一.Selection of raw materials and their temperature control 1.Cement cement should give priority to Portland cement, ordinary Portland cement early strong cement, in order to improve the early strength of concrete, reduce the frequency of freezing damage。2.Sand and stone should be preferred to use inventory sand, because the relative water content of inventory sand is low, the production of frozen blocks is less, and the relative performance is stable;Such as the new sand in winter, the water content of the incoming sand should be strictly required (controlled below 4%) to reduce the freezing probability and the adjustment frequency of the mix ratio during production to ensure the quality of concrete。The relative moisture content of stones is low, the probability of producing frozen blocks is small, and it should be avoided by rain and snow。In order to ensure the normal use of aggregate, it is recommended to cover the sand and stone on the site with sand mesh or felt, so that it is protected from rain and snow, and can play a certain role in insulation。The accumulation height of yellow sand and gravel should be appropriately increased, and if the material is sufficient, 5-8m is appropriate to reduce the freezing layer and protect the internal temperature。3.Mixing water Mixing water is drinking water, winter construction should use hot water mixing, water temperature control at about 60 ° C, but not higher than 80 ° C。4.Antifreeze Antifreeze contains antifreeze components, antifreeze components can reduce the freezing point of water, so that concrete is still hydrating under negative temperature conditions。When testing and using admixtures, it is necessary to strictly control the properties of antifreeze and the amount of admixtures。5.Due to the different fineness of admixtures such as fly ash and mineral powder, the micro-aggregate effect occurs in concrete, which improves the compactness of concrete.优质Concrete mixingThat is, the strength, frost resistance and durability of concrete are improved, but fly ash and mineral powder can extend the hydration time of cement。Therefore, the amount of admixture should be appropriately reduced during construction in winter。二.In order to ensure the normal operation of the equipment and the normal production of concrete, the feeding port of the aggregate bin, the admixture tank and the mixer should be closed, and the hot spot (furnace and electric heating) should be set, and the electric heating should be added in the operation room when there is air conditioning。Conditions should be used boiler heating, heating pipe should be through the bone bin feeding port, admixture shed, pool, mixer shed and operation room, not only save time, labor, but also better ensure the concrete out of the machine temperature and performance。三.Concrete transport vehicles under the jurisdiction of the company's mixing transport vehicles, in the winter before construction outsourcing insulation, to the mixing truck insulation, to ensure that the temperature of the concrete during transport does not lose。After the mixer is loaded, it is strictly prohibited to add water to the car at will to prevent the quality of delivery from being affected by changes in the water-cement ratio of concrete during transportation。After the mixer shaper, the water in the tank should be cleaned in time to prevent ice from causing quality hazards。四.The control test personnel of the production process test the moisture content and temperature of the sand and stone every day, and the number of tests should be increased in rain and snow weather。Depending on the climatic conditions, the concrete only needs to be mixed with hot water, and the aggregate does not need to be heated。The quality inspection personnel should check the temperature of the mixing water before each opening, which should not be higher than 80 ° C to prevent the phenomenon of false coagulation in the concrete;It shall not be lower than 40 ° C to ensure that the temperature of concrete entering the mold shall not be lower than 5 ° C。Strictly control the amount of antifreeze, and extend the mixing time of concrete to ensure the uniformity of concrete。五.Quality control of concrete after application 1.Quality inspection personnel shall be arranged at the construction site, responsible for vehicle deployment and concrete quality control。Compress the unloading time of concrete as soon as possible to ensure the temperature of concrete entering the mold。2.Concrete mixing用途Before pouring concrete, the construction site quality inspector should check whether there are factors affecting the quality of concrete such as frozen blocks or snow on the surface of the formwork。3.After concrete pouring is completed, the construction unit should be notified in time to cover the concrete with plastic film and blanket and other thermal insulation maintenance work to ensure that the concrete is not damaged by freezing before the initial setting.The concrete shall not be watered and cured during winter construction, and the strength of the concrete shall reach 1.Before 2MPa, do not step on it, support the mold and load。4.After the concrete pouring is completed, the quality inspection personnel should remind the tank truck driver to clean the concrete mixing truck with water。5.After mold removal, the difference between the surface temperature of concrete and the ambient temperature is greater than 20℃, and the insulation covering maintenance measures should be taken。The quality of concrete not only needs the strict control of the mixing station, but also needs the support and close cooperation of the construction unit, and the above measures can ensure that high-quality concrete can be produced in winter。

