Bacterial Concrete: A Sustainable Building Material with Advantageous Properties

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Katie Molyneux
Keyword(s):  
Calcium Lactate ◽  
Genus Bacillus ◽  
Conventional Concrete ◽  
Sustainable Building ◽  
Metabolic Functions ◽  
Long Run ◽  
Industrial Use ◽  
Clay Pellets ◽  
Global Carbon ◽  
Bacterial Concrete

Bacterial concrete is concrete in which bacteria are embedded and is a material which exploits the metabolic functions of these specially selected bacteria, genus Bacillus. The bacteria are amalgamated within clay pellets along with the nutrient calcium lactate. When the concrete around the pellet cracks, the pellets break, and the bacteria metabolise the calcium lactate to produce insoluble calcium carbonate, filling cracks up to ~2 mm wide. The addition of the clay pellets and the bacteria to the concrete improves its compressive and tensile strengths, making it better suited for applications where the concrete must endure severe stress. Consequently, the modulus of toughness is improved, though the extent of the improvement depends on the grade of concrete used. Bacterial concrete is industrially advantageous as its low coefficient of permeability and high acid durability factor makes it less prone to corrosion and less likely to require extensive repairs. This is ideal for structures that are difficult or expensive to maintain as well as for use in motorways that endure corrosion from salt used in de-icing. This review will focus on the properties of bacterial concrete and its industrial use. It reveals that despite higher initial costs, the enhanced properties of bacterial concrete compared to conventional concrete, makes it a more sustainable material in the long run with an overall benefit to global carbon emissions.

Determination of Bacterial Concrete Strength Using Bacillus Subtilis and Lightweight Expandable Clay Aggregate

2021 ◽  
Vol 5 (2) ◽  
pp. 351-362
Author(s):  
Dhiraj Ahiwale ◽  
Rushikesh Khartode
Keyword(s):  
Bacillus Subtilis ◽  
Concrete Strength ◽  
Calcium Lactate ◽  
Self Healing ◽  
Conventional Concrete ◽  
Substantial Impact ◽  
Bacterial Form ◽  
Experimental Findings ◽  
The Impact ◽  
Bacterial Concrete

This study examines the impact of bacterial concrete on strength and self-healing. Bacterial concrete has better compressive strength, permeability, corrosion resistance, chemical precursors, alkalinity resistance, and mechanical stress. Bacillus subtilis calcium lactate and spore powder effects are explored in this study, and the influence of this bacterial form on strength and self-healing capacity to crack repair. The Bacillus subtilis concentration 105 cells/mL is used in concrete with calcium lactate 0.3% of cement. In another trial, calcium lactates 0.3% and spore powder 0.5% of cement with Bacillus subtilis concentration of 105 cells/mL and lightweight expandable clay aggregate (LECA) is 30% replaced to the coarse aggregate used in concrete respectively. The conventional concrete and bacterial concrete cubes were molded with dimensions of 150 mm x 150 mm x 150 mm, cylinders with dimensions of 100 mm x 200 mm, and a beam with dimensions of 100 mm x 100 mm x 500 mm. These specimens were evaluated after 7 and 28 days of cure. The compressive, split tensile, and flexural strength of bacterial concrete was raised by 23%, 8%, and 7%, respectively when compared to conventional concrete. Thus, the experimental findings reveal that Bacillus subtilis at 105 cells/ml cells with 0.3% calcium lactate has a substantial impact on the strength and self-healing of bacterial concrete.

scholarly journals Sustainable and Renewable Bio-Based Natural Fibres and Its Application for 3D Printed Concrete: A Review

2020 ◽  
Vol 12 (24) ◽  
pp. 10485
Author(s):  
Salmabanu Luhar ◽  
Thadshajini Suntharalingam ◽  
Satheeskumar Navaratnam ◽  
Ismail Luhar ◽  
Julian Thamboo ◽  
...  
Keyword(s):  
Material Selection ◽  
New Technology ◽  
Real Life ◽  
Natural Fibre ◽  
Environmental Benefits ◽  
Natural Fibres ◽  
Conventional Concrete ◽  
Sustainable Building ◽  
Fibre Composites ◽  
3D Printed

