Waste Sulfur as a Partial Filler Replacement in Self-Placing Concrete

The effect of partial replacement of natural filler by ground waste sulfur originated from the oil refining process on fresh and hardened properties of self-compacting concrete was investigated. Properties investigated were slump flow, V-funnel, L-box, and sieve segregation of fresh concrete mixes; and compressive, flexural, and bond (pull off) strengths, dynamic modulus of elasticity, ultrasonic pulse velocity, dynamic Poisson’s ratio, specific electrical resistance, density, and microstructure of hardened concrete. Results showed a slight decline in compressive, flexural, and bond strengths and dynamic elasticity modulus with increased addition of sulfur. Specific electrical resistance and density were higher for samples containing sulfur. Also, scanning electron microscopy indicated a slight porosity increase of the samples containing sulfur. Having in mind that, in the case of waste valorization in concrete, all properties of self-placing concrete should remain within acceptable levels or improve, this study proved that mixtures containing ground sulfur as a partial replacement for filler can be used for structural applications