Problems Existing in the Practical Application of Polycarboxylate Water Reducer in Concrete Engineering
Feb 24, 2023
Problems Existing in the Practical Application of Polycarboxylate Water Reducer in Concrete Engineering
1. The effect of water consumption on the performance of polycarboxylate concrete mixture
The influence of water consumption is very obvious. In the actual application of concrete engineering, sometimes if the water consumption is increased by 1-3kg/m3, the concrete will have serious bleeding phenomenon, which will cause defects such as pitting, sanding, and holes on the surface. Uniformity and construction quality cannot be guaranteed, thus reducing the strength and durability of the concrete structure.
2. Polycarboxylate concrete is prone to delamination and segregation
In most cases, adding polycarboxylate superplasticizer to concrete will greatly reduce the viscosity of the slurry. At the same time, even if the dosage and water consumption of the polycarboxylate superplasticizer are optimal, and there will be no bleeding, the concrete is prone to stratification and segregation, which is mainly manifested in the coarse aggregate and mortar. , The net pulp is separated and sinks in large quantities. This kind of concrete mixture does not have any vibration in concrete engineering pouring, and the phenomenon of layering and segregation is also very obvious.
3. The compatibility is not ideal
Naphthalene series, aliphatic series, lignin sulfonate, amino sulfonate and other traditional water reducers can be blended in any proportion, so as to meet various concrete preparation requirements. These traditional water reducers The agent can not only dissolve well in water, but also can achieve excellent superimposed effect when used in combination. Polycarboxylate superplasticizer has great limitations, it can only be used in combination with traditional superplasticizer lignosulfonate, and has poor compatibility with other traditional superplasticizers. If it is used in combination with other types of traditional water reducing agents, not only is it difficult to achieve superimposed effects, but the fluidity of the concrete will also be poor, the water consumption will increase greatly, the loss of slump will be serious, and the concrete will be dry and difficult to unload. , the strength and durability of concrete will be seriously affected.
