Impact, Cause, and Remedies for CRC Cracking

In the 1990's, the South Dakota Department of Transportation began a concerted effort to rebuild its aging Interstate highway network. Through analysis of performance and life-cycle cost, continuously reinforced concrete pavement (CRCP) was identified as an alternative of choice for interstate reconstruction in South Dakota. From 1995 to the present, the South Dakota Department of Transportation (SDDOT) has constructed over 250 2-lane miles of CRC interstate highway at an approximate investment approaching $300 million. CRC pavement is designed with substantial reinforcing steel to eliminate the need for transverse joints, which are the primary point of failure on jointed concrete pavement. Instead of joints, CRC exhibits hairline transverse cracks, which normally are spaced at intervals of two to four feet and which are thin enough to resist faulting, spalling, and intrusion of foreign material. However, some recently constructed CRC pavements exhibit cracking that is irregular, with spacing varying from as little as one foot to as much as 10 feet. Some of the cracks appear to be significantly wider than normal, which could allow intrusion of water, chemicals, and other foreign material. Some cracks have begun to deteriorate and spall. Finally, isolated punch-outs-usually located within a single lane and less than 20 feet in length-have appeared on some projects. Several factors could potentially contribute to these problems, including: (1) concrete mix design and composition (2) aggregate type and gradation (3) aggregate thermal expansion coefficients (4) ambient temperature during placement and cure (5) material temperatures at placement (6) reinforcing steel percentage and size (7) reinforcing steel location and lapping (8) slab thickness (9) underlying cushion or pavement layers (10) subgrade or drainage problems (11) paving equipment or operation (12) concrete vibration (13) attack from deicing chemicals (and 14) grade and paving direction The effect of the cracking and distress on long-term pavement life and serviceability is unknown. It is not yet clear whether the problems represent a major structural problem or a relatively minor, cosmetic problem. Whether the cracking and distress will significantly accelerate long-term failure mechanisms, such as steel fatigue, corrosion, or freeze-thaw damage is presently unknown. Research is needed to determine the extent of these problems, assess their impact on pavement performance, investigate their causes, identify ways to preserve existing pavements, and identify how to avoid similar problems in the future. The objectives of this research project are to: (1)  Because the first six tasks of this project will require intensive work best done by Department employees, the technical panel recommends that the work be initiated as an in-house project. If, near the conclusion of the first six tasks, the need for outside expertise becomes evident, the technical panel will recommend shifting later tasks to consultant contract. The Office of Research plans to dedicate approximately one person-year to the entire project to ensure timely completion of this considerable amount of work.Identify factors and interactions among factors that contribute to observed distress; (2) Assess the impact of observed distress on long-term pavement life and performance; (3) Recommend changes to design, specifications, and construction practice to substantially reduce the incidence and severity of distress in CRC pavements; and (4) Recommend cost-effective maintenance and rehabilitation strategies for CRC pavements exhibiting unexpected levels of distress.

Language

  • English

Project

  • Status: Active
  • Funding: $70000.00
  • Contract Numbers:

    SD2004-07

  • Sponsor Organizations:

    South Dakota Department of Transportation

    Transportation Building, 700 E Broadway
    Pierre, SD  United States  57501
  • Project Managers:

    Huft, David

  • Performing Organizations:

    South Dakota Department of Transportation

    Transportation Building, 700 E Broadway
    Pierre, SD  United States  57501
  • Principal Investigators:

    Johnston, Dan

  • Start Date: 20040601
  • Expected Completion Date: 0
  • Actual Completion Date: 20061231
  • Source Data: RiP Project 12582

Subject/Index Terms

Filing Info

  • Accession Number: 01458295
  • Record Type: Research project
  • Source Agency: South Dakota Department of Transportation
  • Contract Numbers: SD2004-07
  • Files: RiP, STATEDOT
  • Created Date: Jan 3 2013 12:39PM