Exploring Exact Effects of Various Factors on Chloride Diffusion in Cracked Concrete: ABAQUS-Based Mesoscale Simulations

Abstract

Chloride ion attack is a major cause of concrete durability problems, and existing studies have rarely addressed the effects of damage zones. In this paper, an improved mesoscale model including five phases was constructed using the finite element software ABAQUS to study the diffusivity of chloride ions in cracked concrete. It was found that the damage zone is negligible when the crack width is less than 50 μm, while the width and depth of the damage zone are about 15 times the crack width and 15% of the crack depth when the crack is greater than 50 μm. The results show that the diffusion of chloride is greatly influenced by the crack width, while it is little-influenced by the crack shape. Low water–cement ratio and adequate hydration of the concrete are also key factors affecting chloride diffusion. In contrast, regular rounded aggregates have a positive effect on reducing chloride diffusion compared to irregularly shaped aggregates, and this effect becomes weaker with increasing service time. In addition, the protective layer can effectively prevent the diffusion of chloride in concrete. Therefore, when designing marine concrete, efforts should be made to ensure that the concrete has a low water–cement ratio, adequate hydration, less cracking and a protective layer.

Study on the Effect of Cracking Parameters on the Migration Characteristics of Chloride Ions in Cracked Concrete

“…The crack is located at the midpoint of the left boundary of the concrete, running parallel to the upper and lower boundaries and penetrating into the interior of the concrete. In the four-phase model, aggregates are assumed to be circular, and according to previous studies, the shape of aggregates has a minimal impact on chloride ion diffusion in concrete [31,32]. The Walraven formula [33] is used to generate aggregates with diameters ranging from 5 mm to 15 mm, with a volume percentage of 50%.…”

Building a Sustainable Future from Theory to Practice: A Comprehensive PRISMA-Guided Assessment of Compressed Stabilized Earth Blocks (CSEB) for Construction Applications

“…During the review of the pertinent articles, researchers discovered that they had used binders, including fly ash, glass powder, lime, coal ash, and cow dung powder, among others. It was observed that the use of all of these binders positively impacted the water absorption characteristics of the CSEBs and effectively subdued the block's maximum water absorption capacity [85,86]. The results were more pronounced when the cement and fly ash were used as binders to stabilize the earth blocks.…”