Class Project #2- Material Research

ARCH-152-800RL Architectural Construction 2

Matthew Gilliard

Glass (Structural Glazing)

A. MATERIAL SPECIFICATIONS

Master Specification Number- 084426 Structural Glass Wall

Manufacturer(s)- A few manufacturers consist of The Hansen group in Denmark/

W&W Glass, LLC in Nanuet, NY/ Crystal units limits in Hendon, London/ Enclos

Corporation in Los Angeles, CA

Is there a common generic term for this material- Glass (Structural Glass) generic term

is Curtain Wall

B. MATERIAL APPLICATION

Materials intended or primary use- Primary uses of structural glazing is

vertical/inclined facades, roof glazing/skylights, atriums, canopies, Brise soleil, feature

entrance boxes, balustrades, lift shafts, and flooring. Glass and glazing play a key role

with the building overall thermal performance, which includes conduction, solar

radiation, thermal break, and comfort.

List emerging or innovative material applications- A few innovation applications of

Glass-(Structural Glazing) would be non-structural glass curtain walls. A non-structural

glass curtain wall uses a structural sealant, which is an adhesive material (mostly

silicone) that constitutes the bonding between two panes of glass. Allowing for an almost

complete glass facade. Other innovative applications would be the use of glass columns,

glass beams, and glass balustrades.

Physical properties-

o Finishes- There are different types of finishes such as glossy, frosted, figured

(patterned/ rolled), transparent, ceramic coated, corrugated, reflective, and tinted.

o Dimensions- Max size 4600mm X 2440mm, Max overall thickness 50mm

o Weight (specify units) - All thickness of glass 2.5 per meters squared for every

mm thickness, Max weight for single ply is 500kg and for Multiply ply it is

1000kg

Acoustic properties- It's expressed in terms of the outdoor-indoor transmission class

rating. High sound transmission loss means great sound insulation, which is desirable in

most applications. A higher fenestration OITC rating can be attained by incorporating

laminated glass. Laminated glass damps vibrations and the air space limits sound

transmissions. Thicker glass helps sound absorption.

Structural properties-

o Primary structure- the glass resists mostly out-of-plane loads in bending and

transfers it to the secondary structure. Secondary structure- consists of the

framework, transoms, and mullions. Most frames are made from aluminum and

steel. Glass can be supported along 2, 3, or 4 edges. The advantages of it being

supported on more than 3 edges are that even if the glass is fractured in one

direction, the redundancy allows the glass to be still supported. The load is

transferred through the support in the frames. Another secondary structure- glass

beam is used to support glass roofs, floors, and foot bridges. Glass fins are used to

reinforce vertical glass panes when supporting lateral loads. The load transfers

from the glazing area to the secondary structure, then carrying the load to the

edges. This puts stress on the edges. In frames the load is transferred by contact.

In most cases an elastic pad is put between 2 hard materials to accommodate

movement and imperfections.

o Non-structural-(frameless glass) - More glass as possible and the transfer of

some of the structural load to the glass. Point supports- to resist concentration

stresses, used to link glass panes but also beams a fins together. The support can

be constituted of a bolt, friction plate, or a more elaborated assembles of both.

With the application of non-structural glass comes the use of (Four hole

connection- this device connects four panes of glass and is able to take in-plane

and out-of-plane loads, Bolts- take the weight and out-of-plane loads, Structural

sealant- is an adhesive material (mostly silicone) that constitutes the bonding

between the pane of glass and the frame or directly between two panes of glass.)

Installation methods- 1. Install in accordance with the glass system provider’s

requirements and the shop drawings. 2. Employ only experienced glaziers who have had

previous experience with the materials and systems being applied. Use tools and

equipment recommended by the manufacturer. 3. Plate-to-plate joints of glass are to be

sealed with silicone sealant. Joint dimensions will be designed to be compatible with

sealant properties and live load movement of the structure. 4. Bolt torque: torque bolts to

torques specified on shop drawings using a calibrated tool. Lock torque bolts into

position to prevent back-off. Reset calibrations regularly to ensure an accurate torque. 5.

