Mahmood Faisal, Kashif Ur Rehman Sardar, Jameel Mohammed, Riaz Nadia, Javed Muhammad Faisal, Salmi Abdelatif, Awad Youssef Ahmed
Department of Civil Engineering, COMSATS University Islamabad, Abbottabad Campus, Abbottabad 22060, Pakistan.
Department of Civil Engineering, King Khalid University, Abha 61421, Saudi Arabia.
Materials (Basel). 2022 Nov 3;15(21):7731. doi: 10.3390/ma15217731.
For the creation of healable cement concrete matrix, microbial self-healing solutions are significantly more creative and potentially successful. The current study investigates whether gram-positive "" () microorganisms can effectively repair structural and non-structural cracks caused at the nano- and microscale. By creating an effective immobilization strategy in a coherent manner, the primary challenge regarding the viability of such microbes in a concrete mixture atmosphere has been successfully fulfilled. The iron oxide nanoparticles were synthesized. The examined immobilizing medium was the iron oxide nanoparticles, confirmed using different techniques (XRD, SEM, EDX, TGA, and FTIR). By measuring the average compressive strength of the samples (ASTM C109) and evaluating healing, the impact of triggered bacteria immobilized on iron oxide nanoparticles was examined. The compressive strength recovery of cracked samples following a therapeutic interval of 28 days served as a mechanical indicator of the healing process. In order to accurately correlate the recovery performance as a measure of crack healing duration, the pre-cracking load was set at 80% of the ultimate compressive stress, or "f c," and the period of crack healing was maintained at 28 days. According to the findings, bacteria greatly enhanced the compressive strength and speed up the healing process in cracked cement concrete mixture. The iron oxide nanoparticles were proven to be the best immobilizer for keeping germs alive until the formation of fractures. The bacterial activity-driven calcite deposition in the generated nano-/micro-cracks was supported by micrographic and chemical investigations (XRD, FTIR, SEM, and EDX).
为了创建可自愈的水泥混凝土基体,微生物自愈解决方案更具创新性且可能取得成功。当前的研究调查革兰氏阳性“()”微生物是否能有效修复在纳米和微观尺度上产生的结构和非结构裂缝。通过以连贯的方式创建有效的固定策略,在混凝土混合料环境中此类微生物生存能力的主要挑战已成功解决。合成了氧化铁纳米颗粒。使用不同技术(XRD、SEM、EDX、TGA和FTIR)确认所研究的固定介质为氧化铁纳米颗粒。通过测量样品的平均抗压强度(ASTM C109)并评估愈合情况,研究了固定在氧化铁纳米颗粒上的触发细菌的影响。经过28天治疗期后,开裂样品的抗压强度恢复情况作为愈合过程的力学指标。为了将恢复性能准确地与裂缝愈合持续时间相关联,预裂荷载设定为极限抗压应力“fc”的80%,裂缝愈合期保持为28天。根据研究结果,细菌极大地提高了开裂水泥混凝土混合料的抗压强度并加速了愈合过程。事实证明,氧化铁纳米颗粒是使细菌在裂缝形成前保持存活的最佳固定剂。微观和化学研究(XRD、FTIR、SEM和EDX)支持了细菌活性驱动的方解石在产生的纳米/微裂缝中的沉积。