually carried out with fresh, non-solidified concrete; the natural stone cover slab is usually pretreated on the underside with adhesive slurry. The natural stone cover plate can be profiled on the underside to improve the adhesive properties. Multi-layer panels are not standardized components, so the relevant natural stone standards should be the basis for the components. The following parameters should be required for the finished multilayer board:
- Adhesive tensile strength> 1.5 MPa
- Flexural strength> 6 MPa
- Compressive strength> 55 MPa
Dimensioning
Large formats must be dimensioned depending on the load. In addition to a static component, the dynamic load on the traffic must be permanently removed when dimensioning. The component thicknesses, due to the dynamic loads of traffic, were derived empirically on the basis of realized objects. The dimensioning of the large formats is supplemented in a static analysis by a calculation of the breaking load, the finite element method or a dimensioning according to Westergaard. The calculations can be used to obtain reliable values for the minimum thickness of the elements depending on the size of the load or the degree of slenderness.
The published design concepts are rather conservative and emphasize operational safety. For large formats with a length of 1250 mm or more, individual evidence must be provided. The degree of slenderness of the large formats is either limited or ensured by static verification. The component thickness of the large formats is significantly influenced from a ratio of nominal length / nominal width of 0.5. In the leaflet "Large formats", a minimum thickness of 14 cm is required for traffic areas from load class Bk 0.3. According to the leaflet "Large formats", component thicknesses of up to 18 cm are provided for in higher load classes or with larger component dimensions.
| Load class | burden | Component thickness (lmax <60 cm) 1 |
Component thickness (lmax> 60 cm) 1 |
Breaking load |
|---|---|---|---|---|
| Within walking distance | Fire department access , occasional car traffic | 10 centimeters | 12 cm | > 22.5 kN |
| Bk 0.3 2 | Car traffic with rare heavy load use | 12 cm | 14 cm | > 30 kN |
| Bk 0.3 | Car traffic with a low proportion of heavy loads | 14 cm | 16 cm | > 35 kN |
| Bk 1.0 | occasional heavy traffic | 18 cm 3 | 18 cm | > 45 kN |
| Bk 1.8 | Heavy traffic, pedestrian zone | 18 cm | - | > 45 kN |
| Name of the traffic load | Type of traffic load | Examples of applications / traffic areas | Required thickness (nominal dimension) 1 |
|---|---|---|---|
| Stationary traffic | Predominantly static exposure, occasional use by cars, rare use by heavy traffic | Lowered, raised areas or areas closed off for vehicle traffic, squares, pedestrian areas or other traffic areas that are only rarely or in exceptional cases used (e.g. by rescue vehicles, cleaning vehicles or those for supply and disposal), fire service entrances | ≥ 100 mm |
| Low traffic | Regular use by cars, occasional use by heavy traffic | Building driveways, squares or other traffic areas on which events occasionally take place, pedestrian zones and other pedestrian traffic areas with little delivery and loading traffic | ≥ 120 mm |
| Medium traffic 2 | Regular use by heavy traffic, but without bus traffic | Pedestrian zones and other pedestrian traffic areas with delivery and loading traffic, lanes of streets 3 | ≥ 140 mm |
| Heavy traffic 4 | Regular use by heavy traffic, including bus services | Pedestrian zones and other pedestrian traffic areas with delivery and loading traffic, bus traffic areas 5 lanes of streets 3 | ≥ 160 mm 6 |
construction
There are three different construction variants for construction methods with large-format elements. For all structures, increased requirements should be placed on the evenness with a permissible deviation of ± 1 cm over a 4 m measuring section.
Conventional base course
The laying of the large formats (covering or ceiling) takes place on unbound base layers. However, the superstructure must meet higher requirements in terms of deformation stability and evenness. For the load class Bk 0.3, a deformation module Ev2> 150 MN / m² should be selected for the upper base layer, deviating from the RStO, and a deformation module Ev2> 180 MN / m² for the load classes Bk 1.0 and Bk 1.8. The superstructure should be dimensioned in accordance with RStO 12 depending on the increased load-bearing capacity requirements.
