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UCC302 CEMENT Dr Arpit Goyal Assistant Professor Civil Engineering Department Thapar Institute of Engineering and Technology, Patiala Outline History of cement industry Raw materials Manufacturing processes Grades and Codal provisions Quality contro...

UCC302 CEMENT Dr Arpit Goyal Assistant Professor Civil Engineering Department Thapar Institute of Engineering and Technology, Patiala Outline History of cement industry Raw materials Manufacturing processes Grades and Codal provisions Quality control Binding materials in the past Principally – lime based materials Major use of pozzolans Bitumen Towards Modern Cement.. 1756: John Smeaton, while planning a material for building Eddystone lighthouse tower, discovered that the best limes for mortar contained a high degree of clayey matter such lime was used along with pozzolana in equal quantities Completed in 1759 (72 feet tall; 93 steps) Newer lighthouse constructed in 1882 Smeaton’s tower moved stone-by-stone to Plymouth, still the most major landmark Beginning of the Industry Portland cement: first patented in 1824 by Joseph Aspdin Named after the natural limestone quarried on the Isle of Portland in the English Channel Isle of Portland, UK (William) Aspdin’s creation A – Alite, or C3S B – Belite, or C2S Kiln for burning Hewlett, 2001 Portland Cement First Produced 1871— Coplay, Pennsylvania, USA 1889 — Hull, Quebec, Canada Indian cement companies More than 70% of the cement in India comes from… Company Production (MT) Installed Capacity (MT) ACC 17,902 18,640 Gujarat Ambuja 15,094 14,860 Ultratech 13,707 17,000 Grasim 14,649 14,115 India Cements 8,434 8,810 JK Group 6,174 6,680 MT = Million Tonnes Jaypee Group 6,316 6,531 Century 6,636 6,300 Madras Cements 4,550 5,470 Birla Corp. 5,150 5,113 http://business.mapsofindia.com/cement/ History of cement production in India Initially, the Indian cement market was dominated by imports The indigenous Indian cement industry traces its history back to 1914 – 1914: produced just 1000t of cement – 1924: Production increased to 0.26Mt – In the same 10-year bracket, India consumed a total of 2Mt of cement Formation of Indian Cement Manufacturers' Association (ICMA) in 1925: To handle industry problems and to campaign for tariffs on imported cement, Between 1925 and the early 1940s: capacity of the Indian cement industry gradually increased to 1.8Mt, with imports dwindling to just ~1000t/yr Associated Cement Companies (ACC) was formed from 11 competing firms in 1936: To combat continued price wars. In 1942: India's cement capacity came under the control of Defense for India rules as part of the war effort 1945 to 1956: the government regulated prices directly 1989 onwards: A free market http://www.globalcement.com/magazine/articles/752-the-incredible-indian-cement-industry Cement map of India (approx.)  Portland Cement An unusual industrial product produced in huge quantities in special plants that can produce nothing else The product is produced by a combination of unusual unit operations involving – mining – very fine scale blending of raw materials – very high temperature clinkering reactions – controlled cooling – Grinding – Blending – finally shipping under controlled conditions Chemical composition is maintained within narrow limits Portland cement production dynamics Typical plant costs range upwards of $250 million - a fairly substantial fixed investment. Plant must produce continuously to pay off capital costs Plant must also produce continuously to maintain kiln integrity - 3 shifts per day! Plant must comply with severe environmental constraints All this must be done to produce a commodity product that sells for Rs. 6 - 8 / kg Primary Components of Raw Materials Necessary for Portland Cement Manufacturing Calcareous material – Containing CaCO3 (primary source – limestone) Argillaceous material – Containing clayey matter, source of SiO2, Al2O3 impurities such as iron and alumina are sometimes present Gypsum – Added in the final stages