Crystal nucleal procoagulant early strength agent for concrete and preparation method thereof

Abstract

The invention discloses a crystal nucleal procoagulant early strength agent for concrete and a preparation method thereof. The crystal nucleal procoagulant early strength agent is prepared from calcium nitrate, sodium silicate and a 18# early strength polycarboxylate water reducing agent, and is characterized in that the parts of the materials used during preparation by weight are as follows: 1.55parts of calcium nitrate, 1.24 parts of sodium silicate and 1 part of 18# early strength polycarboxylate. The crystal nucleal procoagulant early strength agent has the beneficial effects as follows:a hydration nucleation barrier of cement is greatly reduced, the procoagulant effect is obvious, and the early strength increase is better than that of the conventional early strength agent; on one hand, a templating agent in the synthesis process is provided for controlling the growth and the morphology of crystals, and on the other hand, together with C-S-H crystal nuclei in concrete, the crystal nucleal procoagulant early strength agent achieves a synergistic effect on early strength; the crystal nucleal procoagulant early strength agent not only can effectively improve the early strength of the concrete, has no negative effect on late strength, but also can effectively avoid corrosion on steel bars and the concrete, can avoid efflorescence and an alkali-aggregate reaction, and has theadvantages of good cement adaptability, small dosage sensitivity and the like; the preparation process is simple, and the cost is low.

Description

technical field [0001] The invention relates to a crystal nucleus type coagulation accelerator accelerator for concrete and a preparation method thereof, belonging to the technical field of concrete admixtures. Background technique [0002] Concrete early strength agent is one of the earliest admixtures used in the history of admixture development. It can accelerate the hydration and hardening of cement and effectively improve the early strength of concrete. It plays an indispensable role in concrete products in various construction projects, road and bridge projects, municipal projects, water conservancy projects, and concrete projects that require low temperature, negative temperature construction and need to speed up the progress of the project. [0003] So far, the existing early strength agents in my country mainly include inorganic salt early strength agents, organic early strength agents and composite early strength agents. However, there are many defects and limitat...

AI Technical Summary

Problems solved by technology

However, there are many defects and limitations in the use of these accelerators. For example: inorganic salt accelerators are mainly divided into chloride salts, sulfates, nitrates and carbonate accelerators. Chlorides will It accelerates the corrosion of steel bars and is limited in use; the early strength effect of sulfate is poor, and the excessive dosage will cause the reduction of concrete work performance, frosting on the concrete surface, alkali-aggregate reaction, coarsening of the pore structure in the later stage of concrete, and a significant reduction in later strength ; The introduction of too much nitrate ions by nitrate early strength agent can easily lead to the corrosion of concrete; carbonates can easily lead to false setting of cement, stress corrosion and lattice corrosion

Organic early strength agents are mainly alcohol amines, which are generally not mixed alone. They are usually used in combination with inorganic early strength agents. The dosage is very sensitive, and there is a problem of cement adaptability. If the dosage is not appropriate, the concrete will be severely retarded.