Bound base course
Higher load-bearing capacity requirements can be achieved with a “mixed construction” of a water-permeable, bound uppermost base layer and the unbound installation of the paving elements (Tab. 2 - variant 2). Drain concrete and drain asphalt base layers can be used in accordance with the leaflet “Infiltration areas” (draft). This structure has advantages in particular in the case of critical underground conditions and higher traffic loads. The long-term evenness of a traffic area based on rigid base courses is superior to surface paving based on conventional base courses.
Bound construction
There is currently insufficient long-term experience with the bound construction method. This type of construction is not dealt with in the leaflet “Large formats”.
execution
laying
The large formats are usually laid using a vacuum lifting device. The vacuum lifting device must be adjusted to the load of the panels and moved close to the ground. In order to be able to lay the large-format covering elements at the same height, they must be laid down parallel to the base. Building material mixtures of grain group 0/5 with a sand content of around 30% have proven themselves as bedding material. Deviating from DIN 18318, the bedding thickness should be on average 3 cm (± 1 cm) in the compacted state in order to reduce bending stresses caused by a bearing that is as rigid as possible. In the case of larger overhangs, the concrete slabs must be picked up, the bedding readjusted and the covering elements relocated. The straight course of the joint axes must be constantly checked by a sufficient number of auxiliary cords; a local coordinate system is helpful for this. The joint widths must be increased to 8 mm (± 2 mm) due to the component thickness based on DIN 18318 in order to achieve proper filling and thus optimal power transmission of the joints. The joints are filled continuously as the laying work progresses. When finally sludging the joints with finer, broken building material mixtures, suitable, permanently elastic joint stabilizers should be added. The wider joints make it easier for the traffic to remove the joint material. The final grouting of the joints takes place after compaction. Only color-coordinated or non-coloring aggregates may be used for sludging.
Compress
Large-format elements are stabilized by compacting. When compacting the concrete elements, vibratory plates with a set of rollers or those with a so-called plate-sliding device should be used. In the case of large-format components, it is advisable to carry out two vibrations, as such covering elements often react sensitively to joint displacements. The first compression step should be carried out after the first joint filling with a light compression device. After refilling the joints - with large formats made of natural stone, possibly also with the addition of water - the covering should be re-compacted with heavier vibrating plates. The operating weight of the vibratory plates for the second vibrating cycle depends on the plate thickness.
literature
- Gerhard Bennewitz: The Münsterplatz in Ulm - Object Report . E. Schwenk, Betontechnik GmbH & Co. KG, Elchingen-Thalfingen 1995.
- Harald Boehnke: Vinking Rock - paving stones and slabs for our cities . Aumüller, Regensburg 2011.
- Alexander Eichler: Large format slabs and paving stones made of concrete . In: road and highway . No. 6.2006 . Kirschbaum Verlag, Cologne 2006.
- Alexander Eichler: Laying large-format concrete slabs and paving safely . In: Road and civil engineering . No. 4.2009 . Giesel Verlag, Isernhagen (Hann.) 2009.
- Alexander Eichler: Large formats are trendy . In: Road and civil engineering . No. 4.2012 . Giesel Verlag, Isernhagen (Hann.) 2012.
- Josef Eisenmann: Use, construction and dimensioning of coverings . Munich 1999 (unpublished).
- Klaus Krass: Behavior of paving slabs made of large-format paving elements . SF cooperation, Bochum 2001.
- Network paving: paving trade - guild with a future . Peine 2017.
- Gottfried Lohmeyer: Concrete floors in industrial buildings . Federal Association of the German Cement Industry, Cologne 1996.
- Gottfried Lohmeyer, Karsten Ebeling: Concrete floors for production and storage halls . Publishing house Bau + Technik, Düsseldorf 2012.
- Horst Mentlein: Pavement Atlas . Rudolf Müller Verlag, Cologne 2007.