of manufacture as a set regulator  Raw material sources Calcium Silicon Aluminum Iron Limestone Clay Clay Clay Note: Marl Marl Shale Iron ore Marl: Limestone Calcite Sand Fly ash Mill scale deposits with a Aluminum ore high fraction of Aragonite Shale Shale refuse clay minerals Blast furnace Shale Fly ash Sand: Usually a dust problem, as quartz Sea Shells Rice hull ash is hard, remains in the coarse fraction Cement kiln dust Slag http://iti.northwestern.edu/cement/monograph/Monograph3_3.html Quarry PCA Cement Production Schematic depiction of process www.ieagreen.org.uk/jan46.htm Cement manufacturing - Animation https://vimeo.com/465943977 See the interactive video saved in share drive Cement manufacturing processes Wet process – almost outdated now Dry process – mostly used now-a-days 6000 5000 Power Consumption (kJ/kg) Wet process – more uniform 4000 mixing Dry process – higher output, lower power consumption 3000 (3000 kJ/kg as opposed to 5500 for wet process) 2000 1000 0 Dry Process Manufacture of Portland Cement – Step 1 Stone is first reduced to 125 mm (5 in.) size, then to 20 mm (3/4 in.), and stored: Pulverization PCA Dry Process Manufacture of Portland Cement – Step 2 Raw materials are ground, to powder and blended. PCA Dry Process Manufacture of Portland Cement – Step 3 Burning changes raw mix chemically into clinker. Four stages: Preheater, flash furnaces, and shorter kiln. PCA  Burning in kiln Only rotary kilns used nowadays: long ~ 30 – 70 m, 5 – 6 m dia Temperature inside kiln: 850 (at inlet) to 1450 oC (at the outlet) Some reactions require cooling to occur, so happen outside kiln What comes out of kiln is called ‘clinker’ Dry Process Manufacture of Portland Cement – Step 4 Clinker with gypsum is ground into portland cement and shipped PCA Snapshots of a Control Room in a Cement Plant (Courtesy: Ultratech Cement Plant, Ariyalur) Clinker + Gypsum = Portland Cement (+ other blending materials like fly ash for PPC) Clinker – Formed by burning calcium and siliceous raw materials in a kiln. – Size: About 20 mm (3¼4 in.) in diameter. Intregrinding with Gypsum – A source of sulfate – Added as set regulator (Absence: flash set) – It helps control setting, drying shrinkage properties, and strength development. PCA CEMENT – End Product Chemical Composition  Raw materials for cement Calcareous material – Containing CaCO3 – primary source: limestone Argillaceous material – containing SiO2, Al2O3 and Fe2O3 – Primary source: clay Gypsum – Added in the final stages of manufacture as a set regulator Steps in production Selection of raw materials Grinding to correct size Choice of blending process Production of cement clinker by kiln burning of blended raw materials Intergrinding with gypsum to produce Portland Cement Cement Composition Chemical formula Notation Name Typical weight % CaO C Lime, calcium oxide 60-67 SiO2 S Silica, silicon dioxide 17-25 H2O H Water -- Al2O3 A Alumina, aluminum oxide 3-8 Fe2O3 F Iron or ferric oxide 1-6 MgO M Magnesia, magnesium oxide 1-4 K2O, Na2O K, N Alkalis, Potassium & sodium oxides 0.5-1.2 SO3 S Sulphur trioxide 2-3.5 CO2 C Carbon dioxide --  Quality control parameters at cement plant Lime saturation factor (LSF) = C/(2.8S + 1.2A + 0.65F) where C, S, A, and F are the % amounts of CaO, SiO2, Al2O3, and Fe2O3, respectively Generally between 92 – 98% more than 100% => presence of free lime Silica ratio (or modulus) = S/(A + F); generally 2.0 – 3.0 Alumina ratio (or modulus) = A/F; generally 1.0 – 4.0 Potential C3S from Bogue formulation The LSF is particularly important because it dictates the amount of free lime that will be present in the product. Too much free lime can cause unsoundness of the cement. Cement Compound Chemical formula Notation Name Typical weight % 3CaO·SiO2 C3S Tricalcium silicate, Alite 45-60 2CaO·SiO2 C2S Dicalcium silicate, Belite 15-30 3CaO·Al2O3 C3A Tricalcium Aluminate 6-12 4CaO·Al2O3·Fe2O3 C4AF Tetracalcium Aluminoferrite 6-8 CaSO4·2H2O CSH2 Gypsum (calcium sulphate dihydrate) 3-4 Typical composition of Ordinary Portland