The completed project: Wuhan Dadong Lake Deep Drainage Tunnel

LUHPC concrete applied in Shuangliu Yangtze River Bridge

In recent years, with the strong support of national policies, scientific and technological progress and the implementation of green low-carbon transformation strategy, the requirements for green building construction are getting higher and higher, acting as an important role in building construction, the transformation and upgrading of concrete materials and industrial system also put forward a higher demand.

In Hubei, there are a number of construction companies based on the industry and the actual project, to strengthen the research and development of concrete materials, to create a more reliable and durable concrete, so that the concrete permeability and compactness performance is greatly improved, these materials have been successfully applied in cross-river bridges, deep underground tunnels, housing basements, etc., to help the high-quality development of construction industry.

Excellent cases are shared below:

Name: Sewage erosion resistant and highly durable concrete

R&D unit: China State Construct Commercial Concrete Co., Ltd.

Application project: Wuhan Dadong Lake Deep Drainage Tunnel

Performance: Enhanced corrosion resistance and high density

The Wuhan Dadong Lake Deep Drainage Tunnel project is currently the deep drainage tunnel for sewage with the largest transmission flow and the longest transmission distance in China, with a total length of 17.5 kilometres of the main tunnel. During construction, the site was constructed with a double-layer inner and outer bush pipe, using a special concrete developed by China State Construct Commercial Concrete Co., Ltd.—the sewage erosion resistant and highly durable concrete with corrosion-resistant and high-density properties.

In view of the difficulties of easy cracking, leakage and poor erosion resistance of the structure, in order to ensure the integrity and stability of the concrete structure after cement soldification, China State Construct Commercial Concrete Co., Ltd. has used the key technology of preparation and application of sewage-resistant concrete, developed a super-hydrophobic material that can regulate the microstructure of the concrete and reduce the rate of water absorption, overcoming the synergistic enhancement technology of concrete durability under complex sewage environments. The company has developed a special admixture for high sewage erosion-resistant concrete, which achieves the goal of reducing the viscosity of the paste by more than 30%, and the output extension of concrete is more than 700mm, and the T500 (T500 refers to the index of the concrete mobility test) is less than 3 seconds, after 6 hours, the output extension is more than 650mm, and the T500 is less than 5 seconds, and the 28 days strength is improved by more than 10%, and there is no loss of the slump and extension of the concrete in 4 hours. There is no loss of slump and extension in 4 hours, which realises a complete set of construction and quality control techniques for sewage erosion resistant concrete in typical projects; it can prolong the service life of concrete components in sewage environment, and it also helps to improve the treatment efficiency of sewage treatment facilities.

The relevant person in charge of China State Construct Commercial Concrete Co., Ltd. said that the key technology for the preparation and application of sewage-resistant concrete will play an important role in more sewage treatment projects and ensure the long-term service of sewage projects.

Name: LUHPC Concrete

R&D Unit: CCCC WuHan Harbour Engineering Design And Research Co.Ltd

Application project: Wuhan Shuangliu Yangtze River Bridge

Performance: 10 times stronger than red brick

As the widest steel box girder suspension bridge on the Yangtze River, Wuhan Shuangliu Yangtze River Bridge has entered the construction stage of the superstructure catwalk. During the construction of Shuangliu Yangtze River Bridge, a special kind of concrete is used for the prefabricated bridge deck—Lightweight Ultra-high Performance Concrete (LUHPC), which is researched and developed by CCCC WuHan Harbour Engineering Design And Research Co.Ltd.

As an innovative building material, LUHPC concrete is characterised by high strength, lightweight and high durability.

“This concrete has a compressive strength of more than 120Mpa, a tensile strength of more than 6MPa, and the elastic modulus of more than 38GPa. 1m² of LUHPC can support 12,000 tonnes of weight, and at the same volume, it is twice as strong as traditional concrete and 10 times stronger than ordinary clay bricks (red bricks), providing more reliable support for building structures.” the relevant person in charge of CCCC WuHan Harbour Engineering Design And Research Co.Ltd. said.

It is reported that LUHPC makes extensive use of porous lightweight aggregate, and its capacity weight is about 15% lower than that of ordinary concrete (less than 2,100kg/ m³), which can significantly reduce the dead weight of the bridge structure, lower the foundation load, and further reduce the cross-section size under the condition that the bearing capacity remains unchanged, providing new ideas for the innovative design of the new type of bridge structure. At the same time, its excellent impermeability, frost resistance and chemical erosion resistance can maintain good performance for a long time under various harsh environmental conditions, providing a guarantee for the “Centenary Quality Project with Safety Assurance”.

Name：Super high toughness impervious concrete modifier

R&D Unit: Wuhan Alliance Investment Hubei Road Bridge

Application project: Wuhan Alliance Investment & Future Hui Project

Performance: Impermeability far exceeds the “national standard”

After the basement concrete is poured, the concrete surface is smooth and consistent in color, achieving the effect of strong and stable structure, waterproof and moistureproof, as well as sound and heat insulation, effectively preventing the infiltration of groundwater and keeping the basement dry......

This is the application effect achieved by Dr. Sun’s team of Wuhan Alliance Investment Hubei Road Bridge after using HST-1 super-tough high-impermeable concrete modifier to pour concrete on the underground 2 floors of Wuhan Alliance Investment & Future Hui (Phases 1 and 2) located in Ezhou last year.

In 2022, Dr. Sun’s team, through the research of special polymer polymerisation technology and micro-nano water molecule physical penetration technology, copolymerised polymerisation materials with multi-functional components such as waterproofing, impermeability, anti-cracking, densification, water retention, etc., so that the generated modifiers will have excellent impermeability and crack-resistant properties in concrete applications, making the impermeability grade of concrete reach the standard of P20 or above (which is much bigger than the national standard requirement of P6), which is mainly used in the concrete with requirements of impermeability and anti-cracking and high durability.

Dr. Sun introduced the above products compared to the traditional impermeable concrete which is‘water reducer + expansion agent’, has a higher impermeability level, mechanical properties and durability, while saving the levelling layer, waterproofing membrane layer, protective layer and other structures and the corresponding process period, concrete’s own rigid waterproofing effectively removes conventional membrane flexible waterproofing, so that the comprehensive cost can be significantly reduced.

In recent years, Wuhan Alliance Investment Hubei Road Bridge implements new technology industrialisation project for cementitious composite modification, which has been extended to the whole field of cement-based materials and comprehensive utilization of phosphogypsum, it has been applied in the construction of Luochengling Tunnel of the second standard of Xianning-Jiujiang Expressway, and the reconstruction and expansion of the first standard of Beijing-Hong Kong-Macao Expressway. It has the effect of perfecting the industrial chain and strengthening the industrial chain for Hubei Alliance Investment and Hubei Provincial Road & Bridge Group Co., Ltd.