In the heart of China’s ambitious infrastructure projects, a groundbreaking study is reshaping the way we think about concrete—particularly in challenging environments like caverns prone to rockburst, water gushing, and high geostress. Led by CHENG Weifeng of Power China Kunming Engineering Corporation Limited, a collaborative effort involving 10 institutions has yielded promising results that could significantly impact the energy sector.
The research, published in *Yantu gongcheng xuebao* (translated to *Rock and Soil Mechanics*), focuses on the on-site flexural toughness of wet-sprayed concrete enhanced with silica fume (SF) and reinforced with steel fibers. This isn’t just another lab experiment; it’s a large-scale, real-world test that reflects the actual adhesion and hardening properties of wet-sprayed concrete in the field.
“Our goal was to investigate how steel fiber content and silica fume affect the flexural toughness of concrete, especially in high-stress environments,” explains CHENG Weifeng. The team used a large wet spraying machine and incorporated accelerator into the concrete mix, forming specimens on-site to mimic real-world conditions.
The results are compelling. The addition of silica fume and steel fibers increased both the crack load and the ultimate load of the concrete, significantly improving its flexural toughness. As the steel fiber content increased, so did the flexural toughness index. Notably, the load-deflection curves showed a secondary hardening peak in concrete with a steel fiber content of 40 kg/m³, indicating better resistance to deformation and increased residual strength.
“This means the concrete can better resist cracking and improve its brittleness characteristic,” says CHENG. The implications for the energy sector are substantial. In high-stress environments like hydropower projects, where caverns are subjected to extreme conditions, this enhanced concrete could mean more durable, safer, and longer-lasting infrastructure.
The collaborative effort involved institutions like China Power Construction Group Municipal Planning and Design Institute Co., Ltd., Yalong River Hydropower Development Co., Ltd., and Power China Sinohydro Bureau 7 Co., Ltd., highlighting the collective push towards innovation in the field.
As the energy sector continues to expand into challenging terrains, the findings from this research could pave the way for more resilient construction materials. The use of silica fume and steel fibers in wet-sprayed concrete is not just a scientific advancement; it’s a practical solution that could redefine the standards of durability and safety in infrastructure projects.
In the words of CHENG Weifeng, “This is a significant step forward in our quest to build stronger, safer, and more efficient structures in demanding environments.” With the publication of this research in *Yantu gongcheng xuebao*, the industry now has a roadmap to follow, one that could lead to a new era of robust and resilient construction practices.