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To address the issue of resource utilization regarding discarded geotextile, this study innovatively mixed discarded geotextile fibers (DGFs) uniformly into cement-stabilized diabase waste residue as a base filler for road construction. The effect of DGF content on the mechanical properties (MPs) of DGF-reinforced cement-stabilized diabase waste residue was examined via unconfined compressive strength (UCS) and splitting tensile strength (STS) tests. Dry shrinkage (DS), temperature shrinkage (TS), and freeze-thaw cycle (FTC) tests were conducted to investigate the durability change rule of the material under complex environmental conditions. The “anchoring” mechanism of DGFs in cement-stabilized diabase waste residue was analyzed via scanning electron microscopy (SEM). The results show that for a DGF content of 0.2%, the UCS and STS of the specimen reach their peak values. At this moment, with the coefficients of DS and TS minimized, optimal resistance to shrinkage is achieved. Incorporating DGFs significantly enhanced the FTC residual strength ratio of cement-stabilized diabase waste residue specimens compared to those without DGFs. Furthermore, the SEM results further reveal that the DGFs were gradually wrapped with cement hydrates, and their two ends were embedded in the matrix of the cement-stabilized diabase waste residue, acting as “bridges”. Embracing the environmental protection concept of “treating waste with waste”, this study highlights the potential of DGFs as reinforcement materials for cement-stabilized diabase waste residue, introducing a novel approach to the resource utilization of discarded geotextiles.

Small cracks in concrete can develop into larger cracks, reducing the service life of concrete structures. Therefore, the early prevention of fine crack progression is crucial. In this study, a multimicrobial system composed of Bacillus megateriumand Saccharomyces cerevisiaewas used to repair concrete cracks, and its repair efficiency was evaluated through fracture healing observations, permeability tests, acoustic time value detection, and unconfined compressive strength tests. Additionally, scanning electron microscopy, energy dispersion spectroscopy, X-ray diffraction, and Fourier-transform infrared spectroscopy were used to analyze the concrete repair mechanism of the multicomponent microbial system. The results showed that when the ratio of S. cerevisiaeto B. megateriumin the microbial system was 30 %:70 %, the calcium carbonate (CaCO3) yield increased by 10 %, and the mineralization deposition effect was optimal. Under the synergistic action of the two microorganisms, fracture healing proceeded quickly and the pore structure within the fracture became denser, significantly improving the permeability and strength repair rates of the sample and reducing the pulse velocity. For cracks 1.5 mm in width, the permeability and strength repair rates were 63 % and 35.12 %, respectively. The pulse velocity was reduced from 140 µs to 65 µs. The crack filler is mainly composed of CaCO3crystals 5–10 µm in size, and the total calcium content of the multicomponent repair system was as high as 39.5 %, which was significantly higher than that of the single component repair system (36.1 %). The results indicate that the multicomponent microbial repair system maintains a higher calcium precipitation activity in a high-strength alkaline concrete environment and produces denser CaCO3deposits, indicating good repair ability. These repair properties improve the overall performance of concrete. This study confirms the strong potential of multimicrobial systems for efficient, cost-effective, and environmentally-friendly concrete crack repair.