Glossary – our knowledge from A to Z

A fitting that is attached to a wire rope with a fastener or held in place by tension. A rocker mechanism in the bracket enables vibrations in the wire rope to be accommodated.

In this type of construction for a glass façade the conventional loadbearing construction (e.g. of steel or aluminium) is replaced by a delicate net of wire ropes which results visually in an essentially dematerialised structure. The panes of glass are fixed to the wire ropes with special fittings. The great appeal of this type of façade is its lightness and transparency.

This type of construction can be used to construct delicate-looking roofs, façades and bridges. Extraordinary technical and aesthetic achievements are possible in this way.

Computer-aided design is the term used to describe the production of design documents with the help of suitable software.

Computer-aided engineering is the generic term for all computer-assisted working processes. Those processes include: CAD, FEM, CAM, CAQ. The networking of individual parts of a process increases the effectiveness of a project and helps to reduce costs. Computers are being required more and more in order to cope with the complexity of large projects.

Also known as quicklime, this is a white powder that reacts with water and in doing so releases a large amount of heat. This reaction with water leads to the formation of calcium hydroxide (slaked lime). Calcium oxide is a fundamental constituent in the production of glass.

The comparison of measured values with those of a reference or normal condition. The work involves assessing the deviation between two values or whether this deviation lies within certain limits.

Computer-aided manufacturing is the term used to describe the control of production plants plus the associated transport and storage systems by means of suitable software.

This is a multi-layer coloured glass made from flashed glass. A layer of white glass is added to a layer of coloured glass. Afterwards, decoration is introduced with a copper engraving wheel. This decoration remains as a raised relief.

This special shaft controls the inlet and outlet valves of an engine and is driven by the engine itself via a toothed belt or chain. The camshaft is designed to open the valves at the right times, with the exact stroke and in a precisely predetermined sequence, and allow them to be closed by the valve springs.

A cantilever is an element that projects from a building and is therefore unsupported at its outer end, e.g. oriels, balconies, even whole storeys, which may be supported over part of their cantilevering length by corbels or cantilevering beams.

A form of construction supported at one end only.

A cantilevering component, e.g. beam, rafter, purlin, suspended floor slab, spans without support from walls or columns at some point.

A sheet metal covering to the top surface of a parapet, with a fall to the inside so that no water remains on the parapet.

When carbon in the form of an anion bonds with a metal in the form of a cation, the resulting reaction product is the chemical compound carbide.

This is a chemical element. It occurs in nature both in pure form and in chemical compounds. The amount of carbon added to iron determines whether the resulting steel is hard, brittle or malleable.

The hardness and strength of a material are affected by the amount of carbon it contains. However, too much carbon in a material reduces its cold workability considerably.

A colourless, odourless, tasteless toxic gas. It is formed by the incomplete oxidisation of carbonaceous substances. This takes place, for example, during the combustion of such substances when there is not enough oxygen available or the incineration takes place at high temperatures.

The incorrect designation for an unalloyed steel, i.e. a steel without any further alloying constituents.

In construction the elements of a structure, including the roof, that give it its overall contours, but excluding the interior fitting-out.

An erroneous term for rolled glass.

Iron in cast form contains 2–4% carbon which is essentially in the form of graphite, or rather temper carbon, and is not subjected to any further forming work.

This is a steel C-section that is cast into the concrete so that T-head bolts for attaching other items, e.g. ventilation ducts, pipes, etc., can be fixed at any position along its length at a later date.

This is a component that is fitted between the reinforcing bars of a reinforced concrete element so that it is cast into the concrete. The cast-in part is designed in such a way that the action effects to which it is subjected can be optimally transferred to the concrete.

A component that is cast into concrete, e.g. for the fixing of brackets or other similar components.

This is fabricated from a rolled I-section that is torch-cut into two parts along a trapezoidal line. The two halves are then welded together. The resulting beam section can carry considerably heavier loads because of the increased distance between the tension and compression zones.

Filling a pattern with molten glass.

A synthetic resin that is worked in the liquid state to form the final product and solidifies to form the product or part thereof. Casting resin is used to bond panes of glass together. Better sound insulation values can be achieved with casting resin. In Germany the use of casting resin for overhead glazing is, however, only possible with an Individual Approval.

