CIVI 321 Engineering Materials (Week 3-Cement) 2024 Student Notes PDF

2024-02-13 CIVI 321 ENGINEERING MATERIALS A.M. Soliman, PhD, P.Eng Associate Professor Department of Building, Civil & Environmental Engineering (BCEE) 1 CIVI321 ENGINEERING MATERIALS Chapter #3 Cement A.M. Soliman, PhD, P.Eng Associate Professor Department of Building, Civil & Environmental Enginee...

2024-02-13 CIVI 321 ENGINEERING MATERIALS A.M. Soliman, PhD, P.Eng Associate Professor Department of Building, Civil & Environmental Engineering (BCEE) 1 CIVI321 ENGINEERING MATERIALS Chapter #3 Cement A.M. Soliman, PhD, P.Eng Associate Professor Department of Building, Civil & Environmental Engineering (BCEE) 2 1 2024-02-13 CEMENT History of cementing Materials Cement manufacturing Cement hydration Cement microstructure 3 History of cementing Materials Oldest cementing materials: mud mixed with straw to bind un-burnt bricks (ancient Egypt). No resistance to water. Works only in very dry climates. Bricks with straw in Egypt Babylonians used natural bitumen to bind stones and bricks The Tower of Babel 4 2 2024-02-13 Ancient Egyptians used gypsum in the Construction of pyramids of Cheops (300 BC). Setting will not take place in water (non-hydraulic binder, gypsum is soluble in water) Lime mortars (by calcinating limestone) were used in Egypt during Roman period and earlier in Cypris and Greece. Also non-hydraulic binders The Coliseum in Rome Alexander The open court at Edfu 5 Hydraulic Limes Greek and Romans produce hydraulic limes by calcinating limestone containing clayey impurities. They also knew that some volcanic deposits when ground and mixed with lime produce Stronger & resistant to water (The Pantheon at Roma) Eddy stone lighthouse In 1756, John Smeaton (the first person to style himself “Civil Engineer”) was commissioned to rebuild the Eddy stone lighthouse off the coast of England. Conducted many experiments with limes and pozzolans He concluded that “Normal mortars will not resist seawater and that best mortars can be made of limestone containing clayey material.” John Smeaton 6 3 2024-02-13 Development of Portland Cement In 1776, James Parker in England patented a natural hydraulic cement made by calcinating limestone with clayey impurities. In 1824, Joseph Aspdin, a Leeds builder took out a patent on Portland cement prepared by calcinating in a kiln finely ground limestone mixed with finely divided clay. 7 Portland cement: coined by Aspdin for real similarity to a popular natural rock quarried at Portland, England. Portland quarry stone Portland Cement Concrete Aspdin made his material as mysterious as possible, pretending that secret salts were sprinkled into the kiln before burning. Use of Portland cement spread rapidly in Europe and North America. 1871 First American patent (D. Saylor)….. The first plant to start production. In Canada, limes and hydraulic cement were first produced around 1830. By about 1890, local cement production in North America displaced imports from England. 8 4 2024-02-13 MANUFACTURE OF PORTLAND CEMENT 2 1 4 3 5 9 8 6 7 1 Raw material Storage 4 Raw material Preheating 7 Gypsum addition 2 Raw material Grinding 5 Raw material Cooking in Kiln 8 Cement grinding 3 Raw material Blending 6 Clinker storage/cooling 9 Cement storage/loading 9 MANUFACTURE OF PORTLAND CEMENT 2 1 4 3 5 9 8 6 7 1 Raw material Storage 4 Raw material Preheating 7 Gypsum addition 2 Raw material Grinding 5 Raw material Cooking in Kiln 8 Cement grinding 3 Raw material Blending 6 Clinker storage/cooling 9 Cement storage/loading 10 5 2024-02-13 Steps in Traditional Manufacture of Portland Cement 1 Raw material Storage 2 Raw material Grinding 11 2 Raw material Grinding 3 Raw material Blending 12 6 2024-02-13 5 Raw material Cooking in Kiln 6 Clinker storage/cooling Rotary Kiln Clinker Cooking in a kiln at about 1500 °C 13 7 Gypsum addition 8 Cement grinding 9 Cement storage/loading Grinding mill Steel grinding balls 14 7 2024-02-13 Steps in Modern Manufacture of Portland Cement 1 Raw material Storage 2 Raw material Grinding 15 2 Raw material Grinding 3 Raw material Blending Roller mill : one vertical unit Crushing, grinding and classifying 16 8 2024-02-13 4 Raw material Preheating 4 Raw material Preheating 17 18 9 2024-02-13 Inside the Kiln 700°C 1 900°C 2 1150°C 1200°C 3 1350°C 4 1450°C 5 6 1 2 19 Inside the Kiln 700°C 1 900°C 2 1150°C 1200°C 3 1350°C 4 1450°C 5 6 1 2 1 C2S:Dicalcium Silicate (Belite) 20 10 2024-02-13 3 C2S (Belite) + CaO 4 2 C3S:Tricalcium Silicate (Alite) 5 1 C2S (Belite) 2 C3S (Alite) 21 6 3 C3A:Tricalcium Aluminate 4 C4AF:Tetracalcium Aluminoferrite Inside the Kiln, calcium combines with other components of the raw mix to form 4 principal compounds (about 90%) of cement by mass. 2 Tricalcium silicate 3CaO SiO2 C3S 1 Dicalcium silicate 2CaO SiO2 C2S 3 Tricalcium aluminate 3CaO Al2O3 C3A 4 Tetracalcium aluminoferrite 4CaO Al2O3 Fe2O3 C4AF Cement chemists use the following chemical abbreviations to describe oxide composition: A= Al2O3, C=CaO, F= Fe2O3, H=H2O, M=MgO, S= SiO2 22 11 2024-02-13 Typical Oxide Composition of Cement(%) CaO (C) 63% SO3 2% SiO2(S) 20% K2O and Na2O 1% Al2O3 (A) 6% Others 1% Fe2O3 (F) 3% Loss on ignition 2 MgO 1% Insoluble Residue 1 Inside the Kiln, calcium combines with other components of the raw mix to form 4 principal compounds (about 90%) of cement by mass. 2 Tricalcium silicate (Alite) 3CaO SiO2 C3S 1 Dicalcium silicate (Belite) 2CaO SiO2 C2S 3 Tricalcium aluminate 3CaO Al2O3 C3A 4 Tetracalcium aluminoferrite 4CaO Al2O3 Fe2O3 C4AF Cement chemists use the following chemical abbreviations to describe oxide composition: A= Al2O3, C=CaO, F= Fe2O3, H=H2O, M=MgO, S= SiO2 23 23 Potential Composition of Portland Cement Percentages of main components are calculated using Bogue’s equations. Terms between brackets represent the percentage of the given oxide in the total mass of cement C3S = 4.071(CaO) - 7.600(SiO2) - 6.718(Al2O3) - 1.430(Fe2O3) - 2.852(SO3) C2S = 2.867 (SiO2) - 0.754 C3S C3A = 2.650(Al2O3) - 1.692 (Fe2O3) C4AF = 3.043 (Fe2O3) This is a simple method provided in ASTM C150 but there are more advanced methods. 24 12 2024-02-13 In Summary Raw Material Lime = CaO Silica = SiO2 Iron = Fe2O3 Alumina = Al2O3 Grinding Clinker Grinding Portland Cement Cooking at 1450 °C A few % Gypsum C 3S C 2S C 3A C4AF Raw Materials for Manufacture of Portland Cement: Lime (CaO): Limestone, marble, calcite, seashells, etc. Silica (SiO2): Clay, sand, calcium silicate, etc. Alumina (Al2O3): Clay, shale, bauxite, etc. Iron Oxide (Fe2O3): Iron ore, blast furnace dust, etc 25 Reactions in Kiln: Before the burning zone : Formation of C2S (Belite) from free lime and silica. (700-900 °C) In the burning zone : Combination of C2S and free lime to form C3S (Alite). (1200-1350 °C) Gypsum: 4-6% is added to regulate the setting time of the cement and to improve shrinkage and strength development properties. Impurities: Impurities exist in clinker (MgO, alkalis (Na2O and K2O), sulfates, etc.). They lower the melting temperature & improve combination of lime. Their incorporation in silicates improves strength. Caution: Durability problems (ASR) 26 13 2024-02-13 Mechanism Alkali hydroxide Expansion + Reactive silica gel Alkali Silica Gel Moisture + Alkali Silica gel filling microcracks Alkali H O 2 Reactive hydroxide silica Moisture H2O Alkali silica gel filling air pores 27 Mechanism Alkali hydroxide Expansion + Reactive silica Moisture H2O Alkali Silica Gel + Alkali Silica gel filling microcracks Alkali silica gel filling air pores 28 14 2024-02-13 Cement Specifications, Types, and Tests American Society for Testing and Materials (ASTM) American Association of State Highway and Transportation Officials (AASHTO) Canadian Standards Association (CSA) 29 Standard Specification for Portland Cement ASTM C 150 Type I Normal Type II Moderate Sulfate Resistance Type III High Early Strength Type IV Low Heat of Hydration Type V High Sulfate Resistance Note : AASHTO M 85 similar to ASTM 150 30 15 2024-02-13 What Makes them Different? All types manufactured from similar raw materials: – Vary the chemical composition (C3S/C2S/C3A/C4AF) – Vary the physical characteristics Type I Normal Type II Moderate Sulfate Resistance Lower C3A (7.5%) Type III High Early Strength Ground finer Type IV Low Heat of Hydration High C2S-C4AF Low C3S-C3A Type V High Sulfate Resistance Lower C3A (3.5%) 31 TYPE 10 TYPE 20 TYPE 30 TYPE 40 TYPE 50 White 32 16 2024-02-13 Why 5 Types of Cement? Different uses require Different performance Type I General Uses- 90% of used cement Concrete bridges Buildings Highway pavement 33 Type II & V Elements exposed to high-sulfate soils Slab-on-ground Poor Concrete Sewer concrete pipe Concrete post Using adequate cement type + Good concrete mixture Good Concrete = Achieve the desired performance 34 17 2024-02-13 Type III Used where early concrete strength is needed Fast track paving Cold weather concreting Type IV Delayed reaction, low heat generated, No longer common Bridge pier Concrete Dam 35 Special Cements White Cement (low C4AF %) Primarily architectural and decorative concretes 36 18 2024-02-13 Special Cements Masonry Cement Specifically formulated for use in masonry mortars Include limits on max air content and min strength 37 Oil Well Cement Formulated for use in high temp. and pressure down-hole 8 classes of cement (varying Temp., Pressure) – Exposure to up to 120°C (250° F) – Exposure to up to 140 MPa (20,000 psi) 38 19 2024-02-13 Finely-Ground Cements (Ultrafine Cements) Ground very fine for use in grouting into fine soil or thin rock fissures To stabilize in-place materials, to provide strength for foundations. 