HomeMy WebLinkAboutFTC CSU SOUTH VERIZON WTE INFORMAL ROUND 4 - PDP170030 - SUBMITTAL DOCUMENTS - ROUND 4 -INTRODUCTION TO EXTREN®
WHAT IS EXTREN®
EXTREN® is the registered trade name for a proprietary line of standard pultruded fiberglass structural shapes
produced by Strongwell. The EXTREN® line consists of more than 100 different fiberglass shapes, each with a
very specific, proprietary composite design.
Types of glass reinforcements used in EXTREN®
Continuous strand mat: Long glass fibers intertwined and bound with a small amount of resin called a
binder. The mat provides multi-directional strength properties.
Continuous strand roving: Each strand contains 800-4,000 fiber filaments. Many strands are used in
each pultruded profile.
Resins Used In EXTREN®
Isophthalic polyester: A general duty resin which provides adequate corrosion resistance in many
applications.
Vinyl ester: A premium grade resin which has higher strength properties, retains strength
better at elevated temperatures and provides a wider range of corrosion
resistance.
Surfacing Veil
All EXTREN® shapes has a surfacing veil of polyester non-woven fabric which encases the glass
reinforcement and adds a layer of resin to the surface. This combination of fabric and resin provides greater
protection against ultraviolet degradation and corrosives. Surfacing veil also eliminates “fiber blooming” (the
occurrence of glass fibers on the surface) which was prevalent in early stages in outdoor applications.
THE FEATURES OF EXTREN®
EXTREN® structural shapes have numerous features that engineers might use individually or in combination
to solve structural problems.
• HIGH STRENGTH — Stronger than structural steel on a pound-for-pound basis, EXTREN® has been used
to form the superstructures of multistory buildings, walkways, sub-floors and platforms.
• LIGHTWEIGHT — Weighing 80% less than steel and 30% less than aluminum, EXTREN® structural
shapes are easily transported, handled and lifted into place. Total structures can often be preassembled
and shipped to the job site ready for installation.
• CORROSION RESISTANT — EXTREN® will not rot and is impervious to a broad range of corrosive
environments. This feature makes it a natural selection for indoor or outdoor structures in pulp and
paper mills, chemical plants, water and sewage treatment plants, or other corrosive environments.
• NON-CONDUCTIVE — An excellent insulator, EXTREN® has low thermal conductivity and is electrically
non-conductive.
• ELECTRO-MAGNETIC TRANSPARENCY — EXTREN® is transparent to radio waves, microwaves and other
electromagnetic frequencies.
• DIMENSIONAL STABILITY — The coefficient of thermal expansion of EXTREN® shapes is slightly less
than steel and significantly less than aluminum.
— 2 —
THE THREE EXTREN® SERIES
EXTREN® shapes are produced in three standard resin systems which comprise the three series of EXTREN®.
EXTREN® SERIES 500
Resin — Isophthalic Polyester
Standard Color — Olive Green
UV Inhibitor — Yes
( Note: Strongwell began using UV inhibitor in S-500 during the first quarter of 1997.
Stocked items produced before this will not include the UV inhibitor.)
Purpose — General use
EXTREN® SERIES 525
Resin — Isophthalic Polyester with Flame Retardant Additive
Standard Color — Slate Gray
UV Inhibitor — Yes
Purpose — General use when flame retardancy is required
EXTREN® SERIES 625
Resin — Vinyl Ester with Flame Retardant Additive
Standard Color — Beige
UV Inhibitor — Yes
Purpose — Structures where the environment is highly corrosive
NOTE: In addition to EXTREN® products, Strongwell manufactures custom pultrusions. These pultrusions
vary from EXTREN® in either shape, resin type, or reinforcement type, amount, location or orientation.
Designers may choose to vary one or all of these parameters to improve strength, temperature resistance,
corrosion resistance, machinability or some other characteristic. Consult Strongwell with specific needs or
questions.
— 3 —
EXTREN® VS. CONVENTIONAL MATERIALS
Designing with EXTREN® is not much different than designing with other materials. The designer should,
however, keep the following primary differences in mind:
Relatively Low Modulus of Elasticity
The modulus of elasticity of EXTREN® is approximately one-tenth that of steel. As a result, deflection is
often a controlling design factor.
Anisotropic
Pultruded composites are not homogeneous or isotropic; therefore, the mechanical properties of
EXTREN® are directional. When designing with EXTREN®, it is important to consider stresses in both the
transverse and longitudinal directions.
