利用磨细矿渣提高地下水封洞库喷射混凝土耐久性试验研究

Improvement of Shotcrete's Durability by Ground Granulated Blast-Furnace Slag for Underground Water-sealed Oil Storage in Rock Caverns

地下水封洞室由于良好的性能成为广泛使用的储油设施之一,但其"渗而不漏"的特性决定了后期运行需进行排水和油水分离,渗透过大会使后期运行成本增加,对长期安全储油带来不利影响。基于水封洞室良好的围岩条件,利用S95级磨细矿渣在不降低喷射混凝土基本性能的前提下,提高喷射混凝土的抗渗透性,改善其长期耐久性,降低水封洞室的运行成本。通过矿渣掺量对喷射混凝土凝结时间和工作性能的影响研究,选择并优化基本喷射混凝土配合比,并研究了掺矿物掺合料喷射混凝土抗压强度、回弹率、黏结强度和抗渗透性能,研究结果表明:①矿渣虽一定程度延迟了喷射混凝土的凝结时间,但对其回弹率和黏结强度无不良影响;②利用矿渣可改善混凝土工作性能,可进一步降低喷射混凝土水灰比,使喷射混凝土获得良好的后期性能;③掺矿渣喷射混凝土良好的早期自密实性能和后期二次水化特性,使喷射混凝土的抗渗透性能提高。

Underground oil storage in rock caverns became one of the widely-used oil storage facilities owing to its good performance. But due to its characteristic of permeability without leakage,drainage and oil-water separation are required for the operation in the late period. Excessive permeability would increase the running cost and bring about negative effects on its long-term security. On the basis of surrounding rock's good condition,the permeability resistance of shotcrete increased by adding S95 ground granulated blast-furnace slag without reducing shotcrete's basic properties. The long-term durability of shotcrete is improved,and the operation cost of underground oil storage caverns is reduced. The influence of slag ratio on setting time and working performance of shotcrete is analyzed so as to optimize the mix proportion of basic concrete. The compressive strength,rebound ratio,bond strength and anti-permeability performance of the slag-mixed shotcrete are researched. Results showed that: 1) slag delayed the setting time of shotcrete slightly,but had no adverse effect on shotcrete's rebound ratio and bond strength; 2) slag improved concrete's workability,further reduced shotcrete's water-cement ratio,and enhanced the performance of shotcrete in later stage; 3) shotcrete mixed with slag displayed good anti-permeability performance for early selfcompacting properties and secondary hydration.