Frequently Asked Questions
Rebar couplers mechanically connect two reinforcing bars, eliminating the need for overlapping, whereas rebar splices refer to any method of joining rebar, including couplers, welding and tying methods.
Griptec rebar couplers are designed for high-performance applications, including seismic zones, offering superior fatigue resistance and compliance with international.
Fortec / Bartec headed bars deliver high-performance anchors with easy installation, reducing construction time and the need for bending rebars on-site while ensuring structural integrity.
Mechanical rebar couplers provide a stronger and more reliable connection while reducing rebar congestion, material costs and the need for skilled labor compared to lap.
By eliminating unnecessary rebar overlaps, rebar couplers reduce material waste and improve resource efficiency, making them a sustainable reinforcement solution.
Dextra’s rebar splicing solutions comply with international standards, ensuring durability, reliability, sustainability and efficiency in concrete structures.
They are used to eliminate the need for lap splicing, reduce congestion in reinforced concrete, and ensure continuity of the reinforcement.
Dextra is a global supplier of premium rebar couplers with offices in Europe, Thailand, India, America (USA), China and Middle East servicing a global market. You can contact any of our offices by visiting the “Contact Us” page for details.
Unitec, Dextra’s shear-bolt coupler, can be installed on rebar without threads and using only standard tools. Repairgrip, a system using swaged couplers, doesn’t require threaded rebar, either. It needs a specific swaging machine, though.
The most efficient solution for this type of splice, generally called “position splice”, is the use of threaded couplers. Dextra only uses parallel threads which allow position splicing by means of an extended thread on one of the connecting bars. The coupler is screwed completely onto this thread, the bars are then brought end-to-end and the coupler is screwed from the extended to the standard thread on the other bar.
Dextra offers transition couplers that enable the splicing of two different rebar diameters, ranging from D12 to D40
Yes, Dextra’s coupler solutions deliver superior performance compared to rebar lapping, especially under seismic conditions.
Material usage: By using couplers, the amount of rebar required can be minimized.
Faster Installation: The installation of rebar couplers are quicker than that of traditional lapping.
Lower labor costs: Rebar couplers simplify the installation process, reducing the number of skilled labor required.
Enhanced safety: Rebar couplers or splices contribute to a safer work environment by eliminating the need for extensive manual tying of rebar.
Consistent quality: The manufacturing process of Dextra couplers ensures a consistent quality of joints, which can be difficult to achieve with manual lapping.
Rebar couplers can influence the overall cost of construction projects through their impact on labor efficiency and material costs.
Structural requirements: Load capacity, seismic performance, fatigue resistance
Project-spesific constraints: Bar size & compatability, concrete cover & spacing, construction sequences
Installation & site conditions: Ease of installation, tolerances & alignment, weather & environment
Regulatory & code compliance: Building code compliance, approval by authorities
Material standards: Couplers must be made from materials that meet specific strength and requirements, such as those outlined in ASTM (American Society for Testing and Materials) standards.
Design standards: The design of threaded bar couplers should comply with structural design codes, such as AISC (American Institute of Steel Construction) or ACI (American Concrete Institute) standards, which dictate how they should perform under load.
Testing standards: Couplers are often required to undergo rigorous testing to ensure they can handle the expected loads and stresses. This may include tensile strength testing and fatigue testing.
Installation standards: Proper installation techniques must be followed to ensure safety. This may involve guidelines from organizations like OSHA (Occupational Safety and Health Administration) regarding safe working practices.
Certification: Couplers are tested by third-party organizations to ensure they meet industry standards for safety and performance.
Common types include fully grouted coupler and half grouted couplers.
These couplers use grout to fill the space or cavity between the rebar and the coupler, creating a strong bond.
Grouted splice couplers offer high strength and durability, and can accommodate slight misalignments between precast elements.
Precast couplers reduce waste and material usage, contributing to more sustainable construction practices.
Dextra’s precast connections, such as Groutec and TieTec, offer faster installation and enhanced thermal efficiency, making them ideal for insulated precast sandwich panels.
