Chapter 1: Introduction
1.1 Problem summary and Introduction
Cracking is a regular complain in the concrete industry. Cracking occur due to combination of factors. Such as drying shrinkage, thermal contraction, restraint to shortening, sub grade settlement, and applied loads. Cracking can’t be prevented but it can be significantly reduced or controlled when the causes are taken into account and preventative steps are taken. Cracks are largely effect the durability of concrete.
Techniques are available to repair the cracks i.e. Grouting, Grunting, epoxy grouting etc. Self healing is the new and innovative technique to repair the cracks by using bacteria.
Bacterial concrete can be prepared by mixing a cement paste containing bacterial culture along with a calcium-based nutrient (i.e. calcium lactate, nitrogen and phosphorus) are added to the ingredients of the concrete in particular ratio. Apart from its other wonderful properties, due to its major property of self-crack remediation or self-healing, it is also known as self-healing concrete. This technique of using bacteria for calcium carbonate deposition or microbial concrete, called as Microbial induced calcium carbonate (CaCo3) precipitation (MCCP), can be also used for solving various durability issues of construction materials. Bacterial concrete is also known as a ‘SMART BIO MATERIAL’ because of natural capability to precipitate calcite. Several different bacterial strains contribute in the precipitation of mineral accommodate in diffluent natural environments. Microorganisms which are present in nature in abundant, are the resource for significant production of bacterial CaCo3 crystals (calcite) in concrete. As the microbes can penetrate and reproduce themselves in soil or any other environments, there is no requirement to disturb the ground or environment unlike that of cement.
• Self-healing mechanism of bacterial concrete:
When the Bacterial culture is mixed with concrete, the bacteria go into a dormant state, a lot like seeds. All the Microbes need is exposure to the air to activate their functions. Any cracks that should occur provide the necessary exposure. When the cracks form, bacteria presents very close proximity to the crack, starts precipitating calcite crystals. When the cracks form in a concrete structure and water starts to seep through the cracks, the spores of the bacteria germinate on contact with the water and nutrients. Having been activated, the bacteria start to feed on the calcium lactate nutrient. Such spores of bacteria have extremely thick cell walls that enable them to remain intact for up to 200 years while waiting for a better environment to germinate.
Source-: http://www.hitechos.com/wp-content/uploads/2015/01/self-healing-concrete.jpg
Figure:1.1 Self-healing process of bacteria concrete
1.2 Aim and objectives of project
To know the result of replacement of GGBS and Fly-ash on self-healing behavior of Bacterial concrete.
To compare Mechanical properties of bacterial concrete before and after self-healing of cracks.
1.3 Problem Specifications
The application of concrete is speedily increase in worldwide and therefore the development of sustainable concrete is urgently needed for environmental reasons. Cracks are common failure in concrete. Cracks could develop because of addition of far more than water throughout compounding of concrete, or could also be because of shrinkage or creep.
1.4 Brief literature review and Prior Art Search
Sr. No. Title Essential Conclusion
1.
Name of Author :
MohitGoyal,
P. Krishna Chaitanya
Name of Paper:
Behavior of Bacterial Concrete as Self-Healing Material
ISSN No: 2250-2459
Fine Aggregate
Type: Locally available River sand
Specific Gravity: 2.76
FINENESS MODULUS: 2.91
Coarse Aggregate
Type: Quarried and crushed Granite stone
MAX SIZE: 20 mm
Specific Gravity: 2.8 mm
FINENESS MODULUS: 7.19
Grade of cement :M25
Nos. of experiment:3
1. Compressive strength
2. Flexural strength
3. Split Tensile strength
(With different quantity of bacterial solution)
There was significant improvement of compressive strength by 30% in concrete mix with bacteria and more than 15% in fly ash and 20% in GGBS.
2.
Name of Author:
Ravindranatha,
N. Kannan,
Likhit M. L
Name of Paper:
Effect of bacteria on partial replacement of concrete with fly-ash and GGBS
ISSN No: 2321-7308
Type of Bacteria:
Bacillus pasteurii
Nos. of experiment:2
1.Compressive strength
2.lexural strength
Curing period:14 to 28 days
Replacement of GGBS with cement gives higher compressive strength as well as flexural strength compare to replacement of same amount of fly ash with cement.
3.
