Moon Jiho, Taha Mahmoud M Reda, Youm Kwang-Soo, Kim Jung J
New Transportation Research Center, Korea Railroad Research Institute (KRRI), Uiwang-si, Gyeonggi-do 16105, Korea.
Department of Civil Engineering, University of New Mexico, Albuquerque, NM 87131, USA.
Materials (Basel). 2016 Feb 6;9(2):99. doi: 10.3390/ma9020099.
The incorporation of pozzolanic materials in concrete has many beneficial effects to enhance the mechanical properties of concrete. The calcium silicate hydrates in cement matrix of concrete increase by pozzolanic reaction of silicates and calcium hydroxide. The fine pozzolanic particles fill spaces between clinker grains, thereby resulting in a denser cement matrix and interfacial transition zone between cement matrix and aggregates; this lowers the permeability and increases the compressive strength of concrete. In this study, Ordinary Portland Cement (OPC) was mixed with 1% and 3% nanosilica by weight to produce cement pastes with water to binder ratio (/) of 0.45. The specimens were cured for 7 days. Si nuclear magnetic resonance (NMR) experiments are conducted and conversion fraction of nanosilica is extracted. The results are compared with a solid-state kinetic model. It seems that pozzolanic reaction of nanosilica depends on the concentration of calcium hydroxide.
在混凝土中掺入火山灰质材料对提高混凝土的力学性能有许多有益效果。通过硅酸盐与氢氧化钙的火山灰反应，混凝土水泥基体中的硅酸钙水化物得以增加。细小的火山灰质颗粒填充了熟料颗粒之间的空隙，从而形成更致密的水泥基体以及水泥基体与骨料之间的界面过渡区；这降低了混凝土的渗透性并提高了其抗压强度。在本研究中，将普通硅酸盐水泥（OPC）与1%和3%（按重量计）的纳米二氧化硅混合，以制备水灰比（/）为0.45的水泥浆体。将试件养护7天。进行硅核磁共振（NMR）实验并提取纳米二氧化硅的转化分数。将结果与固态动力学模型进行比较。纳米二氧化硅的火山灰反应似乎取决于氢氧化钙的浓度。
