Pedestrian BridgesThin Structural ElementsStairwaysGalleries

KUSSER Graniteworks USA

Prestressed Granite

32

KUSSER Graniteworks USA KUSSER Graniteworks USA

1

1 Hildesheim, 2010length: 15 m (49’ 3”) plate thickness: 30 cm (11 3/4”)safe load: 4.7 kN/m² (93 psf)photo: Kirstin Knufmann

As part of the “Urban Rede-velopment West“ a 19.40 mlong prestressed granite bridge was built in 2010 to connect the center of Gevelsberg directly with the new Ennepepark. The bridge construction was required to be lightweight and slender, without additional structural elements, in order to enhance the existing scale of the En-nepepark. At the same time

the bridge had to meet the requirements of the contract-ing authority in terms of cost and sustainability (care, maintenance and durability). The prestressed granite bridge from Kusser impressed the architects and the client not only because of the slender-ness of its superstructure, but also because of its exceptional resistance to road salt, weathering and abrasion.

2, 3 Gevelsberg, 2010length: 19.40 m (63’ 8”) plate thickness: 45 cm (1’ 6”)safe load: 4.46 kN/m² (93 psf)

design: rha reicher haase associierte GmbH, Aachen construction: Planungsgruppe Scheller, Niederkrüchten

2

3

photos: Patrick Kirschhofer

Pedestrian bridges in prestressed granite

54

KUSSER Graniteworks USA KUSSER Graniteworks USA

64

5

When prestressing the granite, steel strands running through the bridge are tensioned with a force matching the load to be expected, in order to com-press the structure. The ten-sioned strands are fed through grease injected plastic ducts to provide protection against corrosion. A second strong

Longitudinal section of a prestressed granite bridge

The granite used for the prestressed granite bridges has a very high compres-sive strength, several times more than C35/45 concrete, making it ideal for prestress-ing. Because its sand-blasted surface is so resistant to road salt, weathering and abrasion an additional top layer surface material is not required. The thickness of the superstructure is reduced not only because of the prestressing but also by the thickness of a pave-ment which is necessary with other bridge structures. The sand blasted surface of a prestressed granite bridge is excellent for pedestrians, cyclists and vehicles.

Construction principle

6 Span length: 3 m (10’)Plate thickness: 4 cm (1 9/16”)Safe load: 5 kN/ m² (104 psf)

As a comparison: If not prestressed, a plate thickness of 15 cm (6”) would be necessary for a span length of 3 m (10’).

polyethylene tube provides additional protection against UV radiation and mechanical damage. Kusser quarries the light gray fine-grained granite used for prestressed granite bridges in the Bavarian Forest and processes it further in its own factory. This granite is very dense and in contrast to

concrete it neither shrinks nor expands, so that even after decades of service no cracks form in the structure, which would allow water to enter and cause damage. Besides the two polyethylene sheaths and the injection of grease, the dense granite becomes a fourth level of protection

against corrosive damage to the tensioning elements. Together with Zilch + Müller Ingenieure GmbH and the Institute for Building Materials Science at Munich University, extensive trials were undertaken in order to determine the safe values for the engineering and design of prestressed granite bridges.

4 length: 16.1 m (53’)plate thickness: 35 cm (1’ 02”)safe load: 5 kN/ m² (104 psf)

5 Konstanz, 2010length: 8.2 m (26’ 11”)Plate thickness: 15 cm (6”)Planstatt Senner, Überlingen

76

KUSSER Graniteworks USA KUSSER Graniteworks USA

7

8

10

9

Foto: Landeshauptstadt Stuttgart, Tiefbauamt

Foto: Kirstin Knufmann

8 Augsburg, 2010length: 7.10 m (23’ 3 1/2”) plate thickness: 15 cm (6”)

Further prestressed granite bridges (without photos): Stevenage, UK 2010length: 14.35 m (47’) plate thickness: 28 cm (11”)HTA Landscape Design, London

Neuhausen a. d. Fildern, 2010bridge with glass balustradelength: 7.20 m (23’ 7 1/2”) plate thickness: 20 cm (8”)Cheret Bozic Architekten, Stuttgart

10 Stuttgart, 2010length: 9 m (29 1/2’)plate thickness: 19 cm (7 1/2”)

Chicago, 2011length: 5.48 m (18’) plate thickness: 17.1 cm (6 3/4”)design: Linnig Architecture

9 Kappelrodeck, 2009length: 14.60 m (47’ 11”) plate thickness: 32 cm (1’ 5/8”)RS Ingenieure, Achern

Unbeatable slenderness, consistency

7 Hildesheim, 2010length: 15 m (49’ 3”) plate thickness: 30 cm (11 3/4”)

98

KUSSER Graniteworks USA KUSSER Graniteworks USA

In addition to their long service life and slenderness, pre-stressed granite bridges have short production and erection times. They are prefabricated at the factory and tested in ac-cordance with the anticipated loads, so they can be erected on site in a few hours.

