CONSMAT LEC. Concrete and Metals Only PDF
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This document is a lecture or handout on concrete and metal properties. It describes various types of concrete, their components, and uses. It also discusses relevant testing methods.
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LEC 2_Concrete Suitable for work underground, in water, or in humid environments. CONCRETE - a mixture of cement, water, aggregates (like sand and gravel) that hardens over RAPID HARDENING CE...
LEC 2_Concrete Suitable for work underground, in water, or in humid environments. CONCRETE - a mixture of cement, water, aggregates (like sand and gravel) that hardens over RAPID HARDENING CEMENT time to create a solid, strong substance. Finer ground Greater strength development at an early stage than OPC COMPONENTS OF A CONCRETE Often used in prefabricated road work and ٥ Cement concrete construction ٥ Coarse aggregates ٥ Fine aggregates EXTRA-RAPID HARDENING CEMENT ٥ Water Sets and becomes durable faster than OPC ٥ Air and RHC ٥ Admixtures Adding more calcium chloride to RHC ٥ Supplementary cementitious materials Often used in repairing, for concrete drives,. and paths and steps. LOW-HEAT CEMENT Lower heat of hydration and needs less water to mix High chemical corrosion resistance and wear and rupture resistance Used in floors, and surfaces, dams, and large footings. TYPES OF CEMENT (and their uses) ORDINARY PORTLAND CEMENT SULFATE RESISTING CEMENT Simply known as PORTLAND CEMENT or Very low heat of hydration TYPE 1 CEMENT Gains strength at a slower rate Made of silicates of alumina and calcium Reduces the risk of sulfate attack on carbonate concrete Used for general construction and most Used in constructing foundation in soil with masonry work. high sulfate content PORTLAND POZZOLANA CEMENT QUICK SETTING CEMENT Ground Pozzolanic Clinker mixed with OPC Sets faster than OPC, but maintains the Most resistive to chemical reactions within same strength concrete Beneficial for time-sensitive projects, such as underwater structures and in chilly and rainy climates. BLAST FURNACE SLAG CEMENT Ground clinker with up to 60% slag Less expensive, but with many same properties as OPC Used for projects where cost concerns are crucial TYPES OF CONCRETE SLUMP TRUE SLUMP HIGH ALUMINA CEMENT → Concrete just subsides shortly and more or High compressive strength less maintain the mould shape More flexible and workable than OPC → Concrete mixture is cohesive and has good Commonly used in constructions that are workability exposed to high temperatures, such as → Good cement-to-water ratio workshops, refractories, and foundries → Most desirable WHITE CEMENT ZERO SLUMP Prepared from raw materials that don’t → The concrete retains its shape completely include iron oxide → Little to no workability More expensive than other cement types → Best used in road construction Often used in interior and exterior decorative → Low water-to-cement ratio projects SHEAR SLUMP → Top half of the concrete subsides dramatically, CONCRETE SLUMP leaning to one side CONCRETE SLUMP TEST → Has workability, but low cohesion → Measures the consistency of a concrete batch to → Too much water see how easily the concrete will flow. → Ensures that the batches of the same concrete COLLAPSE SLUMP are of constant quality and strength. → doesn’t retain its shape at all and completely collapses → Water-to-cement ratio is too high → Least desirable AGGREGATES COARSE AGGREGATE When the aggregate is sieved through 4.75 mm sieve, these are the aggregate that are retained Aggregate They are the key component in concrete → are the important constituents of the concrete because they give the largest amount of → 60% - 80% of the concrete mix durability and strength → Selected for their durability, strength, and workability → Classification according to size: 1. Fine aggregate 2. Coarse aggregrate FINE AGGREGATE when aggregate is sieved through a 4.75 mm sieve, these are the aggregate that passed through Fill the voids in the coarse aggregate and act as a workability agent TESTS ON CONCRETE Compression Strength Test → Done by breaking cylindrical concrete specimens in a compression-testing machine → Results can be used for quality control, acceptance of concrete, strength estimation, etc. Flexural Strength Test → Evaluates the tensile strength of concrete indirectly → Tests the ability of unreinforced concrete beam or slab to resist failure in bending → Done to specify compliance with standard, as an essential requirement for concrete mix design, etc. Rebound Hammer WROUGHT IRON PROPERTIES → A non-destructive testing apparatus weldable at high temperatures and ductile at low → The rebound of the spring-driven mass is temperatures measured after impact good forming qualities → Output is called rebound number