What is the minimum strength in megapascal (Mpa) required for interior flatwork concrete?

The minimum strength required for interior flatwork concrete is 20 MPa. This standard is established to ensure that the concrete can withstand the anticipated loads and stresses that occur in typical interior applications, such as floors in residential or commercial buildings. This strength level provides a balance between performance and cost-effectiveness, ensuring durability while not unnecessarily over-specifying the concrete requirements. Using concrete of this strength helps to reduce cracking and ensure a long-lasting surface under normal use conditions.

Selecting a strength lower than 20 MPa may risk inadequate performance, resulting in increased maintenance costs or structural issues over time. Similarly, while higher strengths like 25 MPa or 30 MPa provide additional durability and are suitable for specific applications, they typically come with increased material costs and may not be necessary for standard interior flatwork.