Sleeve grouting material for negative temperature reinforcing steel bar connection and preparation method thereof

Abstract

The invention relates to a sleeve grouting material for negative temperature reinforcing steel bar connection, wherein the sleeve grouting material comprises 12-29% of ordinary cement, 14-35% of special cement, 33-49% of an aggregate, 5-12% of a modification admixture, 0.01-0.075% of an early expansion component, 2-5% of a middle-later expansion component, 0.25-1.55% of an antifreeze agent and 0.35-0.7% of a function component according to the weight percentage. The modification admixture comprises an organosilane coupling agent, modified nano-silica and ultra-fine slag powder; the modified nano-silica is prepared by soaking nano-silica in a potassium hydroxide and / or sodium hydroxide saturated solution at room temperature, carrying out ultrasonic dispersion and mixing, then filtering, taking a filter residue, drying the filter residue, keeping the temperature constant at high temperature for 8 h, and then dropping to room temperature. The grouting material has good fluidity when beingmixed with 0 DEG C water at the temperature of -10 DEG C, is directly maintained for 1 d and 7 d at the temperature of -10 DEG C, then is maintained for 7 d at the temperature of -10 DEG C and then is transferred to 20 DEG C water and maintained for 28 d; the physical properties of the grouting material at all ages of maintenance at the temperature of -10 DEG C are better than those of conventional grouting materials; the grouting material, a mould and apparatus are not needed to be heated or insulated, so the cost is effectively reduced and the efficiency is improved.

Description

technical field [0001] The invention relates to the technical field of cement-based building materials, in particular to a negative temperature sleeve grouting material and a preparation method thereof. Background technique [0002] In recent years, the recognition of prefabricated concrete structures from all walks of life has gradually increased, and the sleeve grouting connection technology of steel bars has been more and more widely used. As a kind of steel sleeve bonding material, the importance of sleeve grouting materials is gradually increasing. stand out. [0003] Sleeve grouting construction should generally be carried out at an environment above 5°C. The relevant domestic industry standards also stipulate that the ambient temperature should not be lower than 5°C during grouting construction; when the curing temperature of the connection part is lower than 5°C, heating and heat preservation should be adopted. measure. However, affected by the temperature and the ...

AI Technical Summary

Problems solved by technology

The grouting material provided by the invention needs to control the temperature of the mixing water at 10°C; the minimum temperature for mechanical performance testing is -5°C, and when the ambient temperature is lower than -10°C, the mechanical properties are difficult to meet the requirements

[0005] Another example is the invention patent "Sleeve grout for steel bar connection and its preparation method" with the patent number "201710895233.6", which provides a sleeve grout for non-shrinkage steel bar connection at (-10-5) ° C, but the There are some defects and inconveniences in the use of materials: the dry powder material needs to be kept at a constant temperature of 5°C for 24 hours; the temperature of the mixing water needs to be controlled at 20°C; it needs to be cured at 0°C for 5 hours before it can be placed at -10°C Continue to maintain

[0006] Some of the sleeve grouting materials for steel bar connection provided by the prior art cannot meet the lower temperature environment, and some use and maintenance processes are very complicated, which seriously restrict the use scenarios and application scope of the sleeve grouting material for steel bar connection , which affects the connection quality of the steel bar connection in the low temperature environment

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