Skip to main content

Key Insights

Quick Facts

  • Name: Texas Seal Coat and Surface Treatment Applications
  • Location: Various districts across Texas
  • Customer: Texas Department of Transportation (TxDOT)
  • Size: 300,000+ cubic yards of lightweight aggregate
Challenge: Maintaining Texas roadways in acceptable condition while reducing the high costs of rehabilitation and ensuring long-lasting skid resistance in wet weather.
How Arcosa Helped
  • Our Solution: Provided lightweight expanded shale aggregate with a high polish value for chip seal applications, ensuring durable, skid-resistant surfaces.
  • Why Lightweight Works: The unique cellular structure of lightweight aggregate resists polishing, maintains texture, and withstands traffic wear, enhancing safety and performance.

Final Results

  • Enhanced safety with high skid resistance, durability, and cost-effective roadway maintenance across Texas highways.

Key Quote

“If you cut a sponge in half, you expose its cells inside, each with tiny edges formed by air bubbles. As you wear through the shell of lightweight aggregate, you expose one of its best characteristics – its abrasive texture formed by its cells makes it highly resistant to polishing and stripping.” — Oscar H. Rodriguez, P.E., Construction Materials Engineer

Context:

  • Considerations: Lightweight aggregate’s durability and polish resistance make it superior to conventional aggregates, particularly in wet weather conditions.
  • Lessons Learned: Using lightweight aggregate with a high polish value in chip seal applications provides a long-term, cost-effective solution for roadway maintenance.
Explore Further

Arcosa Lightweight’s Streetman Product Has Highest Polish Value in Texas

It’s estimated that over 300,000 cubic yards of lightweight aggregate is used each year in Texas for seal coat and surface treatment applications. Arcosa Lightweight’s Streetman product boasts the highest polish value of any material used in Texas, based on TxDOT’s Bituminous Rated Source Quality Catalog (BRSQC).

A polish value measures the ability of an aggregate to withstand the polishing effects of traffic wear. It is determined through readings on a test specimen of aggregate after nine hours of polishing in an accelerated polishing machine. Simply put, Arcosa’s material maintains its “roughness” and wet weather skid characteristics, ensuring safety even after years of heavy traffic wear.

Maintaining Roadways

With the fiscal condition of most public agencies, maintaining pavements that are in “acceptable or above acceptable” condition is crucial, as the cost of rehabilitation or reconstruction can be significant. On average, it costs approximately 20 cents on the dollar to maintain these conditions using conventional chip seals, making proactive road maintenance an economical choice.

Oscar H. Rodriguez, P.E., Construction Materials Engineer and industry expert, began his career in TxDOT’s Materials and Tests Division and the Austin District Laboratory. He is well-versed in HMAC designs for high-profile locations, including the Texas Motor Speedway in Fort Worth and test tracks statewide for Goodyear, Cooper Tire, and General Tire. He describes the advantages of lightweight aggregate by likening it to a sponge:

“If you cut a sponge in half, you expose its cells inside, each with tiny edges formed by air bubbles,” Rodriguez explains. “As you wear through the shell of lightweight aggregate, you expose one of its best characteristics – its abrasive texture formed by its cells makes it highly resistant to polishing and stripping.”

Rodriguez Engineering Laboratories, LLC is a leader in construction materials engineering, provides extensive testing and evaluation services for Hot Mix Asphalt Concrete (HMAC), asphalt binders, emulsions, cutbacks, Portland Cement Concrete (PCC), soils, aggregates, and performs full geotechnical investigations. With decades of experience and a team of skilled engineers, Rodriguez Engineering Laboratories is committed to providing clients with precise and reliable results.

District-Wide Use

TxDOT Districts initiate district-wide chip seal contracts in the Fall/Winter for construction in the following Summer. This allows aggregate suppliers ample time to produce and deliver the aggregate, and it provides TxDOT with the necessary time to prepare roadways for chip sealing.

In Texas, both lightweight aggregate (TxDOT Item 302-Type L or PL) and crushed stone (TxDOT Item 302-Type B or PB) are held to identical quality standards, tested on an equal scale.

Related Video

When the summer sun is high and hot….you’ll find it’s seal coat season in Texas. Repair crews use the scorching conditions to preserve miles of asphalt pavement.