APPLICABILITY OF CONCRETE TREATED WITH SELF-HEALING ... · Applicability of Concrete Treated with...

http://www.iaeme.com/IJCIET/index.asp 275 [email protected]

International Journal of Civil Engineering and Technology (IJCIET) Volume 7, Issue 5, September-October 2016, pp. 275–283, Article ID: IJCIET_07_05_030

Available online at http://www.iaeme.com/IJCIET/issues.asp?JType=IJCIET&VType=7&IType=5

ISSN Print: 0976-6308 and ISSN Online: 0976-6316

© IAEME Publication

APPLICABILITY OF CONCRETE TREATED WITH

SELF-HEALING BACTERIAL AGENTS

Ashish Babarao Gawande

Final Year Engineering Student, Department of Civil Engineering,

K.I.T’s College of Engineering, Kolhapur. India.

Yash Suneel Khandekar

Final Year Engineering Student, Department of Civil Engineering,


Ojas Pravin Rahate

Third Year Engineering Student, Department of Mechanical Engineering,


ABSTRACT

In this fast developing world, the face of the earth has transformed from a jungle to a concrete

jungle. These concrete structures provide the concrete foundation for the development of a country.

Large skyscrapers have emerged as the glory of the town. However, concrete has its limits with

respect to durability and long term sustainability. Crack formation micro as well as macro is a

major issue, these cracks eventually lead to formation of fractures and fissures, resulting in

collapse and accident. Concrete treated with healing bacteria, Bacilla pseudofirmus, Sarconima

pasteurii, proves an exceptional solution both for preplanning new projects and renovation of

existing structures as a part of post planning. Healing of cracks occurs in 3-4 weeks just after

formation of cracks, when the bacteria are exposed to moisture. The bacterium fills the cracks

effectively by formation of limestone. Thus, subsequent to healing, the structural strength is

retained. This method of self healing concrete also provides an ingenious method for production of

concrete bricks/blocks. Due to its better durability, it proves to be a better alternative than the

conventional counterparts. Moreover, existing method of brick production utilizing the kilns are

contributing towards rise in pollution levels, should bricks prepared from self healing concrete be

used, pollution levels can be virtually zero.

Key words: concrete jungle, long term sustainability, healing of cracks, limestone, virtually zero.

Cite this Article: Ashish Babarao Gawande, Yash Suneel Khandekar and Ojas Pravin Rahate,

Applicability of Concrete Treated with Self-Healing Bacterial Agents. International Journal of Civil

Engineering and Technology, 7(5), 2016, pp.275–283.

http://www.iaeme.com/IJCIET/issues.asp?JType=IJCIET&VType=7&IType=5

1. INTRODUCTION

Kolhapur is a tourist city at the foothills of the Western Ghats which has a deep-rooted and ancient history.

A number of ancient structures such as forts and pilgrim places are responsible for scenic aesthetics of the

city, which are the main reasons for tourist footfall into the city.

Applicability of Concrete Treated with Self-Healing Bacterial Agents


Ancient nature of these structures is the very reason that imparts the aesthetic beauty in them. Yet,

being old, parts of these structures are in dilapidated condition. Concrete avenues that mark the entry and

transit in the city are in a state of despair, leading to fall in tourist count, also, causing problems for the

residents. The famous panhala fort built by Chatrapathi SHIVAJI MAHARAJ in the seventeenth century

still stands gracefully but the sands of time has led to the deteriorating conditions of some parts of the forts.

Kolhapur being the major cultivator of sugarcane requires large amount of water for irrigation of acres

of farmlands. Irrigation canals present the most favorable medium for irrigation however it lacks in

durability due to formation of cracks.

Present day production of bricks in numerous kilns and furnaces poses a major environmental setback.

Large amounts of pollutants and the poisonous fumes like carbon monoxide, carbon dioxide, oxides of

sulfur and nitrogen and particulate matter are released into the atmosphere contributing to the pollution and

greenhouse effects. Furthermore this method of production is not efficient as a number of bricks get over

burned or broken hence rendered useless. At local level some of these pollutants are injurious to human

health and plant life. At global level this pollutants contribute to phenomenon of global warming and

global warming.

