Corrosion-Induced Crack Quantification in Reinforced Concrete with Portland and Slag-Blended Cement Under Accelerated Exposure

Optimizing the service life of reinforced concrete structures requires replacing traditional Portland Cement (PC) with Slag-Blended Cements (SBCs) that offer refined pore networks, which are vital for inhibiting the propagation of corrosion-induced cracks. In this study, we propose an integrated framework combining Direct Current (DC)-accelerated corrosion tests with computational quantification of cracking. For comparison purposes, the concrete samples with similar compressive strengths (~60 MPa), obtained after 65 days from the mixing process, were exposed to impressed currents while the evolution of cracks was monitored using image processing in MATLAB. It was found that the slag-blended cement significantly delayed the appearance of the crack, which occurred at 141 h, compared with 57 to 70 h for the PC specimen. The delay in corrosion damage initiation by SBC is 1.7 times higher than that by PC. In terms of damage severity, SBC reduced both the total crack lengths by 56% (83 mm for SBC and 189 mm for PC) and the maximum crack width by 22% (0.70 mm for SBC and 0.90 mm for PC). After 111 h of corrosion under the same conditions, the SBC still retained its ability to reduce the crack length (188 mm), whereas PC formed 270 mm cracks. These findings provide a basis for future calibration of sophisticated mesoscale fracture models, such as the Lattice Discrete Particle Method (LDPM) and the Finite Discrete Element Method (FDEM), as well as for creating data sets for future data-driven durability assessment.