改性矿渣纤维的抗酸碱侵蚀特性

Properties on Slag Fiber Modified after Acid and Alkali Solution Treatment

将酸度系数为1.6的改性矿渣纤维分别浸入弱酸、去离子水和水泥水化溶液中,研究酸碱环境对其性能的影响.结果表明:用弱酸浸泡改性矿渣纤维1d后,可显著提高其单丝抗拉强度;用去离子水浸泡后,改性矿渣纤维强度变化不大;用水泥水化的碱性溶液浸泡后,改性矿渣纤维强度则显著下降,其中56d后因纤维发生断裂粉化而使强度消失;用去离子水及弱酸溶液浸泡改性矿渣纤维56d,其表面微观形貌及主要化学成分无明显变化;用碱性溶液侵蚀28d后,改性矿渣纤维表面有大量的新水化相生成,钙、铝、镁等元素流失程度加剧,其表面化学成分分布不均匀性显著增加,有少量的碳硅钙石晶体形成.

Slag fiber modified（SFM） with acidity coefficient of 1.6 were treated with acid solution at pH of 5.0, de-ionized water at pH of 6.8, and cement hydration solution at pH of 13.6 respectively for determination of durability of SFM. The results show that tensile strengths of single slag fiber are increasingly en- hanced with acid solution treatment after 1 day; tensile behaviors of fibers are not affected by de-ionized water; however significant decrease of the tensile strengths under cement hydration solution are detected in different periods and tensile strengths disappear after 56 days duo to the fibers split into small pieces. No apparent change in chemical composition and microscopic shape of the fibers result from de-ionized water and weak acid solution treatment. New hydration products are observed on the surface of SFM after alkali solution treatment with the result that elements of calcium, aluminum and magnesium are obviously extracted from SFM, and chemical composition on the surface of SFM is heterogeneous. A small quantity of scawtite crystal is formed.