Nano C-S-H seed crystal early strength agent for building concrete and preparation method thereof

Abstract

The invention relates to the field of concrete additives, and discloses a nano C-S-H seed crystal early strength agent for building concrete and a preparation method thereof. The preparation method comprises the following steps that (1) acrylic monomer, a silane coupling agent, modified polyoxyethylene ether are added into ammonium persulfate, vitamin C and dodecyl mercaptan to prepare a polymer solution; (2) sodium metasilicate is prepared into a solution A of which mass concentration is 45-50%, and calcium nitrate is prepared into a solution B of which mass concentration is 30-40%; (3) the solution A and the solution B are added into the polymer solution, and the uniform and stable nano C-S-H seed crystal early strength agent for the building concrete is prepared through reaction. Compared with an ordinary early strength agent, the nano C-S-H seed crystal early strength agent for the building concrete has the advantages that the grain size of the particles is small, the distributionis uniform, the reaction process of the cement hydration can be accelerated, the early strength is significantly improved, no electrochemical corrosion phenomenon exists, the production efficiency isgreatly improved, the late strength of concrete members is not affected, and the production and application can be promoted.

Description

Technical field [0001] The invention relates to the field of concrete additives, and discloses a nano C-S-H seed early strength agent for construction concrete and a preparation method thereof. Background technique [0002] Concrete early strength agent is one of the main varieties of concrete admixtures. So far, the early strength admixtures developed at home and abroad mainly include: inorganic salt early strength agents such as chloride, sulfate, nitrite, and silicate; organic early strength agents such as triethanolamine, calcium formate and urea; A variety of composite early-strength additives, such as early-strength water reducer, early-strength antifreeze and early-strength pumping agent. [0003] In the construction process of concrete, it takes a long time from the setting and hardening caused by hydration to the expected strength. Adding an early strength agent can significantly increase the early strength of the concrete, thereby shortening the curing time. The early s...

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Problems solved by technology

[0007] According to the above, the traditional calcium salt, chloride salt and other inorganic early strength agents in the existing scheme have a significant effect and can increase the turnover rate of the formwork, but they introduce a large amount of impurities that can participate in or promote electrochemical reactions to the concrete, which is harmful to key reinforcements (such as steel bars) etc.) cause large electrochemical corrosion, which seriously affects the quality of concrete components. The present invention proposes a nano C-S-H seed crystal early strength agent for building concrete and a preparation method, which can effectively solve the above technical problems

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