Relatively Low Shear Modulus
The shear modulus of pultruded fiberglass shapes is low compared to metals. Accordingly, the designer
should be aware that shear stresses add deflection to loaded beams above the classical flexural
deflection.
The Effect of Temperature
EXTREN® structural shapes are more susceptible to property degradation at high temperatures than are
metals. The designer should keep this in mind where the design temperature is above 150°F. Contrary to
intuitive thinking, EXTREN® shapes become stronger in cold temperatures.
Corrosion Resistance
EXTREN® shapes are often placed in corrosive environments. General EXTREN® shapes offer superior
corrosion resistance when compared to conventional building materials.
EXTREN® Structural Tube Is Not Pipe
EXTREN® tubes have been designed for structural applications such as columns and handrails and not as
fluid carrying pipe. EXTREN® may be used to carry fluids if there is not internal pressure. The end-user
should consult the CORROSION RESISTANCE GUIDE to confirm the suitability of the resin to handle the
fluid being considered and should also test the EXTREN® tube to confirm its ability to carry the fluid
without leaking.
EXTREN® VS. OTHER PULTRUDED PRODUCTS
Referring to the previous discussion of “What is Fiberglass Reinforced Plastic,” the designer should be aware
that two pultruded shapes with identical external dimensions can vary dramatically in physical properties
depending on the resin formulation and the amount and type of reinforcement. Accordingly, this manual
should not be used for fiberglass shapes other than EXTREN®.
The key word in describing EXTREN® is “standard.” EXTREN® is a product line of standard shapes with
standard mechanical properties. If the pultruded product is not EXTREN®, we refer to it as a “custom
pultrusion”.
— 4 —
PROPERTIES OF EXTREN®
INTRODUCTION
The data sheets in this section present the minimum ultimate values from testing in conformance to ASTM
procedures. These values are obtained from coupons machined from EXTREN® structural shapes and function
as a proof test for the EXTREN® composite.
Strongwell verifies the full section bending Modulus of Elasticity using a simple beam concept at the start of
each production run and periodically thereafter. The empirically determined EXTREN® structural design
equations will be a function of the Modulus of Elasticity.
The designer must consider environmental factors in designing for the actual application. These factors
include elevated temperature and corrosive chemicals.
TEMPERATURE EFFECTS
The approximate retention of mechanical properties at elevated temperatures are:
EXTREN®
Temperature Series 500/525 Series 625
Ultimate Stress 100° F 85% 90%
125° F 70% 80%
150° F 50% 80%
175° F not recommended 75%
200° F not recommended 50%
100° F 100% 100%
125° F 90% 95%
Modulus of Elasticity 150° F 85% 90%
175° F not recommended 88%
200° F not recommended 85%
These recommendations are based on the normal EXTREN® proprietary resin system. Strongwell routinely
processes other resin systems to achieve higher temperature ratings for specific applications.
CORROSION EFFECTS
As a general rule, the isophthalic polyester resin used in EXTREN® Series 500/525 is resistant to most acidic
attacks while the vinyl ester resin in EXTREN® Series 625 is resistant to acids and bases. The effect of
corrosive chemicals is temperature dependent with elevated temperature increasing the corrosion activity.
Strongwell incorporates a synthetic veil on the surface of all EXTREN® structural shapes which causes a resin
rich layer which enhances corrosion protection.
UV (ULTRAVIOLET RADIATION) EFFECTS
UV is a sunlight produced environmental attack on FRP composites. The synthetic surfacing veil also aids in
protecting the composite from UV degradation, the effect of which is sometimes referred to as “fiber
blooming.” EXTREN® Series 525 and Series 625 also contain a UV inhibitor to enhance the protection against
sunlight.
There is a large variation in the degree of fading from UV degradation based on the color selected. While this
fading is undesirable, the structural integrity of the composite will remain unaffected if the surfacing veil is
utilized. Coating with materials such as UV stabilized polyurethane based paints are very effective in
maintaining the color and offer the optimum long-term protection from UV attack.
— 5 —
DESCRIPTION OF TESTS FOR EXTREN®
TENSILE STRENGTH
(ASTM D638)
FLEXURAL PROPERTIES
(ASTM D790)
COMPRESSIVE STRENGTH
(ASTM D695)
IZOD IMPACT
(ASTM D256)
BEARING STRESS
(ASTM D953)
COMPRESSIVE SHEAR STRENGTH
(ASTM D3846)
MODULUS OF ELASTICITY
The tensile strength is determined by pulling ends of a test
specimen until failure. The tensile modulus can be calculated by
measuring the ratio of stress and strain. When the tensile
strength is measured in the longitudinal direction, as a first
approximation, it is an indication of relative roving content. For
example, an all roving EXTREN® rod has a higher tensile
strength than the EXTREN® structural shapes which are a
combination of roving and continuous strand mat.
