Finite-element analysis method to ensure the safety of invisible capping beams reinforced via the quick-replacement method

Abstract

This paper presents a Finite-Element Analysis (FEA) method to solve the problem of reduced bridge safety due toinsufficient durability of invisible capping beams. To reinforce a C30 invisible capping beam effectively and reasonably, aquick-repair replacement concrete reinforcement method was utilized, and the strength necessary for the appropriate admixtureassessed. Specifically, the bearing capacity of the reinforced capping beam was studied via a single-point loading test, and theoptimal replacement thickness required to install the beam within two days and restore normal operation within three days wasdetermined using the non-linear software package MIDAS FEA. A finite-element model of equivalent size was employed usingMIDAS FEA to obtain the deflection, tensile stress, and pressure stress at the boundary. The results indicate that C40 earlystrength concrete with 0.1–0.2% sodium gluconate admixture has the appropriate properties to achieve the target. It can be usedto replace deteriorated concrete on the surface of invisible capping beams with a replacement rate of 30%. Further, to achievethe goal of resuming traffic within three days, the analysis results indicate that bilateral replacement with thickness 2 × 10 cm isoptimal and the maximum replacement thickness should not exceed 2 × 20 cm.