FAQs

With the increasing importance of eco-friendly, sustainable construction, basalt fiber reinforced polymers (BFRPs) have steadily gained popularity as the optimal method for concrete reinforcement. The strength, durability and non-corrosive properties of BFRPs, along with a lower carbon footprint, have led to many inquiries from public works engineers, specifiers and contractors. Here are some FAQs about our BASTECH products. If you have additional questions, please feel free to contact us.

How much concrete cover is required for FRP bars?

Concrete cover for reinforcement will vary by application. Basalt rebar is corrosion resistant, and therefore requires less cover than other materials. Minimum concrete cover provided by ACI-440.11-22, Section 20.5, table 20.5.1.3.1

Can basalt rebar be used for horizontal and vertical reinforcement for walls simultaneously?

Yes. Basalt rebar is a popular alternative to traditional steel rebar due to its advantages, such as high strength, corrosion resistance, and thermal stability.

 

In wall construction, basalt rebar can be used in both horizontal and vertical orientations to reinforce the concrete. Horizontal reinforcement is typically used to prevent cracking and provide structural integrity, while vertical reinforcement is used to enhance the wall’s load-bearing capacity and resist bending forces.

 

Its lightweight nature also makes it easier to handle and install compared to steel rebar. However, it is important to ensure that the design and engineering specifications are followed when using basalt rebar to ensure the structural integrity and safety of the walls.

What adhesives can be used to anchor BFRP bars to existing concrete?

There are several adhesives commonly used for this purpose. These adhesives are designed to provide a strong bond between the BFRP bars and the concrete substrate. Here are some adhesives that can be used:

Epoxy Adhesive: Epoxy-based adhesives are widely used for anchoring BFRP bars. They offer excellent bonding strength and durability. These adhesives typically consist of a two-component system that needs to be mixed before application. They provide a reliable bond and have good resistance to moisture and chemicals.

Polyester Adhesive: Polyester-based adhesives can also be used for anchoring BFRP bars. They are generally less expensive compared to epoxy adhesives but may have slightly lower bond strength. Polyester adhesives are available in two-component systems and require proper mixing before application.

Vinyl Ester Adhesive: Vinyl ester adhesives are another option for anchoring BFRP bars. They offer good chemical resistance and bond strength. Vinyl ester adhesives are typically available as two-component systems that require mixing.

It’s important to note that the choice of adhesive should be based on the specific project requirements, such as the load conditions, environmental exposure, and compatibility with the BFRP bars and the existing concrete. Additionally, it is recommended to follow the manufacturer’s guidelines and consult with a structural engineer or adhesive supplier to ensure proper selection and application of the adhesive for anchoring BFRP bars.

What are the creep values associated with BFRP bars?

The creep values associated with Basalt Fiber Reinforced Polymer (BFRP) bars can vary depending on several factors such as the manufacturing process, fiber content, resin type, and testing conditions. Creep is the phenomenon of time-dependent deformation under sustained load.

 

As of September 2021, there is limited publicly available information specifically regarding the creep behavior of BFRP bars. Creep values are typically determined through long-term testing under sustained loads, and specific values can vary based on the particular BFRP product being used.

 

However, it’s worth noting that FRP (Fiber Reinforced Polymer) materials in general, including BFRP, tend to exhibit lower creep values compared to traditional steel reinforcement. This is one of the advantages of using FRP materials in structural applications.

What is the tariff schedule product code for basalt rebar?

Speicific trade agreements should be reviewed. In many cases, there are no tariffs associated with import/export of basalt fiber materials. BASTECH rebar conforms with Buy American standards. Below is an example of the code used for transport into Canada:


6815.19.00 00 – Other

68.15 Articles of stone or of other mineral substances (including carbon fibres, articles of carbon fibres and articles of peat), not elsewhere specified or included.
-Carbon fibres; articles of carbon fibres for non-electrical uses; other articles of graphite or other carbon for non-electrical uses.

What are the splice lengths of basalt rebar?

Splice lengths very by application. For ground slabs, splice lengths per ACI 440.11 are 12” for #3, 14” for #4 and 18” for #5.

Is basalt rebar coated?

No. Basalt FRP is an uncoated, corrosion-resistant reinforcement. Corrosion resistance is inherent to the fibers.

What certifications do you have?

BASTECH rebar is approved by ICC-ES and Florida Department of Transportation.

