Thermal Integrity Profiling for Detecting Flaws in Drilled Shafts [Final Report]
-
2018-12-01
Details:
-
Creators:
-
Corporate Creators:
-
Corporate Contributors:
-
Subject/TRT Terms:
-
Publication/ Report Number:
-
Resource Type:
-
Geographical Coverage:
-
Edition:Final Report, November 2016- December 2018
-
Corporate Publisher:
-
Abstract:Thermal Integrity Profiling (TIP) methods for evaluating drilled shaft concrete integrity have emerged in recent years as a viable alternative to Crosshole Sonic Logging (CSL) methods. TIP methods use measurements of concrete temperatures along the length of the drilled shaft reinforcing cage to identify potential defect locations from zones of low temperature. TIP methods are appealing because they should be sensitive to defects outside the reinforcing cage, an area not evaluated with CSL. To evaluate the ability to detect defects with TIP methods compared with CSL methods, three 4 ft diameter by 30 ft long drilled shafts with ten intentional defects were installed in Waukesha, Wisconsin. The defects varied in location, size, and material. TIP and CSL tests were performed on all three shafts. The results revealed TIP and CSL to be complementary. Each test is particularly well-suited to identifying certain types of defects but limited or incapable of identifying other types of defects. The alignment of detection abilities attributed to each method is such that virtually any significant defect should be detectible by one or both tests. The results indicated TIP is effective for identifying defects due to weak concrete and defects outside the reinforcing cage. Smaller temperature decreases were observed for tremie breach defects and inclusions within the reinforcing cage, and no TIP effect could be discerned for soft bottom defects. CSL results were sensitive to defects within the reinforcing cage, including inclusions, tremie breach effects, and soft bottom conditions but not weak concrete. CSL results were also not affected by defects outside the reinforcing cage. TIP measurements indicated significantly greater sensitivity to defects at times corresponding to roughly half the time to peak temperature. Improvements to TIP interpretation methods would likely improve defect detection.
-
Format:
-
Funding:
-
Collection(s):
-
Main Document Checksum:
-
File Type:
Supporting Files
-
No Additional Files
More +