The design, test results, conditions of construction of ganister sand concrete with microdilitability are introduced in this paper.

This paper introduced the design and selection of mix ratio of micro-expansive concrete,and studied material,mix ratio,properties,construction technology of concrete,then built up high-performance expansive concrete that satisfied the requirement of practical engineering large-span flat arch bridge,the corresponding construction measure are put forward.

Basing on a comprehensive analysis of the current research situation in China and abroad, main problems, the types of expansive agent and the corresponding expansive mechanism of micro-expansive concrete.

Practical example of the preparation of C50 micro-expansive concrete;

The C50 micro-expansion concrete is filled into the steel tube arches and webs of the main bridge of Lhasa River Bridge by pumping construction.

Zhijing River Bridge is a concrete-filled steel tube deck arch bridge with a main span 430 m and the arch rings of the Bridge were filled with the C50 micro-expansion concrete by pumping.

During construction of the major dam of a reservoir, a new construction technique was adopted by using the micro expansive concrete with MgO mixed outside,in which the heat due to hydration was reduced.