Are any concrete additives bad for basalt rebar?

Basalt rebar is generally compatible with various types of concrete additives commonly used in construction. However, it is essential to consider certain factors and potential interactions that may affect the performance of basalt rebar when using concrete additives.

What is the resin content of the rebar?

The resin content of basalt rebar can vary depending on the manufacturer and the specific product. Basalt rebar is typically made by impregnating basalt fibers with a resin binder, which helps provide cohesion and strength to the composite material.

 

The resin content is the percentage of resin, by weight, in relation to the total weight of the basalt rebar. It is an important factor that influences the mechanical properties, such as strength and flexibility, of the basalt rebar.

 

The resin content can be adjusted during the manufacturing process to achieve the desired properties and performance characteristics. Generally, the resin content of basalt rebar can range from around 15% to 30%, but these values can vary depending on the specific product and manufacturer.

Are there any ASTM standards for basalt fiber or rebar?

Yes.

 

  • ASTM D8448/D8448M-22 – Standard Specification for Basalt Fiber Strands
  • ASTM for FRP bars to be published in 2023
Is basalt environmentally friendly?

Basalt is generally considered to be more environmentally friendly when compared to  other construction materials. Here are a few reasons why:

 

Abundance and Availability: Basalt is a naturally occurring volcanic rock that is widely available in many parts of the world. Its availability reduces the need for extensive mining or extraction, which can have significant environmental impacts.

 

Reduced Energy Consumption: The production of basalt fibers and products typically requires less energy compared to other synthetic fibers like fiberglass or carbon fiber. The lower energy consumption contributes to reduced greenhouse gas emissions during manufacturing processes.

 

Lower Carbon Footprint: Basalt fibers have a lower carbon footprint compared to materials like steel. The production of basalt fibers involves less CO2 emissions, as the raw material is naturally occurring and does not require the extensive energy-intensive processes involved in steel production.

 

Corrosion Resistance: Basalt rebar is resistant to corrosion, which means it has a longer lifespan and reduces the need for maintenance or replacement. This durability reduces material waste and the associated environmental impact.

 

Recyclability and Reusability: Basalt fibers and products can be recycled and reused in various applications. At the end of their service life, basalt materials can be processed and incorporated into new products or used as aggregates in concrete.

What sizes are available?

Standard sizes are #2 through #7. Custom diameters are available upon request.

How do you cut basalt rebar?

Grinding wheels and wood blades work well with basalt rebar. Compared to steel, basalt FRP rebar is much easier to cut.

Can you store basalt rebar outside?

Basalt rebar can be stored outside, but it is generally recommended to store it in a covered and dry area whenever possible. While basalt rebar is known for its excellent resistance to environmental conditions, proper storage can help maintain its quality and performance over time. Here are a few considerations for storing basalt rebar outside:

 

Covering: If storing basalt rebar outside, it is beneficial to cover it with a waterproof tarp or similar protective material. This helps shield it from direct exposure to rain, snow and sunlight, which can potentially affect its long-term durability.

 

Elevated Storage: When storing basalt rebar outside, it is advisable to keep it elevated from the ground to prevent contact with moisture or standing water. Placing it on pallets or racks can help maintain air circulation and minimize the risk of moisture absorption.

 

Protection from UV Exposure: Basalt rebar is generally resistant to UV radiation, but prolonged exposure to direct sunlight can gradually degrade the resin coating on the rebar. If possible, consider storing the rebar in a shaded area or use UV-resistant covers or coatings to provide additional protection.

 

Moisture Control: Basalt rebar is not prone to corrosion, but it is still beneficial to minimize its exposure to moisture. Avoid storing the rebar in areas prone to excessive humidity or standing water.

What can basalt rebar be used for?

Basalt rebar can be used in almost any concrete reinforcement.

How much does basalt rebar cost?

In most cases, basalt rebar will lower the total project cost. Basalt rebar is less expensive than other corrosion-resistant concrete reinforcement options.

Can you replace steel with smaller basalt rebar?

Yes, it is possible to replace steel reinforcement with smaller diameter basalt rebar in certain applications. Basalt rebar offers a higher strength-to-weight ratio compared to steel reinforcement, allowing for the use of smaller diameter bars while still achieving the required structural strength. Here are some considerations when replacing steel with smaller basalt rebar:

 

Design Considerations: The replacement of steel reinforcement with smaller basalt rebar should be carried out in accordance with the design requirements and specifications for the specific project. Structural engineers or design professionals should determine the appropriate sizing, spacing and quantities of basalt rebar based on the structural design calculations and applicable codes and standards.

