Optimization of calcium sources for enhanced performance of microbially-induced calcium carbonate precipitation (MICP)-modified recycled aggregate concrete

Chenxia Wang; Shengxian Xiao; Xiangping Xian; Shenghua Wu; Yangsheng Zhou; Yazhen Xu; Linxin Gan; Fubo Cao; Tian Su

doi:10.1016/j.jobe.2025.114410

Optimization of calcium sources for enhanced performance of microbially-induced calcium carbonate precipitation (MICP)-modified recycled aggregate concrete

Chenxia Wang
, Shengxian Xiao
, Xiangping Xian
, Shenghua Wu
, Yangsheng Zhou
, Yazhen Xu
, Linxin Gan
, Fubo Cao^*
, Tian Su^*

^*Corresponding author for this work

Department of Architecture and Civil Engineering

Research output: Journal Publications and Reviews › RGC 21 - Publication in refereed journal › peer-review

5 Citations (Scopus)

Abstract

Microbially induced calcium carbonate precipitation is a green technology with great potential in improving the performance of recycled aggregate (RA). In this study, RA was treated with four different calcium sources: CaCl₂, Ca(NO₃)₂, Ca(CH₃COO)₂, and Ca(C₃H₅O₃)₂. The mechanical properties, frost resistance, uniaxial compression properties, and microstructure of the resulting recycled concrete (RC) were investigated. Additionally, a constitutive model suitable for MICP-modified recycled concrete (MRC) was developed. The results demonstrated that MICP treatment significantly enhances the performance of RA. Specifically, the water absorption and crushing index of concrete treated with Ca(NO₃)₂ decreased by up to 61.82 % and 12.5 %, respectively, while the apparent density increased by as much as 2.94 %. When Ca(NO₃)₂ is used as the calcium source, the primary precipitate is calcite, and the adhesion properties between RA and the precipitate is the strongest. Additionally, the mechanical properties and durability of concrete treated with CaCl₂ and Ca(NO₃)₂ are significantly improved, with Ca(NO₃)₂ showing the most notable effect. Compared to untreated RC, RC treated with Ca(NO₃)₂ exhibited increases in compressive strength, splitting tensile strength and flexural strength by up to 38.9 %, 9.06 % and 25.9 %, respectively. The durability coefficient reached 1.41, significantly higher than those of the other three groups. Furthermore, the constitutive model proposed in this study effectively captures the stress-strain behavior of MRC. On the microstructure level, the pore structure and interface transition zone of concrete treated with CaCl₂ and Ca(NO₃)₂ were effectively improved. Considering both the mechanical and durability properties of MRC, Ca(NO₃)₂ is recommended as the optimal calcium source. © 2025 Elsevier Ltd

Original language	English
Article number	114410
Journal	Journal of Building Engineering
Volume	115
Online published	24 Oct 2025
DOIs	https://doi.org/10.1016/j.jobe.2025.114410
Publication status	Published - 1 Dec 2025

Funding

The study was carried out with the support of the National Natural Science Foundation of China, China ( 51868061 , 52368024 ), the Natural Science Foundation of Inner Mongolia Province (CN), China ( 2022LHMS05011 , 2024MS05028 ), the Faculty Start-up Grant of City University of Hong Kong, China ( 9610660 ).

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

SDG 7 Affordable and Clean Energy

Research Keywords

Calcium source
Frost resistance
MICP
Microstructure
Stress-strain relationship

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10.1016/j.jobe.2025.114410

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@article{f19785c0a83245a598492cb907ffe989,

title = "Optimization of calcium sources for enhanced performance of microbially-induced calcium carbonate precipitation (MICP)-modified recycled aggregate concrete",

abstract = "Microbially induced calcium carbonate precipitation is a green technology with great potential in improving the performance of recycled aggregate (RA). In this study, RA was treated with four different calcium sources: CaCl2, Ca(NO3)2, Ca(CH3COO)2, and Ca(C3H5O3)2. The mechanical properties, frost resistance, uniaxial compression properties, and microstructure of the resulting recycled concrete (RC) were investigated. Additionally, a constitutive model suitable for MICP-modified recycled concrete (MRC) was developed. The results demonstrated that MICP treatment significantly enhances the performance of RA. Specifically, the water absorption and crushing index of concrete treated with Ca(NO3)2 decreased by up to 61.82 \% and 12.5 \%, respectively, while the apparent density increased by as much as 2.94 \%. When Ca(NO3)2 is used as the calcium source, the primary precipitate is calcite, and the adhesion properties between RA and the precipitate is the strongest. Additionally, the mechanical properties and durability of concrete treated with CaCl2 and Ca(NO3)2 are significantly improved, with Ca(NO3)2 showing the most notable effect. Compared to untreated RC, RC treated with Ca(NO3)2 exhibited increases in compressive strength, splitting tensile strength and flexural strength by up to 38.9 \%, 9.06 \% and 25.9 \%, respectively. The durability coefficient reached 1.41, significantly higher than those of the other three groups. Furthermore, the constitutive model proposed in this study effectively captures the stress-strain behavior of MRC. On the microstructure level, the pore structure and interface transition zone of concrete treated with CaCl2 and Ca(NO3)2 were effectively improved. Considering both the mechanical and durability properties of MRC, Ca(NO3)2 is recommended as the optimal calcium source. {\textcopyright} 2025 Elsevier Ltd",

keywords = "Calcium source, Frost resistance, MICP, Microstructure, Stress-strain relationship",

author = "Chenxia Wang and Shengxian Xiao and Xiangping Xian and Shenghua Wu and Yangsheng Zhou and Yazhen Xu and Linxin Gan and Fubo Cao and Tian Su",

year = "2025",

month = dec,

day = "1",

doi = "10.1016/j.jobe.2025.114410",

language = "English",

volume = "115",

journal = "Journal of Building Engineering",

issn = "2352-7102",

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}

Optimization of calcium sources for enhanced performance of microbially-induced calcium carbonate precipitation (MICP)-modified recycled aggregate concrete. / Wang, Chenxia; Xiao, Shengxian; Xian, Xiangping et al.
In: Journal of Building Engineering, Vol. 115, 114410, 01.12.2025.

