外側耐震補強コンクリート接合部のせん断滑り特性に関する実験的研究

Abstract

本研究では、外側耐震補強コンクリート接合部のせん断滑り特性の解明を目的とした基礎的研究として、アンカ一筋によって補強された外側耐震補強コンクリート接合部のせん断滑り特性に及ぼすアンカー筋の埋込み深さ、接合面の目荒らし深さ(接合面の凹凸)、補強部のコンクリート強度の影響について検討を行った。その結果、耐震補強コンクリート接合部のせん断抵抗は、アンカ一筋によるせん断抵抗+接合面の凹凸のかみ合わせによるせん断抵抗で表されること、せん断耐力は、補強部のコンクリート強度に関わらずアンカ一筋の埋込みが深く、接合面の凹凸が著しくなるほど増大すること、接合面に凹凸が無く、補強部のコンクリト強度が小さい試験体は、延性的な荷重滑り量関係を示すこと、などが明らかとなった。

In this study，the effects of the embedded depth of anchor，the unevenness of interface and the concrete strength were investigated as the fundamental research for the purpose of the clarification of shear slip behavior of the placing joint by outside seismic reinforcement. In this experiment，two embedded depths of anchor (the depths are 5d and 10d， in which d is a nominal diameter of anchor)，three unevenness of interface (the 凹凸 slzes are 0，10 and 20 mm) and two water-cement ratios of the reinforcing mortar (the water-cement ratios are 40 and 90 %) were selected as shown in Table 1. the specimen as shown in Fig.1 and the loading apparatus as shown in Fig. 3 were used in this experiment. The results obtained by the experiments can be summarized as follows: 1) the shear resistance of the placing joint reinforced by the anchor can be obtained as the sum of the dowel action by the anchor and the interlocking action caused by the uneven interface. 2) The shear carrying capacity increases with increasing the embedded depth of the anchor and the unevenness of interface of the placing joint，independently of the strength of reinforcing mortar. 3) In the case of the specimen with the flat interface and with the low strength of reinforcing mortar，the ductile load-slip relationship of placing joint can be obtained.