High performance concrete admixtures
Polycarboxylic acid water reducer is an effective cementitious and water reducing agent in cement concrete applications. It is widely used on highways, bridges, dams, tunnels, skyscrapers and other projects.
The water-reducing agent is environmentally friendly, non-flammable, explosive and can be transported safely in trains and cars.
Polycarboxylic acid superplasticizers can be divided into two categories according to their different structure: one type uses acrylic acid or methacrylic acid as a base and grafted polyethers with different side chain lengths. Others are polyethers whose primary bond is maleic anhydride and have different side chain lengths. From there, a number of high-performance water-reducing products with different properties have been developed.
Prior to the formation of the polycarboxylate water reducing agent, there was a need to regenerate the supernatants from the polycarboxylate supernatants. It has the advantage of low dosing, good droplet retention, low concrete shrinkage, high molecular structure control and high yield potential. Significant advantages such as the absence of formaldehyde in the process.
For the synthesis of a water-reducing agent, it is very important to design the molecular structure of the polycarboxylate water-reducing agent, including the main group, the side chain density, and the side chain length in the molecule. The synthetic methods mainly include a grafting-in situ polymerization method, first a polymerization method, then a functionalization method and a direct monomer copolymerization method.
In many concrete projects, traditional high-performance concretes, such as the naphthalene series, do not meet design requirements due to technical limitations.
A new generation water-reducing agent that has attracted a lot of attention at home and abroad, a polycarboxylate water-reducing agent, a highly effective water-reducing agent because it has, in fact, developed an efficient molecular structure based on a diffusion mechanism. cement is widely distributed.
Art and can prevent concrete from sinking without significant delay because at low concentrations it offers a higher softening effect, good flowability, great freedom to adapt cement to various multiparticle synthesis techniques and plenty of room for strong shrinkage of concrete. , very low impurity content and other technical parameters that give the concrete excellent workability, good strength development, excellent durability and a strong water – reducing agent based on polycyclic acid.
Arboxyl has comprehensive technical advantages and environmental protection features that meet the requirements of modern concrete technology.
Therefore, high-performance polycarboxylate water-reducing agents are gradually becoming the primary blend in the production of high-performance concrete.
Polycarboxylic acid additives accounted for more than 80% of all high performance additives in Japan and more than 50% in North America and Europe. In my country, polycarboxylate water-reducing agents have only been successful in the Three Gorges Dam, the Sutong Bridge, the Tianwan Nuclear Power Plant, the Beijing-Shanghai Missile Train and other major national protection systems.for waterways, bridges, nuclear power plants and railways. Projects with significant results.
Working Principle of Conc