Measures in the process of concrete mixing, transportation and unloading

In concrete mixing, measures should be taken to control the temperature of concrete, to control additional temperature and reduce slump loss speed by controlling the temperature of concrete, so as to reduce plastic shrinkage and cracking. At this stage, the following measures can be taken:

The amount of cement is reduced by using water reducing agent or replacing cement with fly ash. At the same time, the aggregate size is increased when the pouring condition is allowed.

If the concrete mixture needs a long distance transportation, retarder can be used to control the setting time, but it should be ensured that the dosage of retarder is correct, which is especially important for underwater concrete engineering.

If a higher slump is needed, an efficient water reducing agent should be used. The high slump produced by some superplasticizers can maintain 2H. The high efficiency water reducing agent can also reduce the friction between the aggregate particles during the mixing process and slow down the heat accumulation in the mixing drum of the transportation mixer.

Sprinkling water into aggregate piles to promote evaporative cooling to reduce the temperature of concrete. If we use cold water (such as groundwater or well water) to moisten, the cooling effect will be better, especially when humidity is high.

When transporting concrete long distance in high temperature and humid season, the delayed mixing of transport mixer can be considered, so that it is still in the state of agitation when it arrives at the site.

If possible, a plan should be made to avoid pouring concrete at the highest temperature of the day. Under dry conditions, the influence of wind and temperature on concrete at night is relatively reduced.

In addition to the design to increase the amount of mixing water to adjust the provisions of the slump givers should not add mixing water at the site.