| 摘要: | ECC 的擬應變硬化行為會導致微裂縫的形成，進而逐漸削弱其強度與耐久性。其自癒能力雖可作為一種潛在的解決方案，但僅對於較窄的裂縫有效。為了提升自癒能力，本研究旨在開發一種創新的 ECC 材料，透過添加固定於矽膠中的枯草桿菌（BS+SG），以增強其力學與自癒性能。本研究共製備四組 ECC 混合物，其中包括一組未添加 BS+SG 的控制組，以及三組分別添加 5%、10%、15% BS+SG（以總拌合用水量之重量百分比計算）的生物 ECC（Bio-ECC）配比。力學性能透過抗壓強度與單軸拉伸試驗進行評估，而物理與傳輸性質則包含孔隙率、超音波脈波速度與吸水率的測定。自癒能力則藉由裂縫寬度癒合率、拉伸強度恢復率以及水密性與脈波速度的回復比例進行評估。結果顯示，添加 BS+SG 有效提升了 ECC 的力學性能。隨著 BS+SG 的添加，抗壓與拉伸強度皆有所提升，其中 Bio-ECC 15% 表現出最高的力學性能。同時，物理與傳輸性質亦有明顯改善，包括孔隙率下降、吸水率降低及脈波速度上升等。此外，混合 BS+SG 可提升裂縫寬度的癒合率及拉伸強度的恢復能力。經過 28 天的癒合後，含有 5% 至 15% BS+SG 的 Bio-ECC 其裂縫癒合率介於 53.5% 至 82.3%，遠高於未添加 BS+SG 的控制組。此結果亦與水密性提升及脈波速度回復率的增加相符。綜合而言，添加 BS+SG 可顯著提升 ECC 的力學、傳輸與物理性質，以及提升其自癒性能。;The pseudo-strain hardening behavior of ECC leads to the formation of micro-cracks that gradually compromise its strength and durability. Autogenous self-healing capability offers a potential solution to this issue, however it is only effective for narrower cracks. In order to improve the self-healing capability, this study aims to develop an innovative ECC material by incorporating Bacillus subtilis immobilized in silica gel (BS+SG) to enhance both the mechanical and self-healing performance. A total of four ECC mixtures were prepared, consisting of one control specimen without BS+SG and three Bio-ECC mixtures containing BS+SG at replacement levels of 5%, 10%, and 15% of the total mixing water. Mechanical performance was evaluated through compressive and uniaxial tensile tests, whereas the porosity, pulse velocity and sorptivity were measured as physical and transport properties. The self-healing ability was assessed via quantification of crack width upon healing, tensile strength recovery, and regain ratio of water tightness and pulse velocity. The result reveals that by incorporating BS+SG effectively enhanced the mechanical performance. Both the compressive and tensile strengths increased with the addition of BS+SG, while Bio-ECC 15% performs highest mechanical performance among the tested mixtures. The improvements were also observed in the physical and transport characteristics, as evidenced by reduced porosity, lower sorptivity, and increased pulse velocity. In addition, the incorporation of BS+SG into mixture enhances both the healing percentage of crack width and recovery of tensile strength. After 28 days of healing, Bio-ECC with 5% to 15% BS+SG showed crack-healing percentages ranging from 53.5% to 82.3%, significantly higher than the control mixture without BS+SG. These improvements were consistent with increased water tightness and higher regain ratios of pulse velocity. In conclusion, the addition of BS+SG significantly enhances the mechanical, transport, and physical properties, and self-healing performance of ECC. |
