Faculty of Engineering Basic Microbiology BIOL 250 SUMMER 2020 Instructor: Bio-concrete or self-healing concrete Name: Student ID #: Section: Table of content 1 Title number Introduction 3 What is Bio-concert? 4 Causes 5 Solution 7 Bioluminescent bacteria in UAE 9 Conclusion 10 References 11 Introduction 2 Concrete degradation is one of the most costly problems of our time. Concrete will always crack, although less so if welldesigned and well-constructed. Cracks will allow water and air to enter into the structure and eventually reach the steel reinforcement. When this erodes, it swells, causing more cracks. Concrete degradation of our infrastructure now requires major repair costs which could have been avoided if we had used selfhealing concrete in the first place. What is Bio-concert? 3 For generations, concrete has been one of the most popular building materials around the globe. From the construction of roads and infrastructures to foundations and engineering projects, the familiar mixture of water, cement, and sand is utilized daily thanks to its easy to use properties and its common and affordable composite ingredients. Of course, no matter how sturdy it’s built to be, the most popular building material in the world still has unavoidable enemies time and Mother Nature. Bio-concrete is a self-healing form of concrete designed to repair its own cracks. It was developed by Dutch researcher and microbiologist Hendrik Jonkers using an extra ingredient acting as a healing agent and requires no human intervention to be repaired once placed. Bio-Concrete set to revolutionize the building industry: Dutch inventor of self-healing concrete named finalist for European Inventor Award. By and large, concrete is an extremely sturdy building material. When constructed correctly and in the right conditions, concrete structures can easily last 50 to 100 or more years! However, in most cases time, wind, rain, and shifts in the earth’s crust can start to form cracks in concrete. These cracks allow debris and water to creep inside the concrete where moisture can slowly eat away at the steel rebar that’s reinforcing almost every concrete structure in the world. As the steel succumbs to this process of wear and tear, the once strong concrete structure continues to crack further and eventually crumble. Causes 4 We know that cracks are a major problem in concrete. It decreases the life of the structure and reduces its stability against earthquakes. From several years researchers are finding the answer to this solution. Well, there are so many techniques to fill the cracks (and for concrete repair) but there is no proper solution to resist the concrete against cracks. Now, they discovered a new technique where a bacteria can repair the cracks formed on concrete. 1. First among them is the use of more water in the mix: To increase the setting time workers usually add more water to the mix which reduces the strength of the concrete. Eventually, it may lead to forming cracks on the concrete. 2. Plastic Shrinkage: It’s a one of the major cause for developing cracks on the concrete. In this Water evaporates quickly from the top of the surface. It causes the top of the slab to dry more quickly than the bottom, and they pull each apart. This is more likely to happen when it is hot, windy or there is low humidity. A provision in curing is the only solution for this kind of failure. 5 3. Cracks formed due to settlements: This type occurs when the ground under concrete settles. This is caused when the soil is poorly compacted. And if the ground has less soil bearing capacity. 4. Rapid drying concrete: It is the main reason. In the current scenario, we are starting a project with a proper planning but not including the calamities which occurs while doing construction and same submitting the last date of completion of a project to the client. If a project takes more than stipulated time builder has to pay the client in return. Take an example of excavation while doing excavation there is a chance of water coming from earth then we have to perform dewatering. Which is not included in the project planning. To balance the time wasted for dewatering builder minimizes time in curing and rapid drying of concrete. In turn, this may lead to forming cracks on concrete in future. and this type of concrete is repaired with some modern techniques but cost incur is very high. These are the main reasons for the cause of cracks in concrete, Apart from above, there are so many reasons for forming cracks in concrete. Solution 6 How Bio-Concrete Fixes the Problem In early 2016, microbiologist Henk Jonkers from Delft University in the Netherlands came up with the solution of a self-healing concrete product. By mixing a new type of bacteria and calcium lactate capsules into the initial concrete mixture, Jonkers created a type of concrete that can actually rebuild itself as moisture enters the