The concept of sustainability and the utilization of renewable bio-based sources have gained prominent attention in the construction industry. Material selection in construction plays a significant role in design and manufacturing process of sustainable building construction. Several studies are being carried out worldwide to investigate the potential use of natural fibres as reinforcement in concrete with its noticeable environmental benefits and mechanical properties. 3D printed concrete (3DPC) is another emerging technology, which has been under-developed for the past decade. The integration of reinforcement is one of the major challenges in the application of this new technology in real-life scenario. Presently, artificial fibres have been used as a reinforcement material for this special printable concrete mixture. However, natural fibre composites have received significant attention by many 3DPC constructions due to their lightweight energy conservation and environmentally friendly nature. These benchmarking characteristics unlock the wider area of natural fibres into the composite sector and challenge the substitution of artificial fibres. Hence, this paper presents a comprehensive review on the current practice and advantages of natural fibres in conventional concrete construction. Subsequently, with a view to the future efficient 3DPC construction, the potentials of natural fibres such as eco-friendly, higher impact, thermal, structural, and fire performance over the artificial fibres were highlighted, and their applicability in 3DPC as composites was recommended.

scholarly journals Photosynthetic textile biocomposites: Using laboratory testing and digital fabrication to develop flexible living building materials

2021 ◽  
Vol 28 (1) ◽  
pp. 223-236
Author(s):  
Assia Stefanova ◽  
Pichaya In-na ◽  
Gary Stephen Caldwell ◽  
Ben Bridgens ◽  
Rachel Armstrong
Keyword(s):  
Construction Industry ◽  
Carbon Capture ◽  
Building Materials ◽  
Pulse Amplitude ◽  
Digital Fabrication ◽  
Considerable Proportion ◽  
Metabolic Functions ◽  
Negative Impacts ◽  
Pulse Amplitude Modulation Fluorometry ◽  
Global Carbon

Abstract Urban development and the construction industry account for a considerable proportion of global carbon dioxide (CO2) emissions. Emerging biological materials, such as those proposed in this paper, seek to utilize the metabolic functions of living microorganisms to reduce some of the negative impacts of humans on the environment. The material explorations demonstrated in this paper propose a living photosynthetic carbon capture textile for the built environment. We demonstrate making practices that integrate living microorganisms within experimental methods of digital fabrication; specifically, harnessing photosynthetic microalgae that feed on waste and are capable of sequestering CO2 from internal building settings. These new biocomposites incorporate flexible textile substrates, i.e. cotton, hessian, polyester, and canvas, which provide a range of algae laden matrices that continue to develop and change during the useful part of the material’s lifecycle. This paper explores biological 3D printing fabrication processes and studies the development of mixtures that are compatible with the fabrication method and support microalgae (Chlorella vulgaris) metabolic processes. A range of incubation methods are assessed, highlighting the need for a support environment. The biocomposites’ performance is tested using imaging pulse amplitude modulation fluorometry (Imaging-PAM) to investigate changes in microalgae chlorophyll fluorescence over a 14 day period.

scholarly journals Stress–Strain Behaviour of Bacterial Concrete Incorporated With Sugarcane Fibres

2021 ◽  
Vol 12 (3) ◽  
pp. 5596-5606
Author(s):  
Ms. P.Kala Et. al.
Keyword(s):  
Bacillus Subtilis ◽  
Stress Strain ◽  
Conventional Concrete ◽  
Positive Type ◽  
Micro Cracks ◽  
Strain Behaviour ◽  
Fine Aggregates ◽  
A Cell ◽  
Mathematical Equations ◽  
Bacterial Concrete

