Study on the influence of artificial sand mica content on temperature control and crack prevention of ultra-high concrete arch dams in high-altitude cold regions

Abstract

To study the effect of artificial sand mica content on temperature control and crack prevention of concrete structures, for concrete with different artificial sand mica contents, all temperature control and crack prevention calculation parameters(excluding creep) were experimentally measured, numerical simulation analysis of temperature control and crack prevention for ultra-high arch dams in high-altitude cold regions was carried out. The research result indicate that the mica content has an impact on the maximum stress of the structure at around 0.1 MPa and on the temperature peak at around 0.7 ℃. The content of artificial sand mica ranges from 6.5% to 2.9%, and changes in mica content have a significant impact on the structural safety factor; When the content of artificial sand mica is below 2.9%, the change in mica content has little effect on the structural safety factor. Within the allowable temperature control standards in the design, even for high-altitude and cold areas with ultra-high concrete arch dams, concrete with an artificial sand mica content of 4.5% can meet the recommended safety factor of 2.0 in the specifications The artificial sand mica removal technology can effectively improve the safety factor of concrete arch dams, avoid the harm of mica in artificial sand to the temperature control and crack prevention of arch dams, provide support for ensuring the safety of arch dams and increasing the selection of raw materials, and have great reference value for the construction of subsequent projects.

Keywords

artificial sand / mica / content / concrete