11, 12 Rosenheim, 2007length: 9.4 m (30’ 10”)plate thickness: 25 cm (9 7/8”)safe load: 5 kN/m² (104 psf) + 5.5 tons in the midspanSEP Baur & Deby Architekten + Stadtplaner, MünchenKusser Graniteworks USA

supplies prestressed granite bridges, stairs and elements as turn-key solutions from one source, including all necessary structural calculations, complete production and assembly.

11 12

Fast and simple installation

Specific values

Density

Compressive strength

Compressive strength48 frost-thaw cycles, 2% NaCl

Flexural strength

Granite

2,660 kg/ m³ (166 lb/ ft³)

214 N/ mm² (31,038 psi)

177 N/ mm² (25,672 psi)

11.3 N/ mm² (1,639 psi)

Prestressed Granite

e.g. 95 N/ mm² (13,779 psi)

e.g. 95 N/ mm² (13,779 psi)

Granite is approx. as light as aluminium, 1/3 lighter than steel.

Granite has a several times higher compressive strength than concrete, it is very frost and corrosion resistant.

In this case the flexural strength in-creases nine fold when prestressed.

1 Granite plate with centric stress, break of element

F

2 Prestressed granite plate without load

3 Prestressed granite plate with centric load

F

in bilaterally mountedgranite plates Fv

Fv

Fv

Fv

the stress cross section builds up. The element can be extreme-ly stressed without reaching the maximum tensile stress (3).

F

Stress distribution

max. compressive strengthmax. flexural strength

high compressive strength potential remains unused (1). By centric prestressing (2) a compressive strength above

If a load is applied on a gran-ite plate, the element breaks as soon as the maximum flex-ural strength is reached. The

compressive strength valuesflexural strength values

max. compressive strengthmax. flexural strength

max. compressive strengthmax. flexural strength

compressive strength valuesflexural strength values

1110

KUSSER Graniteworks USA KUSSER Graniteworks USA

13 14 15

17 18

16

Prestressed granite stairways and elements

Additional projects with pre-stressed granite:

Column in the Michaelibad, a Munich public bath, Artist: Man-fred Mayerle, Munich, 2001

Granite stairs and gallery, public capital and building department Ludwigsburg, Germany, 2004

Gallery, city hall Moosinning, Germany, 2003

Gallery and diving board in a private garden in WiesbadenBüro für Freiraumplanung, landscape architect Ulrike Stryck-Hartmann, Wiesbaden, Germany, 2008

∙ massive granite∙ environmentally friendly ∙ corrosion resistant∙ sustainable∙ slender∙ flexible∙ light yet strong ∙ prefabricated∙ quick installation

6, 7 Prestressed granite stairs, Plus-City Shopping Center, Linz, Austria, 2004

8 “Lichtblicke”, Landesgartenschau 2007 (regional garden festival), WaldkirchenLandscape Architect: Barbara Rainer, Bernhard Dinglerphoto: B. Dingler

9 Axis of the Earth, Magdeburg, Germany, station forecourt, Scale: 1:1.000.000,artist: Timm Ulrichs, 1999 - weighing 10 tons and 12 m (40’) long, the axis in prestressed Nero Assoluto is the main component of an accurate time clock (refer to “Implement-ing Works of Art”, page 6)

10 Flagpoles in prestressed granite, diameter 13 – 17 cm (5 – 7”), height 9 m (30’), 2004

11 three prestressed granite columns, office center, Suhl, Germany, artist: Manfred Mayerle, Munich, 2006

Kuss

er G

rani

tew

orks

USA

- Fe

brua

r 201

1

Kusser Graniteworks USA, withits division, Kusser Fountain-works, is a subsidiary company of Kusser Aicha Granitwerke – a family business with almost a hundred years of history in the quarrying and processing of natural stone. It currently em-ploys some 100 people. A long-standing tradition of excep-tional craftsmanship, state-of-the-art machinery maintained by the firm’s own specialists, and internal planning teams of technicians, engineers, and architects have helped establish Kusser as one of the world’s leading companies in the natu-ral stone industry. In 1989 the first Kusser fountain was in-stalled in the United States. Since 2004, the successful ac-quisition of the former US dis-tributor has established Kusser Graniteworks USA as a perma-nent presence in the US market.

The following brochures providemore detailed information about Kusser products and services:

- General company information‚“Designing with natural stone”- Natural stone for indoor spaces- Natural stone for the outdoors- Prestressed granite- Kusser Fountain SYSTEM- Fountain technology- Floating spheres/ objects- Implementing works of art

Kusser Graniteworks USAKusser FountainWorks3109 East 4th AvenueTampa, Florida 33605813.248.3428800.919.0080fax 813.248.3671kusser@kusserUSA.comwww.kusserUSA.com

Kusser Aicha GranitwerkeJosef Kusser GmbH & Co.KGDreiburgenstraße 594529 Aicha vorm WaldGermanyTel 0049 (0)8544 · 96250Fax 0049 (0)8544 · 962590E-Mail: kusser@kusser.comInternet: www.kusser.com