resistance to corrosion → Assess the in-place uniformity, delineate poor poor strength quality regions, and an in-place method to test high melting point concrete strength CAST IRONS → Strength and quality is tested through → A group of iron-carbon alloys, with carbon measuring the velocity of an ultrasonic pulse content greater than 2% passing through the concrete → Got its name because of its excellent casting → Evaluate the dynamic modulus of elasticity, qualities estimate depth of cracks, and detect internal flaws WHERE ARE CAST IRONS USED FOR? Machines Automotive parts Pots and utensils Anchor for ships LEC4_Metals CAST IRON PROPERTIES hard and brittle WROUGHT IRONS low cost → A tough form of iron suitable for forging and resistance to deformation rolling rather than casting prone to rusting → Malleable (able to be hammered or pressed high weight to strength ratio permanently without breaking) WHERE ARE WROUGHT IRONS ARE USED FOR? IRON & PURE IRON Pipe → Iron is one of the most common elements of the Bars and railings earth Iron doors, gates, fences → Pure iron is a soft, grayish – white metal Plates → Iron is a common element, but pure iron is Special chains and crane hooks almost never found in nature, it only exist on fallen meteorites THE ORE EXTRACTION AND REFINING ADVANTAGES OF STEEL PROCESS High Strength 1. Extraction – iron ores are extracted from open pit Uniformity mining Elasticity 2. Refining – mined ores are crushed to remove Permanence sand and clay away, then refined ores are Ductility transported to blast Furnace site. Toughness 3. Manufacturing – ores goes to the blast furnace; carbon monoxide reacts with the iron ore to form METHODS FOR MAKING STEEL carbon dioxide and pure iron. Melted iron sinks to the OPEN-HEARTH METHOD bottom of the furnace. → the specialty of open hearth is the extreme heat that can be obtained from them due to Mining their regenerative process → Iron ore is generally extracted through open pit mining. The ground is removed from a very large BASIC OXYGEN METHOD area to expose the one beneath. 1. Blowing of oxygen → The mined one is crushed and sorted by grade 2. Remove sulfur, phosphorus and silicon according to the percentage of iron. 3. Heat process → The refined one is taken from the mining site ti 4. Composition of molten steel the blast furnace where the iron uis melted. 5. Alloying to provide steel properties. Processing ELECTRONIC FURNACE METHOD → The ore enters the blast furnace from the top as hot air is blown from the bottom. Pure iron forms and sinks to the bottom. → The melted iron is then mold cast into ingots called pigs STEEL FERROUS METALS Steel Metals that composed of IRONS → basically an alloy of iron and carbon with a Alloy Steel small percentage of other metals such as Carbon Steel nickel, aluminum, tungsten etc. Cast Iron → Steel may not be strong as iron but it is far Wrought Iron more resistant and does not corrode and rust like iron does. PROPERTIES OF FERROUS METALS → Use extreme care where and how lead is used Ferrous Metals because lead vapors or dust are toxic if ingested. - are highly vulnerable to rusting and corrosion when exposed to moisture or an acidic or corrosive Zinc environment due to high content of carbon molecules. → Is brittle and low in strength - MOST ferrous metals have good magnetic → Major use is in galvanizing (dipping hot iron or properties and are considered to be good conductors steel in molten zinc) of electricity. This property makes them suitable for → May also be used for roofing, flashing, and electronics. hardware NON FERROUS METALS Copper Metals which do NOT contain Iron → Resistant to corrosion, impact, and fatigue; very Aluminum ductile Lead → Primary use is electrical wiring, roofing, flashing, Zinc and piping Copper → The oxidization of copper produces what is Bronze called a green “patina” Brass Bronze Aluminum → Originally a copper-tin alloy, but now aluminum → Highly resistant to weather and corrosive or silicon added to copper environments → Now may be “phosphor bronze”, “aluminum → Aluminum can be economically extruded to bronze” or “silicon bronze” many shapes (mouldings, edgings, window → Widely used for casting delicate mold mullions) impressions (Cathedral doors) → It is very malleable, quite ductile, non-corrosive, and strong in proportion to its weight. Brass → Copper with zinc to form an alloy Lead → Used for doors, windows, railings, trim, grilles → Important physical properties include: resistance and for finish hardware to corrosion, its plasticity, and its malleability → Used for waterproofing, sound and vibration STEEL FRAME CONSTRUCTION isolation, and radiation shield. a) Wide-Flange (W) → Can be combined with a tin alloy to plate iron or They are commonly used in industrial steel applications. → (called “terneplate”) They have a straight