プレキャスト床版接合技術「Head-bar® ジョイント」における接合部の耐力評価
プレキャスト床版接合技術として「Head-bar® ジョイント」があるが，本技術ではプレキャストPC床版の接合部は間詰材により一体化される。ここで，昨今の床版取替工事では間詰材の管理材齢28日を待たずに早期の交通開放が要求される場合があり，早期の交通開放を行うためには間詰材の圧縮強度と接合部耐力の関係をより詳細に把握する必要がある。これより，本研究ではHead-barジョイントの接合部耐力評価を行うため，間詰材の圧縮強度とラップ長を要因にした接合耐力確認実験を実施し，破壊機構に基づく耐力算定式を構築した。その結果，計算値/実験値の比の平均は1.04となり，本手法によって接合部耐力を高い精度で推定できることが確認された。
キーワード：プレキャストPC床版接合部，プレート定着型鉄筋，高強度繊維補強モルタル，耐力式
＊１ 技術センター 社会基盤技術研究部 材工研究室
＊２ 土木本部 土木技術部
Evaluation of Bearing Capacity of Joints in Head-bar Joint Precast Slab Joint Technology
A Head-bar® joint is a precast concrete slab joint integrated with fillers. In recent slab replacement projects, it is sometimes required to open newly placed floor slabs to traffic earlier than the controlled age of 28 days. In order to open the slabs to traffic earlier, it is necessary to understand the relationship between the compressive strength of the fillers and the bearing capacity of the joints in greater detail. Therefore, in order to evaluate the joint strength of Head-bar joints, this study conducted joint strength verification experiments using the compressive strength of the fillers and the lap length as factors and a strength calculation formula based on the failure mechanism. As a result, the average ratio of calculated to experimental values was 1.04, and it was confirmed that the joint bearing capacity can be estimated with high accuracy by the proposed method.
Keywords: precast PC slab joints, plate anchored rebar, high-strength fiber reinforced mortar, bearing capacity formula
*1 Taisei Advanced Center of Technology, Infrastructure Technology Research Department, Structire and Material Research Section
*2 Civil Engineering Division, Civil Engineering Department