Tie Yuanyuan, Ji Yongcheng, Zhang Hongzhao, Jing Bingyan, Zeng Xinya, Yang Peili
School of Civil Engineering and Transportation, Northeast Forestry University, Harbin, 15040, China.
Heliyon. 2024 Jul 4;10(14):e34131. doi: 10.1016/j.heliyon.2024.e34131. eCollection 2024 Jul 30.
In the process of research and development of self-healing concrete, it is observed that there are three main factors controlling the self-healing effect of concrete: first, the bacteria with repair ability and strong vitality; Second, the carrying capacity of the carrier and the matching degree with concrete; The third is the concentration of bacteria. This paper focuses on the mechanical properties of Bacillus subtilis self-healing concrete with sisal fiber, PVA, and expanded perlite as the carrier. To better study the mechanical properties of self-healing concrete caused by the carrier, the experiment adopts the design parameters of C30 concrete and conducts experiments on compressive resistance, flexural resistance, freeze-thaw cycle, and sulfate corrosion resistance to analyze the influence of different carriers on the mechanical properties of self-healing concrete, and obtains the best carrier. The concentration gradients of three groups of bacterial solution were set as 2od, 2.5od, and 3od, respectively, for comparison to avoid the influence of bacterial concentration. It compared the impact of bacterial solution concentrations on the specimen's mechanical properties, and the effect of carriers was also analyzed. The experimental results show that the mechanical properties of the specimen using 2.5od bacterial liquid concentration with PVA as the carrier have peaked. With the increase in bacterial solution concentration, the specimens' comprehensive mechanical properties increased first and then decreased. The compression resistance of the specimen with PVA is higher than that of the specimen with sisal fiber and expanded perlite. At the same time, the frost resistance and corrosion resistance of the PVA carrier specimen is also higher than that of the specimen with sisal fiber and expanded perlite carrier.
在自愈混凝土的研发过程中，观察到有三个主要因素控制着混凝土的自愈效果：其一，具有修复能力且活力较强的细菌；其二，载体的承载能力以及与混凝土的匹配程度；其三是细菌的浓度。本文重点研究以剑麻纤维、聚乙烯醇（PVA）和膨胀珍珠岩为载体的枯草芽孢杆菌自愈混凝土的力学性能。为了更好地研究由载体引起的自愈混凝土的力学性能，试验采用C30混凝土的设计参数，进行抗压、抗折、冻融循环和抗硫酸盐侵蚀试验，以分析不同载体对自愈混凝土力学性能的影响，并得出最佳载体。设置三组菌液浓度梯度分别为2od、2.5od和3od进行对比，以避免细菌浓度的影响。比较了菌液浓度对试件力学性能的影响，同时也分析了载体的作用。试验结果表明，以PVA为载体、菌液浓度为2.5od时试件的力学性能达到峰值。随着菌液浓度的增加，试件的综合力学性能先升高后降低。以PVA为载体的试件抗压强度高于以剑麻纤维和膨胀珍珠岩为载体的试件。同时，PVA载体试件的抗冻性和抗腐蚀性也高于以剑麻纤维和膨胀珍珠岩为载体的试件。
