simprolit ^®

An additional advantage of Simprolit blocks that was already mentioned before is their possible application as a permanent thermoinsulating formwork. Namely, Simprolit blocks can be used as a formwork for reinforcement fitting and casting of horizontal and vertical ring beams, for window and door lintels, even for facade columns. Having in mind the fact that they are easily cut (even with a simple wood-saw) and brought to the required forms and dimensions, as well as their fire resistance, Simprolit blocks may also be used for building of a thermal and fireproofing protection coat around metal columns (if it is necessary, inner block cavities could be filled up with concrete - consequently offering a higher degree of fire resistance and much better corrosion protection).

When using Simprolit blocks as a permanent formwork, every Designer of a structural system should also take into account the dimensions of the blocks in order to reduce the amount of the waste material left after cutting.
But even these leftovers should not be thrown away - they can be used to fill up the Simprolit blocks' hollow cavities with bottom.
Generally, the application of Simprolit blocks as a permanent formwork can be classified as following:

Simprolit blocks type "SBD" and "SBDS" have two large hollow cavities, basically provided in order to create a permanent formwork for vertical and horizontal ring beams or facade columns; usually, Simprolit blocks type "SBD" or "SBDS" are used in about 10% of the whole number of blocks (at the wall corners, at the joints of bearing walls, for facade columns and ring beams) and the remaining 90% are Simprolit blocks type "SB" or "SBS", which are used for building of facade walls.

In case that the blocks "SBD" or "SBDS" are not available at the construction site, they can easily be replaced using blocks "SB" or "SBS"; this can be done by cutting the bottom and the rib between the hollow cavities of the block using simple wood-saw.

In such a formwork, the designed reinforcement is installed and concrete of the designed class and quality is casted. Although concreting of the vertical ring beams could be done in segments along the height of the wall, the same procedure is not recommended for column construction. Namely, the column reinforcement usually sticks out from the base, reaching sometimes the height of the whole storey (so that lifting of the blocks would be a very tiresome activity).

In such a case, it is recommended to cut the blocks from the sides (if the column is at the corner) or from the front (if the column is in the wall). After the installation of the cut blocks, the other uncut blocks are moved close to them and the building of the wall continues according to the general rules for building with Simprolit blocks.

However, there is another more practical way to do the same procedure: to form the permanent formwork for vertical ring beams or columns using Simprolit ''SUP'' or ''SOP'' plates (outer and inner side) and Simprolit blocks on the flanks.

Production program of Simprolit elements also contains prefabricated window and door lintels. However, these elements can be made at the construction site as well. For this purpose, the block types "SBD" or "SBDS" should be cut (in the shape of the letter "U"), lined up and filled with concrete in the following way:

If the Designer determines the width of the beam to be corresponding to the width of the block's hollow cavities and that the deflection of the beam must not cause any load transfer to the facade wall underneath, he can use the Simprolit blocks type "SBD" or "SBDS" - cutting the blocks horizontally at the half of their height and then lining them up to form the shape of the letter "U".

Cut block elements have to be lined up one next to other and placed on the flat surface of a wooden lath (in case of a free span) or on the top of the wall. Then, the sides of the blocks must be stiffened with wooden boards, followed by the reinforcement installation and filling of the "trough" with concrete.

Using this method, the costs of formwork and its installation are significantly reduced and there is no need for additional thermo-insulation of the beams in order to avoid ''thermal bridges''.

Besides, it is possible to construct the beams the same way as the door or window lintels (on the ground, placed on the flat surface of a wooden lath and then lifted up and mounted to the planned position), especially if the beam spans are short.

Simprolit blocks may also be used as a permanent formwork for concreting of horizontal ring beams.

However, there is a difference between the above-described method of cutting Simprolit blocks for construction of the permanent formwork for facade beams and the method for construction of the permanent formwork for horizontal ring beams. For this latter method, Simprolit blocks are cut at the flanks and along the inner rib, in a width equal to the block cavity width, at 2/3 of the block's height.

So formed "trough" is not only acting as a thermo-insulation of the horizontal ring beam's sides, but also as a connection between newly poured fresh concrete and ''old'' concrete from the previously built row of blocks.

In this way, forming a spacious truss made of ring beams, with concrete "posts" as vertical and steel reinforcement as horizontal structural members (in each third or fourth row of blocks), Simprolit building system represents effectively the most resistant and seismically safe system in comparison with any other "masonry" building system.