Jump to content

英文维基 | 中文维基 | 日文维基 | 草榴社区

Thermal integrity profiling

From Wikipedia, the free encyclopedia

Thermal Integrity Profiling (TIP) is a non-destructive testing method used to evaluate the integrity of concrete foundations. It is standardized by ASTM D7949 - Standard Test Methods for Thermal Integrity Profiling of Concrete Deep Foundations.

The testing method was first developed in the mid 1990s at the University of South Florida.[1][2] It relates the heat generated by curing of cement to the integrity and quality of drilled shafts, augered cast in place (ACIP) piles and other concrete foundations. In general, a shortage of competent concrete (necks or inclusions) is registered by relative cool regions; the presence of extra concrete (over-pour bulging into soft soil strata) is registered by relative warm regions.

Concrete temperatures along the length of the foundation element are sampled throughout the concrete hydration process.[3] TIP analysis is performed at the point of peak temperature, generally 18 to 24hrs post-concreting.[4] Measurements are available relatively soon after pouring (6 to 72 hours), generally before other integrity testing methods such as cross hole sonic logging and low strain integrity testing can be performed.

TIP can be performed using a probe lowered down standard access tubes or by installing embedded thermal wires along the length of the reinforcement cage.[4] Four thermal wires are commonly installed along the steel cage, each 90 degrees from one another, forming a north-east-south-west configuration. If records at a certain depth show regions with cooler temperatures (when compared to the average temperature at that depth), a concrete deficiency or defect may be present. An average temperature at a certain depth that is significantly lower than the average temperatures at other depths may also be indication of a potential problem. It is also possible to estimate the effective area of the foundation, and to assess if the reinforcing cage is properly aligned and centered.[5]

References

[edit]
  1. ^ Mullins, G., Piscsalko, G., May/June 2012. Thermal Integrity Profiling: An Innovative Technique for Drilled Shafts.
  2. ^ Mullins, G., Kranc, S., May 2007. Thermal Integrity Testing of Drilled Shafts. Final Report Submitted to Florida Department of Transportation, Project BD544-20: Tampa, FL.
  3. ^ Piscsalko, G., Cotton, D., October 2011. Non-Destructive Testing Methods for Drilled Shaft and ACIP Piles. Proceedings from Deep Foundations Institute 36th Annual Conference on Deep Foundations: Boston, MA; 252-532.
  4. ^ a b Mullins, G., December 2010. Thermal Integrity Profiling of Drilled Shafts. The Journal of the Deep Foundations Institute: Tampa, FL.
  5. ^ Sellountou, A., Alvarez, C., Rausche, F., April 2013. Thermal Integrity Profiling: A Recent Technological Advancement in Integrity Evaluation of Concrete Piles. Proceedings from the First International Conference, Seminar on Deep Foundations: Santa Cruz, Bolivia.