1. The concrete conveying machine is used to firstly consider and pump the concrete mix ratio. In addition to meeting the design strength and durability requirements, the concrete should meet the pumpability requirements.
2. The mix design of concrete pumping concrete pumping should conform to the current national standard "Ordinary Concrete Mix Design Specification", "Concrete Structure Engineering Construction and Acceptance Specifications",
Relevant provisions of "Concrete Strength Inspection and Evaluation Standards" and "Premixed Concrete". And should be based on concrete raw materials, concrete conveying distance, concrete pump and concrete distributing machine
The concrete pipe diameter, pumping distance, concrete cloth machine specifications and temperature, and other specific construction conditions are tested. If necessary, the pumping concrete mix ratio should be determined by trial pumping.
3. The pumpability of concrete can be controlled by pressure drowning test combined with construction experience. Generally, the relative pressure drip rate S10 at 10s should not exceed 40%.
4. The slump of concrete pumped by concrete paver can be selected according to the current national standard “Construction and Acceptance Specifications for Concrete Structure Engineering”.
5. The minimum cement consumption for pumping concrete should be 300KG/m3.
6. Pumping concrete should be mixed with appropriate amount of admixture, and should comply with the current national standard "Concrete Pumping Agent". The variety and dosage of admixtures should be determined by experiment and should not be used arbitrarily.
7. The gas content of pumped concrete mixed with air-entraining agent type admixture should not exceed 4%.
8. The mix design of pumped concrete with fly ash must be determined by trial and match, and should comply with the current national standards, “Technical Regulations for Application of Fly Ash in Concrete and Mortar”, “Technical Specifications for Application of Concrete Admixtures”, Ordinary concrete mix design rules and other relevant provisions.