A pitched roof form in which one roof surface or part thereof projects beyond the eaves.

This is a type of rolled translucent glass with an irregular, small or large hammer tecture. Also available in colours.

A manufacturer who marks a product with the CE symbol confirms that it complies with the relevant European safety directives. The CE marking does not necessarily mean that the product has been inspected by independent bodies for compliance with directives and is also not necessarily a mark of quality.

Foam thermal insulation material with a closed cellular structure made from silicate glass. The basic properties such as expansion and chemical resistance correspond to those of silicate glass. Cellular glass is impermeable to water vapour diffusion.

A porous, foam-like elastomer that is used as a seal, a soft backing pad, and for insulating, isolating, noise-attenuating, anti-drumming and many other purposes.

A hydraulic binder used in mortars and concretes.

These are sintered carbides. They are characterised by their extreme hardness, abrasion resistance and especially their stability at high temperatures. Cemented carbides are used for the tips of tools and parts used in metal-cutting processes, non-cutting forming processes and where frictional abrasion is an issue.

A compound of iron and carbon, with the chemical formula Fe3C (an iron carbide), that occurs as a metastable state in steel and white cast iron.

Abbreviation for European Committee for Standardisation, a European standardisation body similar to DIN and ISO.

In centrifugal casting the molten metal is cast in a rotating tubular mould. The centrifugal force causes a compaction of the microstructure, which therefore increases the strength. Centrifugal casting is used to produce cylindrical and conical workpieces, e.g. pipes.

This is a method for smoothing and also finishing surfaces which achieves a consistent, uniform satin finish. The use of ceramic beads results in a much lower breakage rate than is the case with glass beads. This reduces the roughness which in turn decreases the chance of dust and dirt adhering to the finished surface.

This stamp is used to identify a type of glass. It is obligatory for thermally toughened glasses and is applied during the toughening process.

This printing technique enables areas of colour and pictures to be printed. Slides or photographs can be digitalised for the motifs, which are exposed on a mesh screen and subsequently fired at a temperature of 700 °C. Ceramic screen printing is light-fast, solvent-resistant and abrasion-resistant. It also remains stable at temperatures of up to 200 °C.

In this document the manufacturer declares that the product supplied complies with the order. It does not contain any details about test results.

A document used in international trade for verifying the exact place where goods originated. This document enables import quotas or customs duties to be applied as required because such quotas and duties depend on the country of origin.

This test carried out according to DIN EN 10045 determines the brittle failure behaviour of materials depending on the temperature. For welded connections in particular, selecting a suitable notch position enables both the quality of the weld and also the heat affected zone (HAZ) to be investigated separately.

A type of sheet glass with a parallel wire inlay and flat surface achieved by working after rolling so that the view through and reflections are not distorted in any way.

The aim of this process is to convert colouring oxides into other oxides so that the (dis)colouration is as light as possible. For example, in the melt, an iron oxide with a strong colorific effect is converted into an iron oxide with a reduced colorific effect by introducing oxygen. Another method of decolourising is physical decolourisation.

Glass is very resistant to the majority of chemicals. This resistance increases with the SiO2 content and can be influenced by the composition of the glass. Hydrofluoric acid (HF) causes visible damage directly and reacts with the SiO2 to form gaseous silicon tetrafluoride which destroys the structure of the glass.

This amounts to hardening and is used on thin panes of glass 2–3 mm thick. The glass is immersed in a potassium nitrate melt, which results in an exchange of ions. This causes a compressive stress to be generated at the surfaces, which improves the strength. The compressive stress is greater than that generated by thermal toughening.

A self-propelled work platform with an articulated telescopic boom. This is a flexible type of working platform that is easily operated and suitable for many different applications. Battery-driven, electric and diesel versions are available for internal and external deployment.

This is a flaw that often occurs on a cut glass edge. Damage to the surface, e.g. caused by a stone, often displays a similar form.

A surface treatment in which an electrogalvanic process is used to coat workpieces with a protective layer containing chromium. The resulting chromate layers are classed as passive coatings, i.e. they are inorganic non-metallic protective layers.

This element increases the tensile strength through the formation of a solid solution, and reduces the critical cooling rate. It increases the depth of hardness and the resistance to scaling. Above a concentration of 13 % in ferritic and austenitic steels, chromium also helps to prevent corrosion through the formation of a resistant layer of chromium oxide.