An innovative method of growing brick using bacteria and naturally abundant materials proves to be

better alternatives to conventional methods. Self healing concrete is the solution to all.

2. PROBLEMS

• Weak structural nature of old concrete buildings leads to cracks micro as well as macro.

• Due to extensive traffic on concrete roads, live load gets generated leading to wear and tear of the roads.

Water percolates through the cracks reaching the sub surface layer thus disturbing the structural integrity.

This affects the durability of roads and can have hazardous impacts on the traffic.

• Due to their ancient nature of construction, fort has excellent durability yet due to the seasonal variation and

weathering of rocks, their condition is started to deteriorate.

• Temperature variation leads to disturbance in the homogenous nature in the concrete structures leading to

gradual formation of cracks.

• Conventional methods of production of bricks lead to environmental pollution and also wastage of the

bricks.

Figure 1 Micro cracks Figure 2 Macro cracks

3. SELF HEALING CONCRETE MIXTURE

The cracks of 0.2mm can be healed but the cracks more than 0.2mm needs some healing agents o heal.

Because of the everyday chemical as well as physical reactions occurring on road, concrete has matured

self healing process. To enhance it, there is a need of addition of some healing agent for the concrete to

Ashish Babarao Gawande, Yash Suneel Khandekar and Ojas Pravin Rahate


heal properly within a given duration. Selection of concrete suitable bacteria is the most important task.

Also the study of bacteria is must. The bacteria should withstand high alkaline conditions and should

remain active over large span of time along with being chemically inert. Concrete constructions are

designed to last for many years so the bacteria used should also be feasible for a long time.

3.1. Mechanism of Healing

The capsules of bacteria and calcium lactate are inserted with the concrete during construction, the reason

to use it in the capsule form is to avert interaction between them. The capsules used are dormant and can

last upto a century. The concrete structures are bound to have microcracks due to the physical reactions

which decrease its durability. The capsules require water for their nutrition which gets leaked into the

cracks when they are exposed to environment. After reaction with water, calcium lactate forms limestone

which heals the cracks. It spreads throughout the cracks leading to the healing of the cracks .after

formation of limestone, the chances of water leaking inside is next to impossible. It leads to increase in the

sustainability. They are basically added as spores which are inactive having very high survival rate and

when the surviving conditions are against the odd, they active bacteria again forms spores and become

dormant.

3 days 7 days

14 days 28 days

40 days 200 days

Figure 3 Progress of crack healing.



3.2. Self Healing Concrete in Dry Region

Since healing agent requires water for reaction, it is difficult to imply it in a dry region where there is

deficit of water. To encourage the use of self healing concrete in such dry regions, the use of plant fibres

along with self healing agent is suggested. The principle feature of plant fibres is that they have large

storage volume for liquids. They act as a reservoir for the healing agents for the supply of water so that it

can form limestone and the cracks can be healed. It primarily acts as glue. The diameter of plant fibres

should be 200 microns and ideal length should be 10mm.

Figure 4 Fibres in healing agent mix.

4. CASE STUDIES

The various statistics and study regarding the self healing concrete can be understood by the following case

studies.

4.1. Case Study 1

This case study portrays the advantages of cement treated with self healing agents in the form of

comparison between amount incurred in construction of cement road with conventional cement mix vs. the

cement treated with self healing agents.

For the purpose, a cement road of 2km from Kolhapur toll to Shivaji University. This cement road is a

two lane road prepared using conventional methods.

• Length of road = 2 km

• Breadth (2 lanes)= 24 m

• Depth = 0.38 m

• Volume = 18,240 m3



Figure 5 Route map of the stretch of the road considered.