Research output: Journal Publications and Reviews › RGC 21 - Publication in refereed journal › peer-review

TY - JOUR

T1 - Optimization of calcium sources for enhanced performance of microbially-induced calcium carbonate precipitation (MICP)-modified recycled aggregate concrete

AU - Wang, Chenxia

AU - Xiao, Shengxian

AU - Xian, Xiangping

AU - Wu, Shenghua

AU - Zhou, Yangsheng

AU - Xu, Yazhen

AU - Gan, Linxin

AU - Cao, Fubo

AU - Su, Tian

PY - 2025/12/1

Y1 - 2025/12/1

N2 - Microbially induced calcium carbonate precipitation is a green technology with great potential in improving the performance of recycled aggregate (RA). In this study, RA was treated with four different calcium sources: CaCl2, Ca(NO3)2, Ca(CH3COO)2, and Ca(C3H5O3)2. The mechanical properties, frost resistance, uniaxial compression properties, and microstructure of the resulting recycled concrete (RC) were investigated. Additionally, a constitutive model suitable for MICP-modified recycled concrete (MRC) was developed. The results demonstrated that MICP treatment significantly enhances the performance of RA. Specifically, the water absorption and crushing index of concrete treated with Ca(NO3)2 decreased by up to 61.82 % and 12.5 %, respectively, while the apparent density increased by as much as 2.94 %. When Ca(NO3)2 is used as the calcium source, the primary precipitate is calcite, and the adhesion properties between RA and the precipitate is the strongest. Additionally, the mechanical properties and durability of concrete treated with CaCl2 and Ca(NO3)2 are significantly improved, with Ca(NO3)2 showing the most notable effect. Compared to untreated RC, RC treated with Ca(NO3)2 exhibited increases in compressive strength, splitting tensile strength and flexural strength by up to 38.9 %, 9.06 % and 25.9 %, respectively. The durability coefficient reached 1.41, significantly higher than those of the other three groups. Furthermore, the constitutive model proposed in this study effectively captures the stress-strain behavior of MRC. On the microstructure level, the pore structure and interface transition zone of concrete treated with CaCl2 and Ca(NO3)2 were effectively improved. Considering both the mechanical and durability properties of MRC, Ca(NO3)2 is recommended as the optimal calcium source. © 2025 Elsevier Ltd

AB - Microbially induced calcium carbonate precipitation is a green technology with great potential in improving the performance of recycled aggregate (RA). In this study, RA was treated with four different calcium sources: CaCl2, Ca(NO3)2, Ca(CH3COO)2, and Ca(C3H5O3)2. The mechanical properties, frost resistance, uniaxial compression properties, and microstructure of the resulting recycled concrete (RC) were investigated. Additionally, a constitutive model suitable for MICP-modified recycled concrete (MRC) was developed. The results demonstrated that MICP treatment significantly enhances the performance of RA. Specifically, the water absorption and crushing index of concrete treated with Ca(NO3)2 decreased by up to 61.82 % and 12.5 %, respectively, while the apparent density increased by as much as 2.94 %. When Ca(NO3)2 is used as the calcium source, the primary precipitate is calcite, and the adhesion properties between RA and the precipitate is the strongest. Additionally, the mechanical properties and durability of concrete treated with CaCl2 and Ca(NO3)2 are significantly improved, with Ca(NO3)2 showing the most notable effect. Compared to untreated RC, RC treated with Ca(NO3)2 exhibited increases in compressive strength, splitting tensile strength and flexural strength by up to 38.9 %, 9.06 % and 25.9 %, respectively. The durability coefficient reached 1.41, significantly higher than those of the other three groups. Furthermore, the constitutive model proposed in this study effectively captures the stress-strain behavior of MRC. On the microstructure level, the pore structure and interface transition zone of concrete treated with CaCl2 and Ca(NO3)2 were effectively improved. Considering both the mechanical and durability properties of MRC, Ca(NO3)2 is recommended as the optimal calcium source. © 2025 Elsevier Ltd

KW - Calcium source

KW - Frost resistance

KW - MICP

KW - Microstructure

KW - Stress-strain relationship

UR - https://www.scopus.com/pages/publications/105020257874

UR - https://www.scopus.com/record/pubmetrics.uri?eid=2-s2.0-105020257874&origin=recordpage

U2 - 10.1016/j.jobe.2025.114410

DO - 10.1016/j.jobe.2025.114410

M3 - RGC 21 - Publication in refereed journal

SN - 2352-7102

VL - 115

JO - Journal of Building Engineering

JF - Journal of Building Engineering

M1 - 114410

ER -

Optimization of calcium sources for enhanced performance of microbially-induced calcium carbonate precipitation (MICP)-modified recycled aggregate concrete

Abstract

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UN SDGs

Research Keywords

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