纳米材料与纤维改性洞渣混凝土力学性能研究OA

To enhance the mechanical properties of tunnel spoil concrete and promote the sustainable utilization of mineral waste,an orthogonal test was conducted to investigate the effects of varying contents of nano-silica,fly ash,and basalt fibers(with lengths of 6 and 12 mm)on the mechanical properties of tunnel spoil concrete.Based on macro-and micro-scale test results,the optimal mix proportion was determined,and the mechanisms of influences of these materials on the concrete's performance were clarified.The results indicate that the overall properties of the modified tunnel spoil concrete reach their optimum with the incorporation of 1%(mass fraction)nano-silica,10%(mass fraction)fly ash,0.15%(volume fraction)of 6 mm basalt fiber,and 0.1%(volume fraction)of 12 mm basalt fiber.Compared with the unmodified tunnel spoil concrete,the compressive strength and splitting tensile strength of the modified concrete increase by up to 20.0%and 26.3%,respectively.Fly ash and nano-silica promote the formation of C-S-H gel during the hydration process.The fibers enhance the splitting tensile performance,ultimately improving both the mechanical properties and failure mode of the concrete.