The temperature decreases, the rain increases, and the cement and concrete can't reach the expected use intensity. It's very troublesome in the construction engineering in autumn and winter. The main function of early strength agent is to accelerate the rate of cement hydration and promote the development of early strength of concrete. The addition of calcium formate has not only the function of early strength, but also the function of reducing water and strengthening.

1. express cement concrete pavement or bridge deck pavement, especially the level crossing of class I, II and III Highway. When one direction of cement concrete pavement is paved, not only the road under construction can not be opened to traffic, but also the vehicles in other directions of grade crossing can not use calcium formate early strength cement concrete in night construction, which can provide convenient vehicle traffic in the shortest time.

2. For the construction of cement concrete structure in low temperature environment with the lowest temperature not lower than - 5 ℃, calcium formate early strength agent is generally used to accelerate the setting and hardening of cement concrete, so as to prevent the cement concrete from freezing damage under lower temperature, accelerate the turnover of formwork and improve the construction speed. Especially in winter, it can be filled with calcium formate to improve the early strength. According to some data, the amount of calcium formate used in one ton of dry mortar and concrete is about 0.5 ~ 1.0%, and the maximum amount is 2.5%. In summer, the intake of calcium formate is generally 0.3% ~ 0.7% of that of cement. The calcium formate is increased with the decrease of temperature.

3. prestressed reinforced concrete structures, such as prestressed reinforced concrete bridge tensioning at low temperature or early tensioning at normal temperature, need to use early strength agent to accelerate the prestressed tensioning time and improve the production speed of components.

4. rapid repair of cement concrete pavement and bridge. When repairing, it is necessary to narrow the carriageway, cause traffic jams, cut off traffic or force traffic flow to bypass other roads, especially on expressways or other toll roads with good or better benefits, which can be opened to traffic one hour earlier, bringing considerable toll benefits.

The formic acid in calcium formate belongs to weak acid, and there is hydrolysis process in the aqueous solution. Therefore, the aqueous solution of calcium formate should be weak alkaline, and it can also be used in reinforced concrete for industrial grade calcium formate to have the effect of early strength and initial setting.