SILICAWOOD® Blocks can be manufactured also with hollowcore extrusion and slip former machines

1. The Silicawood Raw is stored in large wood storage silos and conveyed to the batching plant either on purposely fit conveyer belts or transferred by bins. The Portland cement is stored outside in large vertical silos to protect it from moisture.

2. As a production run starts, the required amounts of Silicawood Raw, and cement are transferred by gravity or by mechanical means to a weigh batcher which measures the proper amounts of each material.

3. The dry materials then flow into a stationary horizontal planetary mixer where they are blended with the addition of water.

4. Once the load of Silicawood Mix is thoroughly mixed, it is dumped into an inclined bucket conveyor and transported to the hopper of the extrusion or slip former machine . The mixing cycle begins again for the next load.

5. The state-of-the-art system is a dry cast, extrusion process where zero slump Silicawood Mix is forced through the machine. The cores are formed with augers and tubes with the SW concrete being compacted around the cores using high frequency vibrators. The slabs are extruded on casting beds 1200 mm in width and 150 meters long.

6. A longitudinal saw cutting process cuts the slab to customs lengths and after curing

7. Thereafter the custom blocks are removed from the casting bed and transported to an automated stacker or loader which places them in a curing rack that is moved into a curing kiln as per the process described above

 

The Manufacturing Process for SILICAWOOD®  Hollowcore Slabs

 

SILICAWOOD®   Precast hollow core slabs are among the most innovative products in the precast concrete industry. It is cost-effective alternative to poured and traditional concrete methods and to achieve exceptionally light weigt structural products .

The extrusion process involves feeding Silicawood Mix concrete onto rotation screws by means of a moving hopper. The screws force the SW concrete through shaping plates and out of the rear of the extrusion machine, while holes are forced into the concrete panels by circular mandrels, trailing behind the screws. During the process the extrusion machine is propelled by the back pressure of the concrete and together with various vibrating plates it produces the extremely well compacted concrete panel.

The two types of machine used to produce pre-stressed hollowcore floor slabs are extruders and slip-formers. The conventional method is to run the machines on steel beds up to 200 m long,  Travel speed will depend on quality of raw materials, type of machine and depth of slab as well as the combined used of a double machine for co-extruding both Silicawood and ordinary concrete together  A speed of 2 m/minute can be considered for budget purposes.

Hollow core slabs have longitudinal cores. The light weigh material combined with the extrusion process yields a considerable weight saving, making the slabs up to 80% lighter than traditional concrete This reduces managing transport and on site construction costs Normal production width is 1200 mm. Other widths are used as well (e.g. 600 mm, 2400 mm,. Normal slab depths go from 120 mm to 500 mm.

The following steps are commonly used to manufacture Silicawood Hollowcore Slabs

 

  1. The Silicawood Raw is stored in large wood storage silos and conveyed to the batching plant  either on purposely fit conveyer belts or transferred by bins. The Portland cement is stored outside in large vertical silos to protect it from moisture.
  2. As a production run starts, the required amounts of Silicawood Raw, and cement are transferred by gravity or by mechanical means to a weigh batcher which measures the proper amounts of each material.
  3. The dry materials then flow into a stationary horizontal planetary mixer where they are blended with the addition of water.
  4. Once the load of Silicawood Mix is thoroughly mixed, it is dumped into an inclined bucket conveyor and transported to an elevated hopper. The mixing cycle begins again for the next load.
  5. From the hopper the SW Mix is conveyed to another hopper on to the casting machine, which forms the shape of the slab as it moves along the bed. The machine is transferred from bed to bed once it terminates a full run (about 200m), using an overhead crane.
  6. In advance to casting the is the preparation of casting beds
  7. Feed in SW Concrete is done by a fully automatic conveying system that transports the batched material fro the mixer to the extruder casting machine Casting the bed by an extrusion process characterised by high compaction with very low moisture content of mixes. Extruding machines are provided either with or without vibration. They are an excellent choice for high quality, lighter weight deep sections.

    Slipformers feed and vibrate the concrete in two or three stages over moving steel cores. They have the flexibility to make other products of constant cross-section, such as T-beams, lintels etc.

  8. Plotting and identifying the slabs Automatic bed plotters, linked to bed optimisation software, are used to accurately mark saw cut lines, notches and openings.
  9. Creating notches, openings etc in the wet state
  10. Creating water drainage holes
  11. Casting in lifting hooks
  12. Covering the slabs, to retain moisture during curing
  13. Curing the total slab length
  14. Cutting the slabs to the required lengths, widths and angles
  15. Stacks of slabs are removed to the stockyard by crane, sideloader or fork-lift truck
  16. Delivery to site and erection on the building.

 

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