Should C30 or C25 be used for road surfaces?
2 Answers
Road concrete can be labeled as C25. If there is regular heavy vehicle traffic that increases compressive strength requirements, C30 concrete can be used. There are many labels for concrete, with cement pavement concrete being ordinary cement pavement, though not standardized, but certain standards must be adhered to, such as C10, C15, C20, C25, C30, C35, C40, C50, C55, C60, C80. Below is relevant knowledge about concrete: Concrete is commonly used in bridges, culverts, and buildings. Highways typically use flexural strengths of 5.0, 5.5, 6.0 MPa, equivalent to C40, C45, C50 concrete. General main and secondary roads use flexural strengths of 4.0, 4.5, 5.0 MPa, equivalent to C30, C35, C40 concrete. Rural roads are relatively simple and less standardized, generally using C25 or C30 concrete.
I've worked in the construction industry for over a decade, often responsible for on-site road construction management. Based on experience, choosing between C30 and C25 mainly depends on traffic volume and environmental conditions. C30 has higher strength and better compressive resistance, making it particularly suitable for main roads or highways where there's heavy traffic and many trucks, reducing road cracks and depressions. C25 is more cost-effective and works well for internal community roads or rural paths since these areas have lighter loads, avoiding unnecessary resource waste. Last month, we used C25 for a road in a new development zone, and it performed well—but if used on a main road, it would have failed by now. Local climate should also be considered: C30 offers better corrosion resistance in high-humidity areas. Overall, safety comes first—I recommend C30 for busy areas and C25 elsewhere to save budget. Additionally, the aggregate mix ratio affects performance, a detail often overlooked.
