Advanced fiber reinforced concrete mix designs

a technology of fiber reinforced concrete and mix design, applied in the field of advanced fiber reinforced concrete mix design, can solve the problems of reducing the scope of application and placement properties, reducing the degree of mechanical resistance that can be achieved, both in terms of compressive strength, flexural strength or ductility

Inactive Publication Date: 2018-05-24
CEMEX RES GRP AG
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

The concrete mix achieves targeted mechanical properties, including high compressive and flexural strength, ductility, and workability retention, enabling its use in large slabs, bridges, and other structural elements with improved resistance to shrinkage and cracking, while maintaining high workability and ease of placement.

Problems solved by technology

Amongst others, one important disadvantage of the patent application WO 2011 / 053103 is the requirement to prepare a separate slurry containing water, cement and all shrinkage reducers and plasticizers (or water reducers admixture—namely powdered melamine or phosphonates), or fillers as well as fillers.
A further important drawback of the invention according to WO 2011 / 053103 is the fact that the final placed concrete has to be cured using water after placing.
An additional drawback of the invention according to WO 2011 / 053103 is that the volume of paste is very low to ensure limited shrinkage and avoid cracking, thus reducing the scope of application and placement properties and well as the level of mechanical resistances that can be achieved, both in terms of compressive strength and in terms of flexural strength or ductility.

Method used

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  • Advanced fiber reinforced concrete mix designs
  • Advanced fiber reinforced concrete mix designs

Examples

Experimental program
Comparison scheme
Effect test

example 1

[0107]

MaterialUnitQuantityTotal binder contentkg / m3390CEM II 32.5N A-LLkg / m3390w / b eff—0.4Admix System I% total binder content0.80%Admix System II% total binder content0.30%Sand 0 / 4 roundkg / m3736Fine aggregates gravel 4 / 8roundkg / m3461Coarse aggregates gravel 8 / 16 roundkg / m3646Fiber type A - l / d = 65-l = 60 mm,% volume1.00%US = 1350 Mpa, hookedFiber type B - steel - l / d = 60-l =% volume0.20% 16 mm, US = 2350 Mpa, straightEntrained airl / m325Paste volumel / m3308.87ResultsUnitValueSlump class—SF2Slump flowmm700Workability retentionmin80fcMpa32fflMpa4.1fr1Mpa2.6fr3Mpa2.9E modulusGpa27.9

[0108]This example with a low paste volume enable to achieve SF2 slump class (or consistency). In this example, only steel fibers are used in Fiber system B.

example 2

[0109]

MaterialUnitQuantityTotal binder contentkg / m3430CEM I 42.5 Nkg / m3300Fly ashkg / m3130w / b eff—0.55Admix System I% total binder content0.10%Admix System II% total binder content0.20%Sand 0 / 4 roundkg / m3735Fine aggregates gravel 4 / 8 roundkg / m3327Coarse aggregate gravel 8 / 11 crushedkg / m3573Fiber type A - l / d = 50-l = 55 mm,% volume0.35%US = 1780 Mpa, hookedFiber type B - glass - l / d = 57-l =% volume0.20%12 mm, US = 1650 Mpa, straightEntrained airl / m320Paste volumel / m3385.90ResultsUnitValueSlump class—S4Slumpmm165Workability retentionmin85fcMpa35.2fflMpa3.9fr1Mpa3.3fr3Mpa2.6E modulusGpa27.2

[0110]This other example uses only metallic fibers in Fiber system B.

example 3

[0111]

MaterialUnitQuantityTotal binder contentkg / m3510CEM II 42.5 R / A-Pkg / m3330Fly ashkg / m3130Silica fumekg / m350w / b eff—0.45Admix System I% total binder content1.30%Admix System II% total binder content1.30%Admix System III% total binder content2.80%Gluconate retarder% total binder content0.20%Sand 0 / 2 roundkg / m3311Sand 0 / 4 crushedkg / m3543Fine aggregates gravel 4 / 7 crushedkg / m3389Coarse aggregates gravel 6 / 12kg / m3311crushedFiber type A - l / d = 80-l = 44 mm,% volume0.35%US = 2540 Mpa, hookedFiber type A - l / d = 90-l = 50 mm,% volume0.25%Fiber US = 3020 Mpa, hookedtype B - steel - l / d = 60-l = 6 mm,% volume0.20%US = 2130 Mpa, straightEntrained airl / m312Paste volumel / m3423.16Slump class—SF3Slump flowmm810Workability retentionmin120ResultsUnitValuefcMpa57.9fflMpa6.8fr1Mpa8fr3Mpa7.8E modulusGpa30.7

[0112]This example shows an alternative according to the inventions with 2 different types of metallic fibers used in fibers system A and only steel fibers in Fibers system B.

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Abstract

A concrete mix having sand, fine aggregates, binder, fibers, and various admixtures is provided. The mix has a consistency from S2 to SF3, a compressive strength in the range of 30-60 MPa and a ductility represented by fc, ffl, fR1 and fR3 values, wherein the concrete mix contains at least 390 Kg of binder, the concrete mix has a paste volume of 300-600 liters, the concrete mix contains at least two systems of fibers and a general admixture system that is composed of at least 2 sub-admixture systems.

Description

FIELD OF THE INVENTION[0001]The present invention relates to concrete formulations for high mechanical performances in structural designs, fiber reinforcement special mix designs to limit or avoid steel rebars or pre-stressing. More specifically, the invention discloses concrete mix designs with high volumetric content of fibers and that the concrete contains different types of fibers to form a so-called hybrid fiber system.BACKGROUND OF THE INVENTION[0002]Conventional fiber reinforced concrete technology is known, it has been described in various National and International Norms e.g. RILEM 162 TDF International), Model Code 2010 (International), CNR DT 204 (Italy SS 812310 (Sweden), TR63 (UK) ACI 318 (USA) ACI 360 (USA), DBV (Germany), DAFSTB (Austria). Fiber reinforced concrete mix designs containing different types of fibers have been for examples disclosed for example in WO 2011 / 053103 and more recently in CN102976697 and KR100940550. Such concrete are mainly used for pavement o...

Claims

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Application Information

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Patent Type & AuthorityApplications(United States)
IPC IPC(8): C04B28/04C04B16/06
CPCC04B28/04C04B16/0625C04B2111/34C04B2201/50Y02W30/91C04B14/062C04B14/42C04B14/48C04B16/0683C04B24/2664C04B24/38C04B24/383C04B14/06C04B14/4668C04B18/08C04B18/146C04B14/04C04B14/38C04B16/0633C04B16/0691
InventorZAMPINI, DAVIDEGUERINI, ALEXANDREVOLPATTI, GIOVANNI
OwnerCEMEX RES GRP AG