Brief introduction of Concrete Shrinkage Reducer
Brief introduction of Concrete Shrinkage Reducer
Key words
Concrete shrinkage reducer, shrinkage reducer, concrete shrinkage cracks, concrete autogenous shrinkage, drying shrinkage
Causes of concrete cracks
The demand for high-strength, high-performance concrete and self-leveling concrete for special concrete is increasing. In addition, in order to improve the early strength of concrete, the specific surface area of cement is increasing, and high-activity ultra-fine mineral admixture is also added, and the water-binder ratio It is also lower, resulting in a decrease in the internal humidity after the concrete is poured, and shrinkage occurs, which will cause non-load cracks in the internal structure of the concrete, and then concrete cracking will occur, affecting the durability of the concrete. Concrete cracks include self-shrinkage cracks, plastic shrinkage cracks, temperature shrinkage cracks, dry shrinkage cracks, settlement cracks, construction cracks, frost heave cracks, etc.
80% of concrete cracks are caused by self-shrinking deformation of concrete, and only 20% of concrete cracks are caused by external loads. Concrete shrinkage cracks not only affect the aesthetics of construction projects, but also reduce the structural strength of concrete projects, adversely affect the integrity, watertightness and durability of construction projects, and greatly shorten the service life of construction projects.
The impact of concrete shrinkage cracks is extremely extensive, affecting traffic facilities, bridges, pavements, and seaport engineering structures, and has become a problem that has long plagued the construction engineering industry and has not been effectively solved. Therefore, how to reduce concrete shrinkage and control concrete defects and cracks is an urgent problem to be solved in the engineering field, which is very important to improve the application performance of concrete and will produce important social, economic and ecological benefits.
Adding concrete expansion agent is a method often used at home and abroad to compensate for concrete shrinkage, but the amount of expansion agent is relatively large, generally 5% to 13% of the total amount of cementitious materials. It is relatively inconvenient and affects the construction progress.
Concrete shrinkage reducer is a chemical admixture that can effectively reduce the self-shrinkage and drying shrinkage of concrete, and provides a new way to control the shrinkage and cracking of concrete. Concrete shrinkage reducer overcomes the limitations of conventional anti-crack methods such as water curing, expansion agent and fiber addition, and can effectively prevent concrete shrinkage and cracking.
