Work

Study on the Mechanical Properties and Binding Behavior of Chloride in Cement Paste Under Premixed High Concentration of Chloride Ions

Year: 2025

Type: article

Abstract: Chloride erodes steel bars through concrete pores, seriously affecting the durability of reinforced concrete structures. Improving the binding ability to chloride is an important measure. We explored the effects of W/C, curing age, and premixed Cl− concentration on the compressive strength and Cl− binding capacity in cement pastes. The results indicate that a premixed 5% concentration of Cl− can improve the compressive strength, whereas an excessive Cl− negatively impacts the mechanical properties. The total Cl− content in cement pastes is a crucial factor that influences the binding ability of Cl−. When the total Cl− content is within 2% (i.e., the premixed Cl− concentration is 5%), the cement paste has a strong binding ability of Cl−. W/C and curing age indirectly affect the binding ability by affecting the total Cl− content. Furthermore, with the increase in content of Cl−, the adsorption content of Cl− by C-S-H increased, while the proportion of Cl− bound by Fs to the total bound Cl− initially declines and then tends to stabilize. It is worth noting that a premixed concentration of 5% is a “safety limit” for cement paste, but for reinforced concrete, the presence of free Cl− above normative thresholds should not be underestimated.

Source: Materials

DOI: 10.3390/ma18194465

Authors: Aiqin Wang, Xixian Du, Gang Li, Aoli Cao, Yuwei Ma, Yang Zhou

Institutions: Shihezi University, Xinjiang Production and Construction Corps

Language: English

Topic: Concrete Corrosion and Durability

Subfield: Civil and Structural Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $3,137

Funder: National Natural Science Foundation of China