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Richard Sadokpam, 0601431CURTAIN WALLStructural SeminarSubmitted byRichard SadokpamB.Arch 8th Sem.060143GENERAL CONCEPTSCurtain WallCurtain walls are non-load bearing exterior walls with the following characteristics:They are suspended in front of the structural frameTheir own dead weight and wind loads are transferred to the structural frame through point anchorages.The design of the joints between the curtain wall elements and the fastening technique permit the erection of continuous wall surfaces of any size.Grid construction of curtain wallsThe majority of curtain wall consists of a rectangular grid of vertical and horizontal members, framing openings filled with inserts or glass.The inserts and the glazing are the space enclosing elements of the grid curtain wall, while the grid itself forms the framework, within which these are installed. Normally, the grid is attached to the supporting structure, to which it then transfers the entire weight of the curtain wall plus possible wind loads. only in a few cases, the inserts are fastened to the structure directly.The grid is clearly expressed in elevation and gives the curtain wall faade, its characteristic structure.2Richard Sadokpam, 060143Panel Construction of Curtain wallThe term panel construction will be applied to wall assemblies consisting of large, story high panels fastened either directly or indirectlyIt is done by secondary framing to the supporting structure the only components of panel curtain walls are the panels themselvesThe panels combine the twin functions of enclosing space and transferring the dead and live loads to the supporting structureImportant characteristics of such panels is their jointless, continuous outer surfaceSTRUCTURAL PROBLEMS OF CURTAIN WALLLoadsAlthough curtain walls have been defined as non-bearing exterior walls, they are loaded horizontally by the wind and vertically by their own dead weight
it must be remembered that winds produce suctions as well as pressure on the face of a building. These negative forces are important in dimensioning anchors, fasteners and glazing bleads installed from the outside.
In hurricanes for more glass is blown out of buildings than into them.
3Richard Sadokpam, 060143The effect of Wind loading The wind loads acting on a curtain wall are transferred through fasteners to the supporting structure. Thus, the curtain wall is stressed in bending. Its own weight acts as a vertical force. Accordingly, the elements of a curtain wall must be designed for a direct stress and bending combined.
The dead weight of the wall results either in in tensile stress if the units are suspended or in compressive stresses if the units stand on their bottom edge In designing for combined bending and tension there is no need to provide for buckling, but buckling is a distinct possibility where bending and compression are involved.The curtain wall should be made of material capable of resisting bending actionElastic deformationThe elastic deformation of curtain wall is a consequence of the bending due to wind loadsAll the elements exposed to the wind deflect in the direction in which the wind loads actIn grid construction, moreover, the weight of the sprendals and glazing bears on the horizontal members of the grid causing them to deflect vertically.The degree of elastic deformation is variableIt depends on the stiffness and the modulus of elasticity of the components.An effort should be made to prevent these deflections, which to a large extent determine the tightness and proper functioning of the jointsUnfortunately, finding the modulus of elasticity of panels and wall units composed of a number of different materials is not a easy proposition. in such cases, theoretical calculations of the deflection must be supplemented by the results of load tests4Richard Sadokpam, 060143TYPES OF CURTAIN WALLS5Richard Sadokpam, 060143DOUBLE SKIN CURTAIN WALLExterior circulationInterior circulationDouble circulationUNITIZED CURTAIN WALL Unitized Individual unitized Glass flank unitizedSTICK CURTAIN WALL Exposed frame glass Full hidden frame glass Semi hidden frame glass Dry processing concealed frame glassPOINT FIXING GLASS WALL Art steel structure supported Space tensile cable supported Self balancing supported Single cable supportedFULL GLASS CURTAIN WALL
METAL CURTAIN WALL Aluminium single Stainless steel plate Aluminium composite panel Honeycomb panelSTONE CURTAIN WALL Black bolt stone Splint stone Continuous groove stoneTILE CURTAIN WALLPHOTOELECTRICITY CURTAIN WALLVIDEO CURTAIN WALLDOUBLE SKIN CURTAIN WALLDouble-skin dynamic energy saving curtain wall ( thermal shaft curtain wall), according to ventilation principle, it can be divided into natural ventilation and forced ventilation systems, namely exterior circulation double skin curtain wall system and interior circulation double skin curtain wall system.It consists of an outer curtain wall, an inner curtain wall, sun shading device, air inlet device, outlet device. The design idea is to achieve energy saving, environmental protection, and to provide a pleasant working or living environment.Special features of products for exterior circulation double skin curtain wall system:
1.According to air thermal compression principle and chimney effect, the fresh airis let indoor, the fouled air is exhausted to outdoor, this can effectively prevent the dust from entering into the indoor.2.Preeminent winter heat preservation and summer heat insulation function.3.Reasonable lighting function, according to the needs of user, the light adjustmentcan be changed, and the lighting environment can be ameliorated.4.Preeminent sound insulation and acoustic function, creating a serene workingand living environment for the user.6Richard Sadokpam, 060143Interior Circulation Double Skin Curtain WallSpecial features of products for interior circulation double skin curtain wall:System principleShutting down air conduit to indoor in summer, let most of hot air inside the double layer sealed thermal shaft area vent into outdoor.In winter, the greenhouse effect heat--retaining air will be heated by conduit loop system and passed to indoor, reaching energy-saving effect.System structure--whole system adopts unitized structure, outer layer adopts sealed insulation glass, inner layer adopts single glass pivot-hung window, shading louver is installed between the two walls; The outlet is joined with building air-conditioning system.Double Skin Curtain Wall7Richard Sadokpam, 060143PerformanceHeat-insulating property--with admirable heat preservation, heat-insulating property, k value of average heat transmission coefficient can reach to 0.96W/m2K.Sound insulation property--admirable sound insulation performance, weighted noise insulation factor can reach to RW>45dB.Mechanical ventilation--by assorting of curtain wall, heating and ventilation and air-conditioning system, that provides fresh air and realizes energy recovery, the specific discharge, according to different use location, can maximally reach to 100m3/h.Comfortable degree--enough light indoor, favorable temperature.
Double Skin Curtain Wall8Richard Sadokpam, 060143Double Circulation Double Skin Curtain WallSystem principleBy adopting compound ventilation mode, natural draught and mechanical ventilation can alternately operate under the different condition. The air outlet is opened in summer, and it let most of hot air inside double layer sealed thermal shaft vent out of the outdoor. In winter, the air outlet is shut down, by using the greenhouse effect to heat air of inter layer and increase temperature at internal surface, reaching energy-saving effect.System structure--whole system adopts unitized structure, outer layer adopts sealed insulation glass, inner layer adopts single-glass pivot-hung window, louver for adjusting light is in the middle; air outlet is applied blower.Heat preservation propertywith admirable heat preservation and heat- insulating property, k value of average heat transmission coefficient can reachto 1.15W/m2K.Double Skin Curtain Wall9Richard Sadokpam, 060143Sound insulation property--with admirable sound insulation performance,weighted noise insulation reaches to RW>42dB.Mixed ventilation--enting velocity can realize self-control, without relying onbuilding air-conditioning system, design construction is more agility.
Double Skin Curtain Wall10Richard Sadokpam, 060143UNITIZED CURTAIN WALLUnitized curtain wall consist of different components and coated materials fabricated at shop and assembled into a single whole panel with the panel height of one or more storeys, then transported to construction site for erection. The panels are precisely connected to the building with the pre-embeds on the building main structure, the fine adjustment to finish the curtain wall installation is achieved by the adjustment screw.( show as picture)Special features of products for unitized exposed frame curtain wall system, unitized concealed frame curtain wall system, unitized semi- concealed frame curtain wall system:Unitized panels are assembled in the factory, with high degree of precision.Fast installation efficiency, short construction period, easy to protect finishedproduct.That can be simultaneously constructed with major structural of civil work, greatly shortens the construction period for whole building.Structure adopts pressure equalization principle, with drainage system inside, good anti- rainwater leakage and anti-air penetration quality.
Unitized curtain wall11Richard Sadokpam, 060143
Joint location of panels is sealed with special weather resistance rubber strip, that ensures self-cleaning function of curtain wall , and lowers the degree of pollution on the surface.
Socket joint mode is adopted between the plates, with strong earthquake resistanc