HIGH GRADE. The economical alternative to steel fibers and steel mesh.

Transcription

1 HIGH GRADE The economical alternative to steel fibers and steel mesh.

2 Advantages Compressive strength 4 Flexural strength 5 Early shrinkage crack characteristics 6 Shrinkage characteristics 7 Water penetration capacity 8 Extraction characteristics 9 Fracture toughness and fracture energy 10 Sulphate resistance 11 Early strength 11 Structural calculation 12 Application 13 Project examples 14 Literature and sources 15

3 2 / 3 Quality advance The raw material We use pure polyolefine for our Fibrofor High Grade. This ensures absolute alkali resistance, not only on the surface. The fiber material is chemically neutral (inert) and rot-proof, and its water absorption rate is virtually 0%. The fibrillated, bundled fibers The fibrillation The roughness of the surface The fibrillated, bundled fibers and their optimal distribution During the sophisticated production process, special attention is paid to precise fibrillation of the fibers. The fibers are bundled and cut after the actual production process. Fibrillation and bundling allow optimal distribution throughout the concrete matrix. The rough surface The surface finish is deliberately selected to obtain a rough surface. This, among other things, also influences the extraction characteristics We give high priority to the anchoring of our Fibrofor High Grade in the concrete. The roughness and fibrillation of the fibers greatly improve the extraction characteristics. the addition rate 1 kg of Fibrofor High Grade per cubic meter will suffice to obtain optimal concrete reinforcement. The feed rate can be individually matched to special applications. The fibrils

4 Compressive strength The compressive strength is slightly influenced by the addition of Fibrofor High Grade and produces a marginal change compared with base concrete. It lies within the range of other fiber concrete of a conventional type. Average compressive strength after 28 days in N/mm 2 Type of test specimen Cube 150x150x150 mm Designation according to EN 206 Concrete quality C25/30 XC1/D max 32/CI 0.20/F3 Plain concrete (without fibers) With multifilament fibers With Fibrofor High Grade Compressive strength (N/mm 2 )

5 4 / 5 Flexural strength The addition of Fibrofor High Grade increases the flexural strength appreciably (up to 28%). This parameter is used for structural calculations and is countryspecific applied. The significant parameter is determined in a test series with 6 bending beams. The test specimens has a measurement of 150 x 150 x 550 mm (according to EN ) and will be charged in the third-point. Average flexural strength after 28 days in N/mm 2 Type of test specimen Bar 150x150x550 mm* Designation according to EN 206 Concrete quality C25/30 XC1/D max 32/CI 0.20/F3 Plain concrete (without fibers) With multifilament fibers With Fibrofor High Grade Flexural strength (N/mm 2 ) * Third-point testing

6 Early shrinkage crack characteristics Testing of the early shrinkage crack characteristics by shrinkage ring is based on the most stringent test criteria. Investigations have shown that fiber concrete using Fibrofor High Grade will reduce shrinkage cracking by 85% compared with conventional concrete types, which corresponds to quality class FS2. This means that fiber concrete using Fibrofor High Grade has a higher concrete density with minimum micro-cracks and that an earlier utilization of building structures can be expected. Early shrinkage crack characteristics of fiber concrete class FS2 (testing time 5 hours) Type of test specimen Shrinkage ring: ø outside 590 mm ø inside 290 mm Concrete grade High-grade concrete C50 / 60 Base concrete (without fibers) Base concrete (without fibers) with Fibrofor High Grade with Fibrofor High Grade mm 420mm 24mm 110mm Total shrinkage crack lengths

7 6 / 7 Shrinkage characteristics Fibrofor High Grade is capable, among other things, of improving the shrinkage characteristics of the fresh concrete during the early setting phase. This is one of the crucial characteristics of Fibrofor High Grade fibers. In this case, the application of fibrillated Fibrofor High Grade fibers is advisable because its advantages allow concrete shrinkage to be minimised. Investigations have shown that the addition of 1 kg of Fibrofor High Grade per cubic metre of concrete will allow values to be achieved which would otherwise require twice the amount of other fiber types. It must be noted, however, that such an increased fiber addition rate may appreciably reduce the compressive strength. Fiber concrete with Fibrofor High Grade and plain concrete, fiber addition rate 1kg /m 3 Shrinkage cracking (µ) Plain concrete Fibrofor High Grade Time in days (t) Fiber concrete with conventional, fibrillated fibers and plain concrete, fiber addition rate 1.8 kg/m 3 Shrinkage cracking (µ) Plain concrete Fiber concrete Time in days (t)

