Investigation of corrosion in steel. General purpose cement. Why we investigating it, Induce a certain crack and observe what may happen? Fly Ash It is a by-product of coal combustion in power stations. It also provide environmental advantages. Overall performance and quality of concrete. It affects the plastic properties of concrete by improving workability, reducing water demand, controlling bleeding, and lowering heat of hydration. Fly ash increases strength development at later ages, reduces corrosion of reinforcing steel, and generally improves resistance to chemical attack and mobility through a reduction in permeability. Grade 1 Fly Ash It is a supplementary cementitiious material that delivers improved later-age strength, workability and enhances the durability properties of concrete. Commonly used as 20%-30% cement replacement in concrete. Grade 1 Fly ash is used as a single product or may be blended to produce a Fly Ash blended cement. Grade 1 Fly Ash is recommended for use in virtually in conventional concrete applications Special Grad Ash Its an Ultra fine high performance fly ash product that both increases the density and reduces the permeability of concrete by providing a filler effect and a reactive cementitious material. It is particularly effective for providing water tightness in higher strength and high durability applications. Minutes with AdilAbbas( Major Stake holder) (3/05/16) I am having regular meeting with Adil Abbas who is the major stake holder of this project. We have discussed few key points during the meeting and they are: • Look for risk plan • Look for standards- Australian standards quality and prepare client brief • Quality management plan • -Consistency of result-Document work procedure – Report parameters – Work performed -Documents and presentation • All aspects of the project is free from mistakes • Australian standard-recovery procedure • Why Corrosion is a problem? • Documenting the notes and put it into report as appendix. it has to be part of quality plan organising meeting with Adil, documents it with quality plan • Risk assessment-making sure I keep an electronic copy. what if i loose the hardcopy? I need to have a backup • Specification of blended cement-Australian standard • Australian standard of general purpose cement • Australian standard of blended cement Minutes with AdilAbbas( Major Stake holder) (10/05/16) Concentrated salt solution. Normal concrete. add fly ash to cement after 7 days keep them for 14 days, put them into salt solution and check how much is it corroded? Research on slag Work on risk register Work on quality management plan Work on Australian standard- method of testing corrosion Minutes with AdilAbbas( Major Stake holder) (17/05/16) Find out how much cement, water, how much concrete. Slum, water cement ratio Go to companies and find out. Experiment1 beam with normal cement Another 1 partly replace slag and lime Prepare concrete cylinder.. look for method for testing compressive strength for concrete. Blended cement composition. Australian standard will tell composition of slag material which you add that will help determining the mix proportion Decide how much material do I need? Prepare at least 3 compositions • Plane • Limestone and slag • cement and slag. What slum you want. It is important to determine the water cement ratio? What mix proportion do I need Minutes with AdilAbbas( Major Stake holder) (01/06/16) I had a brief discussion regarding the experiment that I have to carry out. Adil Abbas has asked me to go to library and suggested me to look for the Australian standard website in order to find the standards. I was asked by Adil to work on water cement ratio, compression test. With the water cement ratio he has given me 3 types. 1st one is water cement ratio of 0.40. 2nd one is water cement ratio of 0.50 and the 3rd one is 0.60. I was told by Adil that the water cement ratio for casting slump would be 80 to 100mm, if in any case I can’t get it then I have to use chemical plasticizer We are going to use 6 cylinder with diameter of 100mm and 200 mm in height and for beams we will use 4 beams with length 100mm breadth 100mm and thickness 300 mm. I was asked by Adil to find out the mix proportion of the target strength of 40 MPA. Deliverable Quality Criterion/Standard Method of Measurement/testing Time of measurement Person(s) Responsible Recovery Procedure (if required) Report or presentation to hand in Engineers australia-professional engineering (presentation) Australian standard Any college check the presentation At the end of presentation I am responsible Keep another copy, time for the reviewer to comment on the quality Casting for concrete Writing the report Testing Australian standard Harvard standard Relevant publication PROJECT QUALITY MATRIX TEMPLATE Project Title: Investigate corrosion of steel Version: 1.0 Date: File Name: Project Sponsor: MP Project Manager: Ridwanur Ishan Project Client:Adil Abbas Quality Management Plan Project: Prepared by:RIDWANUR ISHAN Date: Purpose: This quality management plan defines the quality management process for the project throughout the life cycle of the problem. Quality issues/targets/standards and requirements for this project: • Temperature facture • Parallex error • Take average reading Team members responsible for quality assurance and control: • RidwanurIShan • • • Quality assurance: Quality assurance