超高性能纖維混凝土於非韌性柱包覆補強工法之有效性

EFFECTIVENESS OF ULTRA-HIGH PERFORMANCE CONCRETE JACKETING FOR RETROFITTING NON-DUCTILE RC COLUMNS

洪崇展(Chung-Chan Hung) ； 郭家維(Chia-Wei Kuo) ； 黃丞毅(Cheng-I Huang)

《中國土木水利工程學刊》 32卷8期 (2020/12) Pp. 693-699

https://doi.org/10.6652/JoCICHE.202012_32(8).0003

摘要

超高性能纖維混凝土（Ultra-High Performance Concrete，簡稱UHPC）具超高抗壓及抗拉強度，其內含之短纖維可有效強化受拉與受壓韌性，提升開裂強度與控制裂縫發展，並改善傳統混凝土脆性剝落問題。本研究調查UHPC於非韌性鋼筋混凝土柱構件擴柱補強之有效性，除了利用UHPC有效縮減補強構件所需放大之橫向截斷面，並進一步探討使用UHPC進行包覆補強工法時，對於構件變形容量與耐震性能之效益。研究方法採用柱構件之反覆側推載重實驗，實驗參數包含柱所受之軸力大小、場鑄式補強工法與預鑄式補強工法、以及UHPC是否內含鋼筋網。結果顯示，利用UHPC補強之柱構件試體，無論是否內含鋼筋網或不同之補強工法，均可在維持與原柱相同橫向尺寸的條件下，有效提升非韌性柱之耐震性能，尤以UHPC搭配鋼筋網進行補強最為優異，其極限側向強度可提升45%，且韌性亦可提升60%。

關鍵字

鋼筋混凝土柱 ； 補強 ； 剪力強度 ； 超高性能纖維混凝土

並列摘要

Ultra-High Performance Concrete (UHPC) is an innovative construction material. It features ultra-high compressive and tensile strengths in conjunction with crack width control ability. This study aimed to investigate the performance of UHPC jacketing for retrofitting shear-deficient reinforced concrete (RC) columns. A number of non-ductile RC columns were built, retrofitted, and experimentally tested under displacement reversals. The experimental variables included the construction approach (i.e., cast-in-place and precast UHPC jackets), axial demand of the columns, and use of steel mesh. The retrofitted columns were designed to have the same dimensions as the original non-ductile column due to the ultra-high strengths of UHPC. Their seismic performance was experimentally evaluated by tests with pseudo-static displacement reversals. The test results demonstrated that it is effective to apply UHPC jacketing for enhancing the seismic-resistant performance of non-ductile RC columns regardless of the construction method and the use of steel mesh. The failure pattern, strength, stiffness, and load versus displacement characteristics of the original column were enhanced substantially.

並列關鍵字

RC columns ； retrofit ； shear strength ； UHPC jacketing