This is a chemical compound of chromium and oxygen. Chromium oxide is mixed with the glass during production, often in conjunction with iron oxide, to give the glass a green colouring.

Electroplating method for improving the surfaces of metals and plastics. The thin layer of chromium provides a shiny coating that protects against corrosion. Chromium plating requires a very high energy input and highly toxic electrolytic baths. Expensive pretreatment of workpieces is essential for a good result.

A lock invented by Jeremiah Chubb. The stepped bit lifts several levers in such a way that the bolt can be moved. This type of lock was common in Germany until well into the 1960s.

U-shaped clamp fixings to fit around the edge of the pane of glass. No holes need to be drilled through the glass. An elastomeric pad prevents contact between the glass and the metal fixing. The glazing edge cover must be guaranteed, even when loads are applied.

In a clamped membrane design the loadbearing connection between the flexible membrane and rigid components is by way of clamping the beading at the edge of the membrane in a special rail, which is usually made from extruded aluminium.

The client is the person who prepares and carries out building works or has them prepared and carried out on his behalf.

Panes of glass with an acute angle, e.g. triangular panes, must be “clipped”, i.e. trimmed off, cut back, because otherwise there is a great risk of the corner being chipped and the whole pane spoiled.

Coatings are as different and versatile as the materials to which they are applied, e.g. a façade construction. Common to all coatings is the fact that they protect and affect the material to which they are applied.

This element improves the resistance to tempering, also the heat resistance.

This is a chemical compound of cobalt and oxygen. Cobalt oxide is mixed with the glass during production to give it an intensive blue colour, but can also be used to remove colour.

Materials expand differently when exposed to high temperatures and this coefficient must be considered during the planning.

The inner strength of a substance that ensues through the interaction of forces of attraction between its individual components. In physics and chemistry we speak of the interaction between atoms or molecules, in soil mechanics the interaction between soil particles.

A failure mode in a loadbearing adhesive joint. Here, the failure occurs within the layer of adhesive or within one of the items being bonded together. According to current approval procedures, a cohesion failure is the only type of failure permitted; adhesion failures are not permissible.

Steel strip, tube or wire wound up into a roll.

This is a method for coating continuous strips of thin steel or aluminium on one or both sides. It represents an alternative to traditional coating techniques.

An apparatus for winding/unwinding strip, sheet or wire products into/from coils.

In this process the glass is drawn vertically out of the melt without the need for a die. The ribbon of glass is bent over a roller at a height of approx. 60‒70 cm and then passes into a horizontal annealing lehr. Irving Wightman Colburn registered his invention in the USA in 1905.

The abbreviated form of colloidal concrete, a method of concreting in which in contrast to conventional concreting the aggregates (e.g. gravel, ballast) are first placed in the formwork and then the ensuing voids injected or filled with grout (colloidal grout). The particular advantage of this concrete is its low shrinkage.

This is a suspended, curtain wall-type external wall construction with a ventilation cavity. In contrast to a warm façade, all parts of the spandrel panel elements are exposed to the exterior climate. All parts of the construction can be designed without a thermal break because there is no connection to the warmer interior of the building.

A flat metal product produced in widths of up to 650 mm and thicknesses of 0.1–6.0 mm. It is available in all steel grades and with any type of surface finish.

Flat products manufactured by cold-forming from hot-rolled strip steel. The cold rolling reduces the cross-section by at least 25%, and after passing through the finishing roll, or rather after pickling or continuous annealing, the strip is wound up into a coil.

The cold and warm areas alternate in this type of façade. The components of the façade are mounted on loadbearing external walls built of masonry or concrete. In the warm zones fixed and moving window elements close off the openings in the structure by means of sections with thermal breaks and insulating glass. In the cold zones the surfaces of the structure are provided with a weatherproof glass skin.

The colour rendering properties of a particular type of glazing are specified by the general colour rendering index Ra. The Ra scale extends up to 100. The optimum Ra value achievable with glazing is 99.

This is anodised aluminium that is coloured either during or after the anodising process.

We distinguish between body-tinted glasses and those with a coloured enamel or other coating.

We essentially distinguish between three types of products used for colouring glass: solvent dyes, temper colours and sulphur dyes.

