Chemical Fixing with fischer
Chemical Anchors were invented in 1963 by Upat GmbH & Co of Germany. They first came into prominence in the construction of the Olympic Stadium for the 1972 Munich Summer Olympic Games.
There was a requirement for fixings into concrete that could withstand very heavy loads using small anchor-anchor spacings and edge distances - something not achieved by normal steel expansion anchors. From those beginnings, technology has developed dramatically to the extent that chemical anchoring has become the norm rather than the exception.
Chemical anchoring can be divided into 2 groups. The first is the original concept whereby a chemical resin and hardening agent are placed together into a glass capsule filled with Quartz Aggregate. A hole is drilled to diameter, the dust cleaned out and a threaded stud with a chisel point on the end is drilled into the capsule, breaking and mixing the contents and bonding the stud to the hole.
View our range of chemical anchors here
In the mid 1980's, the second grouping was developed. Chemical fixing was enhanced with the introduction of a 2 component chemical mortar. Contained in a plastic cartridge and dispensed through a mixing nozzle by means of an applicator or injection gun; this development enabled the chemical anchoring technology to become much more versatile and user-friendly. It could now be utilised into a wider range of building materials and not, like its predecessor only into concrete or natural stone. The ease-of-use and practicality of the chemical injection system for applications in masonry, hollow blocks, cavity floors and so forth has made it the fixing method of choice.
fischer, world renowned supplier of fixings is at the forefront of chemical anchor development. It has taken chemical anchoring into areas where it was believed that chemical anchoring had no place. The use of chemical anchors and chemical mortars in the cracked tensile zones of concrete was for many years believed to be impossible. The fischer group of companies pioneered this technology and today chemical fixings can be done into cracked concrete with absolute safety and exceptionally high loading.
As the market has grown, there has been a proliferation of chemical anchors and chemical mortars with product ranging across the quality and performance spectrums. The consumer however has access to information that can guide them to select the products that they wish to utilise by means of accessing product approvals from the worlds' leading approval authority, the EOTA – European Organisation for Technical Approvals. Products with European Technical Approvals (ETA's) under supervision of EOTA guarantee performance levels with the knowledge that safety and security cannot be compromised. This information is available for all on the following website: www.eota.be
There have been various types of chemicals used in the manufacture of chemical anchors. Originally a polyester resin with styrene as the hardening agent was the most predominant; however over time polyester is carcinogenic and is subject to saponification when exposed to moisture resulting in a loss of approximately 40% in its bonding strength. Furthermore, styrene is a known carcinogenic. Polyesters should therefore only be used for interior applications. fischer does not support the use of polyesters in critical areas where accidents can occur and people can get injured.
After technological improvements which brought about Epoxy Acrylates and Hybrid Polyesters (polyesters with an organic compound), the next development in chemical anchoring was vinylesters (also including Hybrid Vinylesters) and finally, the premium and most secure chemical anchoring available today comprised of pure epoxy. The below chart demonstrates the various types of chemicals used and the corresponding price / performance ratio.