Second Prize for Scientific and Technological Progress in 2023

Project Title:

Design and Construction Technology Package for Prefabricated Concrete Pile-Slab Structures in Road Engineering

Completed by:

Anhui Transportation Holding Group Co., Ltd.,

Anhui Transport Consulting & Design Institute Co., Ltd.

Tongji University

Project Overview:

Since 2017, China's Ministry of Transport has successively issued guiding opinions on the implementation of green highway construction. However, highway development has gradually reached a bottleneck. Challenges include a scarcity of land and soil resources, rising costs for land acquisition and soil sourcing, and increased expenses for soil treatment and land reclamation. The economic feasibility and applicability of traditional highway construction methods relying heavily on land and soil are facing severe challenges.

This project, based on a test section of the Longxi to Lukou segment of the Hefei Ring Expressway, introduces a pile-slab road structure composed of factory-prefabricated slab girders and pipe piles, forming a rigid frame system. This structure features high stiffness, minimal post-construction settlement, reduced land acquisition, fast construction, and significant cost savings. The project innovated on the structural system of pile-slab roads, conducted in-depth research on structural design methods, connection detailing, durability design, and evaluation methods, and successfully implemented them in engineering practice. Since its opening at the end of 2016, the test section has performed well in operation.

Newly Constructed Prefabricated Pile-Slab Structure for Highways

Real View of the Pile-Slab Structure in the Reconstruction and Expansion Project of the Hefei-Anqing Expressway, Anhui Province

Real View of the Pile-Slab Structure in the Reconstruction and Expansion Project of the Longxi–Lukou Section of the Hefei Ring Expressway, Anhui Province

Project Title:

Research and Application of Concrete-Filled Steel Tube (CFST) for Pumped Jacking Construction in Supertall Buildings

Completed by:

Beijing High-Strength Concrete Co., Ltd.

Project Overview:

Concrete-filled steel tube (CFST) construction typically adopts two main methods: jacking and drop placement. In high-rise building applications, jacking is significantly superior in terms of construction efficiency, operational safety, and concrete compaction quality within the steel tubes. However, this method imposes stricter performance requirements on the concrete materials used.

This project, based on the Nord International Plaza (诺德国际广场) in Beijing, focuses on the composite CFST structures used in supertall buildings. It addresses the challenges of achieving self-compacting, pumpable, and micro-expansive concrete under the jacking construction method. Key research areas included mix design and quality control techniques for core CFST materials: optimizing aggregate gradation, selecting appropriate mineral admixtures, and developing well-balanced admixture combinations formed the core technical route. By using high-quality mineral admixtures and advanced composite superplasticizers, the mixture's viscosity was finely tuned to enhance pumpability. The project proposed a complete set of performance control indicators for concrete mixtures before, during, and after pumping. It also defined suitable rheological parameter ranges and selected a dual-expansion system of calcium oxide and calcium sulfoaluminate as an effective high-performance expansive agent.

Nord International Plaza, Beijing