What are the key points of concrete production in the mixing plant in spring and autumn, w
Every season in spring, summer, autumn and winter has the characteristics of each season, and it is for this reason that our four seasons become colorful. Just as we have to wear different clothes in different seasons, the operation and production of the mixing station, in Each season also has different emphasis, such as spring and autumn mixing stations need to pay attention to strong winds and temperature differences, summer mixing stations need to pay attention to high temperatures and rain, winter mixing stations need to pay attention to low temperatures and antifreeze. This is just an overall idea. Please follow along with the editor to understand what you need to pay attention to in each season of the year.
Spring and Autumn
The spring and autumn seasons have some things in common: the temperature difference between day and night is large, there is little rain, the wind speed is large, and the air humidity is small. If these problems are not noticed, it will cause air drying and cracking problems in the concrete. At this time, we should strengthen the quality control of raw materials, strictly control the mud content of sand and stone materials, increase the testing of admixtures, and minimize the use of admixtures. To prevent the use of unqualified raw materials, the amount of additives should also be adjusted according to the situation. Strictly control the water-cement ratio and reduce the amount of admixture and admixture. Increase the amount of cement and water to ensure that the water-cement ratio remains unchanged, and reduce the amount of admixture to prevent abnormalities during setting. Slump can ensure on-site construction performance.
Summer is a season in which the temperature continues to be high and the weather changes over the year. In the hot summer, the amount of water evaporation is large, and the newly poured concrete appears to dry quickly, the setting speed is fast, the false setting, the setting time is long, and the strength decreases, and it will bring cracks, which affects the quality of the concrete. At this time, we should control the temperature of the concrete. In the high-temperature season, the higher the temperature of the concrete, the faster the cement hydration speed in the concrete, and its construction performance is reduced. Therefore, the temperature control of the concrete in summer is especially important. So how should the temperature be controlled?
Cement that has just been ground can not be used, and the cement that is controlled to enter the warehouse cannot be used immediately. The temperature of the cement and the temperature at the time of use need to be detected, and the admixture content can be adjusted in a targeted manner. Mainly to reduce the temperature of the agitated mixture, generally more groundwater is used, and ice blocks can be added to control the temperature of the mixture if necessary. Cooling methods such as water spraying can be used to improve the temperature of the aggregate entering the machine, thereby changing the temperature of the concrete mixture.
Winter temperatures are around -5 ~ 10 ℃, there are many cold winds, low temperatures, and large temperature differences between day and night. At this temperature, the cement hydration is dormant. If you do not pay attention and take effective measures, quality accidents are prone to occur.
1. Material control: Cement is strictly in accordance with the requirements of "Construction Engineering Winter Construction Code", and Portland cement and ordinary Portland cement are preferred. The cement grade is not less than 32.5, and the amount of cementing materials in various mixing ratios is not Less than 300kg / m3. In order to prevent the difficulty in purchasing gravel and sand in winter, or the inconvenience of production due to icing caused by excessive water content in the temporary sand feeding, good quality sand and gravel materials should be stored in the wharf and cargo yard in advance. According to the temperature change, adjust the admixture components in time to meet the needs of winter construction. Generally, the admixture used can be used for construction antifreeze in the temperature range of -5 ～ 0 ℃. If the weather changes, a professional antifreeze should be selected to meet the construction requirements. When the temperature is too low, water should be heated or groundwater should be used.
2. In order to ensure the smooth progress of concrete production and construction in winter, all teams and groups should be organized to carry out special training on technical considerations for winter construction, so as to raise the level of construction personnel's understanding of winter construction. In addition, training on fire prevention, freeze protection, safety, etc. is also required.
4. Strictly produce according to the specified mix ratio, and mix according to the specified mixing time to ensure the temperature and workability of the concrete. During the transportation process, the rotation speed of the drum is guaranteed to ensure that the concrete mixer reduces the heat loss during transportation. When necessary, the concrete mixer truck must be insulated.