Launch Slideshow

Placement begins. The mixture is spread along the straight edge that was prepared earlier. Note that the RCC is placed about 2 inches thicker than the material from yesterday so that it can be compacted that amount to end up at the same elevation.

Suburb self performs RCC

Suburb self performs RCC

  • Next step: compacting the new RCC to the same thickness as the previously placed material. Four passes with a 10-ton Ingersoll Rand DD-90; two with vibration, two without. Prairie Material uses ASTMs D1557 modified Proctor test on both mix design and materials to determine optimum moisture and density.

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    Next step: compacting the new RCC to the same thickness as the previously placed material. Four passes with a 10-ton Ingersoll Rand DD-90; two with vibration, two without. Prairie Material uses ASTMs D1557 modified Proctor test on both mix design and materials to determine optimum moisture and density.

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    PW Staff

    Next step: compacting the new RCC to the same thickness as the previously placed material. Four passes with a 10-ton Ingersoll Rand DD-90; two with vibration, two without. Prairie Material uses ASTM’s D1557 modified Proctor test on both mix design and materials to determine optimum moisture and density.
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    PCA/Wayne Adaska

    Reflective transverse crack through asphalt surface.
  • Prairie Material of Bridgeview, Ill., delivers the mix  400 pounds of cement and 125 pounds of fly ash with BASF Construction Chemicals Delvo hydration stabilizer  to a Blaw-Knox asphalt paver. The mixture reaches 6,000 to 10,000 psi at 28 days. Materials producers are getting better and better at producing a mix that wont fail, says Public Works Director Matt Mann. The reason: Theyre using a new type of equipment  ribbon mixers -- instead of pug mills.

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    Prairie Material of Bridgeview, Ill., delivers the mix 400 pounds of cement and 125 pounds of fly ash with BASF Construction Chemicals Delvo hydration stabilizer to a Blaw-Knox asphalt paver. The mixture reaches 6,000 to 10,000 psi at 28 days. Materials producers are getting better and better at producing a mix that wont fail, says Public Works Director Matt Mann. The reason: Theyre using a new type of equipment ribbon mixers -- instead of pug mills.

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    PW Staff

    Prairie Material of Bridgeview, Ill., delivers the mix – 400 pounds of cement and 125 pounds of fly ash with BASF Construction Chemicals’ Delvo hydration stabilizer – to a Blaw-Knox asphalt paver. The mixture reaches 6,000 to 10,000 psi at 28 days. “Materials producers are getting better and better at producing a mix that won’t fail,” says Public Works Director Matt Mann. The reason: They’re using a new type of equipment – ribbon mixers -- instead of pug mills.
  • Tim Dunne from materials consulting firm Rubino Engineering Inc. of Elgin, Ill., uses a Troxler 3430 surface moisture density gauge to test the pavement. He says theyve been getting better than the required 98% density.

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    Tim Dunne from materials consulting firm Rubino Engineering Inc. of Elgin, Ill., uses a Troxler 3430 surface moisture density gauge to test the pavement. He says theyve been getting better than the required 98% density.

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    PW Staff

    Tim Dunne from materials consulting firm Rubino Engineering Inc. of Elgin, Ill., uses a Troxler 3430 surface moisture density gauge to test the pavement. He says “they’ve been getting better” than the required 98% density.
  • Feathered edges create a weak joint, so a wheel loader cuts a straight edge between one stretch of RCC and the next, ensures concrete on both sides of the joint is full thickness and properly compacted.

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    Feathered edges create a weak joint, so a wheel loader cuts a straight edge between one stretch of RCC and the next, ensures concrete on both sides of the joint is full thickness and properly compacted.

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    PW Staff

    Feathered edges create a weak joint, so a wheel loader cuts a straight edge between one stretch of RCC and the next, ensures concrete on both sides of the joint is full thickness and properly compacted.
  • A public works crew uses asphalt paving equipment to rebuild residential streets using roller-compacted concrete (RCC), a process theyve perfected over the last five years.

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    A public works crew uses asphalt paving equipment to rebuild residential streets using roller-compacted concrete (RCC), a process theyve perfected over the last five years.

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    PCA/Wayne Adaska

    A public works crew uses asphalt paving equipment to rebuild residential streets using roller-compacted concrete (RCC), a process they’ve perfected over the last five years.
  • A crew member sprays a mixture of water and BASFs Confilm along the edge to keep it moist until the adjacent lane can be placed.

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    A crew member sprays a mixture of water and BASFs Confilm along the edge to keep it moist until the adjacent lane can be placed.

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    PW Staff

    A crew member sprays a mixture of water and BASF’s Confilm along the edge to keep it moist until the adjacent lane can be placed.
  • Placement begins. The mixture is spread along the straight edge that was prepared earlier. Note that the RCC is placed about 2 inches thicker than the material from yesterday so that it can be compacted that amount to end up at the same elevation.

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    Placement begins. The mixture is spread along the straight edge that was prepared earlier. Note that the RCC is placed about 2 inches thicker than the material from yesterday so that it can be compacted that amount to end up at the same elevation.

    600

    PW Staff

    Placement begins. The mixture is spread along the straight edge that was prepared earlier. Note that the RCC is placed about 2 inches thicker than the material from yesterday so that it can be compacted that amount to end up at the same elevation.
  • After testing RCC in a heavy equipment parking area, the Illinois public works department now rebuilds at least one residential street a year using 6 inches of RCC topped with 2 inches of asphalt.

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    After testing RCC in a heavy equipment parking area, the Illinois public works department now rebuilds at least one residential street a year using 6 inches of RCC topped with 2 inches of asphalt.

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    PCA/Wayne Adaska

    After testing RCC in a heavy equipment parking area, the Illinois public works department now rebuilds at least one residential street a year using 6 inches of RCC topped with 2 inches of asphalt.
 

Keeping the bean counters happy

On Edgewood Drive, the village saved more than $24,000 in material costs by replacing the old pavement (6 inches of asphalt over a 6-inch stone base) with RCC. The new pavement is 4 inches stone, 6 inches RCC ($58,400) topped with a 2-inch hot-mix asphalt overlay ($23,800). Saw cutting and control joint sealing are contracted out ($3,800), for a project total of $86,000. By comparison, new asphalt streets are required to have a 7-inch hot-mix asphalt base, 1.5-inch binder, and 1.5-inch surface layer for a total of $110,400.

“After seeing the money we’ve been able to save by using material that’s equivalent or maybe superior quality to what we’ve done before,” says Mann, “the board and mayor keep asking ‘Where else can we use this?’” So far the village has reconstructed one residential street a year, but Mann wouldn’t hesitate to use RCC on any village street if the need arises.

What began as an experiment to save money has become an investment in the long-term quality of Streamwood’s streets. Adaska applauds the department’s efforts, adding, “Unfortunately, many cities are still building thin, inadequate streets, but Streamwood is investing in the longevity of its roads by building strong and durable pavement.”

Due to the rapid growth of RCC and increasing interest from public agencies, the newly created RCC Pavements Promotional and Research Council was formed in January 2014. The council is composed of contractors, equipment manufacturers, materials suppliers, and concrete producers. Its goal is to provide education, marketing, and research on RCC to improve and expand its uses. Public works officials interested in learning more about this group should contact Wayne Adaska (wadaska@cement.org).

For information on RCC, contact: Matt Mann (mmann@streamwood.org), Randell Riley (pccman@ilacpa.com), and Theron Tobolski (tgtobolski@prairie.com).

Shelby O. Mitchell is a Berwyn, Ill.-based editor and freelance writer, and a former senior editor of PW. E-mail shelbyo.mitchell@gmail.com.