PERFORMANCE
ENVIRONMENT
PERFORMANCE
Q: How does MST-BAR® strength compare to steel? A: MST-BAR® has a tensile strength of greater than 1000 MPa (145 ksi), in comparison to steel, MST-BAR® can take over 3x the tensile load of steel before failure.
Q: How does MST-BAR® modulus of elasticity compare to steel? A: MST-BAR® has a tensile modulus of greater than 65 GPa (9427 ksi), in comparison to steel, GFRP rebar is more flexible.
Q: How does MST-BAR® strain compare to steel? A: MST-BAR® has a tensile strain between 1.5% to 2.5%.
Q: What is the resistance of MST-BAR® to the Alkali Environment? A: MST-BAR® has tested according to CSA, ASTM & ACI standards for durability criteria, they both retain +90% of ultimate tensile capacity after 2160 hours of direct exposure to an alkali solution with a pH level of 13 at 60 degrees Celsius, in comparison to steel, GFRP rebar is much more resistant than the highest grade of stainless steel.
Q: What is the maximum operating temperature of MST-BAR®? A: MST-BAR® and other GFRP bars that comply with CSA, ASTM, and ACI standards, which have a glass transition temperature of above 110 degrees Celsius, can be in direct contact with heat up to 110 degrees Celsius without losing strength. MST-BAR® at 400 degrees Celsius will lose its tensile strength from 1400 MPa to about 650 MPa, which is still higher than steel rebar at room temperature
Q: What is the minimum operating temperature of MST-BAR®? A: MST-BAR® was tested according to CSA & ACI standards at -40 degrees Celsius, and the effect was zero and in some case increases in performance.
PRICE
Q: How does MST-BAR® price compare to steel rebar and stainless steel rebar? A: MST-BAR® is much less than the cost of stainless steel. MST-BAR's price is very competitive with black steel rebar but when you consider all the savings due to labor costs, corrosion protection additives, cover concrete and transportation the cost could be lower than steel rebar.
Q: How does MST-BAR® price compare to Epoxy-Coated Rebar(ECR) and galvanized rebar? A: MST-BAR® is generally less expensive than galvanized and epoxy-coated rebar and the total installed cost of GFRP rebar is much lower.
Q: Do we have to consider the initial cost of rebar? A: Absolutely not! When factoring in the life cycle of the structure reinforced with MST-BAR® the cost of rebar at the initial stage could be eliminated in your budget since the cost of repair after 10-20 years due to corrosion could be as much as your rebar would cost at the initial stage.
Q: Why using MST-BAR® reduces the cost of the project? A: Engineers are always factoring all the associated costs of the project, Some of these factors can be eliminated or reduced when considering the use of MST-BAR®. · Installation time · Transportation · Handling and cutting · Surface cover and ability to remove waterproofing membranes and 65mm asphalt · DCI, CNI and other corrosion inhibitors · Short & long term maintenance charges
HANDLING
Handling Q: Can we shear cut GFRP rebar? A: NO, GFRP rebar is orthotropic material, GFRP can be cut using a steel saw, a band saw, and or grinder with a diamond blade.
Q: How to tie GFRP rebar together? A: Tie GFRP Rebar with stainless steel or nylon tie wire, you may use a heavy-duty zip tie too. If corrosion or electromagnetic field is not a concern you may use uncoated wires too.
Q: Can we bend MST-BAR® in the workshop or on-site? A: MST-BAR® is manufactured with Vinyl-Ester Thermoset Matrix, you can not bend MST-BAR® after the curing cycle, all the bends have to be fabricated in MST Rebar Plants. Minor adjustments to the bends are possible due to the rebar's inherent flexibility.
ENGINEERING
Q: Can we replace GFRP rebar in ONE to ONE ratio of steel bar? A: MST-BAR is three times stronger and more flexible than steel rebar. It behaves linearly elastic to failure, meaning there is no yield point to be determined, but the material can withstand significantly higher loads. Engineers must follow the codes and standards for GFRP rebar, not steel. In most cases where serviceability is not governing the design and it is based on Ultimate Limit State (ULS), you can simply substitute steel with MST-BAR high modulus. If serviceability is governing the design, then it is recommended to perform proper engineering to ensure all deflections are controlled..
Q: What is the difference between GRADE I, GRADE II and GRADE III GFRP Rebar? A: MST Rebar Inc. manufacture MST-BAR as GRADE III according to CSA, Grade refers to modulus of elasticity of GFRP rebar. MST Rebar Inc only produces #3(10M) in Grade 1 for flatwork application. The remining sizes are all in Grade III. · GRADE I - E > 40GPa · GRADE II - E > 50GPa · GRADE III - E > 60GPa
Q: Can we use MST-BAR rebar in active seismic regions(earthquakes)? A: YES, MST-BAR bars can be used as reinforcement in concrete subjected to seismic loading conditions. MST-BAR is capable of resisting reversal tension-compression cycles without failure. The large deformation, exhibited by GFRP material, allows the GFRP reinforced building to adequately dissipate the seismic energy. Currently more than 100 bridges and structures are reinforced with GFRP rebar in seismic regions. Although it has not been part of the code but there is no limit to why MST-BAR can not be used in seismic regions.
Q: What design guidelines should the designer follow? A: There are a number of design guidelines available from CSA & ACI. Canada · CSA · CAN/CSA-S6-06(Canadian highway bridge design code) · CAN/CSA-S806-02(Design and construction of building component with FRP) USA · ACI · ACI 440.1R-06 · ACI 440R-07 · ACI 440.5-08 · ACI 440.6-08 · AASHTO GFRP-1
ENVIRONMENT
Q: Can we store MST-BAR® under sunlight exposure? A: NO, if it is more than 2 months. MST-BAR® is made from a thermoset Matrix that can be degraded by UV radiation, due to cost competitiveness, MST-BAR® does not have UV-inhibiting binders. Always cover the MST-BAR® from direct UV radiation with a tarp if it is stored outside.
Q: Can we store MST-BAR® under rain and snow? A: Absolutely, MST-BAR® can be stored under rain and snow with no problem since the material can not be corroded.
Q: What does the end of life of MST-BAR® look like? A: MST-BAR is made of Glass Fiber that is 100% recyclable and the resin can be degraded by UV if exposed, however when it is in concrete the material can be crushed with concrete without the need to remove it after +100 years and it can be part of the next recycled concrete which makes the concrete stronger.
Q: Can you cure concrete with seawater? A: Yes, if MST-BAR is being used the concrete can be cured with seawater because of its non-corrosive nature. This could lead to the preservation of enormous amounts of fresh water.