Work

Characteristic analysis of innermost layer of ITZ of cement paste based on modelling the spatial distribution of calcium hydroxide

Year: 2025

Type: article

Abstract: The innermost layer of the interfacial transition zone (ITZ) between cement paste and aggregate was not well understood due to insufficient experimental characterization and numerical modelling. This study simulated the microstructure of ITZ by modelling the spatial distribution of calcium hydroxide (CH) based on the mechanism of crystal redistribution in porous media. The modelling results showed that CH concentrated adjacent to the innermost layer (e.g. 2.5-5.0 μm from the aggregate) due to the large distance map values in this region. However, in the innermost layer (e.g. within 2.5 μm from the aggregate), the distance map values sharply decreased, thereby reducing CH deposition. Consequently, the innermost layer of the ITZ exhibited an extremely loose microstructure. For the ITZ with the water to cement ratio of 0.4, the ITZ’s innermost layer (0.5 μm from the aggregate) reached a porosity of 76.6% at 28 days.

Source: Materials & Design

DOI: 10.1016/j.matdes.2025.114249

Authors: Yuting Chu, Qijun Yu, Yang Yu, Peng Gao, Binggen Zhan

Institutions: Hefei University of Technology, Huainan Normal University

Language: English

Topic: Concrete and Cement Materials Research

Subfield: Civil and Structural Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $3,650

Funders: National Natural Science Foundation of China, Fundamental Research Funds for the Central Universities