Projects and Solutions

By: Matthew W. Singel, P.E.

A city of 93,000 people in West Texas, San Angelo is not immune to the challenging street maintenance decisions that communities face.  In recent years, the City’s maintenance program consisted of ongoing crack sealing and an annual sealcoat program operating on a 24-year cycle.  Recognizing the dwindling street maintenance and reconstruction budgets along with limited personnel and aging equipment, San Angelo looked to roller compacted concrete pavement (RCC) for a long-term pavement solution.

Street Construction a Top Priority

“The City Council of San Angelo feels strongly about all the capital project needs throughout the organization.  However, street reconstruction and stormwater projects have been identified as top priorities at this time,” states Clinton Bailey, San Angelo City Engineer.  A rolling 5-year capital improvement plan (CIP), launched in 2010, set out to identify and examine current and future infrastructure needs while minimizing financial impact on residents.  Additionally, the CIP program strives to maximize the useful life of capital investments by scheduling major projects at the optimum time in a facility’s life cycle. 

RCC Chosen for Long Life, Low Cost

The majority of San Angelo's heavily travelled roadways are in poor condition, making pavement reconstruction necessary to break the cycle of declining road quality.  Bailey’s team looked at options based on both long term life-cycle costs and initial capital expenditures.  A local contractor, Reece Albert, Inc., introduced RCC pavement as an alternative that offers fast placement and attractive initial costs coupled with long-term performance.  An asphalt-type paver fit with a high-density screed, and steel-wheeled vibratory rollers place and compact this stiff-mix concrete pavement.  “Reece Albert is always investigating construction technologies that offer value to our clients.  Our reputation and future success depends on it.  We are confident that RCC pavement adds another viable option to meet our clients’ needs”, states Lon Albert, vice president. 

After investigating roller compacted concrete, the City decided to advertise a project using RCC pavement on a cement and lime stabilized subgrade, as an alternate to the typical hot mix asphalt and dense-graded aggregate (flexbase) pavement section.   When asked about specifying RCC, Bailey noted that “with so many roadway infrastructure issues to deal with and a dwindling maintenance program in place, a long term/low maintenance option was the only option for San Angelo.”

Grape Creek Road was let as the first alternate bid project using RCC.  Adjacent to the San Angelo Coliseum and Fair Grounds, RCC pavement will support traffic for San Angelo’s Annual Stock Show and Rodeo and many other events.

When the bids were reviewed, Bailey was impressed with RCC's attractive bid price and recommended that option for award by the City Council.   Quick to applaud their vision, Reece Albert’s Chris Cornell shared, “Knowing the infrastructure challenges we face in San Angelo, I am pleased that Clinton Bailey and the City Council are taking a significant step to reduce pavement maintenance in the future.”

Cement/Lime Stabilized Subgade Aids Constructability

In preparation for the concrete pavement, the subgrade soils were stabilized with lime and cement to insure the proper support on which to place the RCC pavement.  “A stiff subgrade or subbase layer allows us every opportunity to achieve RCC’s average 98% of optimum density”, states Cornell.  “Achieving a high density is critical to achieving the specified compressive strength and performance over time.”

With the pugmill and paver on site, RCC placement began in mid-October, 2011.  Placed and compacted to 6 inches thick, the 15,000+ square yard project took 5 days of actual paving to complete.  After compaction, a concrete curing compound was immediately applied to maintain the internal moisture that all concrete requires to build strength.  Within two hours, joints were cut using an early entry saw. Within a few days, Grape Creek Road was back in use by the citizens of San Angelo. 

Low Maintenance of RCC is Key

Reflecting on the decision to use RCC pavement, Bailey says, “Building new streets with RCC construction, we are not adding much to our overall maintenance effort; for streets that are reconstructed using RCC, we are basically able to take them off of our maintenance schedule.”  Refusing to rest on the success of Grape Creek Road, the City began working toward its next RCC pavement project for the 2012 construction season.

“RCC pavement is a very good solution for a low-maintenance, sustainable transportation infrastructure,” says Lon Albert.  “San Angelo is implementing a vision that will pay dividends for future generations.  Reece Albert, Inc., will proudly be there to support the community’s needs.”

Click here for more pictures of the Grape Creek Road project.