The flexural strength is determined by placing a test specimen
between two supports and applying a load to the center. ASTM
D790 specifies required span to depth ratios for the test
specimen. Flexural tests on coupon samples are often used to
determine the effects of environmental conditions such as
temperature and corrosive agents.
The ultimate compressive strength of a composite is a force
required to rupture the composite when a load is applied such
that the specimen is crushed. The compressive test is an
excellent indication of the resin matrix to reinforcement bond
and has been adopted by the ANSI A14.5 specification for
fiberglass rail as the primary physical property audit.
The Izod impact is determined by subjecting a specimen to a
pendulum-type collision; the specimen can be notched or un-
notched. The energy required to rupture the specimen due to the
collision caused by the swinging pendulum is used to calculate
the Izod Impact strength.
This test specimen consists of a flat strip with a hole machined
in one end as specified by the ASTM procedures. The testing
consists of clamping the end without the hole and attempting to
tear or rupture the hole in the specimen. The load required to
rupture the hole is used to determine the bearing stress.
In the shear test, a full thickness test specimen is notched on
two sides of the test area such that the applied load is acting
upon only a small cross section. The load can be either tensile
or compressive and the notches can be oriented differently.
This parameter is determined by loading a prescribed length of
the full shape (not a coupon) with a support at each end and
applying a center load. From the measured deflection and the
known load and span, the bending modulus of elasticity can be
determined once the shear deflection effects are identified. This
is a more reliable estimate of the field performance in beam
bending situation that the coupon properties.
— 6 —
The barcol hardness is a measure of the resistance of the surface
of a test specimen to penetration by a needle probe which is
spring driven. The barcol hardness value is generally an average
of multiple measurements on the same part and is an
approximate measure of the composite’s completeness of cure.
In this test, the specimens are immersed in water for a period of
24 hours and the change in weight is measured. This test has
utility in electrical and corrosive applications.
The density is the ratio of the mass (weight) of a specimen to the
volume of the specimen. This parameter is important in
determining the ultimate weight of the finished product.
The ratio of the density of a composite to the density of water.
This test is performed by placing two probes on a test specimen
at a distance of 1/4". A high voltage, low current, arc is passed
between the probes with a specified on/off cycle for this arc. The
time taken for the arc to completely burn a path through the
composite is measured.
In this electrical test, the sample is placed between electrodes
with the electrodes and the sample immersed in non-conducting
oil to prevent a false failure signal. Failure occurs when the
voltage is sufficient to cause the current to discharge through the
composite. This test is occasionally performed after conditioning
the test specimen with water at elevated temperatures.
Weatherometer applies alternating cycles of water, high
temperature, humidity and ultraviolet exposure to measure the
weatherability of a given composite and/or additive. This test is
primarily comparative in nature between composites and/or
formulations. The geographic location of the composite will
determine its actual weatherability.
EXTREN® Series 525 and Series 625 are listed with a VO rating at
UL. In the UL 94 test, a vertically clamped sample is subjected to
a flame from a bunsen burner; the flame height is carefully
controlled by UL specifications.
In the 25 foot tunnel test, a smoke generation value and the rate
of flame spread are determined. This test has been the standard
for years in measuring flammability and smoke generation.
This test requires a much smaller test specimen and essentially
places this specimen in the bottom of a chamber and measures
the smoke that is generated to an optical detector at the top of the
chamber.
This is a less severe flammability test in which the specimen is
held horizontally with one end subjected to a flame for 30 seconds.
BARCOL HARDNESS
(ASTM D2583)
WATER ABSORPTION
(ASTM D570)
DENSITY
(ASTM D792)
SPECIFIC GRAVITY (ASTM D792)
ARC RESISTANCE
(ASTM D495)
DIELECTRIC STRENGTH
(ASTM D149)
WEATHERING
QUV WEATHEROMETER (ASTM G53)
UL 94
TUNNEL TEST
(ASTM E84)
NBS SMOKE CHAMBER
— 7 —
“FIBERGLASS PULTRUSION THICKNESS” RELATIVE TO STEEL, ALUMINUM OR WOOD
STEEL* ALUMINUM* WOOD*
Tensile Flexural Tensile Flexural Tensile Flexural
Strength Rigidity Strength Strength Rigidity Strength Strength Rigidity Strength
50% Mat & Roving (EXTREN®) 2.5 2.15 1.82 1.0 1.49 1.16 .25 .79 .45
70% Roving Only 1.0 1.71 1.12 .4 1.19 .71 .10 .63 .27
(Thermal Cure Rod & Bar)
FIBERGLASS PULTRUSION
CONSTRUCTION
*Copied from Engineered Materials Handbook, Vol. 1, “Composites,” pg. 541.
