Impact of different water-reducing agents on the properties of limonite self-compacting conductive concrete

Abstract The application environment for concrete is becoming increasingly complex, accompanied by an intensification of its functional requirements. This paper presents a method for developing self-compacting concrete with conductive properties using limonite and graphite as the concrete conductive phases. In the process of concrete preparation, the limonite is initially treated by a pre-wetting method to prevent the surface depression caused by the addition of limonite during the concrete curing process. The second stage of the process involved optimising different proportions of limonite and graphite and different dosages of water-reducing agent, defoamer and dispersant to prepare concrete. The influence of different dosages of limonite and graphite and different dosages of water-reducing agent on the mechanics and electrical conductivity of concrete was studied in order to obtain self-compacting conductive concrete with performance indicators meeting the requirements of self-compacting and electrical conductivity. The results demonstrate that the mechanical and electrical properties of self-compacting conductive concrete prepared with polycarboxylic acid superplasticizer and retarding superplasticizer combined with superplasticizer are satisfactory, and the composite superplasticizer can function in conjunction with dispersant. The self-compaction index, slump expansion, expansion time T50 and J-ring expansion of fluid concrete meet the requisite standards. Once the concrete has reached the designated curing age, its compressive strength and flexural strength align with the anticipated design expectations, while its resistivity meets the stipulated conductivity index requirements.