OXYGEN Implementation Guide

Transcription

1 OXYGEN Implementation Guide Published on 21 August 2007 PMA by Arval ZA du Pays de Podensac CERONS - France Tel. +33 (0) Fax. +33 (0) commercial@pma.fr

2 PRESENTATION OF THE SYSTEM The OXYGEN system is an external building facing made from stainless steel with a thickness of 10/10 with drawing of positive and negative spheres and installation on vertical rails and cursors by means of slots (coat hanger installation). GEOMETRIC CHARACTERISTICS Section B-B Welded offset lugs Section A-A

3 Welded offset angle beam profile view Welded offset lugs Weight of cassettes: 9.10 Kg/m2 approximately. TECHNICAL FEATURES Cassettes made from 4301 stainless steel thickness 10/10ths and protection film. Perforation of these cassettes type R8 T 12. Drawing comprising 15 positive spheres, 8 negative spheres, 12½ negative spheres on the edges and 4¼ of spheres in the angles. These cassettes include 4 peripheral returns the 2 vertical returns of which contain offset lugs on stainless steel bracing cut out to the shapes of the drawn elements and fixed by spot welding. ATTACHMENTS These cassettes are hung on notches on a specific supporting vertical aluminium rail and this by means of adjustable sliding stirrups (MD Shells system type attachment validated by SOCOTEC technical examination). This rail is attached to the supporting structure by a galvanized steel U with a thickness of 20/10ths. The upper attachment of the rail must be made of a fixed point supporting the vertical loads (own weight of the rail and the cassettes hung on it).

4 For a rail height of 5400 mm fixed every 1.3 m (overhand of 100 mm) we get: For a rail receiving two cassettes, the most unfavourable stress is: 2 X 12 = 24 dan (pressure) Geometric characteristics of the MD rail: S = 4.3 cm2 Vs = mm I = 8.92 cm4 Vi = mm Under this load the maximum deflection 0.6 mm (<1000/200), maximum stress 13.6 Mpa <σe. Maximum reactions at attachment levels are: 44 dan support 13 (central) 51.2 dan supports12 and dan at the edge Vacuum reactions (detachment): 16.9 dan edge supports: 37.1 dan supports12 and dan support 13

5 To take these stresses, the rail is fixed (every 1.3 m) in a 2 mm thick galvanized steel U itself attached to the structure every 1.8 m. U dimensions: 50 X 75 mm Geometric characteristics of the 2 squares S = 3.44 cm2 Vs = mm I = 8.99 cm4 Vi = mm Therefore we get the following load Maximum deflection: 1 mm < 1800/200 mm - maximum stress: 47 Mpa < 2/3 σe. Maximum reactions under pressure stress: 70 dan on supports No. 8 and 9 Maximum reactions under vacuum stress (detachment): 50.7 dan on supports No. 8 and 9 (detachment) To attach the MD rail on the supports spaced 1.8 m apart, it is therefore necessary to fix the rails in a U profile 50 x 75 mm made from galvanized steel 2 mm thick every 1300 mm. This U profile being attached to the supporting structure at intervals of 1.8 mm.

6 DIMENSION VALUES These cassettes will have a dimension of 1343ht X 817 mm ± 2 mm vertical and horizontal joints between cassettes of 7 mm. CASSETTE SUPPORT - ACCEPTABLE LOADS Acceptable normal wind loads in pressure and vacuum of a 10/10ths steel cassette with dimensions 1343ht X 817 mm: 97.4/(1.343 x 0.817) = 88.7 dan/m2 A safety coefficient of at least 2.5 in relation to the failure of the cassette is applied to this value (see MD Cassettes Specifications). In line with the modified 95 NV rules for a building located on a normal site, the dynamic basic pressure is 60 dan/m2. For a building with a height of 15 m: dynamic pressure of 1.1 x 60 = 66 dan/m2 For a pressure on the offset siding cassette of: ( ) x 66 = 72.6 dan/m2 Vacuum of ( ) x 66 = 52.8 dan/m2 Since the cassettes are fully perforated with an R8 T12 perforation i.e. a perforation rate of 0.9 x (8/12)2 = 0.4. Since the pressure and vacuum apply to the full parts, these values in relation to a full cassette of the same dimensions are: 72.6 x (1-0.4) x 1.6 = 43.6 dan/m2 in pressure 52.8 x (1-0.4) = 31.7 dan/m2 in vacuum The acceptable load value for pressure and vacuum on a full MD cassette justifies the hold of the attachment lugs of the drawn and perforated cassettes. Indeed the attachment lugs in the angle beam made from stainless steel 10/10ths are the same in geometric and layout terms as those of the MD shells. Due to this system of angle beam offset there are two thicknesses of plate for each lug (see diagram below) Welded offset lugs Welded offset lugs axis

