High-performance concrete technology using manufactured sand

Technical Background:

“When it comes to bridges around the world, look to China; and when it comes to Chinese bridges, look to Guizhou.” As the only province in China without any plains, Guizhou boasts towering mountains, deep valleys, and an intricate network of ravines. It is precisely this unique geographical environment that has enabled Guizhou to build over 20,000 bridges spanning its landscape. Covering all major bridge types—suspension, cable-stayed, arch, and girder—Guizhou has earned the prestigious title of “Museum of Bridges of the World.”

Guizhou’s bridges are predominantly built in rugged, mountainous regions characterized by complex topography and geology, harsh climatic conditions, and challenging transportation of sand and gravel required for construction—a situation compounded by the scarcity of river sand. Our team has leveraged technological innovation to adapt to local conditions by processing local ores into manufactured sand, thereby replacing traditional river sand and providing crucial support for the construction of bridge projects in these challenging mountainous areas. Our team has undertaken several major research projects at the provincial and ministerial levels focusing on technologies for using manufactured sand, high-performance concrete made with manufactured sand, and asphalt mixtures incorporating manufactured sand in highway construction. We have established a comprehensive system of technical standards and specifications for the use of manufactured sand in mountainous regions, demonstrating both advanced technology and practical applicability. By setting industry-leading implementation standards, we have successfully addressed key technical challenges related to high-performance concrete made with manufactured sand in mountainous highway construction, supporting the development of a large number of world-class canyon bridges—including the Pingtang Super Bridge—and strongly promoting the advancement of “green transportation.”

Technical Highlights:

(1) Mechanism Sand High-Performance Concrete Technology and Its Promotion and Application

In highway reinforced concrete bridge projects, the superstructure components such as girders and slabs are characterized by “prestressed structures and high concrete strength requirements.” Based on concrete fracture theory and the theory of closest packing, we optimized mix-design parameters—including sand ratio and cementitious material content—for high-strength mechanism-sand high-performance concrete. As a result, we developed C50 to C60 mechanism-sand high-performance concrete with an electrical charge passing through the concrete below 1,000 C. This technological achievement has been comprehensively promoted and applied in the superstructure components—such as girders and slabs—of reinforced concrete bridge projects, with an overall promotion and application scale reaching 16.17 million cubic meters. Typical projects where this technology has been widely adopted include the Liuchong River Supermajor Bridge, the Yachi River Supermajor Bridge, the Hezhang Supermajor Bridge, the Beipanjiang Supermajor Bridge, the Sancha River Supermajor Bridge, and the Xingyi Ring Expressway Project.

(2) Mechanism Sand Self-Compacting Concrete Technology and Its Promotion and Application

By combining a polycarboxylate superplasticizer with high water-reducing efficiency and excellent water-retention properties with a viscosity-enhancing agent, and by incorporating large amounts of either single or combined active mineral admixtures, we have developed self-compacting concrete made from manufactured sand that exhibits a slump greater than 250 mm, a slump flow diameter exceeding 650 mm, a discharge time from the slump cone of less than 15 seconds, and an electrical charge passing through the concrete of below 1,000 C. Meanwhile, we have introduced self-compacting concrete technology into the construction of rubble-concrete structures, shifting the conventional construction process—where concrete is first poured and then rubble is added—from a sequential approach to one in which rubble is laid out first and then concrete is poured. This technological achievement has been widely applied in the pile foundations, main towers, piers, and other primary load-bearing components of several bridges across seven highway projects, with a total application volume reaching 1.06 million cubic meters. The key projects where this technology has been successfully implemented include the Qing Shui River Super Bridge, the Zong Xi River Super Bridge, the Beipanjiang Super Bridge, and the Xianghuo Rock Bridge.

(3) Special Mechanically Produced Sand High-Performance Concrete Technology and Its Promotion and Application

Based on the theory of dense packing of continuous gradation in concrete, and through optimizing mineral admixtures, fine-tuning mix proportion parameters, synergistically enhancing with admixtures, and employing technologies that simultaneously ensure high fluidity and resistance to segregation, we have successfully developed a series of specialized high-performance concrete technologies using manufactured sand, including underwater dispersion-resistant concrete, disturbance-resistant concrete, high-head pumping concrete, and large-volume concrete made with manufactured sand. These technologies meet the demands for high-performance concrete in various structural components and under diverse working conditions along expressways, thereby guaranteeing both the quality and schedule of expressway construction. This technological achievement has been widely applied in the construction of high piers, bridge foundations, and tall towers for reinforced concrete bridges in nine expressway projects in Guizhou Province, with a total application volume of 360,000 cubic meters. Typical projects where these technologies have been implemented include the Pingtang Bridge, the Balinghe Supermajor Bridge, the Malianghe Supermajor Bridge, and the Hezhang Supermajor Bridge.

