BDI’s services were requested to perform a nondestructive evaluation (NDE) and life cycle analysis of a Culvert with the objective of extending the life span of the structure. In coordination with CH2M, BDI developed and implemented a comprehensive NDE testing plan to better evaluate the culvert. Throughout its life, the culvert has been subjected to multiple environmental conditions that have led to chloride ingression through the soil above it and into its roof and ceiling. To determine the levels of chlorides in the material, and also identify if corrosion based degradation was occurring. BDI developed a testing program that involved a thorough visual inspection with acoustic sounding to evaluate the concrete for deterioration, ground penetrating radar (GPR), to evaluate both the concrete and the reinforcement, and half-cell potential (HCP) and chloride ion penetration tests to evaluate the level and potential for reinforcement corrosion. In addition to these tests, three cores were taken for petrographic and compressive strength tests. Incorporating all measured physical properties, BDI was able to determine the remaining life of the structure assuming several corrosion mitigation strategies. This allowed the owner to comprehensively manage its asset and install the most appropriate chloride mitigation system.
- Cost Control – BDI was able to complete the project with the assigned budget despite needing to rent additional equipment for the inspection. Efficient field inspection allowed for a savings in overall cost.
- Schedule Control – Despite water running in the culvert during the inspection (it was supposed to be dry), BDI performed the inspection in waders to ensure the original project schedule would be satisfied.
- Quality – BDI cross checked their NDE results with results from petrography to ensure appropriate correlation factors were put into place prior to developing the service life model. This ensured that the cover depth of the rebar was taken into account when calculating the probability of corrosive activity measured with half-cell potential.