What is the standard limit for the amount of reclaimed asphalt pavement (RAP) in new mixtures?

The standard limit for the amount of reclaimed asphalt pavement (RAP) in new mixtures is typically 20-30%. This range is widely accepted in the asphalt industry as it allows for the incorporation of recycled materials, which enhances sustainability by reducing waste and conserving natural resources without compromising the quality of the new asphalt mix. Using this amount of RAP can also help in achieving cost efficiency while maintaining the performance characteristics of the asphalt.

When considering the other options, lower limits like 10-15% do not fully utilize the potential benefits and efficiency gained from recycling asphalt, and stating that only 5% is allowed underestimates the advancements in asphalt technology and practices that now safely incorporate higher RAP percentages. Additionally, indicating that RAP is not allowed in any new mixtures overlooks the environmental and economical advantages of using reclaimed materials in asphalt production, which continues to grow as sustainability becomes a priority in construction practices.