Usually concrete companies have the following three levels of potential in controlling cost of concrete: Water reducing agents commonly used in mixing plants are usually purchased internally. For a concrete mixing station with an annual production capacity of 400,000 to 500,000 cubic meters, the cost of biological water-reducing agents over the years is about 6 million yuan. Generally, the profit margin of biological water-reducing agent products is about 35%. If the concrete mixing station is built The water-reducing agent factory has its own biological water-reducing agent, which can only increase the net profit by about 2 million yuan over the years, and the cost can be reduced to about 4 yuan per cubic meter of concrete. If a biological water-reducing agent factory is established in a concrete mixing station, the best and most tertiary biological water-reducing agent can be customized according to the concrete, admixture, sand, and stone conditions. In this way, based on biological water-reducing The water agent improves and stabilizes the quality of the concrete while reducing the profit of the water-reducing agent. Mastering the compounding process of various types of water-reducing agents is the way of life for every commercial and mixed enterprise and mixing plant today when they are increasingly unable to "rest on their own money". It is also the direction of competition in the future!
Compound pumping agent
Configuration standards: have certain water reduction rate, slump Drop maintenance properties, low water pressure bleeding and necessary air entrainment properties. Namely: water reduction, plastic preservation, water locking, and air entrainment.
Basic composition: water-reducing component + retardant component + air-entraining component + other modifiers.
Water-reducing components include: lignocellulose, naphthalene-based high-efficiency water-reducing agent, sulfonated sodium thiocyanate high-efficiency water-reducing agent, and sulfamate High-efficiency water-reducing agent, aliphatic high-efficiency water-reducing agent, etc.
Retarding components: lignocellulose, glycogen, phosphate, tartrate, gluconate, citric acid and salts, cellulose and derivatives Things etc.
Water-locking components: various water reducing agents, cellulose and derivatives, etc.
Air-entraining components: Wensha resin (pine soap), alkyl sulfonate, alkyl benzene sulfonate, lignocellulose, etc. .
Efficacy of water-reducing component:
Under the condition of necessary water-binder ratio, ensure mixing The workability of the soil meets the construction technical requirements. For different concrete and admixtures, use consistent water-reducing components, and the dosage should be arbitrary.
Function of retarding component:
Control slump damage and initial setting of concrete time to ensure smooth progress of transportation and pumping. When using different raw materials and different mix ratios, appropriate retardant components should be used in appropriate quantities to avoid problems with abnormal concrete adaptability and initial setting time. When used together with water-reducing components, the water-reducing rate increases.
Water locking component function:
Adjust water locking according to the test mixing conditions of the concrete The type and dosage of components ensure that the workability of the concrete meets the requirements. When naphthalene-based water-reducing agent and sodium gluconate are used together, the water-reducing rate increases significantly. This material includes several categories:
(1) The content of polyvinyl alcohol is less than 0.3%, which has retarding and thickening effects.
(2) The dosage of methylcellulose and carboxymethylcellulose is not large, accounting for only 0.01-0.05% of the concrete dosage.
(3) Hydroxypropyl viscose reduces slump loss and improves consistency. The dosage is 0.01%. There are also dextrin and xylitol mother liquors. , animal glue, etc.
Efficacy of air entrainment component:
Moderate air entrainment can improve the concrete pump It improves performance and workability, and has great benefits on the performance of concrete. There is a certain water reduction rate. Generally, it is appropriate to make the air content of concrete around 2 to 3%, which not only does not affect the strength of the concrete, but also significantly improves various properties of the concrete. When configuring a water-reducing agent, consider its adaptability to various raw materials and pay attention to the interaction between different ingredients.
The air-entraining effect of air-entraining agents is affected by many factors, such as cement fineness, stone particle size, sand mud content, temperature, mix ratio, etc. When fly ash is added, there are many coarse materials, small stone particles, large slump, poor temperature, etc., the air content of the concrete will be high. In other words, the adjustment of the water-reducing agent should be carried out according to the actual situation and based on the experimental results and cannot be subjective.
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