What are the contents of ultra-high pumping concrete technology?

Ultra-high pumping concrete technology is a comprehensive technology, including concrete preparation technology, pumping parameter calculation, pumping machinery selection and debugging, pump pipe arrangement and process control.

1. Main technical contents

Concrete preparation and performance requirements

(1) Selection of raw materials

Cement with high C2S content should be selected, which has a significant effect on improving the fluidity of concrete and reducing slump loss. Coarse aggregate should be graded continuously, needle content should be controlled, and the ratio of maximum particle size to pumping pipe diameter should be considered. Fine aggregate is medium sand, fine sand will dry concrete, while coarse sand will easily isolate concrete; Using mineral admixtures with excellent properties, such as mineral powder, silicon powder, first-class fly ash, etc., can make concrete have good workability; Polycarboxylic acid pumping agent with high water reducing rate and long plastic retention time should be preferred as admixture, and the pumping agent should have good compatibility with cement and admixture.

(2) Preparation of concrete

By optimizing design and technological measures, the prepared concrete has good workability, high fluidity and low viscosity.

But there is no segregation and bleeding phenomenon, so the flow resistance is small and easy to pump.

(3) Selection of pumping equipment and arrangement of pump pipes

The selection of pumping equipment should refer to Technical Specification for Concrete Pumping Construction (JGJ/T 10).

It is stipulated in the technical conditions that the pumping parameters should be checked first, including the model and pumping capacity of concrete pump, horizontal pipeline pressure loss, vertical pipeline pressure loss, special pipeline pressure loss and pumping efficiency.

(4) Process control of pumping construction

The performance of concrete is the first level of smooth pumping. The slump, expansion rate and air content of concrete should be tested, and measures should be taken in time if there is any abnormality. During the pumping process, it is necessary to check the pressure change of the pump truck, whether the pump pipe leaks water and slurry, and the joint condition in real time, and handle the problems in time when found.

2. Technical indicators

(1) concrete mixture has good workability, no segregation and bleeding, slump of 180 ~ 200mm, and high pumping height.

Over 300 meters

Yes, the slump should be > > 240mm, the paving degree should be > > 600mm, and the falling time of concrete by inverted cone method should be < < 15s.

The development of ultra-high pumping concrete technology is a comprehensive technology, including concrete preparation technology, pumping parameter calculation, pumping machinery selection and debugging, pump pipe arrangement and process control.

1. Main technical contents

Concrete preparation and performance requirements

(1) Selection of raw materials

Cement with high C2S content should be selected, which has a significant effect on improving the fluidity of concrete and reducing slump loss. Coarse aggregate should be graded continuously, needle content should be controlled, and the ratio of maximum particle size to pumping pipe diameter should be considered. Fine aggregate is medium sand, fine sand will dry concrete, while coarse sand will easily isolate concrete; Using mineral admixtures with excellent properties, such as mineral powder, silicon powder, first-class fly ash, etc., can make concrete have good workability; Polycarboxylic acid pumping agent with high water reducing rate and long plastic retention time should be preferred as admixture, and the pumping agent should have good compatibility with cement and admixture.

(2) Preparation of concrete

By optimizing design and technological measures, the prepared concrete has good workability, high fluidity and low viscosity.

But there is no segregation and bleeding phenomenon, so the flow resistance is small and easy to pump.

(3) Selection of pumping equipment and arrangement of pump pipes

The selection of pumping equipment should refer to Technical Specification for Concrete Pumping Construction (JGJ/T 10).

It is stipulated in the technical conditions that the pumping parameters should be checked first, including the model and pumping capacity of concrete pump, horizontal pipeline pressure loss, vertical pipeline pressure loss, special pipeline pressure loss and pumping efficiency.

(4) Process control of pumping construction

The performance of concrete is the first level of smooth pumping. The slump, expansion rate and air content of concrete should be tested, and measures should be taken in time if there is any abnormality. During the pumping process, it is necessary to check the pressure change of the pump truck, whether the pump pipe leaks water and slurry, and the joint condition in real time, and handle the problems in time when found.

2. Technical indicators

(1) concrete mixture has good workability, no segregation and bleeding, slump of 180 ~ 200mm, and high pumping height.

Over 300 meters

Yes, the slump should be > > 240mm, the paving degree should be > > 600mm, and the falling time of concrete by inverted cone method should be < < 15s.

(2) The physical and mechanical properties of hardened concrete meet the design requirements.

(3) The concrete conveying displacement, conveying pressure and pump pipe arrangement should be based on accurate calculation, and a detailed implementation plan should be formulated to carry out pumping test at simulated elevation.

3. Scope of application

Ultra-high pumping concrete is suitable for all kinds of ultra-high-rise buildings with pumping height greater than 200m m m.