Name of Author:
EtaveniMadhavi,
D.RahulNaik
Name of Paper:
Strength Properties of a bacterial concrete when Cement partially replaced with flyasand GGBS
ISSN No:
p-ISSN: 2395-0072
e-ISSN: 2395 -0056
Properties of Cement:
Grade: O.P.C. of 43-grade
Specific Gravity: 3.10
Type of Bacteria:
Bacillus pasteurii
Fine Aggregate:
Type: Locally available sand
Specific Gravity: 2.62
Size: Less than 4.75 mm
Coarse Aggregate:
Type: Locally availableAggregate
Specific Gravity: 2.84
Size: 20 mm
Grade of concrete: M40
Curing Period: 7 days, 14 days,28 days
The compressive strength of a bacterial concrete is increased by 10% compare to normal concrete or conventional concrete.
Addition of fly ash with bacterial concrete is also increased by 14% compare to normal or conventional concrete.
Addition of GGBS with bacterial concrete is also increased by 18% to 20% as compared to normal or conventional concrete.
Addition of fly ash and GGBS with bacterial concrete has given almost same compressive strength of conventional concrete.
Spilt tensile strength is increased by 22% when compared with normal concrete
Bacillus pasteruii can be produced from laboratory which is proved to be a safe and cost effective.
From the above it can be also concluded that the Bacillus pasteruii with fly ash can be easily cultured and safely used in improving the performance characteristics of concrete.
4.
Name of Author:
AbhijitsinhParmar,
Ankit Patel
Name of Paper:
Effect of Depth of Crack on the Improvement of Compressive Strength of Concrete By Bacillus Pasteruii
ISSN:2321-9939
Grade: O.P.C. of 43-grade
Specific Gravity: 3.10
Type of Bacteria:
Bacillus pasteurii
Fine Aggregate:
Type: Locally available sand
Specific Gravity: 2.62
Size: Less than 4.75 mm
Coarse Aggregate:
Type: Locally available Aggregate
Specific Gravity: 2.84
Size: 20 mm
Grade of concrete:M40
Curing Period: 28 days
Crack: crack is developed by marble cutter on the
Upper surface of concrete mould after 28
days.
Quantity of bacteria: 25 mlbacteria in 100 ml
Food of bacteria: P-Urathine for
28 days. (every 6 hours)
From the experimental program improvement of the Compressive strength as well as flexural strength reduces with the
increase in the depth of crack. It might be because of at the greater depth bacteria might not be proper contact with air. The use of
this biological repair technique is highly desirable because the mineral precipitation induced as a result of microbial activities is
pollution free and natural.
5.
Name of Author:
AbhijitsinhParmar,
Ankit Patel
Name of Paper:
Improvement of the Concrete Cracks by Using Bacillus Sphaericus
ISSN:2321-9939
Grade: O.P.C. of 43-grade
Specific Gravity: 3.10
Fine Aggregate:
Type: Locally available sand
Specific Gravity: 2.62
Size: Less than 4.75 mm
Coarse Aggregate:
Type: Locally available Aggregate
Specific Gravity: 2.84
Size: 20 mm
Grade of concrete: M40
Nos. of experiment: 3
1. Compressive strength
2. Flexural strength
3. Durability test
Food of bacteria: P-Urathine for
28 days.
(every 6 hours)
The addition of Bacillus Sphaericus in cracks
Improves the compressive strength. Improvement in
strength is around 16.4% at 7th day, 17.3% at 28th
day and 17.6% at 56th day.
6.
Name of Author:
A.T.Manikandan
Name of Paper:
An Experimental Investigation on Improvement of Concrete Serviceability by using Bacterial Mineral Precipitation
ISSN:2321 – 2705
MATERIAL PROPERTIES
(1) Cement:Portland pozzolana Cement
(43-Grade)
(2) Fine Aggregate:Sand used as per IS: 383:1970
Specific Gravity: 2.54
(3)Coarse Aggregate:
Size:20mm
Specific gravity:2.6
(4) Water:
Water confirming to the requirements of IS:456-2000 was taken with the pH value 7.1 at zero turbidity.
(5) Bacteria:
Bacillus subtilis strain 121 was obtained and used in this study from Microbial Type Culture Collection and Gene Bank (MTCC), Chandigarh
(6) Mix Design: Grade: M20
Proportion: 1:1.43:3.10
Water cement ratio: 0.25
bacterial culture: 0.25
The significance of this research is that calcite precipitation by B. subtilis is effective in crack remediation. The use of microorganisms, which are found common in soil, in crack remediation of concrete. In addition, this new bacterial concrete concept of calcite formation of microbes is not only environmentally safe but also cost effective. The development of bacterial concrete will provide the basis for an alternative and high quality concrete sealant ultimately lead to enhancement in the durability of building materials.
