Modified malt syrup retarder as well as preparation method and application thereof

Abstract

The invention discloses a modified maltose syrup retarder as well as a preparation method and application thereof. The modified maltose syrup retarder is prepared from maltose syrup, acrylic acid, an activating agent, unsaturated acid, esters, acrylamide, an initiator, deionized water and liquid caustic soda in a mass part ratio of (79-157):(10-40):(0.5-3.2):(40-80):(20-40):(20-40):(1-5):(500-750):(8-15). The preparation method comprises the following steps: putting malt syrup and acrylic acid into a No.1 reaction kettle according to the mass part ratio of (4-8):1, further adding an activating agent which is 0.5-2% of the total amount of the malt syrup, heating to 70-90 DEG C, stirring and reacting for 4 hours, and cooling to room temperature to obtain an intermediate product A; then adding the intermediate product A, unsaturated acid, esters, acrylamide, an initiator and deionized water in a mass ratio of (100-200):(40-80):(20-40):(20-40):(1-5):(500-750) into a No.2 reaction kettle, heating to 85-90 DEG C, stirring the mixture to react for 4 hours, cooling a reaction product to room temperature, and regulating the pH value to be about 7 by using liquid caustic soda to obtain the modified malt syrup retarder.

Description

technical field [0001] The invention relates to the technical field of retarders for concrete, in particular to a modified maltose syrup retarder and its preparation method and application. Background technique [0002] Since concrete retarder is an admixture that can delay the hydration reaction of cement and will not cause adverse effects on the performance of concrete in the later stage, concrete retarder is widely used in engineering construction. Concrete retarder prolongs the setting time of concrete by delaying the hydration reaction of cement, so that freshly mixed concrete can maintain plasticity for a long time, which is convenient for pouring and improves construction efficiency. According to different chemical compositions, concrete retarders are divided into inorganic concrete retarders and organic concrete retarders. Commonly used retarders include hydroxycarboxylic acids, aminocarboxylic acids, aminocarboxylates, polyols, polyol derivatives and sugars. Sugar...

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Problems solved by technology

Sugar retarders contain a large amount of -OH and -COOH in the molecular structure, so the coagulation accelerator effect is extremely strong, but this kind of retarder has poor high temperature resistance, poor adaptability to water reducing agents, and high dosage will inhibit water reducing , affecting the concrete strength

[0003] In the prior art, sodium gluconate is the retarder with the widest range of use and the most dosage. The dosage is small and the retarding effect is remarkable. However, the sodium gluconate retarder has the hidden danger of overdoping, and the dosage is very sensitive. Insufficient coagulation, super retarded coagulation easily occurs at low temperature, poor adaptability to coarse sand or river sand, high production cost

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