Concrete and Steel Rebar Steel Rebar for reinforcing Concrete Steel - - PowerPoint PPT Presentation

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Concrete and Steel Rebar Steel Rebar for reinforcing Concrete Steel - - PowerPoint PPT Presentation

Jul 15, 2023 144 likes •526 views

Traditional Building Materials Concrete and Steel Rebar Steel Rebar for reinforcing Concrete Steel Rebar for reinforcing Concrete Steel Rebar for reinforcing Concrete Steel Rebar for reinforcing Concrete Advantage Easy to use Initial

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Traditional Building Materials

Concrete and Steel Rebar

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Steel Rebar for reinforcing Concrete

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Steel Rebar for reinforcing Concrete

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Steel Rebar for reinforcing Concrete

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  • Advantage

– Easy to use – Initial Price

  • Disadvantage

– CTE different than for Concrete – Corrodes – Weight – Strength – Maintenance Costs – Costs increase as the Cost of Energy increases – Magnetic

Steel Rebar for reinforcing Concrete

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Steel Rebar can corrode (rust) inside concrete structures

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The Corrosion of reinforcing steel rebar creates enough pressure to crack concrete

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The Corrosion of reinforcing steel rebar creates enough pressure to crack concrete

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Cracked concrete weakens the structure and can lead to catastrophic failures

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Advanced Building Materials

  • Concrete

– Basalt Fiber Reinforced – Basalt Fiber Reinforced Rebar – Structured Water – Pre-Ceramic Coatings/Sealants

  • Fiber Reinforced Composites
  • Thermally reflective Pre-Ceramic Polymeric Coatings
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The Reinforcing Alternative? Basalt Fiber Reinforced Composite Rebar

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What is Basalt?

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What is Basalt?

It is a material born of Volcanic action that can benefit mankind!

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What is Basalt?

  • Naturally Mined Igneous Rock
  • Partially Crystalline Silicate Structure
  • Matrix Reinforced with Plagioclastic Precipitates
  • Primarily Marketed as Rough Stone and Melt-blown Wool
  • Can be made into Continuous Filament, Chopped Strand, Woven and

Non-woven Fabrics

  • Basalt Fibers and Textiles can be used to make High-Strength and

Fire-Safe Composites

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The mechanical characteristics of a high quality basalt fiber are greater than hi-modulus glass fiber, S2 glass, and ВМП (Russia). New proprietary advancements in nano-fiber technology can bring this significantly higher – approaching that of carbon fiber.

Basalt Fiber Reinforced Composite Rebar

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Not all Basalt Fibers are Created Equally

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Basalt Fiber Reinforced Composite Rebar

Material Diameter Fiber Volume Tensile Strength Elastic Modulus Elongation CTE 10-6/oC Steel 11.3-mm n/a 400 MPa 200 GPa >10% 11.7 E-Glass-TG Epoxy 9.5-mm 54% 785 MPa 43 GPa 3.7% 9.9 Carbon-Epoxy 9.5-mm 62% 1,431 MPa 120 GPa 1.4% Basalt-TG Epoxy 9.5-mm 68% 1,235 MPa 95 GPa 3.1% 8.9

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Basalt Fiber Reinforced Composite Rebar

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The steel should be maintained at stress less than limit of proportionality σp. The value of the proportionality limit σp is several times less than the ultimate stress σu. Typical σp value for steel rebar is between 200 and 400 МPа. The σp value for the Thermalguard Basalt rebar is typically greater than 1,000 MPa.

Basalt Fiber Reinforced Composite Rebar

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Basalt Fiber Reinforced Composite Rebar

Existing composite rebar specifications and testing requirements USA

  • ACI 440.3R-4: Guide for the test methods for fiber reinforced polymers for reinforcing or strengthening

concrete structures. Published by the American Concrete Institute.

  • ACI 440.1R-06: Guide for the design and construction of concrete reinforced with FRP Bars. Published

by the American Concrete Institute.

ASTM Standards

  • D 570 Standard Test Method for water absorption of plastics.
  • D 619 Standard practice for conditioning plastics for testing.
  • D 695 Standard test method for compressive properties of rigid plastics.
  • D 790 Standard test methods for flexural properties of unreinforced and reinforced plastics.
  • D 792 Standard test methods for density and specific gravity.
  • D 2734 Void content of reinforced plastics.
  • D 3410 Standard test method for compressive properties of polymer matrix composite materials.
  • D 7205/ D7205M Standard Test Method for Tensile Properties of Fiber Reinforced Polymer Matrix

Composite Bars.

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Basalt Fiber Reinforced Composite Rebar

Design Manuals

  • Isis Design Manual No. 3: Reinforcing concrete structures with fiber reinforced polymers.

