On this post, I’m going to give a very simple definition for over site concrete. I’ll also describe some important steps you must take in order to have a durable over site concrete in your building and I’m doing this because lately I began to see a lot of collapsed over site concrete.
So let’s answer the first question…
What Is Over Site Concrete?
Over site concrete is a term used to describe a mass concrete laid after the damp proof course or DPC.
It is usually referred to as German floor in layman terms.
Over site concrete is usually laid across the length and breadth of a building. It is commonly used on storey buildings.
What are the materials required for Over site Concrete?
If you’re currently at the stage of construction where your engineer recommends over site concrete, below are some of the materials you’ll need to do this.
2. Cement (Ordinary Portland Cement, OPC)
3. Wire mesh
6. Planks (to hold the edges)
7. Rope (Spirit line) to take level.
7 Steps To Prevent Collapse Of Over site Concrete.
In this section, I’m going to be discussing on 8 precautions you must take in order to ensure your over site concrete lasts as much as it ought to.
In order to prevent the collapse of your over site concrete or German flooring especially if its to carry heavy loads, you must ensure that:
1. Ensure the soil used as filling material is compact able. This means the soil must be able to compact when rammed. This also means you must avoid the use of peat as filling material.
2. In order to save future cost of maintenance and repairs of the over site concrete, I’ll recommend you use wire mesh or BRC just as recommended by the engineer as doing so would save you the cost of repairs and other pains when the system begins to fall after a few years.
3. Ensure the area to be concerted is filled and rammed in order to expel voids which may lead to collapse in the future.
4. Ensure the DPM (damp Proof membrane) is well installed before the introduction of the over site concrete. The DPM serves as a capillary cut off. It prevents water from moving from the foundation soil to the upper part of the building. It also prevents the presence of voids as no water can penetrate from the above The foundation to the bottom part of the building.
5. Mix Ratio is another important aspect of over site concrete that determines the strength of the concrete itself. You must ensure the specified mix ratio is used. Avoid cutting corners as the area may become rough if tiles are not installed afterwards.
6. Get your materials ready before the day of the actual job. This also includes processes that ensures the area to be concreted is well rammed or compacted.
Compacting property as I said in a few paragraphs above ensures voids are eliminated.
7. After the actual casting, allow a few days to pass before you go on with removal of formwork used to hold the concrete while in molten state.
Allow a few days in order to allow the concrete set well without deformation. Allowing a good number of days to pass before formwork removal also prevents the formation of cracks.
Now that’s the meaning of Over site concrete and 7 precautions you must take if you’re currently in that stage of building construction.
I do hope you found this useful and if yes, please share with other young engineers out there as this blog was written with them at heart.