Experimental Study of Behavior of Self Healing Concrete

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1 Experimental Study of Behavior of Self Healing Concrete S.Kavitha 1, A.Aswin kumar 2 1,2 Department of Civil Engineering, Dr.N.G.P Institute of Technology, Coimbatore. ABSTRACT- Concrete is the most commonly used building material. Cracks in concrete are the main reason to structural failure. Cracks in concrete occur due to various mechanisms such as shrinkage, freeze-thaw reactions and mechanical compressive and tensile forces. Various tests like compressive strength, split tensile strength, flexural test withm 30 grade of conventional concrete vs Bacterial concrete containing E-coli, Pseudomonas Fluorescens, Bacillus Subtilis with 1 to 5%. A significant increase in the strength was observed due to the addition of bacteria in this study. Calcite carbonate precipitation formation due to microbial metabolic activities is responsible for enhancing strength and durability. This technique is called microbically induced calcite precipitation (MICP). This technique comes under biomineralization category. Keywords: Bacterial Concrete, Self Healing, E-coli, Pseudomonas Fluorescens, Bacillus Subtilis. I. INTRODUCTION Self Healing Concrete means that repairs its own cracks. Self healing is the tightening of cracks, probably due to the precipitation of calcium carbonate and the clogging of particles. When self healing is considered, a crack has healed when it is liquid tight again. When cracks heal in this way, the strength recovery is limited. Self healing can only occur for cracks smaller than 0.2 mm. Another healing mechanism is the tightening of cracks by the use of microorganisms. So we can use the non pathogenic bacteria s such as Bacillus Subtilis, Pseudomonas Fluorescens and Escherichia Coli. And they are non host based bacteria which are capable of multiplying and recharged to be refilled within the concrete. Thus crack can be refilled by these bacteriae. When cracks appears in a concrete structure and water starts to seep in through the spores of the bacteria starts microbial activities on contact with the water and oxygen. A peptone based nutrient supplied along with bacteriae to growth The biologically induced concrete has exhibited better durability and crack repairing performance compared to normal concrete. A. MATERIALS USED II.EXPERIMENTAL STUDY 2.1 Cement: The cement conforming to is 1489 (part-1):1991, ordinary Portland 53 grade of cement is considered for the concrete mix. 2.2 Water: Locally available portable water is used for mixing the concrete. DOI: /IJMTER MCOZ5 164

2 2.3 Fine Aggregate: According to this code IS383:1970 fine aggregate used for the entire specimen were natural river sand. 2.4 Coarse Aggregate: A crushed granite stone of size of 20mm are used for all the specimen. 2.5 Bacteria: The bacteria used are pseudomonas fluorescens, Bacillus subtilis, Escherichia coli. Each bacteria have been mixed in concrete with different percentage. (i.e) 1% to 5% of cement mass. B. SAMPLE COLLECTION The samples of scales were collected from Tamil Nadu Agri Cultural University from Coimbatore district, India. Scale samples were scrapped from IA/PA mild steel heat exchanger tubes employing sterile surgical knife and then further used for the microbial characterization. Figure 1: Sample Bacteria C. CHARACTERISTICS OF BACTERIA BACTERIA NAME Catalase Oxidase Indole Urease Gram ESCHERICHIA COLI PSEUDOMONAS FLUORESCENS BACILLUS SUBTILIS Positive Negative Positive Negative Negative Positive Positive Negative Negative Negative Negative Negative Negative Negative Positive D. CULTURING BACTERIA 1) Prepare Nutrient broth in distilled water. 2) Mix well and dissolve with frequent agitation. 3) Dispense into appropriate containers and sterilize in autoclave at 121 C for15 minutes. 4) Then allow to cool and placed that culture in UV Chamber for 15 minutes and inoculate the bacteria with the help of inoculation loop. 5) After that we can placed the culture in Incubator at 35 C for 24 hours. 6) The prepared culture should be stored at freezer for future All rights Reserved 165

3 7) The color is amber and light brown in color. 8) And again, we should repeat the above process to prepare culture. Figure 2: Growth of Bacteria E. PREPARATION OF NUTRIENT BROTH SOLUTION AND MEDIUM Nutrient broth medium is prepared from 10 gm/lit beef extract 5 gm/lit sodium chloride and 10 gm/lit peptone and shacked well. After centrifugation, the supernatant was extended to the optical density (600 nm) reached of 1 in UV/VIS Spectrometer. Finally, this medium is used to grow the bacterial species Figure 3: Nutrient broth Figure 4: Incubator Figure 5: UV All rights Reserved 166

4 III. METHODOLOGY Collection of Materials Materials testing Bacteria Culturing and Sterilization Mixing of Bacteria Casting And Curing Testing Of Concrete Result and Comparison IV.MIX DESIGN BACTERIAL WATER MIXED WITH CONCRETE Concrete mix has been designed based on Indian Standard Code IS: The proportion of the materials used in the concrete are Cement: Coarse Aggregate: Fine Aggregate: Water: 1:1.7:2.47:0.45 and Bacteria water of 1%, 2%, 3%, 4% and 5% of Bacillus subtilis, pseudomonas fluorescens and E coli Bacteria is mixed in concrete with the volume of cement. TEST ON BACTERIAL CONCRETE V.RESULTS AND DISCUSSION To find the strength of the bacterial concrete, these three test are done. 1) Compressive Strength Test 2) Split Tensile Strength Test 3) Flexural Strength All rights Reserved 167

