Engineering Load Test

Engineering Load Test

   
  

Engineering Load Test

image 
Glaze: 1/8" Acrylic 
Beams: T5 Aluminum
Span Length: 10'0"Width: 4'2"Centers: 25"
Load: 
50.7 lb/sq/ft 
Load/Rafter: 
105.7 lb/lin. ft.
Deflection (inches): 
Vert. = 5.08 in.
Deflection (inches): 
Horiz. = 0.64 in.
Note: Original sheet thickness was 1/8", today we utilize 3/16" as standard glaze thickness. All center to center Rafter dimensions are now 26 1/8". 
   
  

Aluminum Rafter Specifications

image Aluminum structural members: Are all extruded T-5 6063 architectural grade aluminum alloy.
Exterior Finish: Factory raw, White/Brown spray enamel, or electrostatic powder coat custom color.
Nylon Plugs: Proprietary design - White/Brown fastening members.
Glaze Seal: "Santoprene" cup seal - 4 per full Rafter/Barcap length, 2 upper & 2 lower.
   
   

RAFTER PROFILE

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Click to enlarge

 

Aluminum Pressure BarCap Specifications

BARCAP PROFILE:

Engineering Load Test
Click to enlarge

Acrylic Sheet:  Physical Property Specifications

Purpose is to encourage the proper use of acrylic sheet plastic in construction, and to aid architects in designing and preparing specifications consistent with the properties and characteristics of the material. [ Tables and literature from Rohm & Haas, Philadelphia, PA, CO-EX Corp. Rocky Hill, CT.] Commercial grade acrylic sheet is suitable for most building glazing applications.

 

 

Breakage Resistance

The figures below show that various thickness of acrylic sheet have greater impact resistance than other types of glass when impacted with a hard object, such as a stone.

IMPACT RESISTANCE OF ACRYLIC SHEET AND OTHER MATERIALS

MaterialNominal Thickness: Energy to Break (ft-lb)
Acrylic Sheet
Acrylic Sheet
Acrylic Sheet
Acrylic Sheet
2.5 mm
3.0 mm
4.5 mm
6.0 mm
3.0
4.7
11.1
18.1
Single strength Window Glass
Double Strength Window Glass
Plate Glass
Plate Glass
.100 in
.125 in
.187 in
.250 in
0.8
1.8
2.0
1.0
Laminated Safety Glass.250 in1.1
Rough Wire Glass
Polished Wire Glass
.250 in
.250 in
2.2
0.4

AIR CANNON IMPACT STRENGTH

Acrylic Sheet
Nominal Thickness (mm)
Baseball ( 0.32# )Steel Tipped Dart
( 0.6 lb 1/2" Rad. Tip ) 
3.0
6.0
9.0
12.0
18.0
24.0
47 mph
84 mph
105 mph
147 mph
184 mph
220 mph
5 ft.lb.
16 ft.lb.
27 ft.lb.
40 ft.lb.
53 ft.lb.
68 ft.lb.

Light Transmittance

The colorless form, Acrylic sheet is as transparent as the finest optical glass. Its total light transmittance is 92 percent, and haze measurement for colorless sheet averages only 1 percent.

SOLAR ENERGY TRANSMITTANCE and SHADING COEFFICIENTS

Acrylic SheetTransmittance ( % )Transmittance ( % )Shade Coefficients
Vertical
Visible Light Solar Energy
2370 Bronze (Dark)
2412 Bronze (Med.)

2404 Bronze (Light)
10 %
27

49
20 %
35

56
0.46
0.58

0.75
2111 Green
2092 Green
2069 Blue
77
26
55
76
57
71
-
-
0.89
Colorless ( Clear )92850.98
  • 2412 Bronze is our standard (recommend) sheet in bright solariums.
  • Super White Translucent grades are preferred in south face roof areas for alleviation of extreme heat build-up in solariums - this transmits and bathes areas below in a natural cool white light plus delivering all your required light for the growth of plants, yet shades the area for human activity.

Ultraviolet Transmittance: Regular Acrylic glaze sheet ( G & MC ), will block some portions of the UV spectrum, but special grades are required when all ( UF-3 ) or most ( UF-4 ) of the UV needs to be absorbed.

Weight

Acrylic Sheet is approximately less than 50% as heavy as glass and 43% as heavy as aluminum.

Lexan "MacroLux" Panels [ double wall extruded sheet ] is 1/8 the weight of glass.

COMPARATIVE WEIGHTS  (lb/ft² )

Thickness (mm)Acrylic SheetMacroLux PanelsGlass 
Single Glaze
Glass 
Double Glaze
6
8
10
1.45
1.93
2.92
0.266
0.350
0.410
2.07
4.10
5.12
6.15
8.19
10.24

Total Energy Transfer

 

The amount of heat conducted throught Acrylic glazing is lower than for glass of the same thickness.

