Study on the change of structural property of RC building due to drying

2022 Fiscal Year Final Research Report

• Project/Area Number: 19H00791
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Medium-sized Section 23:Architecture, building engineering, and related fields
• Research Institution: Chubu University
• Principal Investigator: Teshigawara Masaomi 中部大学, 工学部, 教授 (50344007)
• Co-Investigator(Kenkyū-buntansha): 丸山 一平 名古屋大学, 環境学研究科, 教授 (40363030) ; 日比野 陽 名古屋大学, 環境学研究科, 准教授 (50456703) ; 浅井 竜也 名古屋大学, 環境学研究科, 助教 (90815846)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: 鉄筋コンクリート / 乾燥 / 力学特性 / 固有周期 / ひび割れ / 初期剛性 / 降伏点 / 数値解析

Outline of Final Research Achievements

Measurements of half-scale RC three-story frame specimens during the drying process showed that the drying shrinkage strain converged to about 700 μ in the frame specimen where the effect of restraint was relatively small, and to smaller values in specimens where the effect of restraint was present. Comparison of the horizontal force-horizontal displacement relationship of the wet and dry specimens obtained by static loading tests showed that the initial stiffness was almost halved by drying, and the deformation at yield and bearing capacity at yield increased and slightly decreased, respectively. Both hysteric curves gradually approached each other during cyclic loading. The results of the numerical analysis based on RBSM for beam-slab specimens showed that the changes in mechanical properties due to drying were reproduced with high accuracy.

Free Research Field

鉄筋コンクリート構造

Academic Significance and Societal Importance of the Research Achievements

コンクリートの乾燥はRC造建物の経時的な力学特性変化を生じさせ，その変化は建物の耐震安全性を評価する上で重要な地震応答変形量に重大な影響を及ぼしかねない。しかし，その影響に関する定量的なデータの蓄積は極めて乏しく，乾燥による応答変形の変動を陽に評価しない現行の耐震設計法に基づく建物は，想定し得ないリスクを内在している。そのため，本研究において，乾燥がRC造架構の力学特性変化に与える影響を実建物に近い条件で定量に把握するとともに，その影響を高精度に再現可能な数値解析技術を発展させたことは，将来の地震被害に関するより正確な予測の実現に貢献する。