Walls are an essential part of a building envelope that function to enclose the living or working space being constructed. They can be of brick, stone, concrete, metal, glass, or others. They are often an intermediate stage in load bearing buildings, and require to be in position before slabs or roofs are put in place. In other framed structures, built of steel or concrete, walls act as cladding for the outside of the building, and as dividers for the space within. Walls are often used for concealing and running services like electricity, communication, data, plumbing, and others.
Introduction to Precast Walls
Precast concrete has been widely used by architects and builders such as verticreteireland.ie as it gives a versatility that is ideal. Precast concrete is prepared in moulds that are reusable, and allow for the mass production of identical items. Most precast walls are made under controlled environments and this enables a high degree of quality. Curing is also controlled, and once the precast walls have set, they are transported to construction sites, where they can be lifted and placed where required. Lifting and transporting impose their own stresses on precast walls, and these have to be taken into consideration when they are being designed. Walls that are built in have only to take note of the imposed loads on them, or wind and other factors; something that will also cause stresses on precast walls. It is also possible to cast precast walls with inserts required for any services, or for openings for windows and doors. The main function of precast walls is to hasten the construction process, which allows the walls to be separately manufactured at locations outside the construction site on which they are needed. There is no need to wait for any sequence of operations, like built up walls will have to do.
Types of Precast Walls
The most common type of a precast wall acts as a cladding or curtain for enveloping the building. They are not designed to bear any load, other their own and the lifting and transporting stresses they will be subjected to. They will have to resist wind forces, but concrete that these walls are made of is able to do this without requiring any special design consideration. These walls are also used as dividers for rooms.
Precast walls can also be designed as load bearing walls that will act as a part of the structure that they are used in. Such walls must be designed for the additional stresses imposed by loads and moments that being part of a structure will cause in them. Some precast walls are designed as shear walls to give a framework additional stability.
Precast Wall Connections
Built in walls will have mortar and other means that secure them to the framework or structure they are built in. Precast walls need to be securely connected to the framework or structure with connections that can be of many kinds. The fastest of these is to use bolted connections that allow these walls to get firmly attached to a framework using bolts and nuts. This will require inserting the proper arrangements in both the precast walls and the framework that allow for the use of bolts and nuts. Accuracy and alignment of these inserts is very vital for ensuring that the walls are fixed in the right places. It is also possible to fix the precast walls to the framework by welding these inserts together. It is also possible to make these connections using dowels or anchor bolts that are matched with their corresponding position in the framework.
Precast Wall Design
Precast walls need to be able to resist the forces imposed by their self weight, stresses caused during lifting, transporting and placing, and for any loads imposed on them. A lot of importance also needs to be given to not only the method of fixing, but also to the treatment of the joints between the walls and the structure, that are often vulnerable points for the entry of water. Care has to betaken to properly seal these joints once the erection has been completed. Many precast walls need to have openings for doors and windows and these openings cause their own kind of stresses due to the discontinuity of the concrete and must be taken into consideration during their design. Even Superior Windows recommends them when constructing a new home.
The Advantages of Precast Walls
The use of concrete in walls always give them a high thermal resistance that can greatly add to the insulation of a building and help in conserving energy and increasing your building energy rating. It is also possible to add insulation easily into precast walls to further increase their heat resistance. While concrete is also better at resisting moisture than brick, use of chemical compounds in the concrete used for their concreting can greatly enhance moisture protection for the outer walls of a building. A lot of care, however, needs to be taken to seal their joints, so that this advantage is not lost.
Concrete gives you better resistance to fire, and this can be enhanced by additives in the concrete. Precast walls will not allow for easy transmission of sound and this can improve the acoustics of a building in which they are used. Concrete is highly durable and the use of precast walls extends this durability to the building in which they are used. They are also less likely to form cracks and this reduces any need for their maintenance throughout their useful life.
Precast walls can save a lot of time in construction and even be given the desired finishes during their production so that they are have the needed aesthetics and looks. You can use colors in the concrete, achieve various finishes with the aggregates used in their concreting, and finishing techniques that give you a virtually finished wall that may at the most only require to be painted. Electrical boxes and conduits can be preinstalled in them and this can greatly reduce completion of the construction. It is needed to use the proper lifting techniques and equipment for their installation.
