Cut off walls are used under dams for the control of sub surfaces seepage and permeability of cut off wall was important. In the construction of cut off walls, plastic concrete is used and the amount of plastic concrete permeability is important. In this study, the permeability of plastic concrete was investigated and the effect of replacing nano silica instead of cement to reduce permeability was studied. So in this research, compressive strength, elastic modulus, and permeability parameters of plastic concrete specimens at different ages (7, 14, 28, and 56 days) and with different percentages of nano silica (0, 1.5, 3, 4.5, and 6%) were investigated. Also, scanning electron microscopy was used to investigate the effect of nano silica on plastic concrete specimens. The results show that as the age of the specimens increases, the compressive strength and elastic modulus increase, and the permeability of the plastic concrete decreases. Also, by adding nano silica to plastic concrete, the compressive strength of the plastic concrete increases and the plastic concrete permeability decreases significantly while its elastic modulus is almost constant.

中文翻译：

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含纳米二氧化硅的塑性混凝土渗透率和弹性模量的试验研究

防渗墙用于坝下，用于控制地下渗流，防渗墙的渗透性很重要。在隔离墙的施工中，使用塑料混凝土，塑料混凝土的渗透量很重要。本研究对塑性混凝土的渗透性进行了研究，并研究了用纳米二氧化硅代替水泥降低渗透性的效果。因此在本研究中，不同年龄（7、14、28 和 56 天）和不同比例纳米二氧化硅（0、1.5、3、4.5 和 6）的塑性混凝土试件的抗压强度、弹性模量和渗透率参数%) 进行了调查。此外，使用扫描电子显微镜研究纳米二氧化硅对塑料混凝土试样的影响。结果表明，随着标本年龄的增加，抗压强度和弹性模量增加，塑性混凝土的渗透性降低。此外，通过在塑料混凝土中添加纳米二氧化硅，塑料混凝土的抗压强度增加，塑料混凝土的渗透性显着降低，而其弹性模量几乎恒定。