The project of “Whole process control technology and application of rheological properties of super flowing concrete” by China West Construction Group Hunan won the second prize of 2020 CCPA Concrete Science and Technology Award (Technology Innovation). Super flowing concrete is a new type of high-performance concrete with high workability.

The specific workability requirements are as follows:

lThe concrete mixture is required to have low yield stress and sufficient plastic viscosity.

lAggregates can be suspended in the slurry of cementitious material without segregation and bleeding.

lForming without or basically without vibration.

lIt is a kind of high-performance concrete which can be fully filled in the gap between formwork and reinforcement to form a dense and uniform concrete structure.

The poor workability of super flowing concrete will bring problems such as great construction difficulty, large material loss, low construction efficiency, low strength, poor durability and other problems. To solve these problems, the research team of China West Construction Group Hunan has made a systematic study on the whole process control of rheological properties of super flowing concrete. The main research included: performance control technology of super flowing concrete with low-grade fine aggregate, performance control technology of production process and construction site.

The main innovations of the project are as follows.

lSilica fume is introduced to prepare super flowing concrete with low-grade sand and stone raw materials, and the corresponding quality assurance measures are formulated.

lTest instruments and methods are developed which can quickly and easily quantitatively evaluate the cohesion of fresh concrete.

lA series of field testing devices and methods for concrete working performance are developed.

lA concrete working performance modifier is developed, which can effectively regulate the concrete segregation state and improve the workability of concrete pumping stage.

lA vibrating method for removing bubbles in segment production is developed

Testing device for anti-segregation & cohesion of pumped concrete

Segregated concrete & concrete with working performance modifier

The new processes, methods and products developed by the project have been successfully applied in Changsha Metro Line 6, Changsha Binjiang international financial center and tunnel project of East 2nd Ring Road in Hengyang City.

Changsha Metro Line 6

Changsha Binjiang international financial center

China West Construction Group Hunan