Concrete early strength agent and preparation method thereof

Abstract

The invention discloses a concrete early strength agent and a preparation method thereof. The concrete early strength agent is prepared from the following components in parts by weight: 1-3 parts of sodium chloride, 1-3 parts of sodium nitrite, 10-20 parts of sodium sulfate, 3-6 parts of calcium chloride, 2-6 parts of urea, 5-15 parts of methacrylic acid, 1-3 parts of silane, 1-5 parts of calcium gluconate, 1-5 parts of triisopropanolamine, 5-10 parts of fatty glyceride, 50-80 parts of polycarboxylate superplasticizer and 2-4 parts of finely grinded cement stone. The concrete early strength agent has the beneficial effects of rapidly drying concrete even in a low-temperature environment.

Description

technical field [0001] The invention relates to a cement external admixture, in particular to a concrete early strength agent and a preparation method thereof. Background technique [0002] Generally speaking, concrete engineering accounts for about half of the entire civil engineering, so the hardening speed of concrete plays a very important role in shortening the construction period of civil engineering. At present, there are many external admixtures used in China to improve the early strength of concrete at 10-40°C, such as cement-water glass slurry early strength agent, which has the advantages of short setting time and high setting rate. Over the years, concrete early strength agents have been widely used in soft soil reinforcement, well wall grouting, water seepage accident treatment, etc., and solved many key problems. Because the concrete mix is ​​cured mainly by the silicate in sodium silicate and the Ca produced by the hydration of cement. 2 + The reaction takes...

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Problems solved by technology

Because the concrete mix is ​​cured mainly by the silicate in sodium silicate and the Ca produced by the hydration of cement. 2 + Reaction occurs to form C-S-H gel to maintain, so the cement-water glass slurry has the problems of low low-temperature strength and poor durability of stone bodies

At a low temperature of approximately 4°C, the hydration reaction of ordinary cement almost stops, and the silicate and Ca in sodium silicate 2 + The amount of C-S-H gel produced by the reaction is seriously insufficient, resulting in low-temperature strength of concrete

At the same time, the calcium content in cement is fixed, and the amount of calcium hydroxide generated by hydration and the reaction between sodium silicate and calcium hydroxide is also certain. Too much sodium silicate is not beneficial to the strength of the stone body, but may make the system decrease in strength

This is because the C-S-H gel needs high alkalinity to maintain its stable existence, and the dissolution of NaOH will cause the C-S-H gel to decompose, resulting in the destruction of the structure

When the concrete material is under low-temperature dry conditions, the silica gel will be dehydrated, and the volume of the stone body will shrink and produce cracks, resulting in the pulverization of the stone body and failing to form effective strength.

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