Improved mixture composition for early-opening heat-conductive concrete

摘要

This study proposes an improved mixture composition for early-opening heat-conductive concrete for pavement. The formulation has a snow-melting function, with a compressive strength of at least 21MPa after 3h of curing. The mix variables were the proportions of graphite, coke replacement, coarse aggregate size and type of metallic material. Heating properties were evaluated as a function of these variables. The heating evaluation was performed by placing a cylindrical (diameter: 100mm, length: 200mm) specimen in a fixing jig, attaching a copper plate to each end of the specimen and passing a 220 VAC electric current between the copper plates. These experiments demonstrated that coke had a better heating effect than graphite, and that heating improved when metallic materials were used. Additionally, using a small (10-mm) aggregate provided better heating properties than a large (13-mm) aggregate.