Retarder used in the preparation of sulfoaluminate cement quick-hardening concrete

Abstract

A retarder used in the preparation of sulphoaluminate cement rapid hardening concrete. The preparation includes: selecting ultra-high-strength sulfoaluminate cement; designing the mix ratio and trial mixing concrete; at the mixing station, adding water reducer and retarder to the concrete according to the mass ratio of cement; when the concrete is transported to the construction site Finally, add early strength agent to concrete according to a certain mass ratio with cement. The retarder is used to manually add to the concrete in the mixing station, and its component is boric acid, and the dosage of the boric acid matched with the ambient temperature is 0.3-0.6% of the cement mass. In the preparation process of sulphoaluminate cement rapid hardening concrete, the fine control technology of adding retarder and early strength agent in stages is adopted to precisely control the setting time of concrete, which can not only meet the needs of commercial concrete production and transportation, but also Guarantee the construction operation time of the construction site and the need for the final rapid opening to traffic.

Description

technical field [0001] The invention relates to a special retarder used in the preparation of sulphoaluminate cement rapid hardening concrete. Background technique [0002] Urban traffic is an important component of road transportation, and smooth roads are crucial to urban construction and the healthy travel of citizens. However, due to insufficient understanding and attention to structural durability in the 1970s and 1980s, coupled with the increasing traffic load pressure, the urban road bridges built have serious fractures and broken roads with the increase in service life. If it is not repaired in time, it will affect the normal driving of the vehicle and even endanger driving safety. As far as the urban area of ​​Beijing is concerned, according to incomplete statistics, there are currently more than 100 overpasses in urgent need of maintenance. However, the traffic pressure in modern cities is very high, especially for the hubs of urban arterial roads, and the mainte...

AI Technical Summary

Problems solved by technology

Another traditional repairing method is to remove the damaged concrete and lay new ordinary concrete with the same or higher grade as the original design, but this will bring the following problems: (1) large shrinkage, which will easily lead to the failure of new and old concrete Pull it apart; (2) The cement concrete itself has low viscosity and poor bonding with the old concrete; (3) The interface defects between the old and new concrete are easy to make the concrete crack; (4) The curing period is long (generally takes 14 days)

This brings great inconvenience to the busy traffic and often causes traffic jams

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