Effects of Fly Ash/Diatomite Admixture with Variable Particle Sizes on the Mechanical Properties and Porosity of Concrete
Effects of Fly Ash/Diatomite Admixture with Variable Particle Sizes on the Mechanical Properties and Porosity of Concrete
复制标题
不同粒径粉煤灰/硅藻土外加剂对混凝土力学性能和孔隙率的影响
DOI：
10.1007/s11595-017-1713-8
复制
发表时间：
2017-10-01
影响因子：
1.6
通讯作者：
Yang Yuanquan
中科院分区：
文献类型：
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作者：
Liu Jun;Wu Kewei;Yang Yuanquan
将粉煤灰与硅藻土均匀混合，在不同的时间尺度内进行研磨，得到了不同粒径的粉煤灰/硅藻土外加剂。研究了外加剂粒径分布对混凝土力学性能和孔隙率的影响。通过对数据的回归分析，得到了外加剂粒径分布与混凝土孔隙率之间的关系。结果表明：随着掺合料粒径的减小，混凝土在第3天和第7天的抗压强度和抗弯强度增大；对于14 d的混凝土，降低粉煤灰/硅藻土掺合料的粒径，混凝土的抗压强度和抗弯强度均有所增加，但随后又有所下降。在d50值为15.2 μm时，混凝土的力学性能得到较大改善。此外，粉煤灰/硅藻土掺合料颗粒越细，微集料效应和火山灰效应越显著，使得胶凝材料的孔隙结构越致密，孔隙率越小，水化程度越高。特别是对于早期固化的试样，对孔隙结构的改善作用较为明显。
Fly ash and diatomite were mixed uniformly and ground within various time scale and fly ash/diatomite admixtures with variable particle sizes were obtained. Effects of particle size distributions of the admixtures on the mechanical properties and porosity of concrete were studied. The relationship between the size distribution of the admixture and the concrete porosity was obtained based on the regression analysis of the data. The results show that compressive and flexural strengths of the concrete at 3 d and 7 d increase with the decrease of the admixture particle size. With regards to the concrete at 14 d, lowering the particle size of fly ash/diatomite admixture leads to the increasing of the compressive and flexural strength of the concrete, before decreasing afterwards again. At thed50value of 15.2 μm, the mechanical properties of concrete were greatly improved. In addition, finer particle of the fly ash/diatomite admixture leads to significant micro-aggregate effect and volcanic ash effect and thus obtains denser pore structure, smaller porosity and higher hydration degree of the cementitious material. Especially for the samples curing at the early stage, the improving effect on the pore structure was obvious.