4.1.1. Construction using Conventional Method

• Amount of Cement = 10.7 bags/m3

• COST of cement required = Rs.5,14,99,280

• Amount of Fine aggregate = 683.24 kg/m3

• COST of fine aggregate required = RS.96,32,945

• Amount of Coarse aggregate = 1108 kg/m3

• COST of coarse aggregate required = Rs.2,45,47,710

• Amount of Plasticisers = 4.6681l/m3

• COST of plasticisers required = Rs.1572

• Total cost of construction = Rs.8,56,81,507

4.1.2. Construction using Cement Treated with Self Healing Agents.

• Amount of cement = 9.23 bags/m3

• COST of cement required =Rs.4,59,64,800

• Amount of Fine aggregate= 673.3 kg/m3

• COST of fine aggregate required = Rs.94,92,816

• Amount of Coarse aggregate = 1006 kg/m3

• COST of Coarse aggregate required = Rs.2,22,88,409

• Amount of Plasticisers = 4.32l/m3

• COST of Plasticisers = Rs.1568

• Amount of SELF HEALING AGENT = 158.15 Kg/m3

• Cost of SELF HEALING AGENT required = Rs.2,61,51,869

• Total cost of construction = Rs.10,38,99,463.



From the above statistics it is clear that construction cost of cement road using treated concrete is more

than that by using conventional methods. Although, the cost of construction has increased by about 2

crores, but on the long run, this method is actually economic. This can be understood by analyzing the

additional cost required for the repair and maintenance of roads made using conventional methods.

Furthermore, the bacteria lasts for a century, hence improving durability manifold. This is explained

elaborately in the Case Study 2.

4.2. Case Study 2

This case study basically indicates one of the many important applications of self healing agents. They

play a major role in increasing the service life of various structures such as buildings, canals, roads etc.

Self healing agents help combat the damages occurring due to ageing by crack filling.

For this case study, a bridge of cement road of span 0.5km located at the Tawade Hotel roundabout,

NH4 (Pune-Bengaluru Highway), Kolhapur is considered for the calculation of its maintenance cost. This

includes crack sealing, application of penetrating sealer, overlays and electrochemical treatment as a part

of routine maintenance on the damages induced due regular service and ageing.

Figure 6 Route map of bridge considered for case study 2.

Cost of maintenance is calculated as follows:

• Crack sealing – Rs.99.645 / sq.ft.

• Penetrating sealer – Rs.332.15 / sq.ft.

• Overlays – Rs.146.146 / sq.ft.

• Electrochemical treatment – Rs.3985.15 / sq.ft.

Note: the above shown values are approximate.

• Length of the bridge = 0.5 km = 3116 ft.

• Breadth of the bridge = 40 m = 131.2 ft.

• Total area = 4.08,819.2 sq.ft.

• Considering that 20% area of the bridge requires repairing, i.e, 8176.38 sq.ft.

• Cost of crack sealing = Rs.8,14,735.38

• Cost of penetrating sealer = Rs.27,15,784.617



• Cost of Overlays = Rs.11,94,945.231

• Cost of electrochemical treatment = Rs.3,25,89,415.4

• Total cost of maintenance = Rs.3,73,14,880.63

With the implementation o f self healing agents, the above incurred maintenance cost can be reduced

manifold.

With self healing agents, the following data was obtained

• Area under consideration for repair = 8176.38 sq.ft.

• Cost of crack sealing (Rs.9.65/sq.ft.)= Rs.78,902.07

• Cost of penetrating sealer (Rs.132.15/sq.ft.)= Rs.10,80,508.617

• Cost of overlays (Rs.46.146/sq.ft.)= Rs.3,77,307.23

• Cost of electrochemical treatment (Rs.0/sq.ft.)= Rs.0.00

• Total cost of maintenance incurred= Rs.15,44,894.28

Due to crack healing properties of self healing agents, the above shown calculations justify its

importance of applicability. It is very clear that a colossal amount of about Rs.3,57,69,986.35 can be saved

on maintenance. Furthermore, by adding of self healing agents, the service life of various structures can be

improved exponentially and hence incur savings in the cost of maintenance.

4.3. Case Study 3

Bricks are the major part of any construction. So bricks should be durable and should last longer without

any damage. We visited a brick kiln in Kolhapur to collect information related to this case study. This case

study focuses on comparison between conventional bricks, concrete bricks and self healing concrete

bricks.

Figure 7 Brick kiln for preparation of conventional bricks

4.3.1. Conventional Bricks

• Dimensions-19*19*9

• Cost of bricks-5-7 Rs.

