Precast concrete foundation construction is an off-site construction technique in which the foundation units are pre-engineered and manufactured in a controlled environment. These units as are pre-engineered, their capacities or the limits are communicated with the purchaser to produce the desired unit.
Some of the important features, advantages and disadvantages of pre-cast concrete foundations are explained briefly in this article.
Precast Concrete Foundation Construction
The precast concrete foundation technique is very prominent today. The airtight and weather resistant property of these types of foundation makes it common.
The design of the precast concrete foundation is performed by considering the following important parameters:
- Determination of soil type and its bearing capacity
- Checking with the precast concrete foundation manufacturer that the foundation unit can safely support the calculated loads.
- Design of the footing
- Checking for the uplift.
Once the foundation units are manufactured and bought to the construction site, they are installed on an undisturbed soil layer.
In the case of a precast pad foundation, the pad foundation unit is placed over a lean concrete layer that was already prepared. Over the pad foundation, a precast column is placed. The bent bars kept out of the column are inserted inside the foundation element as shown in figure 1. The column rebars are embedded inside the precast foundation by a final casting using concrete. When the work is complete, the adjustment devices and arrangements are removed.
In the above figure, the pad foundation is placed over a deep foundation like pile. The pile constructed can also be a precast structure or a pile constructed on-site.
Advantages of Precast Concrete Foundation
The important advantages of precast concrete foundation are:
- The precast concrete foundation is constructed in a controlled environment and hence it follows strict quality control.
- The precast concrete foundation units are stronger and lighter when compared to other competing materials.
- Employing a precast concrete foundation construction techniques helps to minimize the construction period.
- The method helps to undergo the installation faster
- The precast construction method has less weather dependency. Weather is a concern only during its installation.
- The foundation units produced by this method are leak-resistant and are less susceptible to cracking.
- Precast concrete foundation units can be manufactured in varied architectural finishes.
- The manufacture and installation of these units hence are environmentally friendly compared to on-site foundation construction.
- This method reduces the overall cost of the builders and homeowners.
- Precast foundation units can be employed for both residential and light commercial foundation construction.
Disadvantages of Precast Concrete Foundation Construction
The main disadvantages of precast concrete foundation are:
- The foundation units that are precast are heavy and they demand heavy equipment for their proper handling and transportation.
- Proper care and experience are required during their transportation and assembling in order to avoid any chance of damage.
- In the case of precast concrete pile foundation construction, the length is limited due to difficulty in transportation.
- The length alteration or design variation cannot be performed as in the case of on-site construction.
Also Read: Methods of Precast Concrete Construction
Read More: On-Site and Off-site Construction