U-Factor:  ( BTU/hr/sq.ft./ ° F )

Description: WinterSummer
Single Walled
Double Walled
1.15
0.70
0.80
0.46

Chemical Resistance

While most household cleaners can safely be used with acrylic sheet, the material is affected by alcohol, paint thinners, turpentine, and similar petroleum solvents. To clean paint and grease, utilize NAPHTHA or KEROSENE for safe removal. Regular cleaning with a mild dish detergent and plenty of water is preferred, dry with clean cotton or air dry. A good grade of automobile wax can be applied as a polish, and is very useful in removal of minor surface abrasions.  

Acrylic sheet has proved its ability to withstand weather and sun exposure with negligible loss of light transmission and clarity. The manufacturers warranty expresses a 10 year guarantee of less than 3% CHANGE in light transmission and clarity within this interval. No other type of plastic offers this assurance of satisfactory outdoor performance.  

When acrylic sheet is heated to its optimum forming temperature (approximately 325°F - 350°F), it becomes soft and pliable, and can be formed to almost any desired shape. As the material cools in its formed shape, it stiffens and retains the shape to which it has been formed. This permits architects to specify complex designed panels in small quantity at reasonable tooling costs.

Cold Forming

 

Flat sheets of acrylic can be cold-formed ... bent while cold to a smooth contour ... and held to the radius by springing the material into a curved channel support. The recommended radius of curvature for "G sheet" should be at least 180 times the thickness of the sheet.

Minimum Radius of Curvature for Cold-Formed Acrylic Sheet

Sheet Thickness (mm)Min. Radius (in)
1.5 mm
3

4.5
6
8.5
12
11 in
21

32
42.5
60
86

Our standard minimum radius for 4.5 mm sheet is 36"

Acrylic sheet offers equal to or better sound loss characteristics than glass. It also has much better breakage resistance, so it can be used as a transparent sound barrier to reduce noise levels and increase safety at the same time.

Comparison of Noise Reduction Characteristics of Acrylic Sheet and Other Materials

Construction MaterialApproximate dB (A) Noise Reduction
Acrylic Sheet 3 mm
Acrylic Sheet 6 mm
Acrylic Sheet 12 mm
25
29
33
Glass (1/8")
Glass (1/4")
25
27
Plywood (1")
Steel (1/8")
Sheet Lead (1/16")
Wood Stud Partition (4")
26
37
38
38

Thermal Expansion & Contraction Factor

 

Due to the thermal expansion and contraction, acrylic sheet is subject to greater dimensional change than other materials with which it is used in construction. This is factored into account when dimensions are laid out for any project. Considerations must be given to the overall temperature gradient ( max. & min. values ) that the glazed structure will be subjected to, and allowances are made to the sheet dimensions according to those values.

 

Thermal Expansion and Contraction Factor

MaterialExpansion Coefficients ("/"/°F)Typical Modulus (psi)
Acrylic Sheet
Aluminum
Steel
Plate Glass
0.0000410
0.0000129
0.0000063
0.0000050
450,000
10,000,000
30,000,000
10,000,000

Example: (Sheet Location: = 25 1/2" x 14' ) If the ambient temperature at time of dimensional cutting is room temp. - then sheet is trimmed to 25 1/4" x 13' 5/8".  Thereby, if sheet is cold at dimensioning, you must realize it is now contracted, and if the sheet is hot at time of trim, the sheet may be fully expanded. You therefore trim to what the opposite extreme temperature would consist of. Generally, on a sheet at 14 ft., the max. off-cut is approx. 1/2" - 5/8" in length, and approx. 3/16" to 1/4" in width. For smaller sheets, the maximal length off-cut is reduced proportionally.

Temperature / Humidity Bowing

Different temperature and/or humidity conditions on the inner and outer surfaces of thinner acrylic sheet may cause sheet to bow somewhat in the direction of the higher temperature and/or humidity. However, this type of bowing is reversible, and the sheet will return to its original flatness once the temp./humidity differentials are equalized.     Bowing does not affect visibility through flat transparent sheet, but may cause distorted reflection. In translucent or opaque panels where visibility through the material is not required, this nature exhibits a specular disguise to reflective distortions. This will not occur in curved glaze, cold formed or heat formed. This event is lessened by use of thicker glaze panels on narrow width dimensions.

 

Service Temperature

The allowable continuous service temperature range for Acrylic sheet is 170° F to 200° F for exterior applications.

To avoid stress crazing [ light surface checking of panel ], design stress limits for continuously imposed loads should not exceed 1500 psi for acrylic "G" sheet, and 750 psi for acrylic "MC" sheet at or below room temperature.