How to use the performance of concrete pumping agent

Pumping agent is also called concrete pumping agent. It is an admixture that improves the pumping properties of concrete mixtures. Since its advent in the 1960s, concrete pumping technology has undergone earth-shaking changes after half a century of research by scientific researchers and engineering practitioners. Pumping concrete requires the concrete to have greater fluidity and maintain this performance for a long time, that is, the slump loss is small, the viscosity is good, and the concrete does not segregate or bleed. To achieve this, only rely on It is not enough to adjust the concrete proportion, you must rely on concrete admixtures, especially concrete pumping agents. It is difficult for a single-component admixture to meet the performance requirements of pumped concrete.

In order to meet performance requirements, concrete pumping agents are mainly composed of water-reducing agents, water-retaining agents, air-entraining agents and retarders.

　(1) Water-reducing agent, adjust workability and strength to meet engineering needs;

　(2) Air-entraining agent, appropriate air content can reduce the pumping resistance during concrete pumping, prevent concrete bleeding and segregation, and also improve the ability of concrete to resist damage from freeze-thaw cycles;

　(3) Retarder: Due to the need for long-distance transportation of commercial concrete, it is necessary to delay its setting time and reduce slump loss, especially for large-volume concrete and high-temperature construction projects in summer. ;

　 (4) Water-retaining agent, its function is to increase the viscosity of the concrete mixture, so that the concrete can be used under low cementing material dosage and large slump conditions. No bleeding or segregation

The following editor will introduce to you how to use the pumping agent.

1. Add the appropriate amount of water in the table below into the discharge hopper of the concrete delivery pump (car pump, trailer pump or vehicle-mounted pump), start the hopper mixing system, and slowly Slowly add this product, stir for 5 minutes, and then let it sit for a while to make the solution viscous (or add an appropriate amount of water in the table below in a plastic bucket, stir with a wooden stick and slowly add this product, stir for 5 minutes, and let it stand for a while) , make the solution thicker, and then pour it into the unloading hopper).

　2. Unload a small amount of concrete, squeeze the solution into the pump pipe, start the pumping system, and pump the concrete until the solution and the unloaded concrete are about to be pumped out. , continue to unload the concrete and pump continuously until it is opened to avoid material interruption and air intake.

　3. The lubricating agent solution discharged through the pump pipe and the initially unloaded part of the concrete should be discharged outside the building structure.

Performance of concrete pumping agent

According to the standard GB/T 8075-2005 “Concrete “Admixture Definition, Classification, Nomenclature and Terminology” related content, concrete pumping agent is an admixture that can improve the pumping performance of concrete mixture. Based on the above mentioned, concrete pumping agent should meet the following five performance requirements.

　(1) Good water reduction rate;

　(2) Has a certain slump High degree of retention, small slump loss over time;

　(3) Air entrainment meets requirements;

　(4) The setting time of concrete after pouring is appropriate;

　(5) The strength of concrete develops well.

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