Second Prize for Scientific and Technological Progress in 2020

Project Title: Key Technologies for Preparation and Application of High-Performance Concrete in the Millennium Religious Building of North Africa

Completed by: C China State Construct Commercial Concrete Co., Ltd.

Project Overview:

The project was applied in the Djamaâ el Djazaïr in Algeria, the tallest and largest building in Africa and the third largest mosque in the world. Its minaret, rising 265 m, is the tallest in the world and hailed as Islam’s “Millennium Project.” It also marked Algeria’s first use of high-strength ultra-high pumping concrete since its independence in 1962.

Targeting the stringent engineering requirements of a religious landmark and the challenges of North Africa’s harsh natural environment, scarcity of raw materials, and lagging concrete technology, the project:

• Developed mix design technology for high early-strength pumpable concrete based on the European standard system, adapting from comparisons with Chinese standards;

• Optimized domestic mix design methods to establish durability evaluation technology suited to local climate and engineering conditions;

• Innovated a temperature control system for high early-strength mass concrete in core structures, utilizing measures such as ice-water spraying and continuous cold-air injection;

• Conducted simulation experiments based on the concept of matching concrete viscosity coefficients with pumping height, leading to the development of ultra-high-rise pumping technology that ensured compliance with European standard requirements.

Types of Raw Materials in Algeria

Djamaâ el Djazaïr in Algeria

Project Title: Precision Detection of High-Grade Concrete Pavement Distresses and Rapid Repair Technology with Novel Polymers

Completed by: Guangxi Transportation Science and Technology Group Co., Ltd.; Chang’an University; Guangxi Changchang Road & Bridge Construction Co., Ltd.; Nanning Normal University; Guangxi Highway Investment Co., Ltd.

Project Overview:

China has the world’s longest mileage of cement concrete pavement, with Guangxi ranking first among all provinces in pavement scale. As early concrete pavements enter large-scale maintenance and reconstruction, the pressure on pavement upkeep is tremendous. While cement concrete pavement offers high bearing capacity and low construction cost, distresses such as exposed aggregate and pits drastically reduce driving comfort, and issues like flatness, potholes, and insufficient skid resistance pose serious safety risks. Moreover, reduced base strength, slab voiding, and cracking directly shorten service life.

Since 2007, the project team has been dedicated to over a decade of research on key technologies for rapid repair of concrete pavements. Their work has focused on addressing critical issues such as the lack of reliable performance evaluation methods for cement concrete pavements, the insufficient performance of traditional repair materials, and the low efficiency in the use of maintenance funds. Through these efforts, the team established precision identification and quantitative evaluation technologies for pavement distresses, and developed a digitalized recognition, scientific evaluation, and high-performance, low-cost rapid repair technology system for cement concrete pavements.

Distress Extraction and Automated Quantification Process

Comparison – Failure of Similar Repair Technologies after 2 Months vs. Effectiveness of This Project’s Technology after 2 Years