Cliff's Corner: Asphalt Release Agents - Defining These Products & Using In The Correct Manner

The Responsible Use of Release Agents

A recent article discussing asphalt buildup prompted me to address the topic of asphalt release agents. Many people still use diesel fuel as a makeshift release agent due to its low cost (around $3.50/gallon). However, diesel is not a true release agent—it's a fuel acting as a cleaner, and its use can severely harm asphalt. Diesel breaks down the chemical structure of liquid asphalt, weakening its bonding properties. This degradation often leads to premature pavement failures, such as raveling and potholes, which is why Departments of Transportation (DOTs) discourage its use.

In addition to damaging asphalt, diesel poses environmental risks, contaminating soil and groundwater. Fortunately, there are safer, more environmentally friendly alternatives available. Though they may cost more, these products are often derived from renewable sources like soybean oil that are designed specifically for cleaning and degreasing tools, boots, and paving equipment. It's essential to use these products correctly. Avoid applying them during active paving operations when they might come into direct contact with hot asphalt, as this could lead to future maintenance issues. Use them sparingly when absolutely needed and only after paving is complete. Ensure that you use safety precautions like wearing proper PPE and do not under any circumstance forget about the product’s flash point to avoid the possibility of chemical combustion while using these products. Take the time to educate yourself on the product that you are handling and using on the job by acquiring the SDS.

It’s also important to distinguish between cleaning agents and true release agents. Release agents are meant to be applied to clean truck beds and equipment to prevent asphalt from sticking in the first place. These true release agents products will not harm the quality of the asphalt mixture and are usually derived from soap or silicone that provide a slippery surface in the truck beds. Drivers should inspect their trucks for buildup before loading, remove any hardened asphalt using approved, eco-friendly products, then wash and apply a release agent. This ensures the asphalt mix unloads evenly and prevents segregation or cold spots in the pavement. Some asphalt mixes, like OGFC, SMA, and those with aramid fibers, are especially prone to sticking. These typically require extra attention both at the plant and on the job site. Keeping equipment and tools, and even your work truck clean not only improves performance but also shows pride in your work and that’s the mark of a valuable team member.