Tips to Avoid Over Compaction in Construction

Here are some key considerations for those of you running asphalt rollers, soil compactors or both.

Tips to Avoid Over Compaction in Asphalt Roadbuilding

Over compacting asphalt results in decreased pavement quality, which can lead to cracking, rutting or premature failure. Here are some tips to ensure a durable, long-lasting road surface:

• Understand the Optimal Compaction Levels – Ensure you’re following project specifications, which will include a target density range for asphalt. Exceeding this range can damage the aggregate structure within the mix.
• Use the Right Asphalt Roller for the Job – Match the roller to the job. For instance, vibratory rollers are excellent for breakdown passes, while pneumatic rollers may be better for finish passes or chip sealing. Knowing when to use each type prevents overworking the asphalt. And, whichever way you go, be sure the asphalt compactor you use is the ideal size.
• Monitor the Temperature Window – Asphalt compacts best within a specific temperature range. Rolling outside this range, particularly at lower temperatures, can lead to excessive rolling without achieving proper density — or worse, you can damage the mix.
• Avoid Overlapping Passes – Use proper rolling patterns. While it’s essential to maintain consistent coverage, overlapping too much or making unnecessary extra passes can compact asphalt beyond its structural limits and create inconsistencies across the width of the mat.

• Utilize Technology for Real-Time Feedback – Use asphalt compactors that include GPS and intelligent compaction systems that provide real-time density and stiffness measurements. These tools will help ensure you’re hitting, but not exceeding, target levels. The end result is a more efficient job by minimizing overlap and limiting passes to meet density requirements.

Consequences of Over Compaction in Soil

• Cracking and premature pavement failure

• Increased material costs if the pavement needs to be replaced

• Higher fuel and labor costs due to inefficiency

Tips to Avoid Over Compaction in Construction Site Preparation

• Over compaction during site prep can lead to soil instability, drainage issues and difficulties with subsequent construction phases. Use these tips to prevent over compaction on construction sites:

• Assess and Adjust for Soil Type – Different soil types require different approaches. Clay soils are more prone to over compaction, while sandy soils may requi more effort to achieve stability. Always conduct field compaction tests of the soil to determine optimal moisture content and compaction requirements.

• Maintain Proper Moisture Levels – Moisture content is critical. Too little moisture leads to inadequate compaction, while too much can cause over compaction and unstable conditions. Use water trucks or aeration as needed to maintain a good balance.
• Account for Weather Conditions – Wet weather can saturate the soil, making it prone to over compaction. Conversely, dry, hot conditions can evaporate moisture too quickly. Adjust your strategy based on weather forecasts and on-site conditions.
• Use Layered Compaction – Compact soil in thin lifts (layers) to avoid excessive compaction in any single pass. Each layer should meet density requirements before adding the next.
• Select the Appropriate Machine – Padfoot rollers are ideal for cohesive soils like clay, while smooth-drum rollers work better for granular soils.
• Avoid Excessive Passes – Overworking the soil with repeated passes can lead to soil deformation and reduced permeability. Monitor the number of passes to achieve, but not exceed, the target density.
• Utilize Technology for Real-Time Feedback – Much like asphalt compactors, soil compactors also have systems that include GPS and intelligent compaction measurement systems that provide location, pass mapping and real-time stiffness measurements. Use these tools to help hit your targets and meet density requirements.

Consequences of Over Compaction in Soil

• Poor drainage and water pooling
• Increased difficulty in excavating or trenching
• Higher costs due to wasted fuel, time and potential rework

The Bottom Line

Avoiding over compaction requires a mix of proper planning, understanding the material you’re working with and using the right equipment and technology. Here at Volvo, we offer top-of-the-line compactors that come with a range of Compact Assist in-cab machine control systems. Using them can help you minimize costs, reduce waste and achieve high-quality results on the first try.