The metro segments of prefabricated reinforced concrete is a cement product with high technical content which mandate particularly stringent requirements of production technology and quality. As the tunnel main structure with shield construction, it is mainly used for the construction of metro or large pipeline projects.

Being the structure of the tunnel support system, the metro segment is a key part of the tunnel structure which is the outermost layer of the tunnel barrier to resist the soil pressure, groundwater pressure and some special kind of the load. The metro segment will be assembled together with tunnel construction, and the segment quality is directly related to the entire quality and safety of the tunnel and greatly impact the tunnel waterproofness and durability.

Concrete admixture is one of the key materials for metro segment production with extremely stringent production process requirements such as small concrete slump,concrete early strength,low gas content and the good liquidity into the mold, hence higher requirement is demanded for the quality of concrete admixture. At present the domestic segment factories use the foreign brands concrete admixtures such as Sika and Basf. After ten years' development of technology and products of polycarboxylate superplasticizer, Wuhanxuan formed a research and development group particularly for the metro segment water reduing admixture to improve and upgrade technological process, and successfully developed a special kind of polycarboxylate superplasticizer used for the metro segment concrete.

The product was put into use in Changsha Metro Line 3, Line 4 and Line 5 and Wuhan Metro Line 7, and the quality was approved by the contractor and supervisor. At the same time, the segment admixture test of other metro lines is also in progress. The cost-effective product and its value-added after sales service will be Wuhan Huaxuan's core competency in the application of metro segment.