Scholarlink

<p>This study focuses on the effect of the addition of <i>Bacillus subtilis</i> microorganisms as a healing agent and polyvinyl alcohol (PVA) as reinforcing fibres in the cementitious composite as there is limited literature on the effect of healing agent and fibres together in cementitious composite under compression and bending. A total of 12 mixes were prepared based on different dosages of fibres and healing agents. <i>Bacillus subtilis</i> microorganisms encapsulated in gelatine shells coated with resin were added as 1% and 1.5% by mass of binder. In contrast, PVA fibres were employed as the reinforcing material as 0.5, 1, and 1.5% by mix volume. Cubes of the sizes 100 × 100 × 100&#xa0;mm and beams of the sizes 100 × 100 × 500&#xa0;mm having a notch at the bottom face of mid-span were cast to check response under compression and bending respectively as per ASTM standards. Beams were tested under third-point loading to achieve load versus crack mouth opening displacement (CMOD) at the notch to observe the effect on the stiffness, peak load, and post-peak response in the presence of healing agent and PVA fibres. One of the groups tested till failure to carry out an ultimate flexural response while the other tested till service loading to crack the specimens up to a CMOD value of 0.3&#xa0;mm. Water immersion curing was provided to all the specimens and healing was observed at 7, 14, and 28&#xa0;days. After completion of the healing period, specimens were again subjected to third-point loading to investigate recovery of flexural response and it was found that PVA fibres played a significant role in compressive and flexural strength, and the healing agent was able to heal cracks with a significant recovery in flexural stiffness and strength after healing of crack. The combination of PVA fibres and the healing agent is favourable in regaining the load capacity. Compared to the control mix, a reduction of 12% was observed when concrete contained only 1% bacteria. However, the combination of PVA fibres and Bacteria is favourable and the highest compressive strength (36&#xa0;MPa) and flexural strength (5&#xa0;MPa) was observed with 1% PVA fibres and 1% bacteria which is about 44.6% higher than control and restores 94% of its initial flexural strength as compared to control.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Synergistic effects of PVA fibres and healing agent encapsulated gelatine carrier in cementitious composites

  • 期刊论文

  • 发表日期：

    2025年4月8日

查看全文
  • Sadaqat Ullah Khan,
  • Tehmina Ayub,
  • Bilal Ahmed

摘要

This study focuses on the effect of the addition of Bacillus subtilis microorganisms as a healing agent and polyvinyl alcohol (PVA) as reinforcing fibres in the cementitious composite as there is limited literature on the effect of healing agent and fibres together in cementitious composite under compression and bending. A total of 12 mixes were prepared based on different dosages of fibres and healing agents. Bacillus subtilis microorganisms encapsulated in gelatine shells coated with resin were added as 1% and 1.5% by mass of binder. In contrast, PVA fibres were employed as the reinforcing material as 0.5, 1, and 1.5% by mix volume. Cubes of the sizes 100 × 100 × 100 mm and beams of the sizes 100 × 100 × 500 mm having a notch at the bottom face of mid-span were cast to check response under compression and bending respectively as per ASTM standards. Beams were tested under third-point loading to achieve load versus crack mouth opening displacement (CMOD) at the notch to observe the effect on the stiffness, peak load, and post-peak response in the presence of healing agent and PVA fibres. One of the groups tested till failure to carry out an ultimate flexural response while the other tested till service loading to crack the specimens up to a CMOD value of 0.3 mm. Water immersion curing was provided to all the specimens and healing was observed at 7, 14, and 28 days. After completion of the healing period, specimens were again subjected to third-point loading to investigate recovery of flexural response and it was found that PVA fibres played a significant role in compressive and flexural strength, and the healing agent was able to heal cracks with a significant recovery in flexural stiffness and strength after healing of crack. The combination of PVA fibres and the healing agent is favourable in regaining the load capacity. Compared to the control mix, a reduction of 12% was observed when concrete contained only 1% bacteria. However, the combination of PVA fibres and Bacteria is favourable and the highest compressive strength (36 MPa) and flexural strength (5 MPa) was observed with 1% PVA fibres and 1% bacteria which is about 44.6% higher than control and restores 94% of its initial flexural strength as compared to control.