Sulfoaluminate cement composite early strength agent and early strength sulfoaluminate cement

Abstract

The invention relates to a sulfoaluminate cement composite early strength agent and early strength sulfoaluminate cement. The sulfoaluminate cement composite early strength agent is prepared from the following components in parts by weight: 0.15 to 0.3 part of a promoter, 1 to 3 parts of a dense agent and 0.05 to 0.1 part of a conditioner. The early strength sulfoaluminate cement is prepared from sulfoaluminate cement and the sulfoaluminate cement composite early strength agent, and is particularly prepared from the following components in parts by weight: 100 parts of the sulfoaluminate cement, 0.15 to 0.3 part of the promoter, 1 to 3 parts of the dense agent and 0.05 to 0.1 part of the conditioner. By the synergistic action of the three components, the sulfoaluminate cement composite early strength agent promotes early hydration of the sulfoaluminate cement and rapid formation of ettringite and maintains the compactness of the structure of hardened paste, so that the sulfoaluminate cement obtains relatively high hour strength, and the later strength cannot be reduced or is slightly reduced.

Description

technical field [0001] The invention relates to the field of sulphoaluminate cement, in particular to a composite early strength agent for sulphoaluminate cement and early strength sulphoaluminate cement. Background technique [0002] Sulphoaluminate cement (iron-containing aluminate cement) is anhydrous calcium sulphoaluminate cement, which is calcined at low temperature (1300-1350°C) with limestone, bauxite and gypsum as the main raw materials. and dicalcium silicate (C 2 S) is a hydraulic cementitious material composed of clinker mainly composed of minerals, mixed with appropriate amount of gypsum and mixed materials and ground together. This series of cement has excellent properties such as low temperature hardening, early strength and quick hardening, frost resistance, and impermeability. According to reports, in terms of strength development, the 12h-1d compressive strength can reach 35-50MPa, the flexural strength can reach 6.5-7.5MPa; the 3d compressive strength ca...

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Problems solved by technology

[0003] However, the 6h strength of normal sulphoaluminate cement is generally 6-15MPa. For fast-setting rapid-hardening sulphoaluminate cement that requires an hourly strength (such as 4h) with a maximum strength of more than 20MPa, the normal production of sulphoaluminate cement Can no longer meet the early strength requirements

[0004] In order to improve the early strength of sulphoaluminate cement, in addition to changing the mineral composition of sulphoaluminate cement clinker and adjusting the cement components, there have been a lot of researches at home and abroad on the use of admixtures. Studies have shown that sodium sulfate, sodium nitrite, Lithium carbonate, sodium nitrite, etc. have good early strength effects, but will lead to a sharp drop in later strength

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