Comparative study on uniaxial and triaxial strength of plastic concrete containing nano silica

摘要

Plastic concrete is used in the manufacture of cut off wall and its mechanical properties is important for performance of dam. In this paper, in order to investigate the durability and mechanical properties of plastic concrete, uniaxial and triaxial compressive strength tests were performed on plastic concrete specimens in different ages (7, 14, 28, 56 and 90 days) and different percentage of replacement cement by nano silica (0, 1.5, 3, 4.5 and 6%) and compressive strength, the stress-strain behavior, elastic modulus, shear strength parameters of plastic concrete have been evaluated. According to the result, as the age of the specimen increases, elastic modulus, compressive strength and triaxial strength of the plastic concrete enhances. Furthermore, although by increasing the amount of nano silica the strength parameters of plastic concrete are improved and workability of concrete is reduced and the amount of elastic modulus of the specimen is almost constant. The results of shear strength parameters also show that the addition of up to 3% of nano silica increases the cohesion and internal friction angle decreases and with over 3% nano silica this trend is reversed and cohesion decreases and friction angle increases. (C) 2020 Elsevier Ltd. All rights reserved.