Cement CSH2 C4AF (5%) C3A: (8%) – responsible for setting – early strength C3A (10%) – high heat of hydration C3S: C3S (55%) C2S (20%) – early strength gain – high HOH C2S: – ultimate strength – low HOH Bogue equations for finding compound composition Using Bogue equations, oxide compositions are converted into approximate compound compositions % C3S = 4.071C – 7.700S – 6.718A – 1.430F – 2.852SO3 % C2S = 2.867S – 0.7544(% C3S) % C3A = 2.650A – 1.692F % C4AF = 3.043F Cement Hydration The chemical reactions between cement and water: hydration of cement. Hydration products have cementing and adhesive properties. Hydrated compounds have very low solubility. C3S and C2S reactions form calcium silicate hydrate (C-S-H) and calcium hydroxide (CH) 2C3S  6H  C 3S2 H 3  3CH   water     calcium hydroxide Alite tricalciumsilicate C-S- H – Moderate reaction rate – High strength – High heat liberation 2C  S  4H  C 3S2 H 3  3CH  2 water     calcium hydroxide Belite dicalciumsilicate C-S- H – Slow reaction rate – Low initial but high later strength – Low heat liberation Overall major reactions: C3S + C2S + water → C-S-H + CH Young et al., 1998 Hydration products of C3S and C2S Calcium Silicate Hydrate ( C-S-H) – C-S-H constitute 50 to 60% of the solids in the cement paste. – form a continuous binding matrix. – amorphous and fibrous, hence will have a larger surface area. – Main product fir development of strength of the cement mix. Calcium Hydroxide (Ca(OH)2): – This product will constitute 20% of the solids in the paste. – Exists in the form of thick crystalline hexagonal plates and is embedded in the C-S-H matrix. – Soluble in water and will get leached out: cause white patches and efflorescence. – Its growth will fill the pore spaces. – No significant role in strength development. – Highly alkaline: protects steel rebar Hydration products of C3A Forms aluminate-rich gel The gel reacts with sulfate form small rod-like crystals of ettringite (Calcium Aluminate Tri Sulphate Hydrate) It constitutes about 10 to 20% of the solid content. This has a minor role in strength development but contributes highly to durability.  Heat of hydration The reaction of cement with water is exothermic. The reaction liberates a considerable quantity of heat. This liberation of heat is called heat of hydration. The study and control of the heat of hydration becomes important in the construction of concrete dams and other mass concrete constructions. Normal cement generally produces 89-90 cal/g in 7 days and 90-100 cal/g in 28 days.  Heat of hydration Anhydrous cement: cement without water (not bind fine and coarse aggregates) An indication of the rate at which the minerals are reacting can be observed by monitoring the rate at which heat is evolved using a Heat of J/g technique called conduction hydration calorimetry. C3A 867 C3S 502 C2S 260 C4AF 419  Hydration of C3A phase Hydration product of C3A: C3A phase (the most reactive of Calcium aluminate hydrate the four main clinker minerals) CaO – Al2O3 – H20 reacts with the water to form an aluminate-rich gel (Stage I on the heat evolution curve above). The gel reacts with sulfate in solution to form small rod-like crystals of ettringite. C3A reaction is with water is strongly exothermic but does not last long, typically only a few minutes, and is followed by a period of a few hours of Ettringite: calcium aluminate relatively low heat evolution. trisulphate hydrate This is called the dormant, or induction period (Stage II).  Hydration of C3S and C2S phase At the end of the dormant period, the alite (C3S) and belite (C2S) in the cement start to react, with the formation of calcium silicate hydrate and calcium hydroxide. This corresponds to the main period of hydration (Stage III), during which time concrete strengths increase. The individual grains react from the surface inwards, and the anhydrous particles become smaller. C3A hydration also continues, as fresh crystals become accessible to water.  