7.
Name of Author:
C.Mohanasundharam,
R.Jeevakkumar,
K.Shankar
Name of Paper:
An Experimental Study on Performance of Bacteria in Concrete
ISSN:347-5552
MATERIAL PROPERTIES
(1) Bacillus Sphaericus:
Bacillus sphaericus is strictly aerobic gram
positive rod shaped bacterium. It is an insecticide against
certain strains of diseased mosquitoes. Bacillus
Sphaericus are pore forming bacterium, dormant for
several years and would be able to withstand extreme
temperature.
(2) Cement:
Portland Pozzolana Cement (PPC) was used in
casting the specimens. PPC is manufactured by the inter grinding of OPC clinker with 10 to 25 percent of Pozzolanic material.
(3) Coarse Aggregate:
Hard Granite broken stone
< 20 mm
(4) Fine Aggregate:
River sand size < 4.75 mm
(5) Water:
Portable water in laboratory with pH value of not less than 6 and the requirement of IS 456-2000 was used for Mixing concrete and curing the specimen.
(5) MIX DESIGN:
Type of cement: OPC 53-Grade
Maximum nominal size of
Aggregate: 20 mm
(Crushed angular
Aggregate)
Specific gravity of fine
Aggregate: 2.69
Specific gravity of coarse Aggregate: 2.75
Maximum water-cement
Ratio: 0.375
(6) Test:
(a) Test on fresh concrete:
1. slum test
2.Compaction Factor test
(b) Test on hard concrete:
1. Compressive Strength
2. Split Tensile Strength Test
3. Flexural Strength Test
(i) one point
(ii) two pint
Compressive strength:
Days: 7
Increasing of strength in (%):
M20: 6.22
M25: 4.23
M30: 4.85
Days: 28
Increasing of strength in (%):
M20: 7.62
M25: 5.02
M30: 6.92
Split tensile strength:
Days: 7
Increasing of strength in (%):
M20: 9.04
M25: 13.62
M30: 10.73
Days: 28
Increasing of strength in (%):
M20: 3.04
M25: 1.41
M30: 1.82
Flexural strength of prismatic beam:
Days: 7
Increasing of strength in (%):
M20: 12.12
M25: 15.29
M30: 6.89
Days: 28
Increasing of strength in (%):
M20: 4.58
M25: 2.09
M30: 1.91
8.
Name of Author:
AbhujitsinhParmar
Harshad Patel
Name of Paper:
Comparative study on improvement on the concrete cracks by using Bacillus Sphaericus with fly comparative study on the improvement on concrete cracks by using Bacillus Sphaericus
MATERIAL PROPERTIES
(1) Bacillus Sphaericus:
Food of bacteria- P-Urathine
(2) Concrete grade:M20
(for flexural strength study)
Compressive strength study:
OPC & sand ratio: 1:3
Mould size- 70.6 mm x 70.6 mm x 70.6 mm
Compression test carryout after 7th, 28th,56th days
Flexural strength study
Concrete Beams grade M20
Moulds with dimensions of 500 mm× 100
mm× 100 mm
At 28th day artificial cracks depth of 10 mm, 20 mm and 30 mm were developed by marble cutter on the upper surface.
Durability study
clearance around and above the specimen is not less than 30 mm
From the experimental program improvement of the Compressive strength as well as flexural strength
reduces with the finer material mixed to fulfil the
crack portion.
9.
Name of Author:
BeenaKumari
(Research Scholar,
Department of Civil Engineering,
Thapar University, Patiala, Punjab, India)
Name of Paper:
MICROBIAL CONCRETE: A MULTI-PURPOSE BUILDING MATERIAL-AN OVERVIEW
ISSN: 22311963
Microbial concrete and its applications:
(1) Microbial concrete as concrete crackremediation/healing.
(2) Microbial concrete as an alternative surfacetreatment for concrete.
(3) Microbial concrete as antifungal cement mortar.
