There are many types of water reducing admixtures, from the earliest lignosulfuric acid system to the naphthalene system to the latest polycarboxylic acid system. Water reducing admixtures have undergone several generations of evolution.
In many concrete projects, traditional high-efficiency concrete such as naphthalene is less and less able to meet engineering needs due to the limitations of technical performance. A new generation of water reducing agent and polycarboxylate high performance water reducing agent that has attracted much attention at home and abroad. Because it has designed an effective molecular structure based on the mechanism of dispersed cement, it has a super-dispersion type and can prevent concrete slump loss.
It does not cause obvious retardation, exerts high plasticizing effect under low dosage, has good fluidity retention, has large freedom of cement to adapt to wide molecular structure, has a large amount of synthetic technology, and has high room for high performance. The effect is remarkable, which can reduce the shrinkage of concrete and the technical properties of extremely low harmful substances, which gives the concrete excellent workability, good strength development, excellent durability, and good performance of polycarboxylate high-performance water reducer.
Comprehensive technical performance advantages and environmental protection features meet the needs of modern concrete engineering. Therefore, polycarboxylate superplasticizers are becoming the preferred admixture for the preparation of high performance concrete.
Polycarboxylic acid superplasticizer is the third generation of high-performance superplasticizer developed after common superplasticizer represented by wood calcium and superplasticizer represented by naphthalene series. The liquid is light yellow or brownish red transparent liquid. The main component is a series of polycarboxylic acid polymer products with a molecular weight of 5000-50000.
It is a series of water-reducing agents with excellent performance that integrates water reduction, slump retention, reinforcement, anti-shrinkage and environmental protection. It can solve the weaknesses of high-strength, high-performance concrete with high viscosity and poor construction performance. It is used to prepare high-strength, Ideal admixture for high performance concrete.
The blending amount of the polycarboxylic acid superplasticizer is 0.4% to 2.5% of the total weight of the gelling material, and the usual blending amount is 0.8% to 1.5%. Before use, a trial test of concrete should be carried out to obtain the best admixture.
Polycarboxylic acid superplasticizer cannot be mixed with naphthalene-based superplasticizer. When using polycarboxylic acid superplasticizer, the mixer and mixer that used naphthalene-based superplasticizer must be cleaned or the water reduction may be lost. effect. When using polycarboxylic acid superplasticizer, it can be added directly in the form of the original solution, or it can be formulated into a solution with a certain concentration.