- Bernd Möller: Documentation for the calculation of large-format concrete paving elements for surface paving . Dresden 2003 (unpublished).
- Dietmar Ulonska: Traffic fortifications with large-format concrete paving elements . In: road and highway . No. 6/2009 . Kirschbaum Verlag, Cologne 2009.
- Dietmar Ulonska: Traffic fortifications with large-format concrete paving elements . In: road and highway . No. 6/2010 . Kirschbaum Verlag, Cologne 2010.
- Heinz Wolff: The pavement past and present . Deutscher Kunstverlag, Munich 1987.
- Wolf-D Hepach: Schwenk 1847-1997, five generations - one work . E. Schwenk, Baustoffwerke KG, Ulm 1997.
Standards and guidelines
European standards
- DIN EN 1338 Concrete paving stones - Requirements and test methods
- DIN EN 1339 concrete slabs - Requirements and test methods
- DIN EN 1341 natural stone paving slabs for outdoor areas - requirements and test methods
- DIN EN 1342 natural stone paving stones for outdoor areas - requirements and test methods
- DIN EN 1344 paving bricks - Requirements and test methods
Germany
- DIN 18318 traffic route construction work - paving slabs and slab coverings in unbound execution, edging
- Additional technical contract conditions and guidelines for the production of paving slabs, paving slabs and edging (ZTV Pflaster-StB 06)
- Technical delivery conditions for construction products for the production of paving slabs, paving slabs and edging (TL Pflaster – StB 06)
- Guidelines for the standardization of the superstructure of traffic areas (RStO 12)
- Leaflet for paving with large formats (MFG, FGSV 619)
- Working paper - surface pavements with paving slabs and paving slabs in bound design (FGSV 618/2)
- DNV - Leaflet 10/2002
- SLG - leaflet for the planning and execution of traffic areas with large-format paving stones and concrete slabs 06/2009
- QS plaster - 10 quality features for unbound surfaces with large formats made of concrete and natural stone with a minimum thickness of 12 cm
Web links
Individual evidence
- ↑ Leaflet large formats . FGSV, Cologne 2013.
- ↑ a b SLG - Leaflet for the planning and execution of traffic areas with large-format paving stones and concrete slabs 2009 .
- ↑ Gottfried Lohmeyer, Karsten Ebeling: Concrete floors for production and storage halls . Publishing house Bau + Technik, Düsseldorf 2012.
- ↑ a b Heinz Wolff: The plaster in the past and present . Deutscher Kunstverlag, Munich 1987, ISBN 3-422-06011-1 .
- ↑ All roads lead to Rome - Susanne Klischat ( Memento from March 15, 2013 in the Internet Archive )
- ↑ Network paving: paving trade - guild with a future . Peine 2017.
- ↑ Große Straße - Culture Department of the City of Nuremberg ( Memento from September 27, 2012 in the Internet Archive )
- ↑ [Information from the civil engineering office of the market town of Veitshöchheim]
- ^ The Münsterplatz in Ulm - Object Report . E. Schwenk, Betontechnik GmbH & Co. KG, Elchingen-Thalfingen 1995.
- ↑ a b Leaflet on large formats . FGSV, Cologne 2013, p. 17 .
- ↑ a b Alexander Eichler: Large-format slabs and paving stones made of concrete . Kirschbaum Verlag, Cologne 2006, p. 316 .
- ↑ Leaflet “Large Formats” . FGSV, Cologne 2013, p. 18 .
- ^ Gerhard Bennewitz: The Münsterplatz in Ulm - Object Report . E. Schwenk, Betontechnik GmbH & Co. KG, Elchingen-Thalfingen 1995.
- ↑ Harald Boehnke: Vinking Rock - paving stones and slabs for our cities . Aumüller , Regensburg 2011.
- ↑ QS pavement - 10 quality features for unbound pavement surfaces with large formats made of concrete and natural stone with a minimum thickness of 12 cm .
- ↑ Guidelines for the standardization of the superstructure of traffic areas (RStO 12) .