Research on the Durability of Composite Pile Made of Ultra-High-Performance and Common Concrete: Finite Element Analysis

Abstract

The paper is to study the durability of transmission tower foundation using a combination of ultra-high performance concrete (UHPC) and common concrete (NC) in salinealkali region. The composite pile is made of outer UHPC sleeve and core ordinary concrete. Due to the excellent durability of UHPC, the outer UHPC sleeve can prevent chloride ion and sulfate ion corrosion as well as save cost. Computer research technology was used to construct a corresponding natural environment for artificial simulation, hence accelerate the experimental test of the natural environment. It can more directly and effectively reflect the durability problems of the actual projects. This paper follows the application of classical similarity theorem of UHPC-NC foundation under saline-alkali erosive environment in Gansu, concrete test beams with the same material composition and structural characteristics were poured, an accelerated artificial simulation was designed. Results on the finite element simulation revealed that the outer wrapped ring of UHPC can effectively block the transmission of chloride ions from the external environment to the center of the cross-section. Under the same environment and operation time, the penetration depth of chloride ion in UHPC-NC combined cross-section is much smaller than that in pure normal concrete cross-sections. Therefore, it can be seen that the UHPC-NC combined cross-section can prevent the penetration of chloride ions in a saline-alkali environment, thereby effectively improving the durability of the transmission structure foundation, and hence ensuring the safety and applicability of electricity transmission structure during operation phase.