Which of the following statements about tilt-up concrete construction is not true?
a. Panels may be fabricated off site.
b. Use in one- and two-story buildings is most common.
c. Panels are joined by welding.
d. It uses a loadbearing structural steel framework.
The correct answer and explanation is:
The correct answer is d. It uses a loadbearing structural steel framework.
Tilt-up concrete construction does not typically use a loadbearing structural steel framework. Instead, it relies on concrete panels that are cast on-site and lifted into place. These panels are supported by their own weight and typically do not require an additional steel framework to bear the load. The primary structure of tilt-up buildings consists of the concrete panels themselves, which can be reinforced with steel bars to provide additional strength.
Here’s how the other statements break down:
- a. Panels may be fabricated off site: This is true. While tilt-up panels are most commonly cast on-site, they can also be fabricated off-site and delivered to the construction site. This is often done for projects requiring precise or specialized panel designs, but the majority of tilt-up construction uses on-site casting to save time and costs.
- b. Use in one- and two-story buildings is most common: This is also correct. Tilt-up construction is especially popular for low-rise buildings such as warehouses, retail stores, and office buildings. Its simplicity and cost-effectiveness make it a preferred choice for buildings of one to two stories.
- c. Panels are joined by welding: This is true in some cases, but not the primary method. Panels are generally lifted into position using cranes, and the connections between the panels can involve welding, bolting, or even using special concrete anchors. The actual method of joining depends on the design requirements and the structural engineers’ specifications.
Tilt-up concrete construction is an efficient, cost-effective method for building certain types of structures, particularly in commercial and industrial settings. However, it does not rely on a loadbearing structural steel framework as indicated in option d.