Pumped commercial concrete has become the mainstream of commercial concrete due to its convenience and efficiency in construction. Usually before starting to pump concrete, the residual pipe washing water and possible remaining fine sand, stones, etc. in the pump pipe need to be cleaned in advance. At the same time, the inner wall of the delivery pump must be moistened or lubricated. Common methods include: (1) Use mortar with the same mix ratio as the concrete as pipe moistening mortar. Before pumping the concrete, pump the pipe moistening mortar through the pump pipe first, and then pump the concrete. The problem with mortar lubricating agent is that the amount of mortar used for each lubricating pump is 0.5-2m3. Since the lubricating mortar is usually mixed with an unknown amount of water and sand, the strength and other properties are damaged and cannot be used for building structures and recycling. Preparing concrete and discarding it at will will cause serious environmental pollution problems. (2) Use a lubricant to form a water-rich paste on the pipe wall through the paste lubricant. At the same time, the front-end paste will push the water and sediment in the pump to be discharged from the outlet end of the pump tube.
Chinese patent discloses a lubricating agent for long-distance transportation of wet sprayed concrete. Its formula is: water reducing agent component, thickener component, stable The water reducing agent component is sodium lignosulfonate, the thickener component is polyvinylpyrrolidone, the stabilizer component is citric acid monohydrate, and the lubricant component is sodium stearate. . This patented technology uses an acidic stabilizer, citric acid monohydrate, which increases the risk of negative effects on concrete strength and other properties after mixing with concrete. The lubricating agent is composed of a water-reducing agent component and a thickening agent component. The main component has the characteristics of high viscosity. When it does not fully absorb water, it will easily absorb the moisture in the concrete after contact with the concrete, resulting in changes in the performance of the concrete and even failure of the pump.
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