15 Sep 2025
At the 15th National Concrete Design Competition held from 5-6 September 2025 in Guangzhou, a student team from the Design School?at Xi’an Jiaotong-Liverpool University won the Best Functional Design Award in the University Group.
Centered on the theme "Lightweight, High-Strength, and Tough: Mix Proportion Design Based on Concrete Strength, Density, and Toughness," the competition addressed key industry technical challenges while aligning with the demand for "green, low-carbon, and sustainable development. 48 teams from enterprises and universities nationwide?participated in the competition.
The XJTLU team composed of Xiaodong Cheng, Jie Li, Chuyun Cheng, and Rengeng Zheng, who were guided by Dr Jun Xia and Dr Ominda Nanayakkara?from XJTLU’s Department of Civil Engineering. They innovatively employed aramid fiber to reinforce lightweight high-performance concrete (LHPC), which also exhibited certain fire-resistant properties.
Group photo of Professor Peiyu Yan from Tsinghua University (Chief Referee of the Competition) presenting the award
Relying on the mechanical and high-temperature equipment of the Laboratory of the Department of Civil Engineering, Xi'an Jiaotong-Liverpool University, the team added unique features to the design of lightweight high-strength concrete and successfully demonstrated the effectiveness of aramid fibers in improving the compressive and fire resistance performance of concrete.
During the two-month preparation period, the team cast and tested 23 groups of specimens with different mix proportions. Following the technical route of “Establishing Base Mix - Lightweight Parameter Adjustment - Toughness Enhancement Adaptation - Curing Regime Synergy”,?they collaborated closely and iterated step-by-step. Combining experimental validation with theoretical modeling, they achieved a balance between density, strength, and high-temperature resistance.
On-site Presentation by Team Representative Xiaodong Cheng
The team’s concrete design scheme was based on the verified basic mix proportion of Ultra-High Performance Concrete (UHPC) from the research group. A technical route was developed through the collaborative optimization of multiple parameters: For the cementitious system, a composite formula of "cement + granulated blast furnace slag + silica fume" was adopted, which replaced 50% of cement to achieve carbon reduction while ensuring matrix strength; for the aggregate system, Hollow Glass Microspheres (HGMs) were used to replace part of the quartz sand, and the balance between lightweight demand and matrix compactness was achieved through gradation optimization; for the reinforcement system, para-aramid fibers were added, which improved the concrete's strength and high-temperature resistance while ensuring paste fluidity; for the curing system, a two-stage mode of “90℃ water bath curing for 48h + 200℃ dry heat curing”?was adopted to reduce the risk of high-temperature spalling?- specifically, specimens cured by dry heat for 6h showed slight spalling, while those cured for 24h had no spalling.
Spalling of Specimens After High Temperature via Different Dry Heat Curing Methods
The competition was organised by the China Concrete and Cement-based Products Association (CCPA), co-organised by China West Construction Group Co., Ltd. and the Guangdong Ready-Mixed Concrete Association, and hosted by the Ready-Mixed Concrete Branch and the Education and Human Resources Committee.
Story provided by Department of Civil Engineering
Edited by Yi Qian
15 Sep 2025