方形New RC柱受一般強度橫向鋼筋圍束作用下之應力應變曲線模式

Abstract

高樓建築已逐漸成為都會區中的新興趨勢，位於高層結構物底層之柱構件所承受之垂直載重甚高，使用新型高強度強度鋼筋混凝土，其強度較高，設計時無須大幅擴增柱構件斷面，可減少材料用量與成本，增加建築物室內使用空間。 目前國內高強度鋼筋混凝土之相關研究皆為構件層級行為研究，尚缺乏材料層級之應力與應變關係研究，而此關係乃結構設計之根本。因此，本研究依據美國、加拿大與紐西蘭等國家規範設計，並利用本土化的材料與施工方式、設計上常用之箍筋間距及實務上常用的橫向鋼筋配置，包括箍筋間距、彎鉤形式、彎鉤彎轉半徑及伸展長度，變更柱構件之橫向鋼筋提供量，改變箍筋間距與繫筋配置等條件設計八組柱試體，試驗其受同心軸向壓力作用下之行為，透過試驗將圍束效應對柱構件之影響量化比較，檢核配置不同橫向鋼筋量情況下之柱構件韌性行為，並參考現有之應力應變曲線預測模型，對相關控制參數進行迴歸分析，建立本土化柱構件核心混凝土之應力與應變關係曲線預測模型，以供使用高強度鋼筋混凝土之結構設計時分析使用。

Nowadays, high-rise buildings have gradually become a new trend in metropolitan areas. In light of the fact that column members placed below high-rise constructions bear relatively high vertical loads, the application of New RC with its high strength as well as the design without expanding cross-section of column members not only reduce material usage and costs but also increase interior space in a building. Currently, national studies related to New RC was conducted on the behavior of element levels, and little attention has been given to investigation into the relationship between stress and strain of material levels. In addition, several recognized studies in the field of civil engineering across the world are mostly focused on basic research on materials. As a result, based on regulati contextons from the U.S., Canada and New Zealand to name a few, this study utilized local materials and construction approaches with spacing of stirrup in the design and lateral reinforcement in the practice. This included spacing of stirrup, forms of hooks, flexural radius, and development length. By controlling spacing of stirrup and design of tie bar to alter the provided quantity of lateral reinforcement of column members, eight sets of column specimen were created and tested on their behaviors under concentric compression. This experiment aimed to compare the quantitative outcomes of the influence of confined effectiveness on column members, and subsequently to examine the toughness behavior of column members under circumstances of different lateral reinforcement. During the examination, the researcher also performed regression analysis on related control parameters referring to current predictive model of stress and strain. The purpose of this paper is to build a local predictive model of stress and strain for concrete core of column members for future analysis of structural design of New RC.