Effects of Mixed Metakaolin and Silica Fume on Mechanical Properties of EPS Concrete
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摘要: 为研究不同掺量的偏高岭土和硅灰对聚苯乙烯泡沫(EPS)混凝土物理力学性能的影响,以不同掺量的偏高岭土和硅灰作为辅助胶凝材料,分别以0%、5%、10%和15%的掺量代替部分水泥,制备了16组不同配合比的EPS混凝土试件,对其吸水率、抗压强度、抗折强度以及劈裂抗拉强度进行了测量。结果表明:一定量的硅灰和偏高岭土的掺入能降低EPS混凝土的吸水率,并能提高其抗压、抗折和劈裂抗拉强度,但当掺量过高时,又会使吸水率增加,强度下降,且二者掺量均为10%时,EPS混凝土的吸水率最低且力学性能最优;虽然偏高岭土的颗粒尺寸大于硅灰,但其“火山灰效应”更强,因而对EPS混凝土力学性能的提高优于硅灰;偏高岭土的硅灰可以改善EPS颗粒与胶凝基体的黏结作用。Abstract: In order to study the effect of different dosages of metakaolin and silica fume on the physical and mechanical properties of EPS concrete, metakaolin and silica fume with different contents were used as auxiliary cementing materials, and the contents of 0%, 5%, 10% and 15% were used to replace part of the cement, respectively, and 16 groups of EPS concrete specimens with different proportions were prepared. The water absorption, compressive strength, flexural strength and splitting tensile strength were measured. The results showed that the addition of a certain amount of silica fume and metakaolin could reduce the water absorption of EPS concrete and improve its compressive strength, bending and splitting tensile strength, but when the dosage was too high, the water absorption would increase and the strength would decrease, and when the content of both was 10%, EPS concrete had the lowest water absorption and the best mechanical properties. Although the particle size of metakaolin was larger than that of silica fume, its "pozzolanic effect" was stronger, so the improvement of the mechanical properties of EPS concrete was better than that of silica fume. Metakaolin and silica fume could improve the adhesion of EPS particles to the gel matrix.
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Key words:
- EPS concrete /
- metakaolin /
- silica fume /
- physical and mechanical properties /
- bond
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