Clean glazing connectors receiving glazing materials of deleterious substances that might

impair the work. Remove protective coatings that might fail in adhesion or interfere with

the bonding of materials of deleterious substances that might impair the work. Remove

protective coatings that might fail in adhesion or interfere with bond of sealants. Comply

with the manufacturer’s instructions for final wiping of surfaces immediately before the

application of primer and glazing sealants. Wipe metal surfaces with an appropriate

cleaning agent. 6. Inspect each unit of glass immediately before installation. Glass that

has significant impact damage at edges, scratches, abrasion of faces or any other evidence

of damage will not be installed. 7. Sealants: prime surfaces are to receive glazing sealants

where required, in accordance with the manufacturer’s recommendations, using

recommended primers. 8. Locate setting blocks, if required by the drawings, at the

quarter points of the sill, but no closer than 6 inches to corners of the glass. Use blocks of

proper sizes to support the glass in accordance with the manufacturer’s recommendations.

9. Provide spacers to separate the glass from attachment plates. 10. Set the glass in a

manner that produces the greatest possible degree of uniformity in appearance. Face all

glass which has a dissimilar face with matching faces in the same direction. 11. Use

masking tape or other suitable protection to limit the coverage of glazing materials on the

surfaces intended for sealants. 12. Tool the exposed surfaces of glazing materials. 13.

Clean excess sealant from the glass and support members immediately after the

application, using solvents or cleaners recommended by the manufacturers.

Cost analysis-

o Price per SF or applicable cost measurement- (National averages) Float glass

(untempered)- $12 to $64 per SF, Float glass (tempered)- $14 to $70 per SF,

Laminated glass- $23 to $211 per SF, Wired glass- $22 to $30 per SF, Coated

glass- $15 to $80 per SF

C. MATERIAL BACKGROUND

How is the material made- Glass (Structural glazing) is either floated or rolled. Floated glass- the process starts by a narrow flow of glass being fed continually

from a melting furnace onto a tank of molten tin within a nitrogen fed

atmosphere, which prevents the tin from oxidizing. As the plate is in the dishpan

of water, the motel glass stays afloat on the surface of the tin. Remaining at a

constantly high temperature allows the molten glass to spread out evenly. Any

irregularities dissipate. The glass is drawn off the tin bath when the desired

thickness is achieved. Rolled glass- the process starts with molten glass being

poured from the melting tank over a refractory barrier, or weir, and continues onto

the machine slars. Where it flows under a refractory gate called the tweel. The

tweel regulates the volume of the glass before sending the glass between two

water-cooled rollers. The distance between the rollers determines the thickness of

the glass. Finally, the glass may be annealed and cut to size. There are 2 basic

types of rolled glass and those are patterned glass and wired glass. What are its components and where do those components come from-

(Sand) Raw state-Industrial sand and gravel, often called "silica," "silica sand,"

and "quartz sand," includes sands and gravels with high silicon dioxide (SiO2)

content. Place of Origin- In almost all cases, silica mining uses open pit or

dredging mining methods with standard mining equipment. Except for

temporarily disturbing the immediate area while mining operations are active,

sand and gravel mining usually has limited environmental impact. Composition-

72.6

(Soda Ash) Raw State- Soda ash is the trade name for sodium carbonate, a

chemical refined from the mineral trona or sodium-carbonate-bearing brines (both

referred to as "natural soda ash") or manufactured from one of several chemical

processes (referred to as "synthetic soda ash"). Place of Origin- the Origin is the

U.S. Natural and Synthetic Soda Ash Industries. Composition- 13.0

(Limestone) Raw state- “Limestone” means any rock formed mostly of calcium

carbonate (CaCO3), but to geologists, limestone is only one of several types of

“carbonate rocks.” These rocks are composed of more than 50% carbonate

minerals, generally the minerals calcite (pure CaCO3) or dolomite (calcium-

magnesium carbonate, CaMg [CO3]2) or both. Place of Origin- Remarkably,

earth’s limestone holds a thousand times more calcium and carbon than today’s

atmosphere, oceans, coal, oil, and living matter combined. Composition- 8.4

(Dolomite) Raw state-Dolomite: double calcium carbonate and magnesium

CaMg (CO3)2 when theoretically pure, contains a stoichiometric ratio of calcium

carbonates and magnesium: 45, 7% MgCO3 (21, 85% MgO) and 54, 3% CaCO3

(30, 4% CaO). Place of Origin- the Mountains of the Southern Tyrol Alps of the

Mediterranean Realm are acknowledged widely to be the geographical area where

dolomite was discovered. Composition-4.0

(Alumina) Raw state- The principal raw material for the production of

aluminum trihydrate and ultimately alumina, or aluminum oxide, is yellow-brown

bauxite. Depending on the quality of the ore, two to four tons of bauxite is needed

per ton of alumina production. Place of Origin- Physically, bauxite ranges from

clay through to soft rock and can be white, pink, yellow, red or brown, or various

combinations of these colors. Compositon-1.0

What is the process to make the material- SEE ABOVE (HOW IS THE

MATERIAL MADE)