(4) Mechanism Sand Asphalt Mixture Technology and Its Promotion and Application

Through extensive experimental studies, a complete set of application technologies for warm-mix mechanism-sand asphalt mixtures adapted to tunnel conditions in the Guizhou region has been developed. This includes a material design method for warm-mix asphalt mixtures based on the pavement performance of mechanism-sand asphalt mixtures, as well as construction techniques and quality-control methods for tunnel pavement using warm-mix mechanism-sand asphalt mixtures. Furthermore, key technologies have been proposed for the mix-design and engineering application of mechanism-sand graded asphalt mixtures that exhibit excellent skid resistance, resistance to water damage, and resistance to high-temperature rutting, while also ensuring good economic feasibility for projects in the Guizhou region. The relevant research findings have been successfully applied to municipal road projects in Guiyang City, the Liuwei Expressway project, and the Zunbi Expressway project, enhancing the pavement’s resistance to rutting and its moisture stability, and improving driving comfort.

(5) Technical Standard and Regulatory System for the Application of Mechanically Produced Sand in Highway Engineering

Relying on research findings related to manufactured sand, the innovation team has developed a number of standards and specifications, including the "Technical Specification for the Application of Manufactured Sand in Highway Engineering" JTG/T 3681-2024. A standardized system for the application of manufactured sand in mountainous regions has been established, with standards serving as the guiding framework. This system defines technical indicators covering raw materials, technical performance, mix design, construction procedures, as well as quality inspection and acceptance criteria for manufactured sand and high-performance concrete made from manufactured sand. These efforts have addressed key technical challenges in the construction of expressways in mountainous areas, thereby strongly promoting the development of “green transportation.” Meanwhile, an English version of the "Technical Code for High-Performance Concrete Made with Highway Manufactured Sand" has been compiled, aligning with China’s “Belt and Road” initiative and facilitating the international application of China’s technological achievements in manufactured-sand concrete. The standard has also been applied to guide the construction of the F4 project on Georgia’s E60 highway, yielding excellent results.

Honored Achievements:

Second Prize, Guizhou Province Science and Technology Achievement Transformation Award
Second Prize, Standard Technology Innovation Award, China Engineering Construction Standardization Association
First Prize, Building Materials Science and Technology Award, China National Building Materials Federation and China Silicate Society;
Second Prize of the China Highway Society Science and Technology Award, China Highway Society;
Third Prize of the Concrete Science and Technology Award, China Concrete and Cement Products Association;
Special Prize and First Prize of the Guizhou Provincial Highway Society Science and Technology Award;
Special Prize of the Guizhou Provincial Society of Mechanics Science and Technology Award;
First Prize, Guizhou Province Science and Technology Innovation Award for Civil and Architectural Engineering;
Mao Yisheng Bridge and Road Engineering Innovation Team Award;
Technical Specification for the Application of Mechanically Produced Sand in Highway Engineering, JTG/T 3681-2024;
Highway Engineering – Mechanically Produced Sand for Cement Concrete, JT/T 819-2023;
Technical Specification for High-Performance Concrete with Mechanically Produced Sand for Highway Engineering, T/CECS G:K50-30-2018;
Technical Specification for High-Performance Concrete with Mechanically Produced Sand for Highway Engineering—English Translation Version T/CECS G:K50-30-2018 (EN);
Technical Specification for the Application of Self-Compacting Concrete with Crushed Stone and Mechanically Produced Sand in Highway Engineering—T/CECS G:K50-31-2022;
Technical Specification for Concrete Alkali-Aggregate Reaction Suppression in Highway Engineering, T/CECS G:D69-01-2020;
Technical Specification for Mechanically Produced Sand in Asphalt Mixtures for Highway Engineering, T/CECS G: K44-05-2024;
Technical Specification for High-Performance Concrete Made with Mechanically Produced Sand for Expressways in Guizhou Province, DBJ 52/T 055-2015;
Technical Code for Prevention of Alkali-Aggregate Reaction in Concrete for Highway Engineering in Guizhou Province, DB52/T 1704-2022;
Holds more than 10 patents and has published over 10 papers.