Molding method of high-density and low-porosity concrete

Abstract

The invention discloses a molding method of high-density and low-porosity concrete. The molding method comprises the following steps : (1) adopting the total mass of the concrete as a reference, adding 0.05%-0.1% of a powder defoaming agent into the concrete, adjusting the use amount of a water reducing agent to control the slump of the concrete to 30-120mm, and controlling stirring time; (2) placing a test mold on a vibrating platform, pouring newly-stirred concrete into the test mold by two or more layers; (3) at every completion of pouring of one layer, starting the vibrating platform for vibration till defects in the concrete are filled, and discharging macroscopic bubbles; (4) stopping the vibrating platform, carrying out inserting and tamping on the concrete, wherein inserting and tamping are performed once at every 100-150mm in the form of a rectangular lattice; starting the vibrating platform after all parts of the concrete layer are inserted and tamped, vibrating till the concrete is dense and a surface is smooth; (5) repeating the steps (3) and (4) till the concrete is poured completely, and when the concrete above a second layer is inserted and tamped, inserting an inserting and tamping head to a position 0.1m below the surface of the former layer of concrete.

Description

technical field [0001] The invention belongs to the technical field of high-performance concrete preparation, and in particular relates to a molding method of high-density and low-porosity concrete (product). Background technique [0002] Concrete vibrating and compacting is an important link in the concrete production process. The traditional vibrating and compacting method has a relatively rough process, which is prone to honeycomb, holes, pockmarks and other phenomena, which seriously affects the safe use of concrete structures. The reasons mainly include the following reasons: (1) The performance of the concrete mixture is poor, the vibration method and process are unreasonable, and the concrete is not dense; (2) The air-entraining phenomenon of the concrete admixture is serious, which leads to the failure of the concrete mixing The material contains a large number of closed pores, which cannot be effectively eliminated. When the amount of admixture is too large, new air...

AI Technical Summary

Problems solved by technology

[0002] The vibrating and compacting of concrete is an important link in the concrete production process. The traditional vibrating and compacting method has a relatively rough process, which is prone to honeycomb, holes, pockmarks, etc., which seriously affects the safe use of concrete structures.

The reasons mainly include the following reasons: (1), the performance of the concrete mixture is poor, the vibration method and process are unreasonable, and the concrete is not dense; (2), the air-entraining phenomenon of the concrete admixture is serious, which leads to The material contains a large number of closed pores, which cannot be effectively eliminated. When the amount of admixture is too large, new air bubbles will be generated during the vibration compaction process.

(3) The same vibration compaction method is used for concrete with different mixture properties, which is poorly targeted, resulting in poor vibration compaction effect of concrete

However, the traditional vibration method cannot achieve such a high-precision requirement. Therefore, in order to meet the requirements of special working conditions or experiments, it is necessary to develop a high-density and low-porosity concrete forming process.

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