Preparation works of the floor plate
In case you have missed it, construction works of the Nile Institute Rwanda have started & are progressing at a steady pace. While last time the Groundworks & base Foundation works were documented, this time we’re moving on to the advanced foundations in preparation of the floor plate.
After preparing the 36 underground columns, the workers started digging the connection trenches. These could only be dug until the hard soil is reached; the depth of the 3 trenches in the longitudinal direction – like their column depths – differ from each other. The 12 transverse trenches are all the same, providing sufficient depth to ensure stability. This is especially crucial considering the varying soil hardness of the embankment toward the valley.
Rubble is used to fill the trenches, again, heights – at which the foundation ring beams are subsequently cast – will fluctuate. In the transverse trenches, a 50 cm high foundation beam is provided on top of the rubble (variation of stones); the foundation beams in the longitudinal direction are only 15 cm high with the exception of the trench on the valley side, which is also 50 cm. The end result is that all ring beams at the same height will support the 15 cm thick floor plate.
The reinforcing steel of each beam protrudes at the top so that the floor plate that comes on top is firmly anchored. The formwork of the foundation beams is not provided in wood because of the difficulty in propping it up, masonry is provided.
Finally, the base of the floor slab itself is prepared. It is excavated to a solid foundation, then there is a layer of sand, then rubble and finally just below the floor slab a layer of cement of 3 to 5 cm. The pouring of beams and floor plate can now begin.
