Session: 16-01-01: Poster Session: NSF-Funded Research (Grad & Undergrad)

Paper Number: 100113

100113 - The Efficacy of Cellulose Fiber as Bacteria Carrier for Self-Healing of 3d Polymer Microstructures and Concrete. 

Abstract

Microcracks are known to occur at an early stage in constructions utilizing concrete and lattice structures thereby affecting its serviceability and increasing the cost of repair and maintenance. As a result, there is a growing need to use a microbiological crack-healing strategy to arrest and mitigate the impact of the microcracks. The microbial system's distinguishing characteristic is that it allows concrete and 3D polymer microstructures to self-heal. This study addresses the efficiency of microbiologically induced calcite precipitation in increasing the durability and self-healing of cementitious construction materials. The primary focus has been on developing a carrier to protect the bacteria from being crushed during casting and from the harsh environment. The results of the SEM examination demonstrated that cellulose fiber bacteria can live at temperatures as high as 160⁰C, as opposed to direct bacteria (without carrier), which can only survive at temperatures as high as 60⁰C. On the 28^th day of curing, the cellulose fiber bacteria exhibited 35% improvement in split tensile strength, 32% in compressive strength over the control concrete. when compared to regular concrete, the inclusion of 0.45% cellulose fiber bacteria reduced water absorption rate by 67.5%. Furthermore, after 28 days, the Cellulose fiber bacteria self-healed up to 1.5 mm fracture concretes via wet-dry technique and 2.5 mm crack concretes by fully wet technique after 40 days. The temperature test revealed that, as heating period increases at 425⁰C, the compressive strength of control concrete decreases by 45.8%, 56.5%, 64% 74% and 80.5% at heating intervals of 30, 60, 90, 120 and 150 Minutes respectively when compared to Bacteria with 0.45%Cellulose fiber. This is due to thermal expansion, internal cracking, and a lack of adhesion between the paste and the steel reinforcement within the concrete. To address this issue, Lysinibaccilus Sphaericus with cellulose fiber as carrier should be incorporated to concrete during mixing to minimize Concrete strength loss at elevated temperatures. Also, Control Concrete lost 14.2%, 12%, 14.6%, and 16.3% strength after 7, 14, 28, and 45 days of acid immersion test, and 0.23%, 0.43%, 1.2% and 2.16% weight loss respectively When compared to Fiber bacteria Concrete. The result proved that Bacteria specimens with Cellulose Fiber as carrier could tolerate aggressive sulfuric acid precipitation when compared to Control Concrete. Furthermore, Fiber-Sphaericus bacteria capable of producing spores and 3D printed materials to grow bionic mineralized composites with ordered microstructure was utilized. From the research results, Bionic composites outperformed the control microstructure by 50% in terms of specific compressive strength and fracture toughness, and they also self-healed 90% voids created around 3D lattice polymer beam within 15 days. This study contributes towards the development of 3D-architectural hybrid synthetic living materials with live ordered microstructures. 3D polymer scaffold was utilized in this research to replicate the structured β-chitin matrix, whilst bacteria adhering to the polymer surface serve as nucleation sites.

Keywords: Biomineralization, 3D Polymer, microstructures, Concrete, Lattice beam, Fiber-Bacteria, temperature, Absorption, Acid immersion.

Presenting Author: EMMANUEL IGBOKWE Southern University Baton Rouge LA

Presenting Author Biography: Emmanuel Igbokwe is a final year graduate Student of Southern University A&M College Baton Rouge LA. His Academic Major is in Mechanical Engineering with Specialty in Material Engineering.

Authors:

EMMANUEL IGBOKWE Southern University Baton Rouge LA
Patrick Mensah Southern University Baton Rouge