Which item is NOT among the five items to consider when designing the slab-on-grade?

• A. Cranes capability
• B. Modulus of rupture and the subgrade modulus
• C. Concrete color
• D. location of the lifting anchors

Answer: (C)

When designing a slab-on-grade, focus is on factors that affect structural performance and the erection process. The color of the concrete doesn’t influence strength, bearing capacity, or how the slab will be poured, cured, or lifted, so it isn’t a design parameter. The other items—cranes capability, modulus of rupture and the subgrade modulus, and the location of lifting anchors—are all practical considerations that directly impact how the slab is placed, how it carries loads, and how it will be lifted safely during construction. Cranes capability determines whether the lifting and placement can be done safely with available equipment. The modulus of rupture describes the concrete’s tensile strength, while the subgrade modulus relates to how well the soil beneath the slab supports it, both guiding thickness, reinforcement, and jointing. The location of lifting anchors is crucial for safe and efficient lifting and to avoid conflicts with reinforcement and joints.