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Self Healing Concrete

By
Shubham Sunil Malu

ABSTRACT
Self-healing materials are a class of smart materials that have the structurally incorporated ability to repair damage caused by mechanical usage over time. The inspiration comes from biological systems, which have the ability to heal after being wounded. Initiation of cracks and other types of damage on a microscopic level has been shown to change thermal, electrical, and acoustical properties, and eventually lead to whole scale failure of the material. Usually, cracks are mended by hand, which is unsatisfactory because cracks are often hard to detect. A material (polymers, ceramics, etc.) that can intrinsically correct damage caused by normal usage could lower production costs of a number of different industrial processes through longer part lifetime, reduction of inefficiency over time caused by degradation, as well as prevent costs incurred by material failure. For a material to be defined strictly as self-healing, it is necessary that the healing process occurs without human intervention. Some examples shown below, however, include healing polymers that require intervention to initiate the healing process.

A good way to enable multiple healing events is to use living (or unterminated chain-ends) polymerization catalysts. If the walls of the capsule are created too thick, they may not fracture when the crack approaches, but if they are too thin, they may rupture prematurely.

In order for this process to happen at room temperature, and for the reactants to remain in a monomeric state within the capsule, a catalyst is also imbedded into the thermoset. The catalyst lowers the energy barrier of the reaction and allows the monomer to polymerize without the addition of heat. The capsules (often made of wax) around the monomer and the catalyst are important maintain separation until the crack facilitates the reaction.

There are many challenges in designing this type of material. First, the reactivity of the catalyst must be maintained even after it is enclosed in wax. Additionally, the monomer must flow at a sufficient rate (have low enough viscosity) to cover the entire crack before it is polymerized, or full healing capacity will not be reached. Finally, the catalyst must quickly dissolve into monomer in order to react efficiently and prevent the crack from spreading further.

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Experimental Investigation on Concrete with Replacement of Coarse Aggregate by Demolished Building Waste with Crushed Concrete

By
Vijayvenkatesh Chandrasekaran
Student, Department of Civil Engineering, St. Josephs College of Engineering & Technology, India

Abstract:
Large quantities of construction and demolition wastes are continuing being generated which are just being dumped in the landfills. This requires large areas of land which is becoming difficult to find. The best solution would be to recycle and reuse the demolished waste which would not only help in protecting the environment but also help in dealing with construction wastes. Consequently, it have a grave difficulty to produce ecological toxic waste and in addition, obligatory a huge sum of liberty. That says about the project reuse waste crushed concrete maters (WCC) from the lath wastage of crushed concrete replacing from coarse aggregate 20%, 30%, 40% (WCC), 3% of crushed coarse aggregate (lathe waste) to reduce the generation of demolition wastes. (The analysis of demolished crushed concrete aggregate (DCCA) concrete in regular mold cast is to be ready in (7, 14, 28) days hydration and examination to be conduct lying on concrete. Such as compressive strength, split tensile strength, & flextural strength.) The replacing of coarse aggregate uses of waste mater and required strength attain in the conventional M20 grade concrete.

Keywords – Demolished Crushed Concrete Aggregate (DCCA), OPC (53 grade) cement, Lathe waste, Fine aggregate, coarse aggregate.

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Partial Replacement of Cement With Marble Powder in Concrete

By
Vijayvenkatesh Chandrasekaran
Final year student, Department of Civil Engineering, St. Josephs college of engineering & technology, Thanjavur, India.

ABSTRACT:
Marble powder is one of the most active research areas that encompass a number of disciplines including civil engineering and construction materials. The marble industry inevitably produces wastes, irrespective of the improvements introduced in manufacturing processes. In the marble industry, about 50 to 60% production waste. These waste create many environmental dust problems in now a day to day society. In requiring a suitable form of management in order to achieve sustainable development. In this paper explained about the behavior of concrete with partial replacement of cement with added percentage values of marble powder and attain required strength. Partial replacement of marble powder in cement accordingly in the range of 20%, 30%, 40%, by weight for M20 grade of concrete. With this experimental research work the problem of waste production management of this agro waste are will be solved. It analyzed the research work the compressive strength, flextural strength, split tensile strength values at 7, 14, 28 day. The test results show that the compressive strength, split-tensile strength and flexural strengths are achieved up to 30% to 40% replacement of cement with marble powder without affecting the characteristic strength of M20(1:1.5:3) grade concrete.

KEYWORDS: Cement (53 grade), Marble powder, Fine aggregate (M-sand), Coarse aggregate (20mm size).

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Evaluation of Concrete Strength by Partially Replacing Cement by Red Mud And Fly Ash

Guided By: Mr. Anil Kumar Suman
Submitted By: Rashmi Sahu

Chhattisgarh Swami Vivekanand Technical University
Bhilai (C.G.), India
Shri Shankaracharya Technical Campus
Ssgi-bhilai (C.G)

CHAPTER – 01- INTRODUCTION
1.1 GENERAL –
Red Mud is a hazardous waste generated in the Bayer process Alumina production (AL2O3) from Bauxite ore which contains high levels residual alkalinity and toxic heavy metal. Therefore, Red Mud is a hazardous waste of Alumina Industry. The volume of Red Mud which generated in the alumina processing plant depends on the quality of crude Bauxite ore, may be greater than the volume of alumina 1-1.5 times. The alumina processing plant usually disposes liquid Red Mud into reservoirs, which cause the risk of major environment pollution for lowland. The particle dimension of red mud usually less than 1mm . Therefore, dry red mud easy spread into the air and causes dust pollution. It is often exposured to dust cause skin and eyes diseases. Red mud in an liquid state causes harmful effect to human skin. Composition and properties of red mud in the world have been presented by many researchers in their publications.

Fly Ash is a byproduct of coal-fired electric generating plants. The coal is pulverized and blown into burning chamber for immediate combustion. Heavier ash particle (Bottom Ash or Slag) fall to the bottom burning chamber and the lighter ash (fly ash) fly out with exhaust gas, thus the term fly ash. Before leaving the stack, these fly ash particle are removed and collected by electrostatic precipitation, bag houses or other methods.

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Understanding the Concept of Bubble Deck

By
Shubham Sunil Malu

ABSTRACT:
As the infrastructure is developing there is need for some changes in the construction field, as one cannot rely on the same method for a long time as it can have different consequences. The main consequence is the shortage of material and manpower. Also, money matters a lot in construction department along with it the machines, equipment and technology in some region is not at a level, which we want. Hence in order to satisfy these results Bubble deck slab is one of the most effective slab techniques to replace conventional slab in terms of money and materials. Also, it requires less time to construct as compared to conventional slab.

1.0 INTRODUCTION:
Bubble Deck is a revolutionary method of virtually eliminating concrete from the middle of a floor slab not performing any structural function, thereby dramatically reducing structural dead weight. Bubble Deck is based on a new patented technique- the direct way of linking air and steel. Void formers in the middle of a flat slab eliminates 35% of a slabs self-weight removing constraints of high dead loads and short spans.

Incorporation of recycled plastic bubbles as void formers permits 50% longer spans between columns. Combination of this with a flat slab construction approach spanning in two directions – the slab is connected directly to insitu concrete columns without any beams -produces a wide range of cost and construction benefits including:-

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