Nasser Amal A, Sorour Noha M, Saafan Mohamed A, Abbas Rateb N
Department of Civil Engineering, Faculty of Engineering, Menoufia University, Shebeen El-Kom, Egypt.
Department of Industrial Biotechnology, Genetic Engineering and Biotechnology Research Institute, University of Sadat City, Sadat City, Egypt.
Heliyon. 2022 Jul 5;8(7):e09879. doi: 10.1016/j.heliyon.2022.e09879. eCollection 2022 Jul.
Developing bio-based self-healing concrete aims to minimize durability problems related to cracking. In this study, MICP was used as a smart and eco-friendly approach to produce bio-based durable materials. (BP) and (BS) were added into mortar mixtures with 0.25% and 0.5% cement weight. All treated samples exhibited a significant decline in water uptake, capillary permeability, and volume of permeable voids, as compared to control with no bacteria. All treated samples showed significant increase in compressive strength by 28-50%, after 28 days of curing. At the age of 120 days, the flexural strength of all treated samples was significantly increased by 19.29-65.94%. SEM imaging and EDAX confirmed that treated samples were denser with less voids due to MICP. DTA verified that the calcite amount and the crystallinity degree were improved in treated samples. Load deflection of bacterial Reinforced-Laminates had less deformation than control. Reloaded bacterial Reinforced-Laminates exhibited excellent restoration of physico-mechanical properties and performance, after 28, 90, and 120 days, confirming the healing process. Microbial self-healing is an innovative approach for continuous repair of micro-cracks in concrete, improving its durability, thus can reduce the maintenance costs.
开发基于生物的自愈合混凝土旨在最大限度地减少与开裂相关的耐久性问题。在本研究中，微生物诱导碳酸钙沉淀（MICP）被用作一种智能且环保的方法来生产基于生物的耐用材料。以水泥重量的0.25%和0.5%将生物聚合物（BP）和生物硅（BS）添加到砂浆混合物中。与未添加细菌的对照相比，所有处理过的样品在吸水率、毛细渗透率和可渗透孔隙体积方面均显著下降。在养护28天后，所有处理过的样品的抗压强度显著提高了28% - 50%。在120天时，所有处理过的样品的抗弯强度显著提高了19.29% - 65.94%。扫描电子显微镜（SEM）成像和能谱分析（EDAX）证实，由于微生物诱导碳酸钙沉淀，处理过的样品更致密，孔隙更少。差示热分析（DTA）验证了处理过的样品中方解石含量和结晶度得到了提高。细菌增强层压板的荷载挠度变形比对照小。在28天、90天和120天后，重新加载的细菌增强层压板表现出优异的物理力学性能和性能恢复，证实了愈合过程。微生物自愈合是一种用于混凝土微裂缝持续修复的创新方法，可提高其耐久性，从而降低维护成本。
