Effect of basalt fibers on plastic shrinkage properties of concrete in harsh environments

The concrete facing slabs of rockfill dams exhibit heightened susceptibility to plastic shrinkage cracking, a phenomenon aggravated by harsh environmental conditions during construction that significantly compromises structural durability. This study systematically investigates the plastic shrinkage characteristics of basalt fiber concrete under simulated harsh environmental conditions, with particular emphasis on critical infrastructure applications. A free plastic shrinkage test setup and the restrained slab method were employed to quantify free shrinkage strain and evaluate the severity of restrained plastic cracking. The results indicated that increasing the basalt fiber content to 0.10% resulted in a cracking area reduction rate of 89%. Further increases in basalt fiber content resulted in a notably slower rate of reduction in the cracking area. When the W/C (water to cement ratio) was reduced from 0.5 to 0.3, the cracking area reduction rate of basalt fiber concrete relative to plain concrete increased from 55% to 89%. The crack mitigation capacity of basalt fiber demonstrates enhanced efficacy in lower W/C ratio matrices.