Bacterial concrete is one of the methods of rectifying the micro-cracks developed in the structural elements made of concrete. The gram-positive type bacteria Bacillus subtilis when acquainted with concrete produces calcite precipitation which heals the micro cracks in the concrete. Bacillus subtilis was used with a cell concentration of 106. The optimised percentage replacement of fine aggregates with sugarcane fibres of grain size less than 4.75 mm was 0.1 %. The effect of sugarcane fibres on the durability of bacterial concrete is presented in this paper.To study the Stress -Strain behaviour of Sugarcane based Bacterial concrete (SBC), appropriate analytic SS model is developed that resembles the experimental behaviour of the various samples such as Conventional Concrete (CC), Bacterial Concrete (BC) and SBC. This work mainly targets on utilizing the earlier models and offers a new SS model that can well represent the actual SS behaviour of SBC samples. After finding the SS behaviour of CC, BC and SBC specimens experimentally, equations are developed to characterise axial SS behaviour of CC, BC and SBC samples. From these mathematical equations, theoretical stress for CC, BC and SBC are calculated and compared with test values. The proposed equations have exposed good connection with test values authorizing the mathematical model developed.

scholarly journals Performance of Sustainable Nano Concrete

2019 ◽  
Vol 9 (2) ◽  
pp. 3160-3163
Keyword(s):  
Concrete Beam ◽  
Reinforced Concrete Beam ◽  
Nano Materials ◽  
Nano Silica ◽  
Conventional Concrete ◽  
Sustainable Building ◽  
Sustainable Technologies ◽  
Granulated Blast Furnace Slag ◽  
Micro Silica ◽  
Furnace Slag

Sustainable Nano concrete is a concrete having less energy consumption during the production and releases less carbon dioxide as compared to conventional concrete. About one ton of CO2 is discharged in the manufacture of one ton of Portland cement, thus having a large influence on global warming. The concrete industry is adopting sustainable technologies to diminish this impact. This paper presents the investigation on a sustainable concrete having Ground Granulated Blast Furnace Slag (GGBS), which is a byproduct of the steel industry, blended with Nano materials. Mechanical characteristics of concrete mixes having varying GGBS content (60%, 70%, and 80%) by weight of cement were investigated and compared with conventional concrete. To enhance the workability, compression strength, durability and early strength of GGBS based concrete, Nano silica, micro silica and calcium carbonate (CaCO3) were added to the concrete mix. It was found that concrete having 60% GGBS as replacement for cement exhibit improved mechanical properties. Also investigations were carried out on reinforced concrete beam with 60 % GGBS. Results indicate that concrete with 60 % GGBS could be used as a sustainable building material

scholarly journals An Innovative Approach to Produce Soil-Based Building Products

2021 ◽  
Vol 01 (01) ◽  
pp. 58-59
Author(s):  
S. N. Malkanthi ◽  
Keyword(s):  
Building Material ◽  
Building Materials ◽  
Rammed Earth ◽  
Conventional Concrete ◽  
Sustainable Building ◽  
Usual Practice ◽  
Building Products ◽  
High Level ◽  
Strength And Durability ◽  
Earth Block

Soil has been used as a building material in different forms, such as mud, adobe, rammed earth, and bricks. Compressed Stabilized Earth Block (CSEB), a form of soil blocks with different additives including cement, fly ash, and lime, is a sustainable building material with many advantages compared to other conventional building materials. The usual practice of past researchers in producing CSEB was to add different materials like sand to the soil to control its clay and silt (finer) content. A high level of finer content is not desirable when it comes to the strength and durability of CSEB. This study proposes to reduce/ extract the finer content in the soil by washing it using a conventional concrete mixing machine.

scholarly journals Utilization of Bacillus Subtilis Bacteria for Improving Mechanical Properties of Concrete

2020 ◽  
Vol 1000 (1000) ◽  
Author(s):  
Sudipto Nath Priyom ◽  
Md. Moinul Islam ◽  
Wahhida Shumi
Keyword(s):  
Bacillus Subtilis ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Maintenance Cost ◽  
Concrete Technology ◽  
Conventional Concrete ◽  
Culture Density ◽  
Microbial Groups ◽  
Bacterial Concrete

