Summary of self healing concrete preparation

Summary of Self-Healing Concrete PreparationIntroductionPreparation & ProductionCrack Seal EvaluaionConclusionDrawback of ConcreteConcrete can crack and when it cracks, it can cause corrosion of rebar, maintenance is required.Performance of S.H.CBio-mineralization Efficiency and lmbolization ofHealing AgentDrawbacks of S.H.CBio-mineralization With Ureolysis Break down ofurea into ammonia and carbon dioxide which is environmental unfriendly.Strength decrease due to porous healing agent carrier.Preparation of BacillusSubtilis1. Suitable bacteria acting as ahealing agent is the key2. Four governing conditions- 1.Calcium Concentration,2.Concentration of dissolvedinorganic carbon 3. The PH 4.A vailability of nucleationsites3. Eleven available B. subtilisbacterium were cultivatedin4. Luria Bertani (LB) medium,which was adjusted by5. Ca(OH)2 solution to elevatedProduction of Self HealingConcreteAdding Bacteria Freeze Dried Powderto Liquid CultureFracture Crack by 3-Point bending TestCrack-healingIncubationFlexural Strength Recover EvaluationAlthough maximum 0.3mm-width crack gap can be sealed with calciteprecipitation in 28days, the heal rate dropped dramatically with crackdepth increasing. The indepth healing remains a challenge for thefuture researchers.With B. subtilis M9, self-healing concrete was produced with flexural strength of 4.2MPa according to 3-point-bending test. After 28 days of self-healing, the sealed beam flexural strength subjected to second time bending was enhanced about average 14o/o strength recovery rate. Still the strength regain capability needs to be further improved for field study to achieve 50% strength recover by self-healing.Submitted To : Dr. Thanakorn PheeraphanName: Mohammad Abdus Saker ID: st122611
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