Bacterial concrete as a sustainable alternative to conventional concrete

2019 ◽  
Author(s):  
R.M. REIS ◽  
A. KOPPE ◽  
F.M. REIS
Keyword(s):  
Conventional Concrete ◽  
Bacterial Concrete

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.

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.

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.

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.

Correlations between non-destructive (UPV) and destructive tests of conventional concrete using high-early strength cement

2017 ◽  
Author(s):  
Driton R. Kryeziu ◽  
Armend Mujaj ◽  
Visar Krelani ◽  
Mevlan Qafleshi ◽  
Fisnik Kadiu
Keyword(s):  
Conventional Concrete ◽  
Early Strength ◽  
Non Destructive

Bending Strength of Steel Fibre Reinforced Concrete Ribbed Slab Panel

2018 ◽  
Vol 15 (1) ◽  
pp. 15
Author(s):  
AMIR SYAFIQ SAMSUDIN ◽  
MOHD HISBANY MOHD HASHIM ◽  
SITI HAWA HAMZAH ◽  
AFIDAH ABU BAKAR
Keyword(s):  
Reinforced Concrete ◽  
Bending Strength ◽  
Steel Fibre ◽  
Concrete Slab ◽  
Future Application ◽  
Fibre Reinforcement ◽  
Fibre Reinforced Concrete ◽  
Conventional Concrete ◽  
Steel Fibre Reinforced Concrete ◽  
Bending Load

Nowadays, demands in the application of fibre in concrete increase gradually as an engineering material. Rapid cost increment of material causes the increase in demand of new technology that provides safe, efficient and economical design for the present and future application. The introduction of ribbed slab reduces concrete materials and thus the cost, but the strength of the structure also reduces due to the reducing of material. Steel fibre reinforced concrete (SFRC) has the ability to maintain a part of its tensile strength prior to crack in order to resist more loading compared to conventional concrete. Meanwhile, the ribbed slab can help in material reduction. This research investigated on the bending strength of 2-ribbed and 3-ribbed concrete slab with steel fibre reinforcement under static loading with a span of 1500 mm and 1000 mm x 75 mm in cross section. An amount of 40 kg/m steel fibre of all total concrete volume was used as reinforcement instead of conventional bars with concrete grade 30 N/mm2. The slab was tested under three-point bending. Load versus deflection curve was plotted to illustrate the result and to compare the deflection between control and ribbed slab. This research shows that SFRC Ribbed Slab capable to withstand the same amount of load as normal slab structure, although the concrete volume reduces up to 20%.

Flexural Performance of Reinforced Concrete Built-up Beams with SIFCON

2020 ◽  
Vol 38 (5A) ◽  
pp. 669-680
Author(s):  
Ghazwan K. Mohammed ◽  
Kaiss F. Sarsam ◽  
Ikbal N. Gorgis
Keyword(s):  
Reinforced Concrete ◽  
Ultimate Load ◽  
Concrete Beams ◽  
Steel Fibers ◽  
Reinforced Concrete Beams ◽  
Load Carrying Capacity ◽  
Conventional Concrete ◽  
Flexural Performance ◽  
Load Carrying ◽  
Fiber Concrete

The study deals with the effect of using Slurry infiltrated fiber concrete (SIFCON) with the reinforced concrete beams to explore its enhancement to the flexural capacity. The experimental work consists of the casting of six beams, two beams were fully cast by conventional concrete (CC) and SIFCON, as references. While the remaining was made by contributing a layer of SIFCON diverse in-depth and position, towards complete the overall depths of the built-up beam with conventional concrete CC. Also, an investigation was done through the control specimens testing about the mechanical properties of SIFCON. The results showed a stiffer behavior with a significant increase in load-carrying capacity when SIFCON used in tension zones. Otherwise high ductility and energy dissipation appeared when SIFCON placed in compression zones with a slight increment in ultimate load. The high volumetric ratio of steel fibers enabled SIFCON to magnificent tensile properties.

Flexural Resistance of Steel-Coconut Shell Concrete-Steel Composite Beam with Normal and J-Hook Shear Studs

2020 ◽  
Vol 12 (9) ◽  
Author(s):  
Lakshmi Thangasamy ◽  
◽  
Gunasekaran Kandasamy ◽  
Keyword(s):  
Concrete Strength ◽  
Steel Plates ◽  
Coconut Shell ◽  
Core Material ◽  
River Sand ◽  
Concrete Core ◽  
Conventional Concrete ◽  
Moment Capacity ◽  
The Moment ◽  
Core Concrete

Many researches on double skin sandwich having top and bottom steel plates and in between concrete core called as steel-concrete-steel (SCS) were carried out by them on this SCS type using with different materials. Yet, use of coconut shell concrete (CSC) as a core material on this SCS form construction and their results are very limited. Study investigated to use j-hook shear studs under flexure in the concept of steel-concrete-steel (SCS) in which the core concrete was CSC. To compare the results of CSC, the conventional concrete (CC) was also considered. To study the effect of quarry dust (QD) in its place of river sand (RS) was also taken. Hence four different mixes two without QD and two with QD both in CC and CSC was considered. The problem statement is to examine about partial and fully composite, moment capacity, deflection and ductility properties of CSC used SCS form of construction. Core concrete strength and the j-hook shear studs used are influences the moment carrying capacity of the SCS beams. Use of QD in its place of RS enhances the strength of concrete produced. Deflections predicted theoretically were compared with experimental results. The SCS beams showed good ductility behavior.

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