What role does basalt fiber play in concrete?

As a traditional building material, what role does basalt fiber play in concrete? In the face of increasingly complex construction environments and special requirements such as emergency repairs and construction, the disadvantage of low early strength urgently needs to be addressed. At present, there are many studies on early strength concrete, but most of them focus on the mix design, workability improvement, and compressive and flexural strength of early strength concrete. These studies mainly focus on the static mechanical properties of early strength concrete, while there is relatively little research on the dynamic mechanical properties of early strength concrete.

In practical environments, due to the rapid deployment of repair and construction projects, concrete is inevitably subjected to impact loads in the early stages due to various factors such as vehicle movement, bridge vibration, and aircraft takeoff and landing. Therefore, studying the early dynamic properties of early strength concrete is of great significance for the normal use and safety assessment of rapid repair projects. Basalt fiber is a continuous fiber formed by drawing basalt stone after melting at high temperatures, which has various properties such as high strength, high stability, corrosion resistance, and high temperature resistance. Adding basalt fibers into concrete can effectively improve its various mechanical properties. At present, there are many studies on basalt fiber reinforced concrete, but there is still no report on the use of basalt fiber in early strength concrete. Its good mechanical properties will inevitably lead to better early comprehensive performance of early strength concrete.

Basalt fiber is an inorganic fiber material formed by high-temperature melting and drawing of basalt minerals formed by volcanic eruptions. It is a new type of fiber material that has just been developed in China in recent years, and has obvious advantages compared to other high-tech fibers such as carbon fiber and aramid fiber. The unique high temperature resistance of basalt can withstand temperatures up to 700 ℃, and can also reach -269 ℃ (softening point of 960 ℃) at low temperatures, significantly higher than the -60~450 ℃ of glass fiber. When basalt fibers work in structures below 400 ℃, their fracture strength can maintain 85% of their original strength; When working in structures below 600 ℃, its fracture strength can still maintain 80% of its original strength. From these data, it can be seen that basalt fiber-reinforced concrete materials exhibit better high temperature resistance and are one of the building materials with high temperature resistance.