refers to the specific tasks required to achieve the desirable quality outcomes. ……………………. • Refer to Australian standard• Quality control: Quality control refers to process of summarizing and recording the results of the quality assurance process. …………………… • • • Paperwork and reports: Disputes: N/A Approval levels: N/A Plan approved by: Date: PROJECT QUALITY MATRIX TEMPLATE Consequence and likelihood of occurrence of project risks: Project: Risk Consequence rating Possible consequences Likelihood of occurrence Explanation of likelihood rating Material unavailable Medium Experiment will not be done in a proper manner Poor management Medium probability with medium impact Machine not working Low Experiment will not be able to be completed Not following up proper procedure Maintenance Low probability with high impact Risk Response Plan Project Name: Investigating Corrosion of steel Prepared by: Ridwanur Ishan Date: 24/05/16 Description of Risk Identified: Material Unavailable Person(s) responsible for managing this risk: Ridwanur Ishan Risk Rating: Medium Risk Agreed Response: Replace the material with a new one Response: • • • Timeframe required for the risk response: 1 or 2 hrs Timeframe: • • Budget required for the risk response: Depends on the material Risk response budget: • • • Contingency Plans Contingency: • Replace the material with a new one Quality Management Plan Project: Prepared by:RIDWANUR ISHAN Date: Purpose: This quality management plan defines the quality management process for the project throughout the life cycle of the problem. Quality issues/targets/standards and requirements for this project: • Temperature facture • Parallex error • Take average reading Team members responsible for quality assurance and control: • RidwanurIShan Quality assurance: Quality assurance refers to the specific tasks required to achieve the desirable quality outcomes. ……………………. • Refer to Australian standard• Quality control: Quality control refers to process of summarising and recording the results of the quality assurance process. …………………… • • • Paperwork and reports: Disputes: N/A Approval levels: N/A PROJECT QUALITY MATRIX TEMPLATE Consequence and likelihood of occurrence of project risks: Project: Risk Consequence rating Possible consequences Likelihood of occurrence Explanation of likelihood rating Material unavailable Medium Experiment will done in a proper manner Poor management Medium probability with medium impact Machine not working Low Experiment will not be able to be completed Not following up proper procedure Maintenance Low probability with high impact Risk Response Plan Project Name: Investigating Corrosion of steel Prepared by: Ridwanur Ishan Date: 24/05/16 Description of Risk Identified: Materials unavailable Person(s) responsible for managing this risk: Ridwanur Ishan Risk Rating: Medium Risk Agreed Response: Response: • Replace the material with a new one Timeframe required for the risk response: Timeframe: • 1 or 2 hrs Budget required for the risk response: Risk response budget: • Depends on the material Contingency Plans Contingency: • Replace the material with a new one Project Name: Investigating Corrosion of steel Prepared by: Ridwanur Ishan Date: 24/05/16 Description of Risk Identified: Machine not working Person(s) responsible for managing this risk: Ridwanur Ishan Risk Rating: Low Agreed Response: Response: • Call technician and fix or change the machine if required Timeframe required for the risk response: Timeframe: it might take few weeks to replace the machine but to fix the machine may require 1 or 2 weeks depends on how quick the technician can fix the machine Budget required for the risk response: Risk response budget: • Depends on the material Risk Register Project Name: Investigating corrosion of steel Prepared by: Ridwanur Ishan Date: 24/05/16 Risk Root Cause Probability Impact Risk Rating Material unavailable Improper management High Low Medium Machine not working Improper maintenance schedule Low High Medium Probability and Impact Risk Matrix – Risk Rating Impact Low Medium High Probability High Medium High High Medium Low Medium High Low Low Low Medium CONCRETE MIX RATIO AND CONCRETE What Personal Protective Equipment (PPE) is required when handling cement based products? Always wear the correct protective clothing when handling any product containing cement as it is an alkaline substance in a fine powder form: • Gloves – to guard against skin irritation • Face mask – to prevent dust inhalation • Eye protection – to prevent dust from getting in to eyes • Long pants and sleeves – to guard against skin irritation • Safety boots – to prevent injuries to your feet when handling heavy items or using potentially hazardous tools Does the temperature of the air on the day affect the use of concrete products? The ambient temperature can affect the setting times of all types of concrete. If the temperature is less than 10oC, wait until the day becomes warmer and if its over 35oC then postpone the job until it is cooler. What is the difference between cement and concrete? While the terms cement and concrete are often used interchangeably, it is important to note that cement is actually an ingredient of concrete. Cement is the powder added to concrete that provides the basis for the glue that holds the concrete together. Concrete is a mixture of aggregates (stones) and sand and the paste is water and cement. Through