Concrete mixing station is mainly composed of material storage system,Concrete mixing用途Material weighing system, material conveying system, mixing system, powder storage system, powder conveying system, powder metering system, water and admixture metering system and control system and other ancillary facilities。Mixing machine Mixing machine according to its mixing mode is divided into forced mixing and self-falling mixing。Forced mixer is the mainstream used in mixing stations at home and abroad.优质Concrete mixingIt can mix a variety of concrete such as fluid, semi-dry hard and dry hard。The self-falling mixing machine mainly mixes liquid concrete, which is rarely used in mixing stations。The forced mixer is divided into spindle planetary mixer, single horizontal shaft mixer and double horizontal shaft mixer according to the structural form。Among them, the double horizontal shaft forced mixer has good comprehensive performance。Weighing system Material weighing system is a key component that affects the quality of concrete and the cost of concrete production, which is mainly divided into three parts: aggregate weighing, powder weighing and liquid weighing。Under normal circumstances, the mixing station below 20 cubic meters per hour adopts the superposition weighing method, that is, the aggregate (sand, stone) is weighed with a scale, the cement and fly ash are weighed with a scale, the water and the liquid admixture are respectively weighed, and then the liquid admixture is put into the water weighing bucket before mixing。In the mixing station of more than 50 cubic meters per hour, the method of independent weighing of each material is used, and all weighing is controlled by electronic scales and computers。The weighing accuracy of aggregate is ±2%, the weighing accuracy of cement, powder, water and admixture is ±1%。

Concrete mixing stations are becoming more and more common, and more and more people are using concrete mixers。However, many people do not know how to clean a concrete mixer。First, before using the concrete mixer, check that the controller is in good condition。Concrete mixing用途After shutdown, pour the water and stones into the mixing bucket for 10 to 15 minutes for cleaning, and then remove the water and stones。When the operator needs to enter the mixing cylinder for cleaning, in addition to cutting off the power, remove the fuse, but also need to lock the switch box。Secondly, the concrete mixer should be regularly maintained, such as cleaning, lubrication, refueling and so on。Third, we must remember that the accumulation of concrete in the concrete mixing drum cannot be removed by hammering。We had to chisel it out。Fourth, winter use优质Concrete mixing用途Pay attention to cleaning the drum of the concrete mixer with water after the end of the work, and drain the water in the pump, water tank and water pipe to avoid frostbite of the pump, water tank and water pipe。

1) The ground screw bolt of the cement silo is poured into the reserved pit of the foundation. When the center line of the cement silo support is adjusted to coincide with the center line of the foundation, the above four flanges are adjusted on the same level (measuring method: theodolite or transparent plastic hose with diameter of 8-10 and color water measurement method), the concrete can be selected for casting。The grade of the concrete used in the reserved pit should be one level higher than the concrete used in the foundation, and in the winter construction, in order to shorten the construction period, the concrete used should be added with early strength antifreeze。Wait for the foundation concrete to set 5-7 days before installing the cement silo body. When installing the cement silo body, it is necessary to measure the verticality of the cement silo body with a theodolite. The verticality is one thousandth of the height。In order to shorten the construction period, embedded parts can also be used in infrastructure instead of anchor bolts to fix cement silos or mixers。(2) Installation of the mixing machine: the bottom plane of the mixer chassis is properly padded，Attach the legs to the main engine with hinges，Install the cement scale，水秤，After weighing the admixture，Ready to lift，Measure and adjust engine chassis，Make it horizontal，After the center line of each leg coincides with the center line of the foundation, the anchor bolt can be poured into the reserved pit (or welded between the base and the reserved embedded part)..(3) Installation of other parts: after the installation of the main engine and cement silo，Screw conveyor can be installed，Before hoisting，Check the filling of oil and grease at each lubrication point，An empty car running test is to be conducted，Find problems and solve them in time，Part of the dosing machine installation，Position as required by the foundation drawing，The small dosing machine can be placed on the solid foundation pier plane，Large batching machine requires pouring anchor bolts，After the installation of each mechanical part，Check that all lubrication points of various equipment are filled with lubricating oil (the lubricating oil suitable for low temperature conditions must be replaced in winter in Northeast China) or grease，Wiring and empty car running test can be performed according to the requirements of the manual and electrical schematic diagram.It can accurately and conveniently input, adjust and modify the set value and formula number of each material, and multiple common concrete ratios can be stored inside the microcomputer。2. 优质Concrete mixingThe control system has perfect self-locking and interlocking functions to ensure the accurate and reliable operation of the system, and has common fault detection and alarm functions。3. The whole mixing plant is equipped with a good lighting system, and the main control room, mixing area and material area are equipped with lighting。4. The concrete mixing plant uses microcomputer to control the timing requirements of the process, and realizes automatic control of the production process from measurement to feeding, mixing to discharging. The management of the entire production site of the mixing plant is completed by two operators and two auxiliary personnel。5.The weighing system of concrete mixing station is equipped with zero output.Concrete mixing用途Can automatically remove the tare weight, correct the drop, for the single weight single material weighing with a button and fill function, more effectively control the measurement accuracy, with a light alarm device。

The main characteristics of concrete mixing station are as follows: 1.优质Concrete mixing用途The combination structure, modular unit, installation, relocation is very convenient。2.Mixing machine and aggregate lifting adopts JS1000 type double horizontal shaft forced concrete mixer, which has good mixing quality and high efficiency。3.PLD1600 concrete batching machine is used for aggregate batching, which has accurate measurement and high production efficiency。4.Concrete mixing用途The powder is measured by electronic balance with high precision。5.The water is measured by electronic balance, and the batching precision is high。