Caltrans High RAP Hot Mix Asphalt

We’re all aware of hot mix asphalt (HMA) – a core component of construction for as long as most of us can remember. But mix regulations are constantly evolving, and now, the reuse of old pavements, or Recycled Asphalt Pavement (RAP), at high amounts is becoming more common in California.

Although high amounts of Recycled Asphalt Pavement (RAP) have been used in road construction for years, the economic and environmental benefits of higher amounts are bringing new considerations. Recycled materials still contain asphalt binder and aggregates, allowing for efficient reuse that can reduce new aggregate use and reduction of virgin asphalt binder. On top of this, agencies such as Caltrans are testing high RAP mixes to shape future standards. 

For contractors and HMA producers, this evolution is sure to bring some questions. As geotechnical engineers and material experts with decades of experience, G3 Quality is here to guide you toward high RAP compliance and success. Reach out if you have any questions, or to leverage our hot mix asphalt materials design and testing laboratories located throughout California.

The Promise of High-RAP Mixes

Hot mix asphalt has been a mainstay of road construction for decades. While the core ingredients of aggregate and asphalt binder are familiar to most, the ratios and sources tend to evolve over time. One key evolution is the use of high percentages of recycled asphalt pavement (RAP) in new HMA mixes. 

RAP is an environmentally and economically friendly material, containing residual asphalt binder even after roadway wear and tear. And now, Caltrans’ Pilot Projects for high RAP HMA mixes is aiming to test, analyze test data and standardize testing specifications in hopes of higher adoption rates.


“At G3, we’ve definitely noticed an increased interest in high RAP hot mix asphalt mixes over the years. RAP has always been used for our roadways to some extent, but now, the financial and resource-based benefits of higher RAP percentages are turning heads and leading to new Caltrans testing standards.” 

 Matthew Ramos, Internal Quality Director, G3 Quality


RAP itself isn’t new – it’s been recycled into HMA for years. But now, higher percentages of RAP are bringing new considerations; with 50% or more RAP, a mix can achieve higher reductions in new aggregate and virgin binder needs. It’s a delicate balance though, and how RAP is processed and introduced to the mix is critical. The key: good RAP stockpile management and test data analysis to ensure that mix properties are being achieved.


Caltrans’ Pilot Projects: Overseeing High-Percentage RAP Mixes

In short, Caltrans’ high RAP pilot projects are adding stronger testing requirements for high RAP mixes. This oversight is hoped to ensure quality and consistency before and after materials are placed and establish a new standard for high RAP mix designs. As with any pilot initiative, the main goal is to gather data from controlled conditions that will later inform future standards. 

High-RAP hot mix asphalt is just one of the pilot programs that Caltrans has rolled out in recent years. Others include using RAP with rubberized hot mix asphalt (RHMA) which utilizes recycled rubber tires. These mixes maximize reusable materials from old projects into new, cost-effective mixes, pulling the aggregates and residual out of reclaimed asphalt pavement to offer completely new material.


Consulting Clients on High-RAP Hot Mix Asphalt Mixes

For contractors and producers navigating these changes, G3 Quality is offering a helping hand. Our team closely tracks data from Caltrans’ RAP HMA Pilot Projects, allowing us to guide clients toward compliance with these changing standards. 

Caltrans’ Pilot Projects is a methodical approach, one that’s hoped to ensure a smooth transition to higher RAP adoption – and now, test projects are providing real-world data to shape realistic specifications. With decades of hot mix asphalt experience, G3 Quality is ready to partner with clients and lead them to success, ushering in a new wave of sustainable hot mix asphalt. 


Approach G3 Quality to Meet High-RAP Standards

Thanks to materials testing laboratories, G3 Quality is equipped to design high-RAP mixes to Caltrans’ evolving standards. We keep our finger on the pulse of ongoing Pilot Projects data, which informs and optimizes future mixes to ensure quality results that are always in compliance. 

Fill out a form on our Contact page to connect with our team, ask any questions related to upcoming HMA changes, and brace your business for the changes ahead.