8 Water penetration capacity Fibrofor High Grade reduces the water penetration depth in the concrete body. The test specimen was based on a concrete formulation with aggregates 0/16, 350kg/m 3 CEM I 32.5 plus 0.9% plasticiser. The water-to-cement factor was The compressive strength determined was 59.3 N/mm 2 for base concrete and 66.2 N/mm 2 for fiber concrete using Fibrofor High Grade (test pressure 0.8 MPa). The chart shows that the water penetration depth will be reduced by over 25% when Fibrofor High Grade is added. Type of test specimen Cube 150x150x150 mm Water penetration depth Plain concrete (without fibers) with Fibrofor High Grade 1 kg/m cm 1.75 cm

9 8 / 9 Extraction characteristics The reinforcement fibers must be embedded and anchored in the concrete matrix so that the positive fiber characteristics will be retained under structural loading. Monofilament fibers with a smooth surface offer this characteristic only to a certain extent. On the other hand, this is one of the very areas where the special design features and the better technical values of Fibrofor High Grade have their full effect. Extensive scientific investigations show that Fibrofor High Grade offers optimal extraction strength and extraction characteristics. The figures show the directions of the force and the distribution of the forces under tensile stressing and illustrate the benefits of fibrillated Fibrofor High Grade fibers. Monofilament fiber Fibrofor High Grade

10 Fracture toughness and fracture energy Fiber concrete has a very good fracture toughness. Investigations have shown the fracture energy of concrete using Fibrofor High Grade to increase by as much as 240%. As a result, cracking of the concrete which is a very brittle construction material due to soil movements can be minimized. Type of test specimen Cube 150x150x150 mm Fracture energy (up to fracture) of the equivalent flexural tensile strength test Plain concrete (without fibers) 0.56 J 0.90 J 1.04 J with multifilament fibers 1.26 J 1.81 J 2.11 J with Fibrofor High Grade 1.89 J 2.80 J 3.58 J at an age of 3 days 7 days 28 days

11 10 / 11 Sulphate resistance /Early strength Sulphate resistance When used in conjunction with sulphatecontaining substances, concrete reinforced with Fibrofor High Grade offers better technical parameters than other fiber concrete types. Its advantage over plain concrete is even substantial. Early strength Just like conventional fiber concrete, concrete reinforced with Fibrofor High Grade also has an increased early strength. This advantage can be economically exploited especially in slipforming applications and in the prefabrication industry as well as otherwise in concrete construction applications. Sulphate resistance Type of test specimen 40 x 40 x 160 mm Average flexural tensile strengths N/mm 2 measured after the following baths on air-dry specimen Plain concrete (without fibers) with multifilament fibers with Fibrofor High Grade %* % % % % % % % % Solution I Solution II Solution III * This value (100%) is used as the basis for comparing the other equivalent flexural tensile strength values. Early strength Type of test specimen Cube 150x150x150 mm 24-hour compressive strength (N/mm 2 ) Mean value Plain concrete (without fibers) with multifilament fibers with Fibrofor High Grade No. of the test specimen 1 2 3

12 Structural calculation Structural calculations according to EC 2 prove that with the use of Fibrofor High Grade various structural elements do not need any more conventional steel or steel mesh reinforcements. It is also possible to significantly reduce the steel reinforcement requirement by combining reinforcement components (Fibrofor High Grade and steel). Proven reductions of construction steel offer extremely interesting cost savings for our customers. We would be pleased to present you an alternative to conventionally reinforced concrete for your building project. Our civil engineers calculate using a state-of-the-art dimensioning software based on finite element.

13 12 / 13 Application Industrial floors Productionhalls and warehouses Shopping malls Agricultural buildings Transport road Any kind of outside areas Traffic areas/roads Car parks and parking facilities

14 Project examples Outside area Industrial floor Car park Cattle shed Catch and tilting basin Sales area

15 14 / 15 Literature and sources Compressive strength, equivalent flexural tensile strength, fracture toughness and fracture energy, sulphate resistance, early strength, early shrinkage crack characteristics Construction industry engineering approval EMI AG, Budapest, Hungary Equivalent flexural tensile strength Versuchs- und Forschungsanstalt, MA39, Vienna, Austria Shrinkage characteristics Zollo Report "Hardened Concrete Drying Shrinkage", Prof. Dr. Zollo, ACI, Detroit, USA Investigation report MPA Dortmund, Germany Fiber concrete guidelines Austrian Association for Concrete and Civil Engineering, Vienna, Austria Flexural strength and compressive strength Test certification by Dr. Hartl GesmbH., stateaccredited test institution, Seyring, Austria Water penetration depth Akademia Rolnicza, Poznan, Poland

16 Contact us. 05/2017 Brugg Contec AG Gübsenstrasse 80 CH-9015 St. Gallen T info@bruggcontec.com