HeliTie Bar

Manufactured from stainless steel, our HeliTies can be used in a humble nail application whereas our HeliTie Bar, in conjunction with our HeliGrout 25, can be utilised in sophisticated structural reinforcement techniques.

Introduction

The HeliTie Bar is a Grade 304 austenitic stainless steel reinforcing material that has many unique properties.  Being rolled from a plain round wire the fins are work-hardened to a very high level whilst the core remains relatively soft.  The subsequent extrusion process puts the fins into tension and the core into compression.  The tensile strength of the base material is more than doubled during the manufacturing process.  The deformation of the fins makes the bonding characteristics of the HeliTie Bar far superior to alternative standard reinforcing materials.  Grade 316 steel is available for special requirements.

Technical

The University of Darmstadt has performed independent tests on HeliTie Bar to ascertain its tensile loadings.  A full report of this testing including the methods employed, is available on request, but a summary is given in the table below.  One of the properties of the HeliTie Bar is that it performs similar to a strong coiled spring when it is stressed within its elastic limit.  All of the load calculations for the design are based within this elastic limit.

HeliTie Bar Diameter Tensile kN  Cross-Sectional Area mm2
6mm 7.78 8.49
8mm 9.61 10.19
10mm 12.53 13.88


The three most commonly used diameter sizes of HeliTie Bar are 6mm, 8mm and 10mm; also available is 4.5mm for specific applications.  The most commonly used lengths are available 1 metre up to 10 metres but again other lengths are available for specific applications.  

Uses

The uses for HeliTie Bar are both wide and varied and they can be utilised in new build and for many specialised refurbishment requirements.

In general terms the 6mm HeliTie Bar is used for the reinforcing of existing masonry structures.  HeliTie Bar combined with a cementitious grout, HeliGrout 25, can be installed into existing masonry with very little disturbance to create beams which span over window or door openings or over soft areas of ground when footings have failed.  It can also be used to create lintels.  Crack stitching can be achieved by using 1M HeliTie bars.

The 8mm HeliTie Bar is used for new build and remedial masonry reinforcing.  The larger fin dimensions gives a much better bond into a standard building mortar than the alternative round section wire.  The increase in the tensile strength during the manufacturing process also requires less material to be used.

Special Features

  • Grade 304 or 316 austenitic stainless steel
  • Excellent bonding capabilities.
  • Coiled spring properties within elastic limit.
  • High stress material.
  • No sudden or catastrophic failure point.
  • Lengths up to 10M - less wastage.
  • Less intrusive than standard repairs.

For heavy duty applications the 10mm HeliTie Bar is in a class of its own.  It is very strong in tensile and shear and this, together with its bonding capabilities, makes it a truly versatile product.