Dextra’s rebar splices, including precast mechanical couplers like Groutec and Tietec, ensure quick and secure connections, reducing labor costs and construction time.
Dextra’s rebar couplers, such as Groutec, provide a reliable and efficient solution for connecting rebar, ensuring structural integrity and reducing construction time.
The Groutec coupler creates transverse confinement, and the grout has a higher compressive strength compared to concrete, which increases the bond stress and reduces the anchorage/development length.
Yes, technical support is available during both the precast and on-site phases. This ensures proper installation and performance.
The minimum cover and spacing requirements depend on the specific application. Detailed guidelines can be provided upon request.
Tension rods are high-performance bar systems used in tension, typically for cross-bracing roof or façade structures, providing both aesthetic and structural benefits.
PT bars (post-tensioning bars) are used for reinforcing concrete by applying post-tensioning force, while PC bars are typically pre-tensioned before installation.
Post-tensioning bars, or PT Bars, provide high tensile strength and flexibility, allowing for the construction of longer spans and thinner slabs without compromising structural integrity.
Marine tie bars are used in marine construction to provide additional support and stability to structures exposed to harsh marine environments, ensuring long-term durability and performance.
Marine tie bars offer ductile design, quick installation, full range of accessories, corrosion protection options, and compatibility with various wall types.
Corrosion protection options for marine tie bars include bituminous tape, epoxy coating, and sacrificial thickness, tailored to project requirements.
Tension rods provide a sleek and modern look while offering structural support, making them ideal for roofs and facades in architectural projects.
Ground anchors are used to stabilize and support Geotec structures, providing additional strength and preventing movement or settlement.
GFRP (Glass Fibre Reinforced Polymer) is used in ground engineering for reinforcement purposes, such as in soil nails and rock bolts, due to its high strength and corrosion resistance.
Ground anchors are load transfer systems designed to support structures. They are commonly used in geotechnical and construction applications, such as supporting retaining walls and stabilizing slope.
Active ground anchors are pre-stressed and typically used for retaining walls, while passive anchors are fully grouted and used for slope stabilization.
Sonitec is a sonic logging tube system used for monitoring and testing the integrity of concrete in bored pile applications.
A soft-eye is a reinforced opening in a tunnel lining that allows for the passage of a tunnel boring machine (TBM) without damaging the structure
Double corrosion protection systems ensure the longevity and durability of ground anchors, especially in permanent applications
Dextra’s micropile systems are designed for deep foundations, offering fast installation, easy handling, and high load-bearing capacity.
Expandable friction bolts provide immediate support and are easy to install, making them ideal for stabilizing rock in tunneling and mining operations.
GFRP soil nails are non-corrosive, lightweight, and easy to install, making them suitable for various soil stabilization projects.
FRP stands for Fiber Reinforced Polymer. It is a composite material made of fibrous materials (usually glass, carbon, basalt or aramid) held together in a polymer matrix (usually polyester, vinyl ester or epoxy).
Traditionally, rebar is made from steel, which can be prone to rust and corrosion. FRP rebar is known for its high strength, lightweight nature, and corrosion resistance, making it an excellent alternative to steel rebar in various construction applications.
The main components are the resin binder and the reinforcing fibers. The resin binder provides chemical resistance, while the fibers provide mechanical strength. The common ratio is 80/20 with 80% of the material is made of fibers and 20% is made of resin.
Therefore, it is a composite material made of fibrous materials (usually glass, carbon, basalt or aramid) held together in a polymer matrix (usually polyester, vinyl ester or epoxy).
GFRP stands for Glass Fiber-Reinforced Polymer, a specific type of FRP (Fiber-Reinforced Polymer) rebar used in construction.
Glass Fiber Reinforced Polymer (GFRP) is more and more used in the construction industry due to its high strength, lightweight nature, and resistance to corrosion. Here are some common applications:
– Brigdes decks : The use of GFRP can be used into bridges as it reduced the overall weight and combat the corrosive effects of the marine environment which help in reducing maintenance costs and extending the bridge’s lifespan.
