Estimation of internal corrosion degree of reinforcement in concrete using 3D meso-scale simulation

2020 Fiscal Year Final Research Report

• Project/Area Number: 18KK0399
• Research Category: Fund for the Promotion of Joint International Research (Fostering Joint International Research (A))
• Allocation Type: Multi-year Fund
• Research Field: Civil engineering materials/Construction/Construction management
• Research Institution: The University of Tokyo
• Principal Investigator: NAGAI Kohei 東京大学, 生産技術研究所, 准教授 (00451790)
• Project Period (FY): 2018 – 2020
• Keywords: コンクリート / 鉄筋腐食 / 内部推定 / 微細構造解析

Outline of Final Research Achievements

We have developed a simulation system for estimating the levels of internal corrosion along the reinforcing bar length from surface crack information. This innovative system is produced by integrating the technique of Model Predictive Control (MPC) with Rigid-Body-Spring Models (RBSM) of corrosion-induced cracking at the concrete meso-scale. MPC controls the simulated surface cracks such that they match the observed cracks by optimizing the internal expansions of springs representing the steel-concrete interface within the RBSM. The applicability of the system is verified using both synthetic crack width data and crack data collected from in-house laboratory testing. In the laboratory testing, corrosion levels were quantified by 3D scanning of the extracted reinforcing bars. The simulation results agree with the corrosion measurements, demonstrating the potential of the MPC-RBSM system for predicting the corrosion distribution along reinforcing bars using surface crack data.

Free Research Field

土木工学

Academic Significance and Societal Importance of the Research Achievements

インフラ構造物の劣化が社会的な問題にもなっており、その主たる劣化要因である鉄筋コンクリート構造物の腐食は、外観からは内部腐食状況が把握できないために、合理的な構造性能推定や維持管理ができていない。本研究は、数値解析を用いて表面のコンクリートひび割れ情報から内部の鉄筋腐食分を推定するものであり、この手法を発展させ実構造物に適用できれば有用性は非常に高い。学術的にも研究代表者の独自の三次元微細構造解析に新しいアルゴリズムを取り入れた新規性の高い研究である。