a process called hydration the cement and a portion of the water will undergo a chemical reaction and harden into a rocklike mass. Contrary to popular belief, concrete “sets” or “hardens” as a result of the chemical reaction between the cement and the water – it doesn’t just dry out. back to top Literature Review USING SLAG CONCRETE Slags are one of the most natural products of all. Slags are principally divided into blast furnace slag and metallurgical slag. At voestalpine the slags resulting from the steelmaking process are separated into blast furnace and metallurgical slags and then recycled. The separated slags are processed into valuable products. BASIC SLAG Basic slag is a co-product of steelmaking, and is typically produced either through the blast furnace –oxygen converter route or the electric arc furnace—ladle furnace route. To flux the silica produced during steelmaking, limestone and/or dolomite are added, as well as other types of slag conditioners such as calcium aluminates or fluorspar. The major components of these slags therefore include the oxides of calcium, magnesium, silicon, iron, and aluminium, with lesser amounts of manganese, phosphorus, and others depending on the specifics of the raw materials used. Because of the slowly released phosphate content in phosphorus-containing slag, and because of its liming effect, it is valued as fertilizer in gardens and farms in steel making areas. However, the most important application is construction. 2 main types of Slag: BLAST FURNACE AND METALLURGICAL SLAGS LD slag has been successfully used in Austria since 1970s Slag cement is most widely used in concrete, either as a separate cementations component or as part of a blended cement. It works synergistically with Portland cement to increase strength, reduce permeability, improve resistance to chemical attack and inhibit rebar corrosion. Slag cement is used in virtually all concrete applications: ? Concrete pavements ? Structures and foundations ? Mass concrete applications, such as dams or retaining walls Precast and prestressed concrete (-Producing Precast and Prestressed Concrete with Slag Cement-) ? Pipe and Block ( -Producing Concrete Pipe with Slag Cement-; -Producing Concrete Block with Slag Cement-) ? Concrete exposed to harsh environments, such as wastewater treatment and marine applications ? High-performance/high-strength concrete, such as high-rise structures or 100-year service life bridges (-Slag Cement in High Performance Concrete-) Slag cement is also used in non-concrete applications such as soil-cement and hazardous waste solidification. BLENDED CEMENT Blended Cement is manufactured for use in general purpose concrete applications, cement-based products, mortars and grouts where the use of fly ash has been approved. Concrete made with fly ash or slag cement delivers improved later-age strength workability and enhances the durability performance of concrete. Additionally, fly ash and slag are recycled by-products of industry, the use of these in cement blends assists with reducing carbon emissions. Benefits of Blended Cement Cements blended with fly ash when incorporated into a concrete mix can be expected to provide the following benefits; • Improved workability and pump ability • Reduced water demand • Enhanced bleed control • Lower drying shrinkage and creep • Improved resistance to sulphate attack and chloride penetration • Reduced potential for Alkali Aggregate Reaction Product applications The versatility of blended cement makes it an ideal choice for a wide range of applications including: • Domestic construction • Major engineering projects • Pre-cast concrete where high durability and off-form finish are required • Stabilisation including pavement recycling for road construction • Mining applications • Specialist formulations such as adhesives, renders, mortars and grouts General Blend Cement delivers improved workability and later-age strength and enhances the durability performance of concrete Corrosion of steel, How it happens, explain and how it could be prevented? Fig: Showing corrosion of steel What is corrosion? What forms of corrosion can occur in stainless steels? a. Pitting corrosion – The passive layer on stainless steel can be attacked by certain chemical species. The chloride ion Cl- is the most common of these and is found in everyday materials such as salt and bleach. Pitting corrosion is avoided by making sure that stainless steel does not come into prolonged contact with harmful chemicals or by choosing a grade of steel which is more resistant to attack. The pitting corrosion resistance can be assessed using the pitting Resistance Equivalent Number calculated from the alloy content b. Crevice corrosion – Stainless steel requires a supply of oxygen to make sure that the passive layer can form on the surface. In very tight crevices, it is not always possible for the oxygen to gain access to the stainless steel surface thereby causing it to be vulnerable to attack. Crevice corrosion is avoided by sealing crevices with a flexible sealant or by using a more corrosion resistant grade. c. General corrosion – Normally, stainless steel does not corrode uniformly as do ordinary carbon and alloy steels. However, with some chemicals, notably acids, the passive layer may be attacked uniformly depending on concentration and temperature and the metal loss is distributed over the entire