– Slab on ground : GFRP rebars are effective in controlling crack width in slabs on ground caused by temperature-induced shrinkage. Their high tensile strength and low modulus of elasticity help distribute stresses more evenly, reducing the likelihood of wide cracks forming.
– Concrete Reinforcement: GFRP is often used to reinforce concrete structures. It helps improve the durability and longevity of these structures by preventing corrosion.
– Facades and Cladding: GFRP is used in the construction of facades and cladding systems, providing an aesthetically pleasing and durable exterior for buildings.
– Slope Stabilization: GFRP materials are used for slope stabilization and terrace creation, helping to prevent soil erosion
GFRP is a compelling alternative to steel in many applications, especially where corrosion resistance, weight reduction, and long-term durability are critical.
GFRP offers superior longevity and requires less maintenance due to their resistance to corrosion and environmental degradation.
In addition, the non-conductive and lightweight properties of GFRP make it safer and easier to handle, reducing labor costs and improving installation efficiency. Finally using FRP contributes to sustainability efforts by reducing the carbon footprint and promoting the construction of more efficient structures.
Glass Fiber Reinforced Polymer (GFRP) offers several advantages, making it a popular choice in various industries especially when compared with steel. Here are some key benefits:
1. High Strength-to-Weight Ratio: GFRP is significantly lighter than steel, yet it provides twice the tensile strength. This makes it ideal for applications where weight reduction is crucial, such as in aerospace and automotive industries.
2. Corrosion Resistance: Unlike steel, GFRP does not corrode, rust, or rot. This property makes it highly durable and suitable for use in harsh environments, including marine and chemical industries.
3. Electrical and Thermal Insulation: GFRP is non-conductive to electricity and heat, making it a safe choice for electrical and thermal insulation applications.
4. Ease of Installation: GFRP is easier to handle and install compared to traditional materials. It can be manufactured in custom lengths, bends, and shapes, and is easy to cut and machine.
5. Reduced Maintenance Costs: Due to its durability and resistance to environmental factors, structures reinforced with GFRP require less maintenance over their lifespan, leading to cost savings.
6. Environmental Sustainability: GFRP’s long service life and low maintenance requirements contribute to its environmental sustainability. It also helps in reducing the carbon footprint by enabling the construction of lighter and more efficient structures.
Cost is one of the many comparison points between GFRP rebars and traditional steel rebars. The initial cost of GFRP rebars is generally higher than that of black steel rebars in the same size, lower than stainless steel or epoxy steel. When considering the long-term benefits, such as reduced maintenance costs and extended lifespan due to its corrosion resistance, GFRP rebars can be more cost-effective in the long run. Due to the tensile strength is double that of steel, GFRP rebars cost is much more competitive compared with steel rebars after design optimization.
Also, the steel price can highly fluctuate according to the selected manufacturer, the region of production and the date of production while the price of GFRP is more predictable with a decreasing trend due to the manufacturing improvements.
The design of concrete structures utilizing FRP reinforcing is dictated by the ACI 440.11 code for ASTM D7957 compliant rebars.
Bars other than Glass FRP bars per ASTM D7957 may be implemented using the companion design guide PRC440.1 “Guide for the design and construction of concrete reinforced with FRP bars”.
Yes, now there are codes (USA = ACI 440.11 / Europe = Eurocode 2, Annex R) that govern structural & permanent applications for GFRP reinforced concrete.
GFRP rebars are considered environmentally friendly as they offer significant environmental benefits compared to traditional materials like steel. GFRP rebars’ production generates lower CO₂ emissions and consumes less energy. Additionally, GFRP rebars’ corrosion resistance leads to longer lifespans and reduced maintenance, further contributing to sustainability. It is also recyclable (up to a certain extent) which helps minimize construction waste. Also, GFRP rebars often replace heavier, less durable materials, reducing the overall environmental impact. However, the production process and disposal need to be managed properly.
Durabar is a high-strength GFRP rebar solution that provides superior performance and durability.