39 Expansive Cement used where shrinkage (or cracking) is potentially a problem – Floors – Bridge decks 40 20 2024-02-13 Canadian Standards Association (CSA) CSA A5 Types 10, 20, 30, 40, and 50 Slightly different from ASTM C 150 Types I-V Generally, one cement can meet both specs. CSA A3000-03 Types GU, HE, MS, HS, MH and LH Similar to ASTM 1157 Types It included blended cements (will be discussed later) CSA A3000-08 Portland Limestone Cement PLC 41 Performance Specification (Hydraulic Cements - ASTM C 1157) First performance specification for hydraulic cements. Bases qualification of cement on performance attributes rather than ingredients or cement chemistry. Type GU General use Type HE High early strength Type MS Moderate sulfate resistance Type HS High sulfate resistance Type MH Moderate heat of hydration Type LH Low heat of hydration 42 21 2024-02-13 43 44 22 2024-02-13 45 46 46 23 2024-02-13 47 47 3 1 2 Hydration Products 4 48 48 24 2024-02-13 Cement Hydration Cement C3S C2S Water Hydration Products H2O CSH CH + C3A C4AF + Heat Others CSH (Calcium Silicate Hydrate): is the binder (glue) responsible for strength CH (Calcium Hydroxide): does not have an important contribution to strength. 49 50 50 25 2024-02-13 Cement Hydration Cement C3S C2S C3A C4AF Water + H2O Hydration Products CSH + Heat CH Others 51 51 Cement Tests 52 26 2024-02-13 Cement Tests Quality control – Chemical aspects – Physical aspects Performance of cement/concrete – Fresh properties.. Placing and workability – Hardened properties.. Strength and Durability 53 Chemical Tests ASTM C 114 – Chemical analysis to determine oxides – Use this to calculate potential compound composition C3S C2S C3A C4AF (Bogue’s equations) Thermo-Gravimetric Analysis X-Ray Fluorescence Analysis 54 27 2024-02-13 Particle Size and Fineness Individual angular particles with a range of sizes. 85% to 95% are smaller than 45 μm, with the average particle around 15 μm Cement Fineness: Its overall particle size distribution - 1950’s Type I - Today’s cements 300 m2/kg (Blaine) 370 m2/kg (Blaine) Finer = faster hydration, more heat generation, higher early-age strength, less long-term gains 55 Blaine, ASTM C 204 (m2/kg) Measures time to pass air through cement BET Uses gas (i.e. Helium) to measure surface area Wagner, ASTM C 115 ( m2/kg) Pass light through suspension of cement particles, measure intensity, also allows PSD calculation Laser particle analyzer Uses laser diffraction to determine the PSD 56 28 2024-02-13 57 Setting Behaviour Initial Set: From 1 to 4 hours Final Set: From 3 to 6 hours False Set: Rapid setting without much heat liberation, can be remixed. Flash Set: Very rapid setting with significant heat liberation, can’t be remixed (too much gypsum) 58 29 2024-02-13 Cement Paste Time Liquid state Initial Set Soil state Final Set 59 Vicat, ASTM C 191 A 300g needle with 1 mm diameter penetrates under its weight Penetration: Initial set: 25-mm Final set: zero Gillmore, ASTM C 266 Initial set: 2 mm diameter needle, 113 g Final set: 1 mm needle, 454 g NO complete circular impression in the paste surface 60 30 2024-02-13 Soundness ASTM C 151-09 – Accelerated curing of paste bars – Less than 0.80% expansion Free MgO can cause long-term soundness problems (expansion) 61 Heat of Hydration ASTM C 186 Measure heat generated from cement as it hydrates. (Hydrates: Chemical reactions between cement and water) Cement C 3S C 2S C 3A C4AF Water + H 2O Hydration Products CSH + Heat CH 62 31 2024-02-13 Strength ASTM C 109 50 mm mortar cubes Compressive strength is influenced by - Cement composition. - Fineness of the cement. 63 Consistency of Mortar ASTM C 1437-07 Flow table 64 32 2024-02-13 Thermal Analysis Thermogravimetric Analysis (TGA) Differential Thermal Analysis (DTA) Differential Scanning Calorimetry (DSC) 65 Thermal Analysis + Heat 66 33 2024-02-13 Transporting Cement 67 Packaging and Storage Cement Silo (Ready Mix plant) Construction Site 68 34