Various microbes used in microbial concrete:
1. Microbial concrete as crack healer:
1. Sporosarcina pasteurii
2 Bacillus pasteurii
3.Bacillus Sphaericus
2. Microbial concrete as self-healer:
1.Bacillus pseudifirmus
2. Bacillus cohnii
3. Microbial concrete as surface treatment:
1. Bacillus Sphaericus
2. E. coli.
4. As cement mortar and concrete:
1.Bacillus cereus
2.Bacillus sp. CT-5
3.Bacillus pasteruii
4.Shewanella
5.Sporosarcina pasteruii
5. Microbial concrete as water purifier:
1. Bacillus Subitilis
2. Bacillus phaericus
3. Bacillus thuringiensis
4. Thiobacillus
Microbial concrete as non-conventional crack healer:
This is a novel technique in remediation of cracks in concrete in which microbiologically induced calcite precipitation (MICP) is used.
Ca+2 + Cell → Cell-Ca+2 …….(1)
Cl-+ HCO-3 + NH3 → NH4CL + CO3-2 …….(2)
Cell-Ca+2 + CO3-2 → Cell-CaCO3↓……. (3)
Uses:
(1) For remediation of cracks in concrete.
(2) For repairing structure of historical importance to preserve aesthetic value when conventional techniques are not recommended
Microbial concrete technology has emerged as a better technology than many conventional technologies because of its wonderful properties such as its eco- friendly nature, self-healing abilities and ability to increase durability of various building materials. Various investigations done by researchers have improved the understanding on the possibilities and limitations of biotechnological applications on building materials. Improvement of compressive strength, reduction in permeability, water absorption, reinforced corrosion have been seen in different cementitious and stone materials. This method of cementation is quite easy and convenient for practice.
This technology will provide the foundation for high quality structures but to address following mentioned issues, more work is required to improve the feasibility of this technology from practical viewpoints.
(1) Issues related to its cost effectiveness and quality are still to be addressed.
(2) Detailed studies are required to focus on different types of nutrients and metabolic products used for growing calcifying microorganisms.
(3) More work is required to be done on the retention of nutrients and metabolic products in the building material.
(4) The effect of acidic precipitation on the durability of the bio-deposition treatment needs to be investigated because calcium carbonate is dissolved in acidic environments. In future research the durability of the calcite layer under varying conditions is required to be investigated.
10.
Name of Author:
Professor: P H Bhoir, AkshayThakare
(JE Student, Department of Civil Engineering, SMES Institute Nashik, University of Mumbai, Maharashtra, India.)
Name of Paper:
Effect of bacteria calcite precipitation on compressive strength of general concrete cubes.
ISSN: 2348 – 7968
HOW DOES BACTERIA REMEDIATE CRACKS?
Ca+2 + Cell → Cell-Ca+2
Cell-Ca+2 + CO3-2 → Cell-CaCO3↓
Material:
(1) Cement: Ordinary Portland cement (53 grade) as
per IS: 4031 – 1988
(2) Sand: Natural river sand as per IS: 383 – 1970
-Fineness modules: 4.02
-Specific Gravity of sand: 2.78
(3) Course aggregate: 20 mm
Fineness modules: 7.075
(4)Bacteria: Microorganism Bacillus pesteurii,
Bacillus spehaericus.
Method:
(1) By addition of Bacteria in concrete
(2) Curing of cube in Bacterial NBU Solution
Method of making nutrient broth solution (NBU):
Formula / Liter
Enzymatic Digest of Gelatin ……5 g
Beef Extract ……. 3 g
Final pH: 6.8 ± 0.2 at 25 0 C
Check Compressive test.
This experiment is examined to find that the bacteria are able increase the strength of concrete and auto crack/porous healing. Form all the above experimental result we found that microbes proved to be efficient in enhancement of concrete prosperities by acquiring more compressive strength that conventional concrete in same days of curing. And thus we can conclude that the calcium carbonate precipitation by bacteria has filled some porous and voids as well as thereby making the texture more dense and compact. Also it makes the structure resistive to seepage/water permeability and ultimately increase the compressive strength of concrete.
Table-1.1 Literature review
1.5 Plan of our work
1.6 Material/ tools required
1.6.1. Ordinary cement:
Ordinary cement 53 grade (IS 8112-1989). The mixing style of concrete indirectly suggests that of optimizing use of cement for getting the will properties of concrete in inexperienced additionally as hardened state. It’s also affects on the overall economy of the structure. Different type of cement is available for different type of structure and location.
1.6.2. Aggregate:
Fine aggregate: River sand (IS 383-1970) grading requirement.
Which have specific gravity 2.58, aggregate passing through 4.7mm IS sieve.
