CTLGroup provided engineering consulting services to the contractor for the tunnel concrete to verify compliance with the contract requirements. Our firm performed a critical review of the project specifications concrete mixture proportions for feasibility, thermal modeling, and mass concrete services.
A design approach review including pumpability, durability, and service life requirements was performed. Fire spalling resistance and extensive testing was carried out to characterize the concrete performance and support the consulting efforts, including fire, durability, and service life.
CTLGroup completed an explosive spalling fire exposure evaluation for large scale concrete panels which would be used in the tunnel liner. The new test method, based on similar European projects, was not within the capabilities of other North American fire laboratories. To meet the requirements, CTLGroup designed, built, and calibrated a fire testing furnace to assess the suitability of proposed tunnel lining concrete. Testing showed that explosive spalling of the concrete during a fire (before the deluge system extinguished the fire) would not jeopardize the safety of the fire respondents or the integrity of the structure.