Study on the Electrothermal Properties of Cfrp/Cfs Synergistically Modified Steel Slag-Based Concrete

Abstract

This study developed a high-strength conductive concrete incorporating steel slag (SS) as coarse aggregate and recycled carbon fiber-reinforced polymer (CFRP) powder as a conductive filler, aiming to achieve integrated self-heating and anti-icing functionalities. The mechanical and electrothermal performance of the material was systematically investigated. The synergistic effects of CFRP powder and short-cut carbon fibers (CFs) on the electrical and mechanical properties of SS-based concrete were first explored. When the combined dosage of CFRP and CFs reached 2 vol% at a 1:1 volume ratio, the concrete exhibited a significantly reduced electrical resistivity of 70.7 Ω·cm and a 34.3% increase in compressive strength, indicating effective enhancement in both conductivity and mechanical performance. Subsequently, the electrothermal and deicing capabilities of the concrete were evaluated under AC voltages of 10 V and 20 V at ambient temperature (25 °C) and low temperatures (-10 °C and -20 °C). The results demonstrated a notable decrease in heating rate with lower ambient temperatures. At -10 °C and 20 V, the heating rate reached 4.82 °C /min within the first 60 minutes, with the surface temperature peaking at 81 °C and stabilizing between 35-40 °C after 110-150 minutes, effectively achieving deicing. Finally, freshly prepared concrete specimens containing 1 vol% CFs and 1 vol% CFRP were subjected to electrothermal curing at 20 V, 45 V, and 60 V for 48 hours. The specimens cured under 60 V exhibited a significantly enhanced early-age compressive strength of 82.85 MPa, highlighting the potential of electrothermal curing to improve the performance of conductive concrete under low-temperature conditions.

Keywords: Steel slag, CFRP, Carbon fiber, Synergistically Modified, Electrothermal performance