inevitable cracks, gaps, and holes. When water begins to work its way into a concrete structure, the moisture disintegrates the biodegradable plastic shell of the calcium lactate. The calcium lactate then awakens the bacteria which consumes the calcium lactate creating limestone. As this bacterial process occurs, the limestone expands to fill in the cracks created by the water and therefore rebuilds the structure from the inside out, completely sealing the initial point where the crack began. Sealing small cracks that could eventually become larger Perhaps one of the most powerful applications of bio-concrete is that it can be used to seal up small cracks within larger slabs of concrete. It is these small cracks that eventually expand to cause significant damage in buildings, bridges, and other infrastructure. Bio-concrete can seal cracks of up to 0.8mm in width, catching the problem in advance and preventing significant structural damage. An environmentally friendly solution 7 The benefits of bio-concrete extend beyond economic applications. This material will 1- Reduces carbon emissions, making it possible for commercial and residential builders to lower their carbon footprints. By using less concrete to carry out maintenance and repairs, there will be fewer carbon emissions into the environment over time. 2-Sustainable construction is the future of our industry and bioconcrete is at the forefront of promoting this revolution. 8 Bio concrete in UAE CONMIX SIGNS AGREEMENT WITH BASILISK SELF HEALING CONCRETE AS THEIR EXCLUSIVE AGENTS FOR UAE. Conmix has always been associated with the latest technology in construction and as a company we strive to follow the vision of legendary UAE leaders who have converted a sleepy desert hamlet into a world-class destination we call home. The drive of our leaders to be the first and the best at adapting new construction ideas in construction projects drives all of us to look for new and latest developments in the field and to find a way to make them available to our fellow brothers and sisters in UAE. The Government of UAE has already taken many measures towards sustainable construction using innovative methods, cutting edge technology and alternative raw materials. The concept of “Green Concrete” is now widely known and used for almost every major project in UAE. The shift we see coming now is “From Green Concrete to Bio Concrete”. Bio Concrete is Self-Healing Concrete, which consists of a mix with bacteria incorporated into the concrete and calcium lactate food to support those bacteria when they become alive which can otherwise remain dormant for 200 years! As concrete cracks due to various reasons, the bacteria in very close proximity to the cracks start to precipitate calcite crystals in the presence of oxygen. When these cracks are exposed to moisture or water ingress, the spores of bacteria get activated and feed on the calcium lactate nutrient which gets converted to insoluble limestone thereby sealing the cracks formed completely. This makes the structures durable for longer time spans and the maintenance costs are reduced drastically. In order to bring this innovative and one of a kind technology to the UAE and to make it part of every project in the near future, Conmix Ltd. has joined hands with Basilisk Self-Healing Concrete from Netherlands as their exclusive agents for the region. The Agreement was signed on 2nd March 2020 between the two companies at CONMIX Head Office in Sharjah. The patent holders for this latest technology Dr. Henk Jonkers from Delft University of Technology, Netherlands and Mr. Bart Van Der Woerd are in UAE to share their knowledge and train interested change initiators regarding the healing agents, repair mortar and liquid repair systems they have developed. 9 Conclusion At the end, bio concert is one of most important issues of our time which can affect the environment and people. There are many causes of bio concert example, first among them is the use of more water in the mix, Plastic Shrinkage, Cracks formed due to settlements, Rapid drying concrete. However, it has a lot of solution an example, reduces carbon emissions. I recommend to use new technology to develop bio conceret. 