|Wear protective eyewear, gloves, and a safety helmet.|
Required personnel: a minimum of 2 persons
|If you are using guy wires, cast the foundations for them at the same time.|
Prepare for the concrete works for the instrument foundation and optionally for the guy
- Make a cast mold from wooden boards for the concrete foundation.
- Dig a hole for the foundations.
Spread a layer of gravel and level the gravel with a wooden board. Compact the
gravel with a plane compactor or similar device.
Take into account individual site requirements and use drainage pipes if the ground on the site is wet.
For the instrument foundation, fasten the wedge bolts to the lower ends of the
Check the foundation bolt pattern and place the foundation bolts into the hole so that approximately 50 mm (2 in) of the foundation bolt threads are above the surface. For the bolt pattern and dimensions, see Foundation bolt pattern.
- For the guy wire foundations, place the foundation bolts with anchors into the hole.
Execute the concrete works.
To make sure the concrete meets cubical strength requirements, use prefabricated concrete that is delivered and pumped by a concrete delivery truck.
If you make the concrete on the site, pay special attention to the mixing ratio, mixing and working times, and to the purity of the water (potable water).
- Water the cast molds and pour or shovel the concrete in the cast molds.
- Proceed gradually layer by layer until the form is full. Vibrate the concrete on the mold or use a hammer on the cast mold.
- To level the surface of the concrete foundation, use a wooden board. Check with a spirit level.
- Cover the concrete foundations.
Loosen the cast molds after 2 to 3 days and remove the cast mold after a week. To achieve compressive cube strength, wait for 28 days for the concrete to harden.