Autogenous healing performance of internal curing agent-based self-healing cementitious composite

Su, Yi; Huang, Cihang; Jeong, HyunGu; Nantung, Tommy; Olek, Jan; Baah, Prince; Lü, Na

doi:10.1016/j.cemconcomp.2020.103825

Cited by 21 publications

(10 citation statements)

References 46 publications

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“…In other words, for repairing cracks smaller than 200 μm, EP particles as an internal curing agent releasing water inside the specimen to promote the hydration reaction of cement particles to fill the cracks are more effective than water from the external environment to promote the hydration reaction of cement particles to fill the cracks. This conclusion was verified in a study by Su et al (2020). Compared with the 30EP specimen, the specimens mixed with self-healing agents (30EP-B and 20EP-B) exhibited the same healing performance, achieving a 100% healing rate.…”

Section: Healing Rate For Different Initial Crack Widthsmentioning

confidence: 58%

Statistical and experimental study on microcrack of mortar by a self-healing agent of bacteria adsorbed by expanded perlite

Li,

Sun,

Wang

et al. 2023

MMMS

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PurposeThe purpose of this paper is to add expanded perlite (EP) immobilized microorganisms that replace part of the standard sand in mortar to improve the self-healing ability of mortar cracks and reduce the water absorption of mortar after healing.Design/methodology/approachBacillus pseudofirmus spores were immobilized with EP particles as self-healing agents. The effects of adding self-healing agents on the compressive strength of mortar specimens were observed. The ability of mortar specimens to heal cracks was evaluated using crack microscopic observation and water absorption experiments. The filler at the cracks was microscopically analyzed by scanning electron microscope and X-ray diffraction experiments.FindingsFirst, the internal curing effect of EP promotes the hydration of cement in mortar, which generates more amount and denser crystal structure of Ca(OH)2 at mortar cracks and improves the self-healing ability of mortar. Second, the self-healing ability of mortar improves with the increase of self-healing agent admixture. Adding a self-healing agent of high admixture makes the planar undulation of calcite crystal accumulation at mortar cracks more significant. Finally, the initial crack widths that can be completely healed by adding EP and self-healing agents to the mortar are 200 µm and 600 µm, respectively.Originality/valueThe innovation points of this study are as follows. (1) The mechanism of the internal curing effect of EP particles on the self-healing ability of mortar cracks was revealed by crack microscopic observation tests and microscopic experiments. (2) The effect of different self-healing agent amounts on the self-healing ability of mortar cracks has been studied. (3) The effects of EP particles and self-healing agents on healing different initial widths were elucidated by crack microscopic observation tests.Graphical abstract

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Section: Healing Rate For Different Initial Crack Widthsmentioning

confidence: 58%

Statistical and experimental study on microcrack of mortar by a self-healing agent of bacteria adsorbed by expanded perlite

Li,

Sun,

Wang

et al. 2023

MMMS

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“…Only a little cement remains unhydrated, while monosulfate tends to form a loose structure, resulting in microcracks after loading [ 53 ]. The addition of zeolite particles can effectively elevate the self-healing effect of cement-based composites as the internal curing agent releases additional water for secondary hydration [ 18 ]. Furthermore, the compressive strength of the cement-based composite with 30% zeolite was increased by 15%.…”

Section: Components and Mechanisms Of Lightweight Aggregate Self-heal...mentioning

confidence: 99%

“…The biological self-healing system may have more negative impacts than the chemical self-healing system. However, Table 4 , Table 5 and Table 6 indicate that a high content of the self-healing admixtures did not result in a significant reduction in flexural strength, tensile strength, and compressive strength [ 17 , 18 , 19 ]. Meanwhile, a slight improvement in strength development was likely due to the deposition of self-healing products from healing agents, therefore filling mortar pores and enhancing both compressive strength and split tensile strength [ 24 ].…”

Section: Performance Of Lightweight Aggregate Self-healing Concretementioning

confidence: 99%

A Review of Lightweight Self-Healing Concrete

Feng

Zhou

2022

Materials

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Cementitious composites often crack because of their low tensile strength. The ability of self-healing cementitious composite to automatically repair cracks has attracted widespread attention. Lightweight aggregate (LWA) has a low density and a high porosity which can provide storage space for a healing agent. The healing mechanisms and healing compositions of lightweight self-healing concrete (LWSHC) have been summarized in this research. The workability, compressive strength, crack repairing, and durability of LWSHC performance is also illustrated. A LWA with interconnected pores and a high strength should be integrated into LWSHC to increase the crack closure rate and mechanical properties. Expanded perlite is the most suitable LWA carrier for bioremediation. The chemical healing agents are better than the biological healing agents at present since the biological healing agents have more negative effects. A sodium silicate solution is a good choice as a chemical healing agent. Vacuum conditions, high-temperature processing, and the use of coating technologies on LWAs can improve the healing effect of LWSHC. The addition of fibers also enhance the self-healing ability of LWSHC. Further, the use of numerical simulation supports the healing performance of LWSHC. The goal of this research is to investigate the most appropriate component of LWSHC to ensure a high crack closure rate, strength healing ratio, and great durability while being lightweight. It can then be adopted in high-rise and large-span concrete structures to extend the service life.

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“…Concrete is a brittle material with high cracking susceptibility. Cracking can result from a variety of causes that include plastic, autogenous and drying shrinkage, thermal stress, mechanical loading, differential settlement, and various other damage mechanisms 1 – 3 . This cracking behaviour, which is nearly inevitable, can jeopardize the mechanical strength and durability performance of concrete civil infrastructure.…”

Section: Introductionmentioning

confidence: 99%

Effect of autogenous crack self-healing on mechanical strength recovery of cement mortar under various environmental exposure

Suleiman

Nehdi

2021

Sci Rep

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While research on self-healing of cement-based materials has recently gained considerable attention and made sizable progress, there is still ongoing debate and controversy regarding the effect of crack closing induced by autogenous self-healing on mechanical strength recovery. Despite that several techniques have been used to capture and quantify the self-healing of surface cracks, the resulting effect on mechanical strength has not, to date, been explored and quantified in a rigorous and systematic manner. Therefore, in this study, a broad array of multi-scale techniques including non-destructive shear wave velocity, high-resolution X-ray computed tomography (µCT), and 3D image analysis was deployed to examine the effects of autogenous crack self-healing on the mechanical strength recovery in various mortar specimens. The influence of microstructural changes induced by additives such as swelling compounds, silica-based additions, and carbonating minerals on strength recovery under diverse environmental exposures was further explored. The results capture the relationship between the crack closing mechanism imparted by self-healing and mechanical strength recovery, therefore elucidating the discrepancies in mechanical strength recovery results reported in the open literature.

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Autogenous healing performance of internal curing agent-based self-healing cementitious composite

Cited by 21 publications

References 46 publications

Statistical and experimental study on microcrack of mortar by a self-healing agent of bacteria adsorbed by expanded perlite

Statistical and experimental study on microcrack of mortar by a self-healing agent of bacteria adsorbed by expanded perlite

A Review of Lightweight Self-Healing Concrete

Effect of autogenous crack self-healing on mechanical strength recovery of cement mortar under various environmental exposure

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