A (mostly) vertical component that carries and transfers loads primarily in the direction of its longitudinal axis. DIN 1045-1, the standard for plain, reinforced and prestressed concrete, defines a column as a linear compressive member.

In order to be able to reflect the simultaneous application of several loads in a better way, the action affects are multiplied by factors (≤ 1). Combination values form part of the semi-probabilistic partial safety factor concept.

Construction works on site may only begin after the issue of the legally binding building permission to the client and after the building authority responsible has been notified in writing of the commencement of works.

The compatibility of laminated safety glass must be considered with respect to loadbearing adhesive joints, the hermetic edge seals of insulating glass and polyvinyl butyral (PVB) sheets. Incompatibility with adjacent materials can alter the material in such a way that it no longer fulfils its intended function. The result is failure of the adhesive joint, leaking edge seals or delamination phenomena in laminated safety glass products.

Many different materials and surface finishes come into contact in buildings and structures. It is therefore especially important to check that all materials in contact with one another are compatible or that they are separated by intermediate layers. seele checks the compatibility of the materials used for every construction project.

This is the amount, expressed as a percentage, by which a membrane bay has to be cut undersize because of its stretching behaviour so that the bay achieves the desired geometry after prestressing. Owing to the method of manufacture, compensation is usually greater in the weft direction than in the warp direction.

A term from structural analysis. In glass construction this is the possibility of transferring shear stresses across the interlayer or casting resin. However, according to German regulations any beneficial effects of composite action may not be taken into account for laminated safety glass.

A composite construction results when the load-carrying capacity of an element is realised by the combination of different materials. Glass is ideal as a material for composite construction because it can accommodate enormous compressive forces, but quickly fails when subjected to tension. In such cases, steel can accommodate the tensile forces.

In this form of construction at least two different, separate materials are joined together by means of fasteners in an interlocking way in order to combine the advantages of both materials. Generally, composite construction refers to the combination of concrete and steel. However, other combinations, e.g. with timber, are possible.

Such a material is made up of two or more materials that unite the positive properties of the individual materials in a new material. Often simply referred to as a composite.

A timber or metal section cut at two angles simultaneously (sometimes referred to as jack rafter cut).

A method of glazing in which the sealing to the rebate for the pane of glass is achieved by a preformed gasket which is compressed in some way (screws, springs, cams, wedges, serrations) by a metal glazing bead.

The compressive strength of a material is its resistance to the effects of any compressive forces acting on it. An element will fail if the compressive stress induced is greater than its compressive strength. Most materials exhibit different compressive and tensile strengths, e.g. stone, steel.

Float glass has a compressive strength of 700–900 N/mm².

In optics a concave surface is a form that curves inwards.

This is a mix of cement, aggregates (sand, gravel, chippings) and water. When the cement reacts with the water (hydration), the aggregate is interlocked by the ensuing crystal lattice and can therefore transfer high compressive forces. Owing to its much lower tensile strength, concrete is often strengthened with steel reinforcement (reinforced concrete).

Water vapour condensing out of the air that collects on a cool surface. On external components with poor thermal insulation (e.g. single glazing) there is a risk of the temperature dropping below the dew point when the outside temperature is low, which leads to condensation collecting on the internal surfaces.

Condensation collects, e.g. on single or double glazing during the cold months of the year, when the surface of the glass is colder than the adjacent layer of air. Owing to the fact that the hermetic edge seal to the pane is less efficient in thermal terms, condensation always starts to collect at the lower edge of the pane.

In science this is the matter in a bonded state as opposed to a gaseous state.

This is similar to a pavilion roof but circular on plan.

This is the colloquial term for a connecting rod, the connection between a rotating crankshaft and a component with a linear motion, e.g. a piston.

Knowledge of the theory and practice of the construction of buildings and structures.

A loadbearing member that is rigid over several spans. If floor beams or purlins are designed as continuous members, the span moments are reduced due to the relieving effect of the support moments. Deflections are also much smaller. Continuous beams are statically indeterminate systems and therefore require a more complicated analysis.

The air circulating in the cavity of an insulating glass unit transports heat quickly from one pane to the other, which leads to a worsening of the U-value.

A cylindrical vessel with a refractory lining which tapers towards the top.

