Introduction

Roller-compacted concrete (RCC) as a paved surface offers facility owners and pavement designers a concrete pavement alternative that may better meet the requirements of specific pavement projects than conventionally cast-in-place concrete pavements. RCC pavement applications can be tailored to the specific needs of a project, particularly those associated with roadway projects within the residential, commercial, and urban roadway sectors. RCC pavement has been used in the following applications:

• Heavy-duty applications
  • Ports and airports
  • Military installations
  • Intermodal facilities
• Light commercial industrial applications
  
  • Warehouses and manufacturing facilities
  • Commercial and industrial parking lots
  • Maintenance and storage yards
• Roadway applications
  
  • Highway frontage roads and shoulders
  • Minor arterials
  • City streets and local roads

An important benefit of RCC is its cost-effectiveness and ease of construction. RCC pavement essentially mirrors a conventional portland cement concrete (PCC) pavement in terms of joint spacing and design thickness. However, RCC is engineered and constructed differently than conventional concrete, involving different placement and design considerations even though the concrete mixture is made of the same constituent materials. Some of the differences include the following [1]:

• RCC is placed with asphalt-type pavers, not with the typical slip-form concrete paving machines or vibrating screeds.
• RCC mixtures require compaction with the use of vibratory, tamper bar screeds, and typically but not always with either static or vibratory rollers to achieve a target density. RCC does not involve the use of internal vibration that typically is used to consolidate concrete used in conventional paving operations.
• RCC mixtures have “negative” slump. Any slump in an RCC mixture is too much.Conventional concrete paving mixture soften involve a slump between 1 and 4 inches, depending on placement method.
• RCC mixtures require a different type of mixing than conventional concrete mixtures. RCC mixtures are most efficiently produced in horizontal, twin-shaft mixing chambers in a continuous or batch fashion.
• RCC mixtures are relatively dry and depend on the inherent stiffness in the plastic state to support the paver screed and rollers during placement and compaction operations. As a consequence, RCC pavements typically have been finished with rolling to achieve the specified density.Recently, admixtures have been developed and introduced into the market which allow for a broom finish. These technologies are reducing the occurrence of inconsistencies including minor surface tearing, checking,pitting, or even pockmarks. Alternately,diamond grinding can be used to achieve a specified level of smoothness and adequate surface friction.
• RCC mixtures have suffered only minor spalling distress under freeze/thaw action and typically are not susceptible to freeze/thaw damage. Therefore, air entrainment typically is not required in RCC mixtures.
• Historically, transverse joints have not been sawcut in RCC pavement. However,recently this practice has been changing.
• RCC is not reinforced, and dowel bars are not used at joints (except in transition areas)to supplement the transfer of load. The load transfer along the transverse cracks provided through aggregate interlock, in conjunction with good frictional resistance along the subbase interface, is sufficient to assure long-term joint/crack performance.