The Influence of CO Cured Manganese Slag on the Performance and Mechanical Properties of Ultra-High Performance Concrete.

Bai, Ligai; Yang, Guihua

The presence of toxic elements in manganese slag (MSG) poses a threat to the environment due to potential pollution. Utilizing CO curing on MS offers a promising approach to immobilize toxic substances within this material, thereby mitigating their release into the natural surroundings. This study investigates the impact of CO cured MS on various rheological parameters, including slump flow, plastic viscosity (η), and yield shear stress (τ). Additionally, it assesses flexural and compressive strengths (f and f), drying shrinkage rates (DSR), durability indicators (chloride ion migration coefficient (CMC), carbonization depth (CD)), and the leaching behavior of heavy metal elements. Microscopic examination via scanning electron microscopy (SEM) is employed to elucidate the underlying mechanisms. The results indicate that CO curing significantly enhances the slump flow of ultra-high performance concrete (UHPC) by up to 51.2%. Moreover, it reduces UHPC's η and τ by rates ranging from 0% to 52.7% and 0% to 40.2%, respectively. The DSR exhibits a linear increase corresponding to the mass ratio of CO cured MS. Furthermore, CO curing enhances both f and f of UHPC by up to 28.7% and 17.6%, respectively. The electrical resistance is also improved, showing an increase of up to 53.7%. The relationship between mechanical strengths and electrical resistance follows a cubic relationship. The CO cured MS demonstrates a notable decrease in the CMC and CD by rates ranging from 0% to 52.6% and 0% to 26.1%, respectively. The reductions of leached chromium (Cr) and manganese (Mn) are up to 576.3% and 1312.7%, respectively. Overall, CO curing also enhances the compactness of UHPC, thereby demonstrating its potential to improve both mechanical and durability properties.

MANGANESE; CONCRETE; POISONS; SHEARING force; SCANNING electron microscopy

Fluid Dynamics & Materials Processing, 2024, Vol 20, Issue 8, p1717

1555-256X

Academic Journal

10.32604/fdmp.2024.051506