多元矿物掺合料对珊瑚砂混凝土性能的影响

因珊瑚砂混凝土成型初期吸水量大,引起强度波动,影响混凝土耐久性,本文采用矿物掺合料对其进行改性研究.将5wt％偏高岭土(MK)、15wt％粉煤灰(FA)、15wt％矿粉(GGBS)分别以单掺、复掺和三掺形式加入珊瑚砂混凝土中,研究多元矿物掺合料对其抗压强度、抗氯离子渗透性能及体积稳定性的影响,利用XRD、SEM对其机理进行研究.结果表明,矿物掺合料能优化水泥浆体的水化产物组成与亚微观孔结构,增强浆体与骨料间的结合,通过不同的组合方式加入到珊瑚砂混凝土中,其28 d抗压强度提高17.7％～21％;氯离子渗透系数降低66.7％～71.0％;干燥收缩率降低36.7％～57.0％.

Influence of Mineral Admixtures on the Properties of Coral Sand Concrete

Due to the high water absorption of coral sand aggregate , which can influence its strength development , also has bad influence on its durability .As commonly known , the addition of mineral admixtures can improve the properties of concrete .Hence, this study investigates the influence of 15wt％fly ash (FA), 15wt％ blast furnace slag (GGBS) and 5wt％ metakaolin (MK) on the mechanical properties, chloride permeability and drying shrinkage of CSC .In addition, the intrinsic mechanism and microstructure development of CSC are characterized by X-ray diffraction ( XRD) and scanning electron microscopy ( SEM) .The obtained results show that the combination of MK , GGBS and FA can optimize the hydration products and microstructure of CSC .Added mineral admixtures in CSC with different combination solution , the compressive strength increased by 17.7％-21％at 28 d, its chloride ion diffusion coefficient and drying shrinkage are reduced by 66.7％-71.0％and 36.7％-57.0％, respectively .