7 Each offset angle beam is attached to the cassette by 8 weld spots according to the following layout Welded offset angle beam Weld spots type B Weld spots type A Type B weld spots: cassette + angle beam Type A weld spots: weld of the 3 plates (angle beam cassette angle beam return) Minimum diameter of weld points 10 mm Maximum stress on the cassette in normal wind: 43.6 x x 0817 = 47.9 dan, i.e. a shearing stress for each weld spot of 47.9/(2x6) = 4 dan. Even though they are perforated, the cassettes are also drawn positively and negatively which increases the transversal inertia of the cassette compared to a full cassette having the same dimension, compensating for the bending difference at the level of the upper and lower edges of the cassettes. A static load test can be run on a trial cassette to define more clearly the failure loads and thereby the acceptable vacuum wind load (the most unfavourable load direction for the cassette suspension system). PACKING AND TRANSPORT A delivery invoice is glued to each package stating: Customer order reference. Batch reference. Customer name. Product type. Facing thickness. Bundle content (number and length). Colour reference of pre-coated plate. The weight of the bundles may in no case exceed 2.5 tons. OXYGEN products and their accessories are to be transported under conditions that preserve the integrity of the characteristics of the products (shimmed up packages, carefully stacked and strapped, tarpaulin-covered trucks)

8 ORGANIZATION PMA is the product manufacturer and does not install the product. The panels are to be installed by contractors having the required professional qualifications. Design and studies prior to executing the facade are not incumbent on the maker PMA nor on the distributor companies. On request, PMA can provide technical assistance The purpose of the present specification is not to give details on all points of implementation but to state the main technical definitions of the panels and their particular characteristics. To help in the study of the facades, it is complemented in the appendix with particular point design suggestions and finishing elements. HANDLING, STORAGE AND UPKEEP Handling operations are carried out in consideration of the particular features of the products. They are to be handled vertically by the edges. The products are stored on a flat surface, slightly inclined in the longitudinal direction without stacking more than two packages. Storage time on the work site is to be reduced to the minimum. The essential precaution consists in avoiding water from entering by runoff or condensation between the panels. Store sheltered from sunlight. The removable protective film covering the visible sides of the pre-coated panels must be removed within 15 days. Metal facades have to be normally maintained in accordance with the prescriptions of the Professional Rules for Metallic Siding (article exterior maintenance). Although naturally cleanable by runoff of rainwater, if needed, they can be cleaned periodically with household detergent, without chlorine added, with no use of abrasive or solvent, followed by rinsing with fresh water. Maintenance notably consists of: eliminating various vegetation (such as moss) and any incompatible matter that might be deposited on the facing surface repairing any localized degradation as soon as detected, such as incipient corrosion caused, for example, by exterior deterioration actions.

9 Get in touch with us for any further information you may require. IMPORTANT The content of this document is based on data relative to construction and to materials properties. It is designed to assist PMA customers in implementing its products. Based on the construction processes and methods known at the time of its publication, this Implementation Guide cannot be considered final and may be revised and/or modified at any time. In case of doubt or difficulty, the user is asked to consult PMA before continuing his project.