Use of Methylcellulose-Based Pellet to Enhance the Bacterial Self-Healing of Cement Composite.

Indong Jang,Jihyeon Min,Chongku Yi,Dasom Son,Yongjun Son

doi:10.3390/ma14206113

Abstract

In this study, a new type of bacterial carrier using methylcellulose was presented, and its applicability to self-healing concrete has been explored. Methylcellulose, the main component of a 2 mm pellet-shaped carrier, can remain stable in alkaline environments and expand in neutral or acidic environments. These properties allow bacteria to survive in the high-alkaline and high-pressure environments of early age concrete, and the number of bacteria increases rapidly in the event of cracks, accelerating crack closure. The results show that the survival rate of bacterial spores inside the mortar was increased, and the pellet provides an enhanced biological anchor suitable for bacterial activity, bacterial growth, and mineral precipitation. Further, the results indicate an improved self-healing efficiency compared with mixing bacteria directly into the cement composite.

Highlights

Pellet to Enhance the BacterialThe occurrence of micro- to macro-crack propagation increases the probability of the entry of substances into concrete, thereby reducing the durability of the material and the overall durability of the built structure [1]
Another self-healing concrete process is the autonomous healing, which involves the incorporation of capsules containing healing agents or bacteria spores to the composites including electrodeposition [9,10], epoxy injection [11,12,13], polymers [13,14,15], and shape-memory alloys [16]
As inferred from the bacterial survival experiment that was conducted, the survival rate inside the cement mortar was improved as the number of bacteria at 28

Summary

Introduction

The occurrence of micro- to macro-crack propagation increases the probability of the entry of substances into concrete, thereby reducing the durability of the material and the overall durability of the built structure [1] Such propagation can be inhibited by self-healing processes of cementitious materials, the autogenous healing mechanism [2], which is an intrinsic repair property of cementitious material. Autogenous healing can be accelerated by applying mineral admixture [3], fiber [4,5], nanofiller [6], and curing agent [7,8] Another self-healing concrete process is the autonomous healing, which involves the incorporation of capsules containing healing agents or bacteria spores to the composites including electrodeposition [9,10], epoxy injection [11,12,13], polymers [13,14,15], and shape-memory alloys [16].

Methods

Findings

Discussion

Conclusion