Study of the Hydration Temperature Field in the Hinge Seal Layer for a Large-Volume UHPC Arch Base

Abstract

For large arch bridges, the sealing hinge layer at the arch footing is critical to the long-term performance and durability of the structure. This study investigated the temperature distribution of the sealing hinge layer inside a large UHPC arch seat during the hydration process in a natural environment, based on a design of a 600-m-span reinforced concrete rigid skeleton arch bridge. A certain suggestion for the design of a large-volume UHPC layer was proposed through the consideration of temperature and age effects of the thermal field solid finite element analysis of early-age UHPC hydration heat. The results show that UHPC has a hydration induction period of 10 h and reaches the peak temperature of 69°C in 20 h. Then, the hydration heat is gradually released in 70 h after pouring. The maximum temperature difference between the core and surface reaches 40°C. The results also show that the early temperature field and heat release rate of UHPC are affected by initial temperature. The actual heat release of some materials of UHPC components at 75 h is equivalent to that at 300 h, and the minimum effective age was found close to 100 h, where the heat release reaches 0.25 of the total heat release. A simplified algorithm for the spatially time-varying non-linear temperature field of the UHPC sealing hinge layer under the influence of temperature and age is proposed, which provides a simple calculation method for the temperature control of the UHPC arch seat during the hydration process in real projects.