As the economy gathers strength, mobility improvements to surface transportation systems will play a key role in sustaining growth nationwide. With U.S. highways moving 72% of the country’s goods (equating to nearly 17 trillion dollars), traffic congestion can significantly impact the economy. Currently, traffic congestion costs the economy billions of dollars each year in wasted time and fuel for commuters and freight companies alike.

As the nation’s largest highway network and an essential factor in the state’s economic vitality, the Texas highway network has been especially vulnerable to the impact of traffic congestion. Over the past five years alone, vehicle traffic has risen by nearly 16%, subjecting many motorists to significant delays caused by a combination of limited roadway capacities and deteriorating pavement conditions. In addressing these issues, the Texas Department of Transportation (TxDOT) has undertaken significant highway-improvement projects in transportation corridors critical for efficient freight movement and connectivity across the state.

THE CHALLENGE

• Grayson County in North Texas lies at the heart of 12 major metropolitan markets and is directly in the path of the rapid expansion of the Dallas-Fort Worth metroplex. To help manage traffic congestion resulting from population growth in the region, TxDOT initiated a major reconstruction of U.S. Highway 75 between the cities of Sherman and Denison. The goal was to improve mobility and freight reliability along this strategically important trucking route that connects Texas with markets nationwide.
• The three-year project involved the addition of main lanes, frontage roads and U-turns, as well as ramps and bridges. It also addressed the dire need for pavement improvements along this 12.7-mile stretch of aging highway. To mitigate gridlock and safety concerns for motorists needing to drive through work zones, the paving plan closed lanes at 7:30 p.m. to remove sections of failed pavement and make full-depth concrete repairs, then reopened the lanes the following morning at 6 a.m.
• Throughout the large-scale pavement-repair work, planning, coordination, production, and performance requirements created challenges that would require an innovative rapid-strength concrete solution, as well as strong collaboration among project partners, to meet the accelerated construction schedule. According to Marc Trevino, project manager for O. Trevino Construction, the team needed an advanced concrete mix that would achieve a high early strength of 1,800 psi within six hours, maintain excellent workability in hot Texas temperatures, and achieve an ultimate strength of 4,000 psi at 28 days.

THE SOLUTION

• In search of an ideal rapid-strength paving solution, the project team reached out to the ready-mix concrete experts at Holcim. “The company’s excellent reputation, knowledge, and experience in meeting TxDOT’s speed of construction and high-quality pavement requirements clearly ranked them as our partner of choice for this demanding job,” said Trevino.
• To ensure a quick turnaround and increased job-site efficiency, the team relied on RAPIDFORCE six-hour high-early-strength concrete for the pavement upgrades. This state-of-the-art concrete technology developed by Holcim attains extremely high mechanical resistance soon after pouring and achieves a high ultimate strength, for a very durable highway pavement.
• “The effect of high temperatures on the setting time of concrete is a concern on Texas job-sites, due to the reduced time in which the material must be placed, consolidated, and finished,” explained Brad McFarland, performance manager at Holcim. “Based on our detailed approach to designing RAPIDFORCE mixes, the concrete can be transported, handled, and easily placed for up to two hours in any climate condition, without its workability being affected.”
• For the U.S. Highway 75 project, materials needed to meet TxDOT’s stringent quality and performance standards. Upon successful completion of local raw material assessments and testing by Holcim, the team locked in and used a custom RAPIDFORCE concrete mix for achieving the strength and workability characteristics required by TxDOT and the work crews.

THE RESULTS

• Over the three-year life of the project, Holcim produced and supplied 2,500 cubic yards of RAPIDFORCE concrete. The paving work was completed successfully and ahead of schedule.
• Depending on weather conditions, the team adjusted the concrete mix daily, ensuring a high degree of consistency and reliability. “The quality of the RAPIDFORCE concrete from batch to batch was excellent and kept our work crews very productive,” said Javier Ramirez, project supervisor for O. Trevino Construction. “With the mix retaining its slump for up to two hours, we could all see a big difference in workability, and we consistently surpassed the six-hour high early strength needed to reopen the work zone to traffic.”
• Upon the completion of the Grayson County paving project, O. Trevino Construction was awarded a new TxDOT contract for full-depth concrete repairs on the stretch of U.S. Highway 75 extending from the Collin-Grayson County line northward to the Oklahoma state line. The team on this project is relying on 1,800 cubic yards of the six-hour RAPIDFORCE high early-strength concrete to keep the job moving on a schedule that, like the preceding project, requires all pavement repair work to be performed during the evening and early-morning hours.
• “Thanks to the outstanding performance of RAPIDFORCE high-early-strength concrete, as well as Holcim’s customer service and reliable supply, we are on track to complete this new paving project in about 70% of the time allotted by TxDOT and move on to our next job,” said Trevino.