Copper forms bivalent and trivalent copper oxide in the presence of oxygen. Copper oxide is mixed with the glass during production to give it a blue or red colouring, depending on the valency.

A steel alloy with a high weathering resistance because a protective layer of iron oxide (rust) prevents further corrosion media from attacking the steel. COR-TEN is suitable for welding and forging, and owing to its characteristic rusty brown appearance, is employed by architects for its aesthetics.

For joining together mitred corners. They can be nailed, screwed or glued.

The perimeter cable of a membrane roof is fixed to the corner plate via a special fitting at the end of the cable. The corner plate is in turn connected to another component, usually of steel, to which it transfers the load.

The topmost moulding on a building.

A double-leaf façade in which the cavity is divided horizontally and ventilated per storey. The cavity is normally accessible, hence the name.

This is the unwanted, undesirable reaction of a material with substances in its surroundings. It occurs most of all with metals.

Corrosion protection prevents a material being damaged by external influences. Paints and coatings are typical corrosion protection systems. However, there are also materials that require no protection against corrosion, e.g. stainless steels.

A substance that has a corrosive effect on a material. Corrosive media include, for example, indoor air, outdoor air with or without industrial pollutants, water, soils and chemicals.

This is sheet metal with a wave-type cross-section. The sheet metal is usually comparatively thin and so it is the wave-like form that gives this material its high rigidity and load-carrying capacity. Corrugated sheet metal can be flattened and also bent to form a cylinder.

A counternut is an additional nut used in a bolted connection which is tightened against the main nut. The nuts deform and this increases the friction force in the flanks of the thread which prevents the nuts from being turned, i.e. loosening. Also known as a lock or check nut.

A point fixing that holds glazing in place by means of a component fitted into a hole drilled through the glass. The hole for a countersunk fixing must be partly cylindrical, partly conical.

Chloroprene rubber profiles for sealing windows and ideal for using as the frame and overlap seals, but also for gasket glazing.

This is a general term for delicate pink to dark red glasses that are coloured by dissolving gold chloride in the glass melt. Also known as gold ruby glass, it has been ousted from the market by the less expensive, more yellowish selenium ruby glass and the often somewhat brownish copper ruby glass.

A crane is a machine for lifting and transporting building materials and components on the building site.

This special shaft is a component in a reciprocating or piston engine which, with the help of conrods, converts the movement of one or more pistons into a rotation. Together, the components necessary for converting the movement are known as a crank drive.

These robust, compact elevating platforms mounted on long, wide, rubber crawler tracks are ideal for applications on unstable surfaces, e.g. on building sites. They have their own drive unit, are extremely manoeuvrable and can therefore adapt well to the given ground conditions.

The slow deformation of a material subject to a constant load. Polyvinyl butyral (PVB) sheets are very susceptible to creep at high temperatures, which can reduce the residual loadbearing capacity of a pane of glass. SentryGlas® (SG) has much better properties in this respect.

This is a method for the graphic determination of the forces in the members of statically determinate frameworks. It was invented by the Italian mathematician and structural engineer Antonio Luigi Cremona.

The screwdriver recess in the head of this type of screw is in the form of a cross. Crosshead screws have almost completely replaced slotted screws in industrial production.

A large manually blown globe of glass is rotated to form a circular disc which, after annealing is cut into panes. This glass is characterised by its concentric structure. The thicker section, or boss, left in the centre where the pontil rod was attached is the bull’s eye or bullion sometimes seen in old windows and imitated today. This form of glass production is no longer common.

A fluid or solid primary product used for steel castings or in the form of ingots.

Abbreviation for Common Understanding of Assessment Procedure, an approval procedure for obtaining a European Technical Approval when there is no guideline (ETAG) available. The object of the approval is submitted to all the European technical approval bodies in order that they can give their opinions. This process can be very lengthy.

This is scrap glass that is recycled by mixing it, in the form of fragments, into the glass melt. Hollow or pressed types of glass should not be used as cullet.

A graphical method for solving problems in structural analysis. In order to be able to use this method, four forces with known directions are required and the magnitude of at least one of these forces must be known.

A precautionary measure against risks resulting from the fact that a business partner is located in a different currency zone or uses a different currency.

An unworked straight edge.

This is the part of a biological cell that is enclosed within the cell membrane.