Final answer:
In concrete tilt-up wall buildings, the strength of concrete for slab-on-ground must account for high compression and adequate shear resistance. Lightweight concrete mixed with aggregates (shale, clay, or slate) is commonly used, with additional steel reinforcement to ensure robustness and durability. Common strengths range from 3,000 to 5,000 psi (20 to 35 MPa).
Step-by-step explanation:
The question concerns the most commonly used strength of concrete for slab-on-ground applications in tilt-up wall buildings. The strength of concrete is particularly important in such structures because it must be strong enough to support the buildings weight and various loads. It is understood that concrete has high compressive strength but lower shear strength, which is a consideration in its application.
For concrete tilt-up wall buildings, a mixture of lightweight concrete is often utilized. This type of concrete, comprising of lightweight coarse aggregate and fine aggregates like shale, clay, or slate, provides significant advantages. The benefits of lightweight concrete include a reduction in load, leading to faster building rates, enhanced longevity, and improved thermal protection compared to traditional brick. Also, the integration of steel and steel-reinforced concrete has been crucial in modern building to compensate for concretes lower shear strength.
When selecting the concrete strength for slabs in such structures, engineers take into account the ultimate compressive and shear strengths. Although not specified here, a common concrete strength used for slab-on-ground in tilt-up constructions is 3,000 to 5,000 psi (pounds per square inch), also known as 20 to 35 MPa (megapascals).