BE895522A - Steel wires for reinforcing mouldable materials, esp. concrete - where each wire has regular undulations of specific wavelength - Google Patents

Abstract

Each wire is bent so it possesses a regular or sinusoidal undulation. The wire has a dia. (d) of max. 1.2 mm, and a length of min. 45d and max. 65d. The wavelength (lambda) is min. 7d and max. 10d; and the max. amplitude (a) of the undulation is between 1d and 1.5d. The steel wire has a tensile strength above 110 kg/sq.mm, but below 150 kg/sq.mm. The pref. steel wires each have a length of 60 mm; a dia.(d) of 1 mm; a wavelength (lambda) of 8 mm with amplitude (a) of 1 mm; and a tensile strength of 130 kg/sq.mm. Used to reinforce mouldable materials which may or may not contain a hydraulic binder, but esp. for the optimum reinforcement of concrete.

Description

       

  Filiform elements usable for the reinforcement of moldable materials in particular for concrete.

  
The present invention relates to filiform elements, called fibers, which can be used to

  
the reinforcement of moldable materials with a hydraulic or non-hydraulic binder.

  
Among the different types of fibers that can be used for such reinforcement, there is a family of filiform fibers of different dimensions provided with regular corrugations distributed over their length.

  
In the prior art, the fibers belonging to this family cannot constitute an effective reinforcement of concrete: In fact, to ensure satisfactory anchoring, in the materials to be reinforced, ripples of high amplitudes have been used and of short wavelength. Such geometrical characteristics create very significant difficulties of implementation during the kneading of these fibers in concrete because of their very high propensity to hang together to form balls of fibers entangled in concrete. Such implementation difficulties have condemned the use of this type of fiber.

  
However, after a study of all the factors governing the reinforcement of the stony material reinforced by fibers belonging to this family, it was possible to conceive a wavy fiber of the kind described which is optimized and differs from fibers of the prior art by an effect of real concrete reinforcement without the implementation difficulties encountered previously.

  
To arrive at such a conception, it was necessary to study the influence of the following factors:
- the amplitude of the ripple
- The wavelength
- the length of the fiber
- the diameter of the fiber - the nature of the constituent steel, characterized mainly by its tensile strength
- the own resistance of the matrix which must be reinforced.

  
To guarantee an effective reinforcing effect in concrete, for example, it is necessary that, whatever the stress exerted on it, the fibers remain there as long as possible anchored. Such a condition is satisfied without creating any difficulty in implementation, if the following characteristics are adopted to reinforce conventional concrete used in construction:
- maximum amplitude of the ripple
 <EMI ID = 1.1>
- nature of the steel: its breaking tensile constant is greater than 110 kg / mm and less than
150 kg / mm
- fiber diameter (d) 1.2 mm max. Example of optimal fiber:
 <EMI ID = 2.1>
- breaking tensile stress 130 kg / mm <2> In the accompanying drawings. FIG. 1 represents a wavy fiber on a 1/1 scale; FIG. 2 represents on a larger scale a fragment of the fiber represented in FIG. 1.

  
We distinguish the diameter d, the wavelength and the amplitude a.

  
It is understood that the invention is not limited to the details described above given only by way of example.

CLAIMS

  
1. Filiform element usable for the reinforcement of moldable materials in particular for concrete, this filiform element having regular undulations distributed over its length, having the following characteristics:
- maximum amplitude of the ripple
 <EMI ID = 3.1>
- type of steel: breaking tensile constant greater than 110 kg / mm and less than 150 kg / mm.


    

Claims (1)

2. filiform element according to claim 1, characterized by:  <EMI ID = 4.1>