What is the common 28 day compressive strength of concrete used in tilt-up construction for the panels and what is the typical lift compressive strength?

• A. 4000 PSI, 2000 minimum
• B. 6000 PSI, 3000 minimum
• C. 4500 PSI, 1800 minimum
• D. 5000 PSI, 2500 minimum compressive strength prior to erection

Answer: (D)

In tilt-up work, the concrete mix is chosen so the panels have enough long-term strength and enough early strength to be lifted safely. The common target is about 5000 psi at 28 days for the panel’s compressive strength, providing the necessary stiffness, durability, and capacity for service loads. The lift strength, which is the strength the concrete must have before erection to withstand hoisting and handling forces, is typically around 2500 psi as a minimum. This ensures the panel can be lifted safely without delaying construction, while the higher 28-day strength still governs the final design and performance. Values like 4000 psi with a 2000 psi lift or other higher/lower pairs either undercut the required long-term capacity or add unnecessary cost, whereas 5000/2500 aligns with common practice for reliable erection and structural performance.