surface of the steel. Hydrochloric acid and sulphuric acid at some concentrations are particular aggressive towards stainless steel. d. Stress corrosion cracking (SCC) – This is a relatively rare form of corrosion which requires a very specific combination of tensile stress, temperature and corrosive species, often the chloride ion, for it to occur. Typical applications where SCC can occur are hot water tanks and swimming pools. Another form known as sulphide stress corrosion cracking (SSCC) is associated with hydrogen sulphide in oil and gas exploration and production. e. Intergranular corrosion – This is now quite a rare form of corrosion. If the Carbon level in the steel is too high, Chromium can combine with Carbon to form Chromium Carbide. This occurs at temperatures between about 450-850 deg C. This process is also called sensitisation and typically occurs during welding. The Chromium available to form the passive layer is effectively reduced and corrosion can occur. It is avoided by choosing a low carbon grade the so-called ‘L’ grades or by using a steel with Titanium or Niobium which preferentially combines with Carbon. f. Galvanic corrosion – If two dissimilar metals are in contact with each other and with an electrolyte e.g. water or other solution, it is possible for a galvanic cell to be set up. This is rather like a battery and can accelerate corrosion of the less ‘noble’ metal. It can avoided by separating the metals with a non-metallic insulator such as rubber. Steel rusts, copper oxidises and other metals, except those which are most inert, are broken down in a similar way. This type of material destruction is given the general name of corrosion. It occurs when the material reacts with its surroundings and is converted into other substances to corrosion products. Almost all corrosion which occurs in normal working environments is of electrochemical type. It occurs in galvanic cells, corrosion cells, which function roughly in the same way as a flashlight battery. The battery has a carbon rod in its centre, and a casing of zinc plate. The carbon rod is called the cathode, the zinc plate the anode. Inside the battery, there is also a paste or sludge which is called electrolyte. When you switch on a flashlight, current runs from the carbon rod through the bulb to the zinc plate. From there, the current goes through the electrolyte back to the carbon rod. The current takes with it zinc particles from the plate, which becomes corroded and, in due course, begins to leak. The cathode is inert (- pole), the anode is reactive (+ pole). Galvanic cells which cause the corrosion can form when two different metals (or one metal and another substance which conducts electricity in the same way as a metal, for example, graphite) come into contact with an electrolyte. Corrosion caused by such material combinations is called by the common name of galvanic corrosion. Galvanic cells, often extremely small, also occur on individual metal surfaces. This is connected to the fact that industrial metals consist of microscopic gran- ules of varying composition, and can also be due to various impurities on the surface, such as oxide scale, slag residue, etc. The granules and particles are, as with various metals, of varying degrees of inertness in relation to one another. DAMP AND OXYGEN Without damp, no corrosion occurs, nor does it occur without oxy- gen. But oxygen and damp are present in the air. A certain level of damp is necessary for corrosion to occur. If the relative humidity of air exceeds 60%, a very thin film of damp forms on the metal surface, and this functions as an electrolyte. If a steel surface has impurities on it, such as dust, salt, etc., it can corrode if the relative humidity is less than 60%, because dirt absorbs damp. Outdoors in Sweden, the humidity of the air is always sufficiently high for steel, for example, to rust. Indoors, air is heated, and as a rule, so dry that steel does not rust. When the temperature falls, for example in a factory closed for vacation, there is a risk of corrosion WHEN STEEL RUSTS When the film of damp covers the steel surface, a very large number of galvanic cells are formed, all functioning in the same way as a flash- light battery. A current flows from the more inert granules or particles (cathodes) through the steel to the more reactive parts of the steel surface (anodes). The current returns from the more reactive parts out in the film of damp (electrolyte) and through it back to the more inert parts. Where the current leaves the anode, rust forms. After a time, the entire surface is covered with rust, which also spreads downwards into the steel. As long as there is access to damp and oxygen, rust will form. The speed of corrosion depends on the difference of inertness between the metals or metal granules, the electrical conductivity of the electrolyte, the supply of oxygen and differences in size between anode and cathode. A screw can be anode or cathode. EXPERIMENT References http://met-tech.com/corrosion-investigation/ http://www.sciencedirect.com/science/article/pii/S0257897205003877 http://corrosion.ksc.nasa.gov/corr_fundamentals.htm http://corrosion.ksc.nasa.gov/corr_metal.htm http://www.slg.jp/e/slag/character.html http://www.cement.org/for-concrete-books-learning/concrete-technology/durability/corrosion-of-embedded-materials
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