Does the material have any historical or cultural significance- The first glass

product which was used by early man, was created by nature. Rhyolite lava flows

from volcanoes and swiftly cools and creates obsidian glass. Around the world,

many early cultures discovered these properties and utilized this glass in weapons,

tools, and decorations. It was the Romans who began the use of glass for

architectural purposes, with the discovery of clear glass around 100AD. The glass

was only used in important building and most luxurious villas. D. ENVIRONMENTAL IMPACT

Expected life expectancy in a commercial application- Exterior walls- Glass

fiber profiled sheet cladding- 27 years, Structural glass curtain wall- 43 years Interior walls- De-Mountable glass reinforced gypsum partitioning- 29 years, De-

Mountable glass partitioning- 29 years Maintenance requirements- Except for cleaning, glass is generally maintenance-

free. Glass used in masonry walls requires frequent cleaning when the building is

new to remove alkalis that leach out of the masonry and will etch the glass if left

on too long. Some acids used in common masonry cleaners, such as hydrofluoric

acid, can dissolve the glass surface and mar it permanently. The deteriorating

effect of cleaners is acutest if the glass has a reflective coating on the exterior

surface. Cleaning methods for glass should be mild and non-abrasive. The glazing

seals between the glass and framing must be replaced periodically to maintain

good performance. Properly installed silicone wet seals should last 10 to 20 years;

gaskets 15 to 20 years.

Recycling/ Biodegradability opportunities- Glass is typically not recycled: since

they consist of a mix of glass, metallic glass coatings, sealants, and aluminum

spacers. It requires a significant and costly effort to separate the constituent

materials. Furthermore, glass is manufactured from relatively inexpensive and

abundant raw materials, which makes glass recycling unattractive. At the end of

their service life, glass is generally discarded as general trash. Crushed glass is

sometimes utilized as hard fill. Most glass manufacturing plants recover glass

discarded during the float glass manufacturing process and combine them with

other batch materials for subsequent production. Overall, the most promising

strategy to limit the amount of glazing in the waste stream is find ways to extend

the service life.

Works Cited

Basic Structural Design Considerations and Properties of Glass and Aluminum Structures.

Research Center for Advanced Technology in Structural Engineering (RCATISE)

Department of Civil and Structural Engineering, Hong Kong Polytechnic University, n.d.

Web. 22 Mar. 2014.

<http://www.hkisc.org/proceedings/2006421/11_SLChan%20facade2006b.pdf>.

"Glass: Overview & Cost Considerations." Market Intelligence. Reed Construction Data, LLC,

2014. Web. 22 Mar. 2014.

<http%3A%2F%2Fwww.reedconstructiondata.com%2Frsmeans%2Farticles%2Fglass-

overview-and-cost-considerations>.

"GLASS TENSION TRUSS STRUCTURES." INNOVATIVE STRUCTURAL GLASS INC

(2005): 1-17. Web. 22 Mar. 2014. <http://www.structuralglass.com/specs/ISG-

TensionStructures.pdf>.

"Hansen Glass Processors." ThermoSpanTM Structural Glazing - For Elegance and Strength

(n.d.): 1-16. Hansen Glass. Web. 22 Mar. 2014.

<http://www.hansengroup.biz/brochures/ThermoSpan2005A.pdf>.

Heiserman, David L. "Building Construction & Finishing." Building Construction & Finishing.

Sweethaven Publishing Services, LLC, 18 May 2013. Web. 22 Mar. 2014. <http://free-

ed.net/free-ed/Resources/Trades/carpentry/Building01/?iNum=1104>.

High Performance Laminated Glass for Structural Efficient Glazing. Stephen J. Bennison, Maria

HX Qin and Philips S. Davies, n.d. Web. 22 Mar. 2014.

Oldcastle Glass. "Structural Glass Systems." StackwallTM/Vision Vue® Walls and Canopies

(n.d.): 1-30. Web. 22 Mar. 2014.

<http://crabtreeglass.com/products/oldcastleglass/structural/structuralglass.pdf>.

"Typical Life Expectancy of Building Components." N.p., n.d. Web. 22 Mar. 2014.

<http://www.costmodelling.com/downloads/BuildingComponentLifeExpectancy.pdf>.

WBDG. N.p., n.d. Web. 23 Mar. 2014.

<http://www.wbdg.org/design/env_fenestration_glz.php>.