Heat of hydration Ferrite reaction also starts quickly as water is added, but then slows down, probably because a layer of iron hydroxide gel forms, coating the ferrite and acting as a barrier, preventing further reaction. Alite is the major phase in Portland cement responsible for setting and development of "early" strength. The other silicate, belite contributes "late" strength, due Hydration product of C4AF: to its lower reactivity. Hydrated calcium ferrite CaO – Fe2O3 – H20 Alite is more reactive because of its higher Ca content.  Heat of hydration The period of maximum heat evolution occurs typically between about 10 and 20 hours after mixing and then gradually tails off. In a mix containing PC only, most of the strength gain has occurred within about a month. Where PC has been partly- replaced by other materials, such as fly ash, strength growth may occur more slowly and continue for several months or even a year. Hydration rate and strength development of cement compounds hydration of pure compounds Development of strength of pure compounds CEMENT SPECIFICATIONS - ASTM, BIS, and EN (Euronorms) Indian Standard (BIS) Cements Ordinary Portland Cement (OPC) – IS:269-2015 – classified as 33, 43 and 53 grade; – grade implies the 28-day strength of the cement mortar made using standard sand Portland-Pozzolana Cement (PPC) – IS:1489 (Part 1)- 2015 (Flyash based); Part 2 (calcined clay) Portland-Slag Cement (PSC) – IS 455-1976 Portland Cement, Low Heat – IS:12600-1989 Rapid Hardening Portland Cement – IS:8041-1978  ASTM Classification (C 150) Type I: General purpose Type II: Moderately sulphate resistant, and moderate heat of hydration Type III: High early strength Type IV: Low heat of hydration Type V: Sulphate resistant Type IA and IIA for air-entrained cements Typical Composition ASTM Compound composition (%) Type C3S C2S C3A C4AF I 45-55 20-30 8-12 6-10 II 40-50 25-35 5-7 10-15 III 50-65 15-25 8-14 6-10 IV 25-35 40-50 5-7 10-15 V 40-50 25-35 0-4 10-20 Ordinary Portland Cement ‘Conventional cement’ Prior to 1987, there was only one grade of OPC. After 1987 higher grades (3 in no.) of OPC introduced – OPC 33 grade – OPC 43 grade – OPC 53 grade Grade classification is done on the basis of strength of cement at 28 days when tested as per IS 4031 (Part 6)- 1988. Use of high grade cements offer many advantages for making stronger concrete (via high quality limestone, modern equipments, better PSD, finer grading, control over constituents etc. Physical requirements of OPC (Tested as per IS 4031) Chemical requirements of OPC (Tested per IS 4032) Best before use: 3 months Pozzolanic Cement Pozzolans: are siliceous or aluminous materials, which possess by themselves little or no cementitious properties, but in finely divided form react with calcium hydroxide in the presence of moisture at ordinary temperatures to form compounds possessing cementitious properties (definition according to ASTM C595). CH + Reactive SiO2 (or Al2O3) + H2O  C-S-H Reaction is - Lime consuming - Pore refining - Slow (low heat of hydration) - Accelerated by alkalis and gypsum https://www.downtoearthorg.in/coverage/strong--fetish-8929 Portland Pozzolana Cement- fly ash based IS:1489 (Part 1)- 2015 Manufactured by the intergrinding of OPC clinker with 15 to 35% of FA Fineness (min): 300 m2/kg 28 days Comp strength: equivalent to OPC 33 Calcium hydroxide is hydration product of cement Portland Pozzolana Cement- Calcined clay based Ternary blend of clinker, calcined clay & limestone Clinker that needs to be burnt at very high temperatures Reduction in clinker content by between 1400 and 1500°C. about 50% intended to significantly Calcined clays are burnt at approximately 800°C. reduce the total CO2 emissions. Limestone is added without processing Gypsum for workability 55  Portland-Slag Cement (PSC) IS 455-1976 GRANULATED SLAG Courtesy: M. Alexander GRANULATED SLAG Courtesy: M. Alexander Comparison between Cement, Fly ash and Silica Fume PPC - Benefits costly clinker is replaced by cheaper pozzolanic material Soluble calcium hydroxide is converted into insoluble cementitious products resulting in improvement of permeability. Lower heat of hydration PPC is finer than OPC and also due to pozzolanic action, it improves the pore size distribution As the fly ash is finer and of lower density, PPC gives more volume of mortar than OPC.  