The manufacture of our concrete lintels adhere to SANS1879:2004.
Our moulds permit the manufacture of lintels that are 60mm high by 150mm width. The weight of the lintels is approximately 22.5kg per linear metre. They contain a varying number of high tensile 4 mm Moos wire.
The concrete mixture is made up of dolomitic sand, 13.2 mm crushed stone and 52.5 N high rapid hardening cement. This allows the prompt strengthening of the lintels to allow us to take them off the moulds after 48 hours.
According to the length of the lintels (given by the distance between load bearing points), the recommended number of wires for them is as follows
PRE-STRESSED BEAMS SPECIFICATION
|Wire Selection||Wire Positioning||Span (Metres)||5w||> 4.5|
|7w||4.6 > 5.5|
|8w||5.6 > 7.5|
|9w||7.6 > 10|
NORMAL SLAB LINTELS
|Lintels Specifications||Size of lintels: 60mm x 150mm|
|Weight of lintels: 22.5kg per linear metre|
|Pre-stressed wire: 4.0mm Moos wire @ 1700 Mpa|
|1670 N/mm Tensile Strength|
|Breaking load = 21K/N|
|Designed Strength 69MPa @ 14days (as per cube test from Geopractica Soils & Materials Testing)|
These are special lintels made on order that can be used in long spans over 8 meter long and where there are no walls supporting the slab but rather the structure is placed on columns joined by reinforced concrete beams. Thus, the connection between lintels and reinforced concrete beams is essential. At times also, these lintels can contain a varying number of steel sections such as Y12 or Y16 to further enhance their strength. Naturally, we do not hold stock of these lintels but they are manufactured when needed as per the specification given by the project engineer.
In general, the price of these lintels per lineal meter is substantially higher (1.5 to 3 times) than normal lintels. This is not only due to the cost of the lattice itself (see picture below), but also increased handling and labour costs associated to their production.
The lintels below have a lattice steel section at the end of the lintels only to assist with physical connection to steel from a reinforced concrete beam.
Lintels with lattice throughout the length of the lintel are shown below.