10 References 1. https://www.giatecscientific.com/education/bio-concrete/ 2. https://www.generalkinematics.com/blog/what-is-bioconcrete/ 3. https://www.buildsoft.com.au/blog/bio-concrete-is-this-thefuture-of-construction 4. https://civilread.com/self-healing-concretebio-concretecauses-of-cracks-in-concrete/ 11 Page |1 —————————————————————————————————————————– ———————- BIOC 230 – Microbiology Summer 2020 Report#1 About: Sick building syndrome (SBS) Name ❖ Submitted to: ❖ Date: ❖ Section: ID # Page |2 Table of Contents: Introduction 3 The Symptoms of Sick Building Syndrome 3 Causes of Sick Building Syndrome 4 Factors Associated with Amplified Incidence of (SBS) 5 IAQ – Inadequate Ventilation 6 Indoor Chemical Contaminants 6 Outdoor Chemical Contaminants 6 Solutions to Sick Building Syndrome 7 Sick Building Syndrome in UAE 8 The legionella and cooling towers 9 The relationship between legionella, cooling tower & sick building 9 Conclusion &Videos 10 References 11 Page |3 Introduction: The term “sick building syndrome” (SBS) is described in a situation where building occupants experience the following: Acute health and comfort upsets due to the time spent in a building, but no specific illness or disease can be identified. This condition is usually temporary but some buildings have long-term problems due to design constraints. The intensity of this problem tends to magnify or repeat when the building maintenance is inconsistent or deviated from it’s stipulated operating procedures or original design. Indoor air problems can not only be caused due to poor building design but also due to the nature of activities by the occupants. In 1984, a WHO Committee Study reported 30 percent of new and redesigned buildings worldwide complaint of the indoor air quality.(1) Sick building causes are frequently pinned down to flaws in the heating, ventilation, and air conditioning (HVAC) systems. Other causes have been attributed to contaminants produced by outgassing of some types of building materials, volatile organic compounds (VOC), molds (see mold health issues), improper exhaust ventilation of ozone (byproduct of some office machinery), light industrial chemicals used within, or lack of adequate fresh-air intake/air filtration. Symptoms are often dealt with after-the-fact by boosting the overall turn-over rate of fresh air exchange with the outside air, but the new green building design goal should be able to avoid most of the SBS problem sources in the first place, minimize the ongoing use of VOC cleaning compounds, and eliminate conditions that encourage allergenic, potentially-deadly mold growth.(2) The Symptoms of Sick Building Syndrome: SBS symptoms can affect your skin, respiratory, and neurological systems. You may mistakenly selfdiagnose yourself with a cold or flu.Among the possible symptoms are: • throat irritation • difficulty concentrating • breathing difficulties • forgetfulness • tightness in the chest • fatigue • runny nose • irritability • allergy-like symptoms, such as sneezing • nausea • burning sensations in the nose • body aches • dry, itchy skin rashes • fever • headaches • chills • dizziness Page |4 Discomforts may result from other causes also and include an illness contracted outside the building, high allergies level, job stress, dissatisfied work environment and other psychosocial factors. All these symptoms are medically defined and the causes can be identified for a therapy or cure. How ever, studies show that all symptoms may be caused aggravated by the indoor air quality problem that percolates in the human system. If you have allergies or a current respiratory illness, you may notice an increased severity in your symptoms. For example, people with asthma might be at a higher risk for asthma attacks due to SBS.It’s also important to note that SBS affects everyone differently. While everyone who spends time in a particular space might go through some of the above symptoms, these can vary. Some people may not experience any symptoms at all. Others may experience symptoms after leaving the building in question — this may be due to repeated or long-term exposure.(3) Causes of Sick Building Syndrome: The term “sick building syndrome” is used when the exact cause of your symptoms can’t be identified. However, there are a variety of possible causes you can ask your doctor about. The culprits behind SBS may include: • • • • • • • • • • • • • • • • • buildings with poor ventilation, such as schools, offices, and public spaces high levels of dust tobacco smoke rooms with poor lighting outdated computer displays that cause eye strain the presence of mold or fungus formaldehyde (mostly found in wood furniture and floors) asbestos chemicals in the air from cleaning products pesticides carbon monoxide ozone from the use of printers and fax machines high levels of stress at school or work low workplace morale heat or low humidity noisy work environments insect or animal droppings Given the variety of factors that can cause SBS, it’s difficult to pinpoint one single cause. You might be able to work with your employer to eliminate possible risk factors. This way, you can get to the source of the problem. Page |5 Factors Associated with Amplified Incidence of Sick Building Syndrome: ❖ Personal Factors: Female gender Lesser in building hierarchy (more menial job) ❖ Individual Factors: Paper dust Cigarette smoke Office dust More use of computers ❖ Building Factors: Great inside temperature (over 23°C in air-conditioned buildings) Low fresh air aeration in air-conditioned office (
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