OPC PPC Pozzolanic components are added to OPC to create PPC. OPC OPC is made by preparing and then grinding a mixture of clinker, gypsum, and pozzolanic elements (15–35 %), such as limestone and additional raw materials including argillaceous, calcined clay, volcanic ash, fly ash, or silica fumes, make up the calcareous, and gypsum. primary constituents. Compared to PPC, initial strength is higher. Over a lengthier time frame, PPC has more strength than OPC. It is less suited for bulk casting because the hydration reaction It produces less heat than OPC because its hydration process is produces more heat than PPC does. slow. less resilient in harsh weather. less costly than OPC. More costly than PPC. Cheaper than OPC. It contains both industrial and organic waste, making it Emits CO2 when it is being manufactured. environmentally favourable. For all kinds of construction activities, it is appropriate. For It is suitable for quick construction but unsuitable for bulk instance, mass concrete pouring for bridges, RCC casting of concreting due to the heat-related difficulties outlined above. structures, and even plastering and other non-structural activities. Inferior to PPC. It takes 30 minutes to set initially, and 280 PPC requires more time to set than OPC. It takes 30 minutes to set minutes to set completely. The quicker setting time facilitates initially, and 600 minutes to set completely. Better finishing is quicker building. made possible by the slower setting time. OPC has 225 sq.m/kg of finiteness. It is less finely ground than OPC has a 300 sq.m/kg finiteness. It has a finer texture than OPC. PPC. As a result, it is less durable due to its increased As a result, it is more durable due to its decreased permeability. permeability. OPC cement is available in grades 33, 43, and 53. No specified grade of PPC cement is available. Lower than PPC. Superior to OPC. It is less resistant to alkalis, sulphates, chlorides, and other It is more resistant to alkalis, sulphates, chlorides, and other substances. substance Rapid Hardening Cement Also know as ‘High Early Strength Cement’ Follows IS 8041-1990 RHC develops higher rate of strength development 3d strength of RHC is equal to 7d strength of OPC Rapid rate of strength development is attributed to – higher fineness of grinding – higher C3S and – lower C2S content. RHC gives out much greater heat oh hydration during the early period, hence should not be used in mass concreting. Rapid Hardening Cement - Applications Pre-fabricated concrete construction Formwork required to be removed early Rapid Hardening Cement - Applications Road repair work Cold weather concreting Sulphate Resisting Cement (SRC) Follows IS 12330-1988 WHY SRC? OPC is susceptible to the sulphate attack, viz. MgSO4 Sulphates reacts with – free calcium hydroxide to form calcium sulphate and – hydrate of calcium aluminate to form calcium sulphoaluminate (approx.. 227% more volume than original aluminates) Expansion causes cracks SRC - Recommendations Remedy of sulphate attack: – the use of cement with low C3A (lower that 5%) – low C3AF content – (2C3A+C3AF) lower than 25% Use of SRC is recommended in following conditions: – Concrete to be used in marine condition – Concrete to be used in foundation and basement, where soil is infested with sulphates. – Concrete used for fabrication of pipes which are likely to be buried in marshy region or sulphate bearing soils. – Concrete to be used in the construction of sewage treatment works. High Alumina Cement (HAC): IS 6452:1989 Also known as calcium aluminate cement or aluminous cement. It is composed of calcium aluminates, unlike Portland cement which is composed of calcium silicates. Raw materials used in manufacturing of HAC: limestone and bauxite. Hydration products of HAC: CAH10, C2AH8 and alumina gel (these aluminates give high strength to concrete).  