1 As an example, a 50% mat & roving fiberglass pultrusion would need to be 1.16 times as thick as an aluminum part to achieve the same “flexural strength.”
EXTREN® vs. TRADITIONAL MATERIALS
(PROPERTY COMPARISON)
400 Commwealth Ave. P. O. Box 580
Bristol, VA 24293-0580
(540) 645-8000 FAX (540) 645-8132
EXTREN® THERMAL CARBON 316 HASTELLOY ALUMINUM FIBERGLASS SPRAY-UP
500/525 EXTREN® 625 CURE ROD STEEL STAINLESS C-276 6061-T61 PONDEROSA RIGID PVC COMPRESSION (30-50%
MECHANICAL SHAPES SHAPES AND BAR (M1020) STEEL (ANNLD.) T651 PINE RIGID PVC 10% GLASS MOLDING (SMC) GLASS)
Tensile Strength LW 30 1 30 1 100 1 35 30-35 50 45 42 6.2 7.8 8-20 9-18
(x 103 psi) (Yield) CW 7 1 7 1 — 35 30-35 50 45 — — — — —
Tensile Modulus LW 2.5 2.6 6 30 28 26 10 — .39 .47 1.6-2.5 .8-1.8
(x 106 psi) CW .8 1 — 30 28 26 10 — .39 .47 1.6-2.5 .8-1.8
Flexural Strength LW 30 30 100 35 30-35 50 45 .725 11 11.7 18-30 16-28
(x 103 psi) CW 10 10 — 35 30-35 — 45 9.4 11 11.7 — —
Flexural Modulus LW 2 2.2 6 30 28 26 10 1 .35 .45 1.3-1.8 1-1.2
(x 106 psi) CW .8 .8 — 30 28 26 10 — .35 .45 — —
Izod Impact LW 25 25 40 N/A 8.5-11 — — — 1.6 1.6 10-20 4-12
(ft-lb/in) CW 4 4 — N/A — — — — 1.6 1.6 — —
Specific Gravity 1.7 1.7 2 7.8 7.92 8.96 2.5 .52 1.38 1.39 1.5-1.7 1.4-1.6
PHYSICAL
Density (lbs/in3) .062-.07 .062-.07 .072-.076 .284 .29 .324 .092 .019 .052 .052 .054-.061 .05-.059
Thermal Conductivity 4 4 5 260-460 96-185 71 1200 .08 1.3 — 1.3-1.7 1.2-1.6
(BTU/SF/HR/oF/in)
Coefficient of Linear
Expansion 5.2 5.2 3 6-8 9-10 13.5 1.7 37 23 10-18 12-20
(10-6 in/in/oF)
1 Minimum Ultimate Property From Coupons
EXTREN® vs. TRADITIONAL MATERIALS
(QUICK CHEMICAL RESISTANCE COMPARISON CHART)
*Assuming Room Temperature
Hydrochloric Phosphoric Sodium Soduim Acid
Sulfuric Sulfuric Acid Hydrochloric Acid Hydrofluric Phosphoric Acid Hydroxide Hydroxide Chloride Wet
MATERIALS Acid Dilute Concentrate Acid Dilute Concentrate Acid Aicd Dilute Concentrate Dilute Concentrate Salts Bleach Chlorine Nitric Acid
EXTREN® R NR R R NR R R NR NR R NR NR R
Series 500 & 525 (Below 30%) (Below 5%)
EXTREN® RRRRRRRRRR R RR
Series 625 (To 75%)
Carbon Steel NR R NR NR NR NR NR R R NR NR NR NR
(1020) (Above 85%)
316 Stainless R R NR NR NR R R R NR NR NR NR R
(Below 5%) (Above 85%)
Hastelloy C R R R R R R R R R R R R R
Aluminum NR NR NR NR NR NR NR NR NR NR NR NR NR
CHEMICAL ENVIRONMENT* R=RECOMMENDED NR=NOT RECOMMENDED
400 Commwealth Ave. P. O. Box 580
Bristol, VA 24293-0580
(540) 645-8000 (Customer Service)
FAX (540) 645-8132
(ASTM E662)
FLAMMABILITY
(ASTM D635)