 

Strength Equivalence: Basalt rebar has different material properties compared to steel, so it’s important to ensure that the smaller diameter basalt rebar being used provides equivalent or greater strength compared to the steel reinforcement it is replacing. The tensile strength of the basalt rebar should be determined and compared to the required strength of the structural element.

 

Reinforcement Spacing: When using smaller diameter basalt rebar, the spacing between the bars may need to be adjusted to maintain the required reinforcement ratio and ensure proper load distribution. This will depend on the specific design requirements and may require modifications to the reinforcement layout.

 

Design Code Compliance: The use of basalt rebar as a replacement for steel should comply with the relevant design codes and standards for the specific application and jurisdiction. It’s important to consult the applicable building codes and guidelines to ensure compliance.

How long does basalt rebar last?

Basalt rebar is known for its durability and resistance to corrosion, which contributes to its long lifespan. While the exact lifespan of basalt rebar can vary depending on factors such as environmental conditions, installation quality and maintenance practices, it is generally expected to have a significantly longer service life compared to traditional steel reinforcement.

 

Basalt rebar does not rust or corrode like steel reinforcement, which is one of its major advantages. It is not susceptible to the same types of deterioration caused by moisture, chloride ions or other corrosive elements. As a result, basalt rebar can maintain its structural integrity and strength over an extended period.

 

In typical applications, basalt rebar is expected to last at least 50 to 100 years or more, depending on the specific conditions and maintenance practices. However, it’s important to note that the service life of any structure is influenced by various factors beyond the rebar itself, such as the quality of the concrete, exposure to chemicals or extreme temperatures, and structural design considerations.

Can you recycle basalt rebar?

Yes. Basalt rebar can be recycled and reused in various ways, making it an environmentally friendly option. Recycling basalt rebar offers several potential benefits, including resource conservation and waste reduction. Here are a few ways in which basalt rebar can be recycled:

 

Melting and Remanufacturing: Basalt rebar can be melted down and remanufactured into new basalt fiber products. The process involves heating the basalt rebar to its melting point and then extruding or spinning it into new fiber strands for use in various applications.

 

Aggregate Replacement: Basalt rebar can be crushed and used as aggregate material in the production of new concrete or other construction materials. The crushed basalt rebar can be incorporated into concrete mixes as a substitute for natural aggregates.

 

Reinforcement in New Structures: Basalt rebar that is in good condition and meets the required specifications can be reused as reinforcement in new construction projects. This reduces the need for new material extraction and helps conserve resources.

How do basalt rebar's thermal conduction properties compare to steel reinforcement?

BFRP rebar and steel rebar have different properties when it comes to thermal conduction.

 

Steel rebar, being a metal, is a good conductor of heat. It has high thermal conductivity, meaning it can transfer heat relatively quickly. When steel rebar is used in reinforced concrete structures, it can provide a pathway for heat to move through the structure, which can lead to thermal bridging. This can result in localized heat transfer and potential energy inefficiencies in buildings, especially in areas with extreme temperature variations.

 

BFRP rebar, which is made from basalt fibers embedded in a polymer matrix, has lower thermal conductivity compared to steel rebar. Basalt fibers have inherently low thermal conductivity, meaning they are not as efficient at transferring heat. Therefore, using BFRP rebar in reinforced concrete structures can reduce the potential for thermal bridging and improve energy efficiency.

 

The lower thermal conductivity of BFRP rebar can also provide benefits in terms of thermal expansion and contraction. Steel rebar has a higher coefficient of thermal expansion than concrete, which can lead to internal stresses and cracking in concrete structures exposed to temperature variations. BFRP rebar, with its lower thermal conductivity and coefficient of thermal expansion, can help mitigate these issues and improve the durability of the structure.

 

In summary, BFRP rebar has lower thermal conductivity compared to steel rebar, which can reduce thermal bridging and improve energy efficiency in reinforced concrete structures. Additionally, BFRP rebar’s lower coefficient of thermal expansion can help mitigate potential issues related to temperature-induced stresses and cracking.

Have More Questions?

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