Utilization of concrete as a building material is well-known worldwide and increasing continuously due to its sustainability, low maintenance cost, durability performance, etc. Ingredients of concrete, its constructional methodology, exposure conditions are moderating and improving day by day. However, this study covers a laboratory investigation of Bacterial Concrete. The bacterial concrete technology is based on the application of the mineral producing microbes. Some microbes like Bacillus subtilis which have the properties of bio-calcification can precipitate CaCO3 effectively inside concrete structures. This CaCO3 precipitation can fill the pores and therefore, the cracks internally and finally make the structure more compact. In this experimental study, Nutrient Broth (NB) media was employed for the growth and spore formation of Bacillus subtilis bacteria. Four different bacterial culture densities (0.107, 0.2, 0.637, and 1.221) were estimated at OD600 and directly added to concrete matrix maintaining previously fixed water to culture ratio (0.5:0.5). 100 mm cubical concrete specimens were cast, subjected to compressive and tensile strength tests for different curing ages and finally compared with Conventional Concrete (OD600=0). Significant increase in mechanical strengths was observed due to addition of Bacillus subtilis bacteria in concretes which have the culture density of 0.637. Soon cylindrical concrete specimens of 100 mm diameter and 200 mm height were prepared for Ultrasonic Pulse Velocity (UPV) analysis. The test results obtained from UPV analysis reveal that specimens prepared with culture density of 0.637 show higher pulse velocity than other microbial groups. Afterwards, this paper proposes a UPV vs. compressive strength relationship curve for different strengths of concrete.

scholarly journals Bacterial Concrete- A Sustainable Solution for Concrete Maintenance

2019 ◽  
Vol 8 (11S) ◽  
pp. 227-232 ◽  
Keyword(s):  
Concrete Slab ◽  
Research Work ◽  
Construction Materials ◽  
Self Healing ◽  
Conventional Concrete ◽  
Sealing Capacity ◽  
Sustainable Materials ◽  
Positive Results ◽  
Bacterial Concrete

Cracks formed in concrete are inescapable and are one of the major reasons for the weaknesses of concrete. Majorly water along with other components penetrate through these cracks resulting in corrosion thereby reducing the strength of concrete directly hampering its life. The objective of present research work is to promote sustainable development and to identify sustainable materials for treating cracks formed in concrete. Various researches have shown positive results by adding calcite precipitating bacteria in concrete, also known as bacterial concrete or self-healing concrete. This research is dedicated to check the suitability of mixing these self-healing calcite depositing bacteria with concrete in order to increase the compressive strength of concrete, reduce its permeability and seepage of water by bio-mineralization process. Substantial increase in strength is observed in concrete specimens when casted with bacterial solution. The study has devised methods or ways to test the effect of use of bacteria in concrete. Tests on concrete slab with various combinations of bacterial solution as well as varied percentage of bacterial solution have been conducted. Use of bacterial solution for surface application on slab to test the sealing capacity is done. Results have been compared with conventional concrete. Biological modifications of construction materials are the need of the hour for strength improvement and long term sustainability. The present study proposes a promising sustainable repair method for concrete.

scholarly journals The Structural Performance of Externally Strengthened RCC Beams Made with GPC

2019 ◽  
Vol 8 (3) ◽  
pp. 2855-2860
Keyword(s):  
Conventional Concrete ◽  
Sustainable Building ◽  
Near Surface ◽  
Polymer Sheets ◽  
Concrete Production ◽  
Load Carrying ◽  
Externally Bonded ◽  
Near Surface Mounted ◽  
System 2 ◽  
Bottom Face

Cement is one of the prime ingredients in construction but at the same time a source of CO2 emission during its manufacture. In order to create a sustainable building material, Geopolymer concrete (GPC) was proposed by Davidovits in 1988 which could be viable substitute for conventional concrete production. In this study, totally 21 beam specimens were prepared with GPC of M30 grade which were externally strengthened by two systems of strengthening namely Externally Bonded Reinforcement System (EBR) and Near Surface Mounted System (NSM). Strengthening of existing beams will enhance the service life and service loading conditions of beams. In EBR system, 2 numbers of 6, 8 and 10mm diameter bars are bonded at the bottom face of RCC beams and in NSM system, different types of polymer sheets are attached at the bottom face of the beam such as Carbon, Glass and Aramid. Results show that, the beam specimens made with Carbon Fiber Reinforced Polymer (CFRP) sheets perform better than the other strengthening methods, and have 67% better load-carrying capacity than the control beam (beams without strengthening applications).

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