flange and are most often used in residential construction b) American Standard (S) Two types of testing process: They have a Sloped flange and are most often 1. Measure depth of penetration used in residential construction Rockwell hardness test Brinell Hardness test c) HP-Section (HP) Vickers Hardness test These are generally heavier and longer than I- Meyer Hardness test beams. Appearing like the capital letter ‘H’, they 2. Measure height of rebound have longer flanges. Scleroscope Hardness test d) Channel (C) NON-DESTRUCTIVE TESTING Like one half of the S-Section, these have a C- Rockwell Hardness Test shaped cross-section. They are used in → Indicates hardness value by depth that the supporting lighter loads since they are not as penetrator advances into metal under known strong as the other beam shapes. pressure → Designed by various letters and numbers (A, B, e) Angle C, D) Angle Steel is 'L' shaped; the most common type of Steel Angles are at a 90 degree angle. The Brinell Hardness Test legs of the “L” can be equal or unequal in length. → Indenting the metal surface with a 10-mm diameter steel ball at a load of 3000kg for 30 f) Tee (WT or ST) seconds and the impression is measure by a WT shapes are cut from a wide flange. ST low-power microscope Standard load of 500kg is shapes are cut from American Standard Beams used for nonferrous metal. → Brinell Hardness Number (BHN) is expressed as TESTING OF METALS the load P divided by a surface area of the Two categories: indentation. 1. NON-DESTRUCTIVE 2. DESTRUCTIVE Meyer Hardness Test → Less sensitive to the applied load than that of NON-DESTRUCTIVE Brinell Hardness - Test performed without breaking the sample → Cold-worked material: relatively constant and independent of load HARDNESS TESTING → Annealed materials: increases continuously with used to determine hardness of metal load because of strain → capacity to resist wear and deformation can be used to predict properties and performance of the metal Vickers Hardness Test increases, and the ductility decreases as → Based on an optical measurement system hardness increases → Specifies a range of light loads using diamond indenter → Used for very thin material → Typical Loads : 10 g to 1 kg Scleroscope Hardness Test → The Scleroscope test consists of dropping a diamond tipped hammer, which falls inside a ٥ Proportional Limit - Point the needle stop moving glass tube under the force of its own weight from ٥ Yield Point - Beyond PL and start to stretch a fixed height, onto the test specimen. The ٥ Necking - Reduction in diameter height of the rebound travel of the hammer is ٥ Ultimate Strength - Highest travel of measured on a graduated scale. needle/Maximum pull before breaking ○ Height of rebound is converted to hardness ٥ Breaking Stress reading DESTRUCTIVE - Test performed by breaking the material to determine the quality of material TENSILE TEST IMPACT TEST a. Charpy Test b. Izod Test SAMPLE PROBLEM TORQUE TEST A steel alloy bar 100mm long with a rectangular cross sectional area of 10mm x 50mm is subjected to tension with a load of 200kN and experiences an DESTRUCTIVE TESTING increase in length of 0.10mm. If the length is entirely Tensile Test elastic, calculate the modulus of elasticity of the steel → Maximum amount of pull a material can alloy. withstand → Indicates elastic limit, yield point, percent of area reduction and percentage elongation → Tensile Strength - maximum load divided by the original cross-sectional area → Tensile Strength of metal increases as hardness Impact Test → Measures toughness of metal or ability to withstand sudden shock or impact → TWO TEST: a. Charpy Test b. Izod Test I. 10-mm-square specimen II. Swinging Pendulum of fixed mass raised to standard height SAMPLE PROBLEM Charpy Test A rod with a length of 1 m and a radius of 20 mm is ٥ Specimen mounted in fixture and supported made of high-strength steel. The rod is subjected to a at both ends with V or notch placed on the torque T, which produces a shear stress below the side opposite direction of pendulum’s swing proportional limit. If the cross section at one end is ٥ Pendulum strikes, knife edge strikes sample rotated 45 degrees in relation to the other end, and ٥ Difference in height of pendulum at the shear modulus G of the material is 90 GPa, what beginning and end indicates amount of is the amount of applied torque? energy used to fracture specimen Izod Test ٥ One end of specimen is gripped in clamp with notched side toward the direction of pendulums swing ٥ Amount of energy required to break specimen on scale Torsion Test → Determine the behaviour of a material exhibits when twisted or under torsional forces as a result of applied moments that cause shear stresses about the axis → Indicates torsional shear stress, maximum torque, shear modulus and the angle of twist