Prefabrication: when and why
To prefabricate - to precast - concrete components for various purposes is not a new method. On the contrary, it has been used since the beginning of the twentieth century. Prefabrication technology has continually been refined and developed since then. Compared with traditional construction methods or other building materials, prefabrication, as a construction method, and concrete, as a material, have a number of positive features.
It is an industrialized way of construction, with the inherent advantages of:
- High capacity - enabling the realization of important projects
- Factory made products
- Shorter construction time - less than half of conventional cast in-situ construction
- Independent of adverse weather conditions
- Continuing erection in Winter time until -20°C
- Quality surveillance system
It offers the customer the performance to fulfill all Requirements:
- Opportunities for good architecture
- Fire resistant material
- Healthy buildings
- Reduced energy consumption through the ability to store heat in the concrete mass
- Environmentally friendly way of building, with optimum use of materials, recycling of waste products, less noise and dust etc.
- Cost effective solutions
When to use precast concrete?
Most buildings are suitable for construction in precast concrete. Buildings with an orthogonal plan are, of course, ideal for precasting because they exhibit a degree of regularity and repetition in their structural grid, spans, member size, etc. Irregular ground layouts are, on many occasions, equally suitable for precasting. Modern precast concrete buildings can be designed safely and economically with a variety of plans and with considerable variation in treatment of the elevations to heights up to twenty floors and more. With the introduction of high strength concrete, already currently used in Consolis' business units, the sizes of load bearing columns can be reduced to less than half of the section needed in conventional concrete structures.
Precast concrete offers considerable scope for improving structural efficiency. Longer spans and shallower construction depths can be obtained by using prestressed concrete for beams and floors. For industrial and commercial halls, roof spans can be up to 40 m and even more. For parking garages, precast concrete enables occupiers to put more cars on the same construction space because of the large span possibilities and slender column sections. In office buildings, the modern trend is to create large open spaces, which can be split with partitions. This not only offers flexibility in the building but also extends its life because of the easier adaptability. In this way, the building retains its commercial value over a longer period.