The fineness modulus of fine aggregate 2.48
Course aggregate: The course aggregate is chosen for bacterial concrete is well graded and the maximum size of coarse aggregate used approximately range from 10 mm to 20 mm
1.6.3. Water:
Water is the most important part for making of concrete as it is required for reaction for the hydration process. If the water is use in excess amount then the concrete will lead to the bleeding and if the water is use in fewer amounts it will not bind the material. Eventually, strength and durability both will be adversely affect when water is excess or not in the scenario investigation portable water is used.
1.6.4. Admixture:
Fly Ash: Fly ash is the coal combustion product which is composition of the fine particles which are come out of the boiler with the flue gases. Ash that falls in the bottom of the boiler is called bottom ash. Depending upon the source and makeup of the coal being burned, the components of fly ash vary considerably, but all fly ash includes substantial amounts of silicon dioxide, aluminum oxide and calcium oxide.
Source-http://www.my.all.biz/img/my/catalog/25333.jpeg
Figure:1.2 Fly-ash
The particle sizes in fly ash vary from less than 1μm to more than 100 μm with the typical particle size measuring less than 20 μm. Only 10% to 30% of the fly ash particles by mass are larger than 45 μm. Generally we are using use fly ash in partial replacement of cement.
GGBS (Ground granulated blast-furnace slag): Ground slag is used as a cementitious material in concrete. The normal ratios of aggregates and water to cementitious material in the mix remain unchanged. GGBS is use as a direct replacement for Portland cement. Replacement of GGBS varies from 30% to up to 85%. Typically, 40 to 50% used in most instances.
Source- http://www.succinite-inc.com/resources/ck/images/ggbs1.jpg
Figure:1.3 GGBS
1.6.5. Self-healing agent:
We are supposed to use bacterial spores as self-healing agent as their chemical process develops lime as result and heals the cracks itself. It is required to keep in consideration that the bacteria used for this purpose of healing cracks should survive in higher pH environmental condition.
Source- http://www.denniskunkel.com/DK/Bacteria/261306D.html
Figure1.3: Bacillus subtitles bacteria
Chapter 2:
Design: Analysis, Design Methodology and Implementation
2.1. AEIOU framework:
Figure 2.1: AEIOU framework
On site we saw there, contractor, site engineer, structural engineer and labors.
And labor doing different activities such as filling of concrete mortar in micro cracks, process of manufacturing concrete, material testing etc. Environment refers to the condition of the site where the concrete was being used. On site we interacted with contractor, site engineer and structural engineer, too.
2.2. Empathy Mapping:
Figure 2.2: Empathy mapping canvas
For the Empathy mapping canvas, we started empathy thinking as user who related to current problems of cracking in concrete that user are facing in daily life.
We are choosing contractor as user because contractor is the person who mostly use concrete as a material. Stakeholders are the people who are around the user and they have an interest to make our building sustainable eco-friendly, too.
Activity is the part of work which we observed on construction site related to concrete technology.
Another part of this canvas is happy story and sad story. Story is a description of imaginary people and events which happened related to Self-healing bacterial concrete. There are two stories shown in the canvas sheet: happy and sad story. Happy story shows advantages of Self-healing bacterial concrete and sad story shows the difficulties faced by the people in routine life because of the absence of bacterial concrete.
From Empathy canvas sheet, we conclude that,
We have decided to add bacteria as healing agent to prevent problem of cracking in concrete structure.
2.3. Ideation Canvas:
Figure 2.3: Ideation canvas
Ideation canvas gives to direction to think about problem related to concrete technology and solution of them in proper way.
The people belong to concrete technology play particular role to reach a situation by their activities such as: Grouting, designing, planning, filling of cracks were going on.
Situation means what happening in a particular place or location at particular time on construction site.
Props mean solution of the given problem for suitable situations.
2.4. Product Development Canvas:
Figure 2.4: Product development canvas
The product development canvas give overview of people, purpose, product experience, product function, customer revalidation, product feature, component ,reject design.
Product is element that is produce by stakeholder and used by related users. We are adding self-healing property in conventional concrete by using bacteria as a self-healing agent.