Committees

  • American Concrete Institute (ACI): 440 – Composites for Concrete.
  • American Concrete Institute (ACI): 400H – Reinforced Concrete (rebar)
  • American Concrete Institute (ACI): 440I – Pre-stressed Concrete (Tendons)
  • American Society of Testing and Materials (ASTM): ASTM D20.18.01 – FRP Materials for concrete.
  • American Society of Testing and Materials (ASTM): ASTM D20.18.02 – Pultruded Profiles.
  • American Society of Testing and Materials (ASTM): ASTM D30.20.01 – Composites for Civil Engineering.
  • AASHTO Bridge Subcommittee: T-21 – FRP Composites
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Thermalguard Basalt Fiber Reinforced Composite Rebar Features, Advantages and Benefits

  • Higher Service Temperature: Service Temperatures available to greater than 250oC (380oF).
  • Coefficient of Thermal Expansion: Closely approximates that of concrete.
  • Non-Corrosive: Alkali resistant and will not corrode, when exposed to a wide variety of corrosive elements.
  • Lightweight: 25% the weight of steel rebar.
  • High Strength to Weight Ratio: Typically about 4 to 6 times stronger than steel; allowing for greater design flexibility and

lower concrete utilization to accomplish the same task.

  • Excellent Fatigue Resistance: Performance in cyclic loading is very good.
  • Excellent Impact Resistance: Has excellent resistance to sudden and severe point loading.
  • Non-Conductive: Electrically non-conductive and, therefore, has very low thermal transference.
  • Non-Magnetic: In snot affected by electromagnetic fields. Excellent for applications involving MRI and other types of

electronic testing facilities.

  • Cost: Very competitive with steel rebar; considering transportation and maintenance cost in addition to the purchase price.
  • Vertical Integration Possibility: Possibility of reduced manufacturing costs. Thermalguard owns the “Core Technology for

the X-Grip™ rebar (Patent Pending) and that of the resins used in the production of the rebar. In addition, Thermalguard has several strategic alliances for cost effective provision of the Basalt Fiber; including manufacturing technologies, sales and distribution, and civil engineering technologies, as the need may arise.

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Thermalguard Basalt Fiber Reinforced Composite Rebar

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Standard Grip X-Grip

Thermalguard Basalt Fiber Reinforced Composite Rebar

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Thermalguard Basalt Fiber Reinforced Composite Rebar with X-Grip™

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Testing of Composite Rebar ASTM 7205

In order to avoid slippage of the terminal ends during testing, both ends are anchored into sleeves with structural adhesive. These copper sleeves are typically made in the lab’s machine shop. A small deformation sensor is placed at the midpoint of the specimen, to test the strain. Detailed information can be found in ASTM 7205. 1. Basalt Fiber Rebar 2. Thickness of copper sleeve. Example: 3-mm OD rebar = 12-mm OD copper sleeve. 3. Q235 strengthened sheet thickness: 2mm. 4. Structural Adhesive.

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Testing of Composite Rebar ASTM 7205

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Why use the Thermalguard X-Grip™?

The bond slip of the X-Grip™ helical/axial grip Basalt Rebar is negligible after the peak, during pull-out testing.

Smooth & Sanded Composite Rebar X-Grip™ Composite Rebar

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Why use the Thermalguard X-Grip™?

Failure mode of a spiral wrapped Composite Rebar Failure mode the X-Grip™ wrapped Composite Rebar Conclusions: The X-Grip™ provides superior gripping strength over smooth, sanded

  • r spiral wrapped composite rebar
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Coils of Basalt Rebar at a Job-Site

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Basalt Rebar Straight lengths and Prefabricated shapes

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Other Issues related to the strengthening of Concrete

Ordinary (Plain) Concrete has two major deficiencies 1. Low Tensile Strength 2. Low strain at Fracture. Cause: Micro-cracks and Micro-fractures. The propagation of micro-cracks and micro-fractures under applied stress is responsible for the low tensile strength of the material Solution: Fiber reinforcement of concrete (FRC) Fibers, if randomly dispersed throughout the concrete matrix, provides a more efficient distribution of the internal and external stresses by creating a three dimension reinforcing network.

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Fiber Reinforced Concrete (FRC)

Primary Role of the Fibers in FRC The primary role of fibers, in hardened concrete structures, is the modification of the cracking from macro-cracks to micro-cracks to nano-cracks.

  • Smaller cracks will reduce the permeability of the concrete.
  • Smaller cracks will enhance the ultimate strain of the concrete.

The secondary advantage of FRC is increased toughness (or residual load carrying capability after the first crack), while increasing impact resistance.

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  • Currently used Fibers

– Steel Fibers:

  • Can Corrode
  • Balling

– Carbon Fibers

  • Cost

– Glass Fibers

  • Can be attacked by Chloride (chemical stability)
  • Lower long term wet strength at moderate (70C – 158F) temperatures

– Synthetic Fibers

  • Cost
  • Low Modulus of elasticity
  • Poor Bond
  • Combustibility
  • Low Melting Point

– Basalt Fibers

  • Not all Basalt Fiber is created equally

Fiber Reinforced Concrete (FRC)

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Advantages of using Basalt Fibers

  • When using ½-inch Basalt Chopped Fiber, satisfactory workability is maintained up to

between 0.5% and 1.0% by dry volume weight.

  • As compared to Polypropylene fibers, a greater volume of fiber could be incorporated.
  • Considerable increase in the toughness and impact resistance of concrete, as compared to

plain concrete.

  • The mode of concrete failure is changed from Brittle to Ductile, when subjected to

compression, bending and impact testing.

  • Alkaline resistant.
  • CTE is approximately the same as concrete.
  • Non-Magnetic and non-conductive.

Basalt Fiber Reinforced Concrete (FRC)

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Basalt Rebar and Basalt Fiber Reinforcement

non-metallic, stronger than steel and corrosion resistant