Thermal Integrity Profiling Accelerates Construction of Railroad Projects
(Room Sagamore 2)
19 Sep 17
2:30 PM
-
3:00 PM
Tracks:
AREMA Full Schedule, AREMA Technical Sessions- Structures
Railroad bridge projects are often subject to demanding schedules with limited outage windows. Cross-hole Sonic Logging (CSL) is the most common test method to assess the integrity of drilled shafts. However, the minimum age for testing is three days per ASTM recommendations, and generally five to seven days for larger shafts. Thermal Integrity Profiling (TIP) is a non-destructive testing technology that utilizes the temperature generated by curing cement (hydration energy) to assess the quality of cast in place concrete foundations. The results can be analyzed once the shaft reaches peak temperature, generally one or two days after placement. The temperature measurements, along with placed volume and installation details, are used to model the effective shaft radius, shaft shape, and concrete coverage beyond the reinforcing cage. The alignment of reinforcing cage can also be evaluated. On two recently completed railroad projects CSL testing was specified and replaced by TIP testing in order to meet rigid construction schedules. Both satisfactory and anomalous shafts were observed. For both projects the preliminary results were quickly relayed to the client and a full report was submitted two to three days after placement, sooner than CSL field testing could be performed. Construction of the piers or remediation of the shafts continued on an accelerated schedule. Results from both projects are presented along with case histories from various projects where defects were detected by TIP and confirmed via exploratory coring.