高強度混凝土含開孔深梁之修復

REPAIRING OF HIGH-STRENGTH CONCRETE DEEP BEAMS WITH WEB OPENINGS

呂文堯(Wen-Yao Lu) ； 李岱融(Tai-Jung Lee) ； 陳鼎周(Ting-Chou Chen) ； 林敏哲(Ming-Che Lin)

《技術學刊》 32卷2期 (2017/06) Pp. 127-138

摘要

本研究旨在以貼碳纖維 (CFRP) 或低壓灌注環氧樹脂 (LPEI) 方式修復含開孔深梁。共製作18 支含開孔深梁進行兩次剪力強度試驗，第1 次試驗中，6 支控制梁不含CFRP，其餘12 支梁在試體兩面包覆兩層寬度40 mm 之CFRP，6 支沿水平方向補強，另6 支沿垂直方向補強。第1 次試驗結果顯示，開孔尺寸60  40 mm 深梁之剪力強度較開孔尺寸68  68 mm 之剪力強度高出17%。水平方向包覆碳纖維之試體，其平均約可提升6% 之剪力強度，垂直方向包覆碳纖維之試體，則平均約可提升8% 之剪力強度。本研究於第1 次試驗後，選取12 支剪力破壞之含開孔深梁，6 支控制梁於正反面各貼1 層CFRP，另6 支則以LPEI 修復並再次進行試驗，比較兩次試驗結果得知，以LPEI 修復之試體平均可提升18% 剪力強度，而以貼1 層CFRP 方式修復剪力破壞之含開孔深梁應仍屬可行。

關鍵字

深梁 ； 梁腹開孔 ； 剪力強度 ； 碳纖維 ； 低壓灌注環氧樹脂

並列摘要

The objective of this study was to investigate the repairing effectiveness of carbon fiber reinforced polymer (CFRP) or low pressure epoxy injection (LPEI) on the deep beams with web openings. A total of 18 high-strength concrete deep beams with web openings were tested. Six controlled beams were not strengthened by CFRP; twelve beams were wrapped with two layers of 40 mm wide CFRP strip on both sides of specimens, and; six of them strengthened in the horizontal direction and the others in the vertical direction. In the first phase of test, all beams were failed by shear. Test results indicated the shear strengths of deep beams with openings sized 40 mm by 60 mm were about 17% higher than those with openings sized 68 mm by 68 mm. The shear strengths of deep beams with web openings strengthened by CFRP wrapped in the horizontal direction can be enhanced by about 6%, the shear strengths of deep beams with web openings strengthened by CFRP wrapped in the vertical direction can be enhanced by about 8%. After the first phase of test, 12 deep beams with web openings were chosen to repair and then tested once more. Six controlled beams were wrapped with one layer of CFRP on both sides of specimens. The other beams were repaired by low pressure epoxy injection (LPEI). The results in the second phase of test indicate that the shear strengths of CFRP strengthened beams can be enhanced about 18% by LPEI. Moreover, they showed that six controlled beams may be repaired by being wholly wrapped with one layer of CFRP on both sides.

並列關鍵字

deep beams ； web openings ； shear strengths ； carbon fiber reinforced plastics (CFRP) ； low pressure epoxy injection (LPEI)