Good resistance to acidic and sulphate environments  Good performance at high temperatures due to formation of a ceramic bond; hence used in refractory linings for furnaces Loss of strength with age due to a gradual conversion of hydration product (CAH10 to C3AH6) Other Special Cements RAPID SETTING CEMENT PC + Plaster of Paris, or PC + calcium OIL WELL CEMENT aluminate cement For cementing steel casings to rock Setting times are as low as 10 minutes formations during oil drilling Poor durability and strength Pumped as slurry which needs to be fluid under service conditions, and WHITE CEMENT then harden quickly Architectural purposes Reduced C3A and fineness Lowered iron contents in the clinker Sometimes retarders are used for set and accelerators for strength Pigments can be added to get coloured cement White cement was used in the ASTM Headquarters in West Conshohocken, Pennsylvania Tests on Cement Physical properties – cement tests Field testing Laboratory testing  Fineness test (Sieve test)  Standard consistency test  Setting time test (Initial setting time and final setting time)  Soundness test  Strength test  Specific gravity  Heat of hydration test  Chemical composition test Fineness or Surface Area of cement Decides rate of strength development and heat of hydration Defined in terms of surface area per unit weight Blaine air permeability apparatus IS 4031 Part 2 Name Range Requirement Blaine air permeability Refer to IS:5516 Min 225 m2/kg apparatus 3gm weighing balance Physical properties – cement tests Fineness test (Sieve test)  Different cements are ground to different fineness.  Disadvantage of fine grinding – cement is susceptible to air set and thus deteriorate early.  Increase in fineness of cement is found to increase drying shrinkage of concrete.  The finer cement has quicker action with water and gains early strength though its ultimate strength remains unaffected.  Maximum no. of particles in a cement sample should have size less than 100 microns. Standard consistency test  IS Code: 4031 (Part 4) : 1988  Vicat apparatus as per IS: 5513:1976  Water required to make the cement paste workable  Also known as ‘normal consistency’  The Standard or Normal consistency for Ordinary Portland cement varies between 25-35% 1.Needle for determining the initial setting time 2.Needle for determining the final setting time 3.Plunger for determining the standard consistency  Video Link Standard consistency test https://www.youtube.com/watc h?v=fL6E0E1LOBg Procedure:- Polished brass 10 mm dia, 50 mm length 1.Take 400g of cement 2.Assume standard consistency is 28% and add the same quantity of water 3.Mix the paste thoroughly within 3-5 minutes: Called gauging time. 4.Now fill the paste in Vicat mould correctly any excessive paste remained on Vicat mould is taken off by using a trowel. 5.Then, place the VICAT mould on Glass plate and see that the plunger should touch the surface of VICAT mould gently. 6.Release the Plunger and allow it to sink into the test mould. 7.Note down the penetration of the plunger from the bottom of mould indicated on the scale. 8.Repeat the same experiment by adding different percentages of water until the reading is in between 5-7mm on the Vicat apparatus scale. Setting of cement  Stiffening of cement paste from plastic stage to solid state  IS Code 4031 (Part 5)  Initial setting time is regarded as the time elapsed between the moment that the water is added to the cement, to the time that the paste starts losing its plasticity.  