Factors Affecting the Physical Properties of Microbial Induced Calcium Carbonate Precipitation (MICP) Enhanced Recycled Aggregates

Microbial-induced calcium carbonate precipitation (MICP) can enhance the physical properties of recycled aggregates. Compared to traditional technologies, MICP offers environmental benefits and produces no pollution. However, its mineralization efficacy is significantly influenced by the process par...

Full description

Saved in:
Bibliographic Details
Main Authors: Jin Zhang, Cong Wang, Zhipeng Wang
Format: Article
Language:English
Published: MDPI AG 2024-09-01
Series:Buildings
Subjects:
Online Access:https://www.mdpi.com/2075-5309/14/9/2851
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850258333131341824
author Jin Zhang
Cong Wang
Zhipeng Wang
author_facet Jin Zhang
Cong Wang
Zhipeng Wang
author_sort Jin Zhang
collection DOAJ
description Microbial-induced calcium carbonate precipitation (MICP) can enhance the physical properties of recycled aggregates. Compared to traditional technologies, MICP offers environmental benefits and produces no pollution. However, its mineralization efficacy is significantly influenced by the process parameters. To investigate this, an MICP mineralization test was conducted by manipulating various process parameters throughout the mineralization process. The water absorption rate, apparent density, and calcium carbonate content of the mineralized recycled aggregates were assessed to discern the impact of these parameters on the mineralization outcome. Further analysis using techniques such as thermogravimetric analysis (TG), X-ray diffraction (XRD), nuclear magnetic resonance (NMR), and scanning electron microscopy (SEM) were employed to elucidate the mineralization mechanism of the recycled aggregates at a micro-level. The findings indicated that the MICP treatment induced bacteria to precipitate CaCO<sub>3</sub>, forming calcite crystalline CaCO<sub>3</sub> within the pores and microcracks. This led to a denser interfacial transition zone and, consequently, improved the physical properties of the recycled aggregates. Optimal mineralization was achieved when the bacterial solution concentration was 1.4, the temperature and pH were 35 °C and 9, respectively, and the urea concentration, Ca<sup>+</sup> concentration, and mineralization time were 0.5 mol/L, 0.5 mol/L, and 7 days, respectively. Under these conditions, the mineralized recycled aggregate exhibited a 16.07% reduction in water absorption, a 1.07% increase in apparent density, and a 2.28% change in mass.
format Article
id doaj-art-edaaff0b1bb64636b8b5638d63780c70
institution OA Journals
issn 2075-5309
language English
publishDate 2024-09-01
publisher MDPI AG
record_format Article
series Buildings
spelling doaj-art-edaaff0b1bb64636b8b5638d63780c702025-08-20T01:56:12ZengMDPI AGBuildings2075-53092024-09-01149285110.3390/buildings14092851Factors Affecting the Physical Properties of Microbial Induced Calcium Carbonate Precipitation (MICP) Enhanced Recycled AggregatesJin Zhang0Cong Wang1Zhipeng Wang2School of Civil Engineering, Architecture and Environment, Hubei University of Technology, Wuhan 430068, ChinaSchool of Civil Engineering, Architecture and Environment, Hubei University of Technology, Wuhan 430068, ChinaSchool of Civil Engineering, Architecture and Environment, Hubei University of Technology, Wuhan 430068, ChinaMicrobial-induced calcium carbonate precipitation (MICP) can enhance the physical properties of recycled aggregates. Compared to traditional technologies, MICP offers environmental benefits and produces no pollution. However, its mineralization efficacy is significantly influenced by the process parameters. To investigate this, an MICP mineralization test was conducted by manipulating various process parameters throughout the mineralization process. The water absorption rate, apparent density, and calcium carbonate content of the mineralized recycled aggregates were assessed to discern the impact of these parameters on the mineralization outcome. Further analysis using techniques such as thermogravimetric analysis (TG), X-ray diffraction (XRD), nuclear magnetic resonance (NMR), and scanning electron microscopy (SEM) were employed to elucidate the mineralization mechanism of the recycled aggregates at a micro-level. The findings indicated that the MICP treatment induced bacteria to precipitate CaCO<sub>3</sub>, forming calcite crystalline CaCO<sub>3</sub> within the pores and microcracks. This led to a denser interfacial transition zone and, consequently, improved the physical properties of the recycled aggregates. Optimal mineralization was achieved when the bacterial solution concentration was 1.4, the temperature and pH were 35 °C and 9, respectively, and the urea concentration, Ca<sup>+</sup> concentration, and mineralization time were 0.5 mol/L, 0.5 mol/L, and 7 days, respectively. Under these conditions, the mineralized recycled aggregate exhibited a 16.07% reduction in water absorption, a 1.07% increase in apparent density, and a 2.28% change in mass.https://www.mdpi.com/2075-5309/14/9/2851recycled aggregate (RA)microbial induced calcium carbonate precipitationperformance improvementmicroscopic analysis
spellingShingle Jin Zhang
Cong Wang
Zhipeng Wang
Factors Affecting the Physical Properties of Microbial Induced Calcium Carbonate Precipitation (MICP) Enhanced Recycled Aggregates
Buildings
recycled aggregate (RA)
microbial induced calcium carbonate precipitation
performance improvement
microscopic analysis
title Factors Affecting the Physical Properties of Microbial Induced Calcium Carbonate Precipitation (MICP) Enhanced Recycled Aggregates
title_full Factors Affecting the Physical Properties of Microbial Induced Calcium Carbonate Precipitation (MICP) Enhanced Recycled Aggregates
title_fullStr Factors Affecting the Physical Properties of Microbial Induced Calcium Carbonate Precipitation (MICP) Enhanced Recycled Aggregates
title_full_unstemmed Factors Affecting the Physical Properties of Microbial Induced Calcium Carbonate Precipitation (MICP) Enhanced Recycled Aggregates
title_short Factors Affecting the Physical Properties of Microbial Induced Calcium Carbonate Precipitation (MICP) Enhanced Recycled Aggregates
title_sort factors affecting the physical properties of microbial induced calcium carbonate precipitation micp enhanced recycled aggregates
topic recycled aggregate (RA)
microbial induced calcium carbonate precipitation
performance improvement
microscopic analysis
url https://www.mdpi.com/2075-5309/14/9/2851
work_keys_str_mv AT jinzhang factorsaffectingthephysicalpropertiesofmicrobialinducedcalciumcarbonateprecipitationmicpenhancedrecycledaggregates
AT congwang factorsaffectingthephysicalpropertiesofmicrobialinducedcalciumcarbonateprecipitationmicpenhancedrecycledaggregates
AT zhipengwang factorsaffectingthephysicalpropertiesofmicrobialinducedcalciumcarbonateprecipitationmicpenhancedrecycledaggregates