Coarse Aggregate UHPC
Aggregate-fiber synergy
Optimizing coarse aggregate and steel fiber distribution to achieve uniform mechanical properties along the casting direction, mitigating strength gradients.
Lianlian, Xie · Bihua, Zhou · Yao, Yiming · Xu, Qizhi · Zhong, Rui · Hongyu, Zhou · Wang, Jingquan
Cement and Concrete Composites 2026
Specifications
- Maximum compressive strength difference
- {'zh': '52.53', 'en': '52.53'} MPa
- Maximum flexural strength difference
- {'zh': '16.77', 'en': '16.77'} MPa
- Coarse aggregate content
- {'zh': '17', 'en': '17'} %
- Steel fiber content
- {'zh': '2.5', 'en': '2.5'} %
- Excessive coarse aggregate content
- {'zh': '30', 'en': '30'} %
Advantages
Quantifiable distribution
A hybrid ResNet50+U-Net deep learning model and morphology-based image processing can automatically segment coarse aggregate and quantify steel fiber distribution, providing reliable data for mix optimization.
Optimal mix identified
The mix with 17% coarse aggregate and 2.5% steel fiber shows relatively uniform internal distribution and favorable mechanical performance, achieving synergy between aggregate skeleton and fiber bridging.
Gradient causes revealed
The study explicitly identifies the downward migration of both coarse aggregate and steel fiber as the cause of mechanical property gradients, guiding process control.
Avoid brittle failure
Insufficient fiber dosage leads to brittle failure, while an appropriate dosage (e.g., 2.5%) ensures ductile behavior.
Applications
- UHPC structures：Used for homogeneity design and construction control of large-scale UHPC structures, avoiding local strength deficiency from aggregate settlement.
- Precast component production：Guides mix design and casting process in precast production, ensuring property consistency along height and improving component reliability.
- Fiber-reinforced composites：Optimizes steel fiber dispersion to avoid clustering and brittle failure, enhancing ductility of the composite.
- Impact-resistant structures：Achieves stable bridging through uniformly dispersed steel fibers, improving energy dissipation under impact loading.