台灣位於板塊交界的地震頻繁帶，許多老舊建築物並不符合新的耐震規範，為了使建築物在強震來臨前後能保有一定的耐震能力，建築物的耐震補強成了重要議題，其中，斜撐補強是在構架間增添斜向構件，以提升構架的側向強度與勁度，此補強方式不需將柱間填滿，所以同時可以保持原有的通風採光。傳統混凝土雖有不錯的抗壓強度，但韌性與裂縫控制能力不佳，因此受反覆載重作用時，容易會造成混凝土剝落、開裂以及壓碎。超高性能混凝土(Ultra-High Performance Concrete, UHPC)不僅具有高抗壓及高抗拉的特性，亦具有良好之變形韌性，藉由內部纖維的橋接效應，能抑制裂縫發展，並有效減緩或避免混凝土剝落與壓碎，因此適合使用於構架中的斜撐，達到良好之耐震提升效果，本研究設計一組鋼筋混凝土構架，對其進行耐震評估，並以評估結果進行超高性能混凝土預鑄斜撐及接合處錨栓設計與檢核，在另一組相同配置下的混凝土構架進行預鑄斜撐補強，並透過兩組試體於反覆側推載重下，探討此種補強工法的有效性。由實驗結果得知，超高性能混凝土預鑄斜撐大幅提升構架的側向強度與勁度，並在失去側向強度貢獻前，有效維持柱體的完整性，使斜撐破壞後，構架仍可維持與空構架尖峰強度相近之側向強度。

Taiwan is located in the frequent earthquake zone. Many old buildings do not reach the new earthquake resistance standards. In order to ensure that the buildings can maintain a certain earthquake resistance before and after strong earthquakes, the seismic reinforcement of buildings has become an important issue. Brace is to add diagonal members between the frames to improve the lateral strength and stiffness of the frames. Although nomal concrete has great compressive strength, its toughness and crack control ability are not ideal. Therefore, when subjected to cyclic loads, it is easy to cause concrete to flake, crack and crush. Ultra High Performance Concrete (UHPC) not only has high compressive strength and high tensile properties, but also has good deformation toughness. With the bridging effect of fiber, it could inhibit the development of cracks and effectively slow or avoid that concrete flake and crush, so it is suitable for diagonal bracing in the frame to achieve a good seismic improvement effect. In this study, there are two RC frames, one is unretrofit frame and the other is UHPC brace retrofit frame. Due to test result, UHPC brace greatly improves the lateral strength and stiffness of the frame, and effectively maintains the integrity of the column before losing the contribution of the lateral strength. After UHPC brace is damaged, the frame can maintain the lateral strength whitch is close to the peak strength of the unretrofit frame.

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