Minimum IST is 30 min  Final setting time is the time elapsed between the moment the water is added to the cement to the time when the paste has completely lost its plasticity and has attained sufficient firmness  should not be more than 10 hours (600 minutes)  Vicat apparatus (IS: 5513 – 1976)  Video Link Setting Time Test https://www.youtube.com/watc h?v=3tKuexK4zto 1.Take 400g of cement Needle for IST: 1.13 mm dia, 2.Add water = 0.85 P (P is Standard consistency of cement) 50 mm length 3.Start the stopwatch at the moment water is added 4.Now fill the mix in Vicat mould, removing excessive paste by using a trowel 5. Place the VICAT mould on non porous plate, allow the plunger to touch the surface of mould gently 6. IST: FST needle: Release needle 30 mm length, fitted with a brass Note penetration of the needle from the bottom of mould attachment to indicated on the scale leave a circular cutting edge 5 mm Repeat until the needle stop penetrating 5mm from in diameter bottom of the mould 7.FST: The cement shall be considered as finally set when, upon applying the needle gently to the surface of the test block, the needle makes an impression thereon, while the attachment fails to do so  Specific Gravity of Cement Specific Gravity of cement is the ratio of the density or mass of cement to the density or mass of a reference substance. Procedure Requirement of test: To know the behavior of the material in 1.The Flask should be free from the liquid water. We can know whether the material will sink or floats in which means it should be fully dry. Weigh the the water. empty flask, which is W1. 2.Next, fill the cement on the bottle up to half S.G > 1; Material will sinks in water of the flask around 50gm and weigh it with its stopper. And it is W2. S.G < 1; Material will float in water Specific gravity of cement ranges from 3.1 to 3.16 g/cc 3.Add Kerosene to the cement up to the top of the bottle. Mix well to remove the air bubbles in it. Weigh the flask with cement and Generally, water is used as reference but in case of Cement; kerosene. And it is W3. kerosene is used. Why?? 4.Empty the flask. Fill the bottle with kerosene up to the top and weigh the flask for counting Specific gravity of kerosene is 0.79 g/cc W4. Apparatus Required: Le-Chatelier Flask of 250 ml or Specific Gravity Bottle / Pycnometer of 100 ml Compressive strength testVideo Link https://www.youtube.com/watch?v=5zb4gILa IS 4031 Part 6 HWY  Not made on neat cement paste…. Why??  Size of cube 70.6 mm  1:3 cement to sand ratio (200 gm cement + 600 gm standard sand)  Water = (P/4+ 3) percent of dry mass  Tested under Compressive Testing Machine [CTM] at 28 days of curing  loading rate of 35 N/mm2/min  Average of three values is taken as final strength values Moulding room : Temperature : 27 ± 2°C, RH : 65 ± 5 percent. moist room : 27 ± 2°C and RH not less than 90%  Video Link Soundness Test https://www.youtube.com/watch?v=KntJtqXqjUI  IS 4031 Part 3  Excessive expansion after setting: due to  presence of excess lime  Inadequate burning or insufficiency in fineness of grinding  Too high proportion of magnesium content or calcium sulphate content Permissible magnesia content in cement: Max 6% Permissible gypsum: 3 to 5 % depending upon C3A content Le Chatelier test Procedure: 1. Find normal consistency(P). 2. Add 0.78 P of water to the cement to make paste 3. Lightly apply oil to the Le-chatelier mould and place it on a glass plate. 4. Now pour the cement paste into mould and close the mould using lightly oiled glass plate and to avoid misplacement place a weight on it. 5. Then, submerge the whole assembly for 24Hrs in water bath at a temperature of 270C 6. Remove the entire apparatus from water and then calculate the distance separating two indicator points using measuring scale and note it as L1. 7. Again submerge the whole assembly in a water bath at temperature of boiling point for 3hours. 8. Measure the distance between two indicator points and note it as L2. Expansion = L1 – L2 Types of Cement Expansion Limits OPC 10mm PPC 10mm Rapid Hardening 10mm cement Low heat cement 10mm Super sulphated cement 5mm Packing and storage Bags of 50 kg capacity for local use. These are stored for short period of time in air tight room avoiding moisture and dampness, at some distance from walls and at some height from floors. The stack should be covered with suitable coverings to avoid circulation of air through the stack and not more than ten bags should be stacked one over another.