Chapter 3:
Implementation
3.1. Application of bacterial concrete:
1. Residential and commercial building
Figure 3.1
2. Underground retaining wall
Figure 3.2
3. Marine structure
Figure 3.3
Figure 3.4
4. Canal
Figure 3.5
5. Pre-stress concrete
Figure 3.6
6. Bridge abutment
Figure 3.7
Chapter-4:
Conclusion
4.1 Advantages of Bacterial Concrete
Improved mechanical properties of concrete
Requires less maintenance
Repairs hair cracks it self
Environment friendly concrete
Enhance durability of concrete
4.2 Comparison of bacterial concrete and conventional concrete
Particular Bacterial concrete Conventional concrete
Initial cost Higher Lower
Maintenance cost Lower Higher
Strength Higher Lower
Durability Higher Lower
Permeability Lower Higher
Corrosion to reinforcement Less More
Resistance to acid attack More Less
Co2 Emission Less More
Table -4.1: Theoretical comparison
4.3. Scope of future work
1. To extend work by casting cubes of conventional concrete and bacterial concrete
2. By conducting various tests of concrete to give beneficial property of our product
3. Get further information about specific bacterial species
References:
Literature
1. Abhijitsinh Parmar, Ankit Patel:- Effect of Depth of Crack on the Improvement of Compressive Strength of Concrete By Bacillus Pasteruii in September 2013. (IJEDR1303013)
2. Abhijitsinh Parmar, Ankit Patel:- Improvement of the Concrete Cracks by Using Bacillus Sphaericus in January 2013. (IJEDR302016)
3. Abhujitsinh Parmar, Harshad Patel:- Comparative study on improvement on the concrete cracks by using Bacillus Sphaericus with fly comparative study on the improvement on concrete cracks by using Bacillus Sphaericus article in Journal of Civil Engineering and Management in January 2013
4. A.T.Manikandan, A.Padmavathi:- An Experimental Investigation on Improvement of Concrete Serviceability by using Bacterial Mineral Precipitation Volume II, Issue III, (IJRSI)
5. Beena Kumari:- Microbial concrete : A multipurpose building material an overview (Research Scholar, Department of Civil Engineering, Thapar University, Patiala, Punjab, India). International Journal of Advances in Engineering & Technology (IEAET), Jan., 2015
6. C.Mohanasundharam, R.Jeevakkumar, K.Shankar:- An Experimental Study on Performance of Bacteria in Concrete. Volume-2, Issue-6, November-2014 . International Journal of Innovative Research in Computer Science & Technology (IJIRCST)
7. Etaveni Madhavi, D.Rahul Naik:- Strength Properties of a bacterial concrete whenCementpartially replaced with fly ash and GGBS. Vol. 5 Issue 02, February-2016 published by (IJERT)
8. Mohit Goyal, P. Krishna Chaitanya:- Behavior of Bacterial Concrete as Self-Healing Material. Volume 5, Issue 1, January 2015 published by International Journal of Emerging Technology and Advanced Engineering (IJEATE)
9. P H Bhoir, Akshay Thakare:- Effect of bacteria calcite precipitation on compressive strength ofgeneral concrete cubes.( JE Student, Department of Civil Engineering, SMES Institute Nashik, University of Mumbai, Maharashtra,India)
10. Ravindranatha, N. Kannan, Likhit M. L:- Effect of bacteria on partial replacement of concrete with fly-ash and GGBS. Volume: 03 in May-2014 published by IJRET
Websites:
1. Self-healing process of bacteria concrete
http://www.hitechos.com/wp-content/uploads/2015/01/self-healing-concrete.jpg
2. Fly-ash
http://www.my.all.biz/img/my/catalog/25333.jpeg
3. GGBS
http://www.succinite-inc.com/resources/ck/images/ggbs1.jpg
4. Bacillus subtitles bacteria
http://www.denniskunkel.com/DK/Bacteria/261306D.html
5. Residential and commercial building
http://www.stapl.co.in/sites/default/files/imagecache/full-zoom/files/projects/4/329/featured-4-329-night-view2.jpg
6. Underground retaining wall http://saturnconcrete.com/basement-retaining-wall
7. Marine structure
http://www.pci.org/uploadedImages/Siteroot/Project_Resources/Transportation_Systems/MarineWEB.jpg?n=1297
https://s-media-cache-ak0.pinimg.com/564x/b5/0c/0a/b50c0aa68db6f587ea409b9b98503dbb.jpg
8. Canal
http://www.guntert.com/images/products/canal/boathead.jpg
9. Priestess concrete
http://www.designingbuildings.co.uk/w/images/e/ee/Prestressedconcrete.jpg
10. Bridge abutment
http://4.bp.blogspot.com/9nFSnnFanAw/VTvwfthD9lI/AAAAAAAADHw/Mn2YTmEyNBg/s1600/bridge_abutments1.jpg
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