Concrete composition and method for preparing same

Abstract

Provided is a concrete composition which comprises a binder, water, a fine aggregate, a coarse aggregate and an admixture, wherein the water / binder ratio is 30-70 mass%, the slump flow value is 35-75cm, and a single component admixture, which uses component A, component B, component C, component D and water and in which the ionic strength derived from component A is 0.02-0.8, is contained at a proportion of 0.5-3.0 parts by mass relative to 100 parts by mass of the binder. Component A: A polycarboxylic acid-based water-reducing agent comprising: a copolymer of an unsaturated monocarboxylic acid monomer and / or an unsaturated dicarboxylic acid monomer and / or a salt of these; and an unsaturated monomer which can be copolymerized therewith and which has a polyoxyalkylene group constituted from 1-300 C2-4 oxyalkylene units per molecule, and / or a salt of the copolymer. Component B: A water-soluble cellulose ether. Component C: A gum. Component D: An anti-foaming agent.

Description

technical field [0001] The present invention relates to a concrete composition and a preparation method thereof, in particular to a concrete composition with high fluidity and improved material separation resistance, and a preparation method of the concrete composition. Background technique [0002] In recent years, in order to improve operability and save labor, concrete compositions with medium fluidity (slump flow value of about 35 to 50 cm) or high fluidity concrete compositions (slump flow value of about 50 cm to) have been used. Examples of highly fluid concrete compositions are progressively increasing. Tunnel lining construction can be cited as an example. When pouring in a small space with poor operability, by using a highly fluid concrete composition, the high fillability can be used to improve operability and save labor for compaction. However, such highly fluid concrete compositions tend to segregate materials such as aggregates. The segregation of the material...

AI Technical Summary

Problems solved by technology

However, the stability of active ingredients such as viscosity-increasing components and water-reducing components in a one-component admixture is very important for the stabilization of the properties and physical properties of concrete compositions. However, as described in Patent Document 4, in In the combination with water reducing agent, cellulose ether is prone to salting out, causing problems such as the loss of stability of the single-liquid admixture in a short period of time

In addition, as described in Patent Document 5, the conventional method of increasing the viscosity of the liquid through a specific glue to stabilize the cellulose ether in the liquid, although it improves the stability of the single-liquid type admixture, is difficult to apply to all general Commercially available water reducing agents, so there are problems such as the need to select water reducing ingredients with low solid content concentration

If a water-reducing component with a low solid content concentration is selected, the water-reducing performance of the single-liquid type admixture will decrease. Especially when preparing a concrete composition with high fluidity, the concrete manufacturer cannot use a measuring device due to the increase in the amount of addition. One-time measurement, etc., which causes reduction in production efficiency of concrete compositions

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