• Fuel used-coal and biomass

• Gases emitted



GASES COAL BIOMASS

SO2 (mg/Nm cube) 5.2-943.2 18.3-52.4

CO (mg/Nm cube) 355-3579 2622-5026

CO2 % 1.0-2.4 1.7-2.0

In a brick kiln in Kolhapur, approximately one lakh bricks are prepared out of which 20% are damaged

and are of no use. In addition to this, fuel is required for burning which causes pollution. Some experts say

that pollution from brick kilns is worse than that of factories.

Burning of coal in brick kilns leads to formation of smoke which emits gaseous pollutants like sulfur

dioxide, nitrogen oxide and particulate matter. A substance known as poly aromatic hydrocarbon is also

emitted which causes vomiting, diarrhea, nausea and eye irritation and even cancer.

4.3.2. Concrete Bricks

• Dimensions- 6*8*12 in.

• Cost of brick-13 Rs

4.3.3. Self Healing Agent Bricks

Bricks made with self healing agents and concrete do not cause any type of pollution or harm to the

environment. There is no fuel required for their production that’s why there is no pollution occurring. Also

self healing agent bricks last longer as compared to conventional bricks due to the ability of self healing

agents to repair the bricks.

5. CONCLUSION

• Self healing concrete is a new technology developed in Delft University, Netherlands. This concrete has

bacteria in the form of capsules which remain dormant till 100 years unless it receives water which is its

nutrient to become active and multiplicate. Capsules receive water only when exposed to the environment

which is possible when cracks appear in the structures.

• The bacteria heal the cracks or gap within three to four weeks by producing limestone as its byproduct.

• The cost of construction for constructing cement road has increased by about 2 crores with the

implementation of self healing agents in the cement. However, on the long run, this method is actually

economic. This can be understood by analyzing the additional cost required for the repair and maintenance

of roads made using conventional methods.

• From our case study of analysis of maintenance cost required for a bridge, we conclude that by adding of

self healing agents, the service life of various structures can be improved exponentially and hence incur

savings in the cost of maintenance.

• Method of preparation of conventional bricks involve the process of baking the bricks in large kilns. This

process is not environmental friendly as it involves release of poisonous gases into atmosphere, contributing

towards green house effect.

• We can prepare bricks using self healing concrete which are environmental friendly as they are not produced

in kilns and are more durable than conventional bricks.



REFERENCE

[1] E. Schlangen, H. Jonkers, S. Qian & A. Garcia, “Recent advances on self healing of concrete”

[2] Tae-Ho Ahn1 and Toshiharu Kishi2, “Crack Self-healing Behavior of Cementitious Composites

Incorporating”, Journal of Advanced Concrete Technology Vol. 8, No. 2, 171-186, June 2010

[3] Renée M. Mors, Henk M. Jonkers, “Bacteria-based self-healing concrete

[4] Asst. Prof. Mr. Samir A. Al-Mashhadi, Asst. Prof. Dr. Ghalib M. Habeeb and Abbas Kadhim Mushchil,

“Control of Shrinkage Cracking in End Restrained Reinforced Concrete Walls”. International Journal of

Civil Engineering and Technology (IJCIET), 5(1), 2014, pp.89–110.

[5] Klaas van Breugel, “SELF-HEALING MATERIAL CONCEPTS AS SOLUTION FOR

AGINGINFRASTRUCTURE, 37th Conference on Our World in Concrete & Structures,29-31 August

2012, Singapore

[6] http://ntl.bts.gov/lib/59000/59900/59971/Economy-of-Preventive-Maintenance.pdf

[7] N. Ganesh Babu and Dr. S. Siddiraju, “An Experimental Study on Strength and Fracture Properties of

Self Healing Concrete”. International Journal of Civil Engineering and Technology (IJCIET), 7(3),

2016, pp.398–406.

[8] http://repository.tudelft.nl/assets/uuid:e8436dfd-3eb8-4105-a11b-a9cd0158e9f2/290398.pdf

[9] http://www.iitk.ac.in/nicee/skj/Research_Papers/2002_spectra_Bhuj_Roads%20&%20Bridges.pdf

[10] J. S. Kamyotra, “ Brick Kilns in India”

APPLICABILITY OF CONCRETE TREATED WITH SELF-HEALING ... · Applicability of Concrete Treated with...

Documents

Transcript of APPLICABILITY OF CONCRETE TREATED WITH SELF-HEALING ... · Applicability of Concrete Treated with...