5 COMPRESSIVE STRENGTH TEST Bacillus subtilis, Pseudomonas Fluorescens and E coli with the ratios of 1% to 5% is added with Concrete. The Compressive Strength test were performed on one conventional concrete and Bacterial Concrete. The Compressive Strength result are described to the given table: Table.1.Compressive strength for 28 days S.No Ratio of bacteria Compressive strength for 28 days E-coli Bacterial Bacillus subtilis Pseudomonas Fluorescens 1 1% % % % % days 1% 2% 3% 4% 5% cc E coli psuedomonas fluorescens Bacillus subtilis cc Graph.1.Compressive Strength Test 28 days SPLIT TENSILE STRENGTH Bacillus subtilis, Pseudomonas fluorescens and E coli with the ratios of 1% to 5% is added with Concrete. The Split Tensile Strength tests were performed on one conventional concrete and Bacterial Concrete. These were tested at the curing stages of 7, 14 and 28 days. S.NO Ratio of bacteria Table.2. Split tensile strength for 28 days Split tensile strength for 28 days E-coli Bacterial Bacillus subtilis Pseudomonas Fluorescens 1 1% % % % % All rights Reserved 168

6 28 days % 2% 3% 4% 5% cc E coli psuedomonas fluorescens Bacillus subtilis cc FLEXURAL STRENGTH TEST Graph.2. Split tensile strength for 28 days Bacillus subtilis, Pseudomonas fluorescens and E coli with the ratios of 1% to 5% is added with Concrete. The Flexural Strength test were performed on one conventional concrete and Bacterial Concrete. These were tested at the curing stages of 7, 14 and 28 days. S.NO Ratio of bacteria Table.3. flexural strength test for 28 days Bacillus subtilis Flexural strength for 28 days E-coli Bacterial Pseudomonas Fluorescens 1 1% % % % % days 5 0 1% 2% 3% 4% 5% cc E coli psuedomonas fluorescens Bacillus subtilis cc Graph.3. flexural strength test for 28 All rights Reserved 169

7 VI.CONCLUSION Based on the results achieved during this study following conclusions are Bacillus subtilis, Pseudomonas Fluorescens, E coli can be produced from the lab which is proved to be safe and cost economic. From that we can conclude that the bacterial approach has the ability to repair its own cracks due to self-healing capacity of concrete. The bacterial water added are 1% up to 5% has considerably filled the cracks present in the concrete and it is also found that the compressive strength of bacterial concrete is nearly obtained to 70% of controlled cube, the flexural strength of bacterial concrete is nearly obtained to 60% of controlled concrete and the split tensile strength of bacterial concrete is nearly obtained to 40% of controlled concrete. From the above, it can be concluded that the pseudomonas fluorescens will give maximum strength compared to the all other bacteria added in the concrete hence they are preferable. REFERENCES 1. S.A. Abo-El-Enein, A.H. Ali, FatmaN.Talkhan, H.A. AbdelGawwad(2012), Microbial Bio Cementation to improve the Physico-Mechanical properties of Cement Mortar, International Journal of Engineering and Technology, Vol 1, No Virginie Wiktor, Henk M.Jonkers(2011), Quantification of Crack Healing in Novel Bacteria based Self Healing Concrete, International Journal of Engineering Trends and Technology (IJETT), Vol 5,No M.V. Seshagiri Rao, V. Srinivasa Reddy, M. Hafsa, P. Veena and P. Anusha(2013), Bio-Engineered Concrete - a Sustainable Self-Healing Construction Material Vol. 2(6), C.Mohanasundharam, R.Jeevak kumar, K.Shankar(2014), An Experimental Study on Performance of Bacteria in Concrete, Journal Of International Academic Research For Multidisciplinary,Vol 2, No Ramakrishnan, Ramesh.K, Panchalan & Sookie S Bang(2012), Improvement of Concrete Durability by Bacterial Mineral Precipitation. 6. Wasim khaliq, Muhammad Basitehsan N(2015), Crack Healing in Concrete using various Bio Influenced Self- Healing Techniques. Advances in Environmental Reasearch, 7 (3) Mohit Goyal, P. Krishna Chaitanya(2015), Behaviour of Bacterial Concrete as Self Healing Material, International Journal of Research in Engineering and Technology. Vol 5, Issue 1, VarenyamAchal, Abhijit Mukherjee & M..Sudhakara Reddy(2013), Microbial Concrete-a way to Enhance Durability of Building Structures, International Journal of Advances in Environmental Research, Vol Srinivasa Reddy, Seshagiri Rao M, Sreenivasa Rao D & Rahul K(2013), Studies on Bacterial Concrete Exposed to Elevated Temperature & Thermal Cycles, ISSN: , Vol.3, No Henk M. Jonkers & Erik Schlangen A Two Component Bacteria-based self-healing concrete 11. IS 383: 1970, Specification for Coarse & Fine Aggregate from Natural Source for Concrete, Bureau of Indian Standards, New Delhi, India. 12. IS 516: 1959, Methods of Tests for Strength of Concrete, Bureau of Indian Standards, New Delhi, India. 13. IS , Concrete Mix Proportioning-Guidelines, Bureau of Indian Standards, (BIS All rights Reserved 170