Concrete inner curing material: SAP
Key words
Concrete internal curing, SAP, concrete self-shrinkage, concrete cracking, super absorbent polymer
In order to add water to the cement hydration inside the concrete and fundamentally solve the problem of early self-shrinkage and cracking of concrete, the high water absorption properties of SAP material are used to replenish water to the concrete.
Polymer water absorbent resin (SAP for short) is a typical functional polymer material, referred to as SAP. It can absorb hundreds of times or even thousands of times its own weight in water, and has a strong water retention capacity, so it is also known as super absorbent or high water retention agent.
A certain amount of SAP is added during the preparation of concrete. When the concrete is mixed with water, the SAP quickly absorbs water and is evenly distributed in the concrete, thereby forming a reservoir inside the concrete. The addition of SAP can supplement additional water, which can significantly reduce the self-shrinkage of low-water-to-binder ratio concrete, delay the decline of the relative humidity inside the concrete, compensate for humidity, and alleviate the drying phenomenon. Due to the small amount of SAP, it has no adverse effect on concrete, so it is an ideal internal curing material.
The fast-expanding material used in water conservancy projects is pure super absorbent resin. It is mainly used for plugging of dam holes in flood season, water blocking of prefabricated joints in basements, tunnels and subways; it is used for urban sewage treatment and dredging projects. The slurry is solidified for easy excavation and transportation.
