Precast concrete is concrete that is cast and cured in a controlled factory environment using reusable molds, rather than being poured and formed on the construction site.
In this process, the concrete is mixed, placed into specific molds or formwork, compacted, and allowed to cure under controlled conditions to achieve the desired strength and quality. Once the elements are hardened and ready, they are transported to the project site and assembled into the structure.
Precast concrete is used to produce a wide range of components, including:
Wall panels
Beams and columns
Floors and slabs
Staircases
Bridge segments
Because it is manufactured off-site, precast concrete offers higher quality control, faster installation, and consistent finishes compared to traditional site-cast concrete. It is known for its durability, versatility, and efficiency, making it a popular choice in modern construction.
What are Advantage pre cast concrete slab than insitu concrete?
Advantages of Pre-cast Concrete- Pre-cast concrete slabs are usually the correct size as it is manufactured off site.- Pre-cast concrete saves a lot of time on site as it is manufactured off site.- Pre-cast concrete also saves a lot of space on site as pre-cast concrete is usually on site when required.- Pre-cast concrete saves money in terms of labour on site as pre-cast concrete can usually be assembled by semi skilled operatives.Disadvantages of Pre-cast Concrete- Pre-cast concrete lacks design and dimension flexibility as the manufactures may only have fixed shapes and sizes.- Pre-cast concrete may affect the construction programme as the delivery on site may not always be on time.- Pre-cast concrete may incur addition financial costs as delivery on site may not always be on time.- Pre-cast concrete allows for a very small margin for error as the incorrect dimensions of pre-cast concrete may result in changing the entire design.
Pcc = portland cement concrete or pre cast concrete
A simple explanation: PRE tensioned- cables are tensioned, and the concrete is cast around it. The tensioning is done BEFORE casting the concrete (PRE = before). POST tensioned- cables are placed inside of ducts or are greased to prevent bonding to the concrete, the concrete is cast around the cables, and then the cables are tensioned after the concrete has reached a desired strength. The tensioning is done AFTER the concrete is cast (POST = after).
Cast in place. Concrete is poured where at its permanent location. For example, a manhole cast in-situ will be formed and poured at the pipe connection. This is the opposite of pre-cast, meaning it is cast off-site and transported to its permanent location.
Pre-cast concretes are manufactured in a pre-cast plant or on site (tilted-up construction). Cast in steel moulds with precise dimension. Very good quality control. Delivered and erected on site. Cast in-situ are constructed on site using fresh concrete from trucks and placed by workers. Quality Control is the responsibility of the site manager.
The present bridge is a pre-stressed concrete box girder bridge.
Natchez Trace Bridge in Franklin, Tennessee
it is Pre-cast i do not know why but it is like that.
42 mpa for pre tension and 35 mpa for post tensioned
To calculate the weight of a pre-cast concrete tilt-wall panel, you would need to know the volume of the panel and the density of concrete typically used in such panels. You can then multiply the volume by the density to determine the weight. The formula would be weight = volume x density.
Concrete molds are used to make the concrete to certain pre-defined shapes after the liquefied concrete dries. The moulds are pre-made containers made of wood, stone or plastic with different shapes.