Concrete in various floor works There are many designs and work to build a house in Korat รับสร้างบ้านโคราช . Or in general, usually choose a floor job, depending on the type of work by the prestressed concrete work and the pull after Formwork and bracing is another floor work that should be knowledgeable for use in building construction. The details of the pre-tensioned prestressed concrete and Formwork and bracing which also applied in Ratchaburi รับสร้างบ้านราชบุรี are as follows:
pre-stressed prestressed concrete
Post-tensioned prestressed concrete This is done by prestressing the concrete by pulling the steel wires after the concrete has fully hardened.
- However, the slab formed by the latter tensile system tends to shrink due to the elastic compression. Therefore, such a phenomenon affects other adjacent structural parts. This can be solved by making pre-tensioned prestressed concrete to be completed first. and then build other structural parts later. However, an expansion joint may be created as well.
- Group of wires that have not been drawn. It is hung in a way that will cast beams or floors. The wire will be coated. or covered with steel pipes for stringing steel wire
- After the concrete has hardened according to age. Start pulling the wire with one end attached to the platform. The other end was pulled with a jack until the required force was achieved.
- Then use the end of the anchor wedge to secure the end of the wire to the end of the slab or the jacked side beam. and then withdraw the jack Then let the wire try to shrink back. will be able to transfer the compressive strength to the concrete causing the concrete slab or beam to bend as shown in the picture This may end at the later pre-tensioned prestressed concrete. Or may be compressed grout into steel pipes. In order to achieve the adhesion force between the wire and the grout in the case of using steel conduit, the balance between the hanging of the beam under load and the rising deflection of prestressed concrete. pull back
- The principle of making pre-tensioned prestressed concrete with wire group is The deflection is zero under the load that will be on the slab or beam.
- The lines of the wire group are parabolic arcs that are laid out according to the curve diagrams that are intended to occur in the concrete.
- A group of straight wires representing a parabolic curve at different angles. Used to make pre-stressed pre-stressed concrete. Because pre-stressed concrete cannot form a parabolic curve.
5. Formwork and bracing
Short-mixed concrete, called fresh concrete, must be supported in the desired form with a solid enough formwork. until the concrete hardens, an age that can support its own weight Therefore, the formwork can be dismantled. Due to the weight of concrete, formwork configuration should be done by the engineer.
- Slab formwork. may be made of plywood or hardboard
- Steel or wood.
- hanging arms
Support columns are used to support the formwork until the concrete hardens. and until it is old enough that the concrete can support its own weight.
- Steel support columns. It has a magnet or has a nut tip with threads that can be height adjusted to fit the height of the mold. The keys on the nut heads can be shaped in various shapes according to your needs, such as U-shape or T-shape.
- Wooden struts are cut to a slightly lower height than required for ease of work. Which will use a wedge to push into the top or bottom end of the pole to support it tightly instead of using the thread of the steel column.
- Once the support columns are placed, they should also be attached to the bottom of the support columns.
- When the area under the formwork is large We should have a wooden support. before transferring the weight from the tong onto the support column
- Formwork can be removed when the concrete is strong enough to support its own weight. The supporting pillars will still be used after the formwork is dismantled. until the concrete reaches the required age with the highest strength
- Krathong floor slabs have specific patterns according to each manufacturer’s factory.
- A standard, simple casting form that is common standard. This will save a lot of costs. Therefore, standard formwork should be used as much as possible.
- Side support
- Horizontal mounting brackets, vertical mounting brackets.
- bottom edge bracket
- T-shaped and L-shaped struts (dollhouses) are used to support the belly of the beams.
- When the load is increased. We can maintain the size of the beam cross-section. or concrete pillars to remain the same by adding iron making the original formwork reusable It will save a lot of cost of formwork and bracing.
- The formwork struts should be fixed both vertically and horizontally. to prevent buckling and help hold the end of the pole stable
- Support under the support column. It will help distribute the weight on the floor wider. And it will be of great help in cases where the concrete slab on which the supporting columns stand has just been cast.
- Flying formwork is a formwork that is fully assembled into a frame. with support poles and stretching kit which can be moved by using a lifting crane
- Raised floor construction is a technique for constructing floors for multi-storey buildings. by casting the floors of multi-storey buildings at ground level and curing until it can be used and then lifted by hydraulic jacks.
