International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056 Volume: 05 Issue: 03 | Mar-2018 www.irjet.net p-ISSN: 2395-0072 © 2018, IRJET | Impact Factor value: 6.171 | ISO 9001:2008 Certified Journal | Page 3195 AN EXPERIMENTAL STUDY OF CRACK PATTERNS ON REINFORCED CONCRETE BEAM T Krishna Thulasi 1 , S Subathra 2 , T P Meikandaan 3 1 M.E. (Structural Engineering) Student, Department of Civil Engineering, New Prince Shri Bhavani College of Engineering and Technology, Chennai, Tamilnadu, India 2 Assistant Professor, Department of Civil Engineering, New Prince Shri Bhavani College of Engineering and Technology, Chennai, Tamilnadu, India 3 Associate Professor, Department of Civil Engineering, Bharath Institute of Science and Technology, Chennai, Tamilnadu, India ---------------------------------------------------------------------***--------------------------------------------------------------------- Abstract - Concrete cracks are caused by overloading, corrosion, shrinkage or poor workmanship. When looking at a specific cracking pattern or defect in concrete, sometimes the causes can be attributed to a specific reason other times the pattern may have multiple causes leading to its current state. In better understanding some of the causes of concrete cracks as well as different cracking pattern types, engineer, construction managers, and other may be able to avoid major structural catastrophes. In this experimental study, around 6 beam specimens of M20 is cast, Beam size of 1500 x 100 x 200 millimeter. During loading the pattern of cracks i.e., initial cracks and the crack propagation is studied. Flexure and Shear crack is studied. The ultimate capacity of beam is also studied. Key Words: Flexure, Shear, Corrosion, Shrinkage, Overloading, Crack propagation, Catastrophes. 1. INTRODUCTION Concrete cracks, in fact, it is designed to crack to be able to fully engage the reinforcing steel. Concerns with concrete cracking come up when owners are maintenance workers and unsure of what to look for or are unaware of the implications of certain cracks. Some types of cracking indicates a structural issue, when others do not indicate any type of issue, when others do not indicate any type of issue other than normal weathering. There are many different causes of cracks, which can lead to different type of crack patterns. Each type of cracking pattern can be associated with a likely cause. If this cause is recognized, it can be identified as structurally vital or non-vital. It is of particular interest in discerning between these two so that the failures and damage of these can be avoided or at least predetermined to minimize economic damage, future deterioration, and in severe cases the loss of human life. The occurrence of various crack patterns in the building mostly takes place during construction and/or after completion. A building component develops cracks whenever the stress in the components exceeds its strength. Stress in the building component is caused by externally applied forces/loads. Almost all the types of cracks in Reinforced Concrete Beams are fundamentally defined by the principle cause or mechanism associated with the function of cracks. An occurrence of the cracks is often a subject that raises numerous questions. Cracks may appear in structures, either at the initial stage or with time. It should first of all be accepted that cracks of some type are unavoidable in any structure. Cracks may be only at the surface or may extend to more than one layer of materials such as paint, plaster, walls, or through cracks, etc., Cracks due to different causes have varying characteristics and by the careful observations of these characteristics, one can diagnose the cause of cracking for adopting the appropriate remedial measures. Allowable crack width as per IS: 456 - 2000 varies according to climatic conditions from 0.1 mm to 0.3 mm. 1. 1 Scope of the Investigation 1.2 Classification of Cracks - Nature Wise 1.2.1 Structural Cracks: These cracks occur due to incorrect design, faulty construction or overloading and these may endanger the safety of building. Example: Extensive cracking of RCC column of any structural element. Fig -1: Structural Cracks 1.2.2 Non-Structural Cracks: These occur mostly due to internally induced stresses in building materials and do not endanger the safety of a building but may look unsightly, or may create an impression of faulty work or may give a feeling of instability. In some situations due to penetration of moisture through them, non-structural cracks may spoil the To know the different types, nature and effects of cracks in structure, in order to avoid major structural catastrophes and loss of life.