Chemical Anchor Technical Handbook

Theory Section
About Building Materials
Chemical Anchoring
Contents Applications
Product Overview
Base Materials
Concrete
There are many kinds of base materials. It is important to know their
individual properties in order to determine the permitted load and to
select suitable anchors. Only in this way is it possible to ensure that
anchors are safe and of a high quality. Concrete, light building materials
and masonry (including full stone and hollow brick) are the most
commonly used building materials.
Concrete consisting of a mixture of cement, aggregates, water and
possibly other additives, is a synthetic stone. It is produced after the
cement paste hardens and cures. Although it has a relatively high
compressive strength, it has only a low tensile strength. Because of
this, steel reinforcing bars are cast in concrete to take up tensile forces.
This is then referred to as reinforced concrete.
The following factors decide on the concrete type:
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Dry gross density (light concrete, normal concrete, heavy concrete)
Compressive strength
Place of production, use or ceramic bond condition
Consistency
Density of the reinforcing bars
The composition and the processing of the material determine the
concrete’s properties. A crucial attribute for concrete is compressive
strength. Normal concrete without accelerating additives obtains its full
minimum compressive strength after 28 days and is ideal for anchoring.
After this time has elapsed, the testing procedure defined in EN206-1 is
performed to determine the strength class of the concrete. This is
generally between C12/12 (B15) and C50/60 (B55). For special
purposes, higher quality concrete is available, but C20/25 is the most
commonly used concrete class.
C20/25 stands for the following:
C = Concrete
20 = Compressive strength f ck of the concrete test cylinders
(diameter 150 mm, height 300 mm) in N/mm 2
25 = Compressive strength f ck,cube of the concrete test cubes
(edge length 150 mm) in N/mm 2
Additional
Information
Additional
Information
Product Details
Chemical Anchoring
Theory
Product Details
Product Overview
Chemical Anchoring
Theory
Contents Applications
1.1.1