The "Civil Engineering Students’ Technical Club" (CEST) is a technical club of NIT Rourkela. The Club aims to provide a platform for the students to think, reflect, and wonder about the phenomena involved in Civil Engineering.
Self-Sensing Concrete in Smart Structures
Concrete is one of the most widely used structural material used extensively in building various types of infrastructures. However, physical effects, including surface erosion, ageing, cracking, etc. and chemical products such as carbonation, sulphate attack leads to cement degeneration. Hence, to assess the health of the cement and avoid sudden accidents, Self-sensing Concrete is introduced. Self-sensing concrete (SSC) refers to a structural material that can monitor itself without the need of embedded, attached or remote sensors. By measuring the electrical resistance of the SSC, the stress, strain, crack, and damage can be monitored. Compared with conventional structural materials which require additional sensors for monitoring or detection, the SSC is advantageous in its high sensitivity, suitable mechanical property, biological compatibility, identical lifespan with concrete and easy installation and maintenance.
Structure and Composition:-
Self-sensing concrete has a highly complex structure and has both multiphase and multi-scale composition. Self-sensing concrete may be considered a two-phase material consisting of functional fillers dispersed in a concrete matrix at the macroscopic level. There is a third phase in self-sensing concrete at the microscopic level: the interfaces between functional fillers and concrete matrix and those between available fillers. The composition of self-sensing concrete determines its structure and sensing properties. Self-sensing concrete consists of the matrix material, functional filler, and material to aid filler dispersion. Generally, all types of concrete can be used as the matrix of self-sensing concrete. The selection of composition materials and their mixing proportions is critical in fabricating self-sensing concrete.
Processing of Self-Sensing Concrete:-
Self-sensing concrete is a multi-component system with complex thermodynamic and dynamic characteristics. Thus, the processing technology aims to incorporate each component into the composite to obtain self-sensing concrete with the desirable properties. The processing technology of self-sensing concrete includes three steps: mixing/dispersing, moulding, and curing. Mixing/ dispersing is the most important one as this decides the distribution of functional filler, hydration products, pore characteristics, and water content inside a concrete matrix. These varieties in structure induced by the processing technology will have substantial effects on the sensing property of self-sensing concrete.
The sensing behaviour of the self-sensing concrete means the corresponding relationship between its electrical and mechanical properties. Such parameters can characterize the sensing properties of the self-sensing concrete as sensitivity, input/output range, linearity, repeatability, hysteresis, signal to noise ratio, and zero shifts. The sensing properties not only depend on the compositions and structures of the self-sensing concrete but also depend on the loading states and external environments. The electrical property of self-sensing concrete has a direct response to mechanical property under different temporal and spatial conditions. Strain, stress, crack, and damage inside the self-sensing concrete can therefore be detected through measurement of the electrical signal of the self-sensing concrete. Understanding the sensing mechanisms is the foundation of designing and optimizing self-sensing concrete—the sensing property results from the change of conductive network inside the composite under external force or deformation.
With high sensitivity, excellent mechanical property, natural compatibility, lifespan identical to concrete structures, easy installation, and little maintenance needed, self-sensing concrete has been used to develop new facilities for structural health monitoring and traffic detection applications. Self-sensing concrete can be used for structural health monitoring in bulk, coating, sandwich, bonded, and embedded forms. In pavements of bridges, the ISSC (Intrinsic Self- sensing Concrete) can detect many traffic data, such as traffic flow rates, vehicular speed and traffic density. Structural parameters such as stress (or force), strain (or deformation), damage, and cracking can be monitored through changes in the electrical resistance of self-sensing concrete. Therefore, self-sensing concrete can provide useful input to ensure the safety, durability, serviceability, and sustainability of infrastructures.
Getting into a government job, and that too via something as prestigious as OPSC Examinations undoubtedly takes constant efforts and perseverance. But figuring out the right direction towards this acme can be a lot painstaking. We talked to Ms. Priyanka Padhy, a 2018 Civil Engineering graduate of NIT Rourkela, who has achieved meritorious results in the OPSC Assistant Executive Engineer (AEE) 2019 by emerging as the Girls Topper and has secured the laudable Rank 10. As an alumna of the institute, we believe, she can be the best person to guide the students who carry this aspiration in their hearts. Following is an excerpt. CEST CLUB (CC) : Walk us through your childhood days. Ms. Priyanka Padhy (PP) : I have completed my 10th as well as 12th standard from Saraswati Sishu Vidya Mandir, Neelakantha Nagar, Berhampur, Odisha. I believe school life is the most important phase of life where one learns basic principles of behavior and etiquette. My school life nurtured me to develop good ha
Starting From stone age days to stepping into the 21st century, Taking shelter in a small cave to living in a luxurious Skyscraper, Civilization has evolved a lot. With all the technical advancement, we are capable of doing things, which were beyond the scope of our imagination a century ago. Despite all this development, we still can’t conquer natural disasters. Earthquakes are one of the most devastating forces, in which the seismic waves traveling through the ground can annihilate buildings, take lives, properties, and can cost a tremendous amount of money and resources to restore normalcy. Why Does The Building Collapse? Buildings are generally prepared to handle vertical forces from their weight and gravity, they cannot handle side-to-side forces transmitted by earthquakes. This flat load during quakes vibrates floors, columns, bars, and the connectors that hold them together. The difference in movement between the foot and top of buildings creates extraordinary stretch, ca
OPSC Examinations is one of the most difficult and esteemed examinations which can be only cleared by hard work and determination . We had an opportunity to have a talk with Mr. Bikash Kumar Kanhar , who with his constant efforts and persistence has become an Assistant Executive Engineer (AEE). Being an alumnus of the institute, he took out time from his schedule to guide the students and help them achieve their goals. Here is an excerpt. CEST Club (CC) : Enlighten us about your life before joining NIT Rourkela. Mr. Bikash Kanhar (BK): I was born and brought up majorly in a town called Paralakhemundi , situated in the Gajapati district of Odisha . Due to my parent’s job, we had to shuffle from place to place which is why I changed as many as 3 schools during my primary level education. I joined Jawahar Navodaya Vidyalaya after qualifying in the JNV entrance selection test and spent 7 years of my life there, completing my matriculation and inter