No.55/64, Yangon Industrial Park, Mingalardone Garden City, Yangon. Email: pmyint@scg.com, aungchit@scg.com Tel: 09-73027698, 09-450003302 Background: SCG Myanmar Concrete & Aggregate SCG White Cement SCG Chemical SCG CementBuilding Materials SCG Packing Grey Cement CPAC Refractory Business RMC Precast & Posttension Aggregate 2 Mortar Business SCG Business in Myanmar • Cement Plant • Ready Mixed Concrete • SCG Cement • Post-Tension system • SCG Roof • SCG Smart Board • Precast • SCG Smart Wood • SCG Insulation • Elephant Gypsum Board • SCG Sourcing • • • • • • Steel SCG Packaging SCG Chemical Automotive Agricultural Other 3 Background: SCG Myanmar Concrete & Aggregate Brief History of SCG Concrete Established in 1952 as the third oldest company in SCG after Cement and Fiber Cement business In the early stage, main products are precast concrete element i.e. piles, electric poles and bridge girders CPAC started ready-mixed concrete (RMC) business in 1963 as the first and largest RMC producer in Thailand Key Milestones 1991 - Focused on ready mixed concrete and aggregates while the others were spun off 1994 - Started business in Cambodia 1995 - Started business in Myanmar By CPAC name 2001 - Started business in Laos via franchise system 2007 - Started business in Vietnam 2010 - Started business in Indonesia 2016 – CPAC brand migrated to SCG Concrete Background: SCG Myanmar Concrete & Aggregate SCG Ready-Mixed Concrete Products Special Functions • Fast/ Super Fast Setting Concrete • Low Heat Concrete • Self-Compacting Concrete • Slip Form Concrete • High Strength Concrete • Self Leveling Mortar • Underwater Concrete • Easy Working Concrete • Extra-long Working Concrete • Etc. Durability Functions • Waterproof Concrete • Marine Concrete • Sulfate Resisting Concrete • Freezing Room Concrete • Roof Slab Concrete • Acid Resisting Concrete • Durable Floor Concrete • Etc. 5 Decorative Functions • Porous Concrete • Stamped Concrete • Colored Concrete • High Quality Surface Finish Background: SCG Myanmar Concrete & Aggregate High Strength Concrete 6 Background: SCG Myanmar Concrete & Aggregate Marine Concrete 7 Background: SCG Myanmar Concrete & Aggregate Water Proof & Roof Slab Concrete 8 Background: SCG Myanmar Concrete & Aggregate Durable Floor Concrete 9 Background: SCG Myanmar Concrete & Aggregate Fast Setting Concrete 10 Background: SCG Myanmar Concrete & Aggregate Self-Compacting Concrete Self-Leveling Mortar 11 Background: SCG Myanmar Concrete & Aggregate Underwater Concrete 12 Background: SCG Myanmar Concrete & Aggregate Porous Concrete 13 Background: SCG Myanmar Concrete & Aggregate Low Heat Concrete 14 Background: SCG Myanmar Concrete & Aggregate Background: SCG Myanmar Concrete & Aggregate MYANMAR 2017 Plant Network Mandalay Plant(1,2,3) Naypyitaw Plant Yangon Plant(1,2,3,4,5,6,7,8,9) Mawlamyine Plant(1,2) Myeik Plant Background: SCG Myanmar Concrete & Aggregate SCG Ngwe pin lal SCG Mingaladon Yangon City Plant Network 2017 SCG Secondary Business Center SCG Central Plant SCG South Dagon SCG Thaketa SCG Kandawlay Plant SCG Thilawa 1 & 2 Background: SCG Myanmar Concrete & Aggregate Policy & Strategy Environmental responsibilities Waste reduction Alternative raw materials ECO and Green products Innovation creations High Value Added Products and Services Research and Development is considered as a significant role to achieve 18 Background: SCG Myanmar Concrete & Aggregate Eco Products Alternative Raw Materials 19 Background: SCG Myanmar Concrete & Aggregate Innovative Research & Development 20 Background: SCG Concrete Penetration into ASEAN Laos (2001) Myanmar (1995) Vietnam (2007) Cambodia (1994) Penetration into ASEAN 1994 - Started business in Cambodia 1995 - Started business in Myanmar 2001 - Started business in Laos via franchise system 2007 - Started business in Vietnam 2010 - Started business in Indonesia Indonesia (2010) 21 Precast Business Precast Products RC Pile Prestressed pile U-Ditch Box Culvart Agenda Introduction to PostPost-tensioned Slab System Materials, Equipment and Construction Method PostPost-tensioned Slab Design Principle Installation Works Quality Inspection PostPost-Tension Slab Design for Earthquake Building Modification Agenda Introduction to PostPost-tensioned Slab System Materials, Equipment and Construction Method PostPost-tensioned Slab Design Principle Installation Works Quality Inspection PostPost-Tension Slab Design for Earthquake Building Modification Post-tension vs Pre-Tension Prestressed Technology Pre-Tension (Precast) Post-Tension Eugene Freyssinet - 1928 : Began to use high-strength steel wire - 1946 : Post-tension gain momentum in Europe Structural concrete floor slabs Types of construction Prestress Non prestress Modes of reinforcing Cast in place Reinforced Concrete (RC) Post-Tension Patterns of cast in place slab Two-way flat plate Two-way flat slab with drop panels. One-way beam and slab. One-way joist slab. One-way wide module joist slab. Two-way joist slab Precast slab X Pre-Tension Slab • Solid plank • Hollow core Post-tensioned concrete floors system POST-TENSION CONCEPT • 1. Concrete Casting and Curing Post-tensioned concrete floors system POST-TENSION CONCEPT • 2.Tendons Stressing and Force Transfered Post-tensioned concrete floors system POST-TENSION CONCEPT • 3. Tendons Anchored and Grouted Post-tensioned concrete floors system Types of Post– Post–tension Slab System 1.Bonded System 2.Unbonded System Post-tensioned concrete floors system ADVANTAGES OF BONDED SYSTEM • Bonded • After grouting, stressing forced transfer all along entire strands. • When slab is receiving a damage, it will only has localized damage (more suitable to residential buildings with modifications). ADVANTAGES OF UNBONDED SYSTEM Unbonded Less covering (smaller equipment) Less friction (from grease in tube) Easy to install (ready made from factory) No grouting needed Materials – Post-tensioned Bonded System (Strand) NORMINAL SIZE : 12.70 mm. or ½ inch GRADE : 270 k TYPE : LOW RELAXATION BREAKING FORCE : 18.73 TONS TRANSFER FORCE : 14.20 - 15 TONS DESIGN FORCE : 10.80 TONS Materials – Post-tensioned Bonded System Concrete for Post - Tension slab 28 day Compressive Strength 320 ksc (or) 31.5 MPa (Cylinder) 380 ksc (or) 37.5 MPa (Cube) Concrete Strength Before Stressing 240 280 ksc (or) 23.5 MPa (Cylinder) ksc (or) 27.5 MPa (Cube) CPAC Post-tension : Design & Application Silo Bridge Sport Stadium Buildings 35 Post-tensioned Buildings Car park Condominium Office Shopping Mall Complex 36 Advantages of Post-Tension Architecture - More convenience for putting the wall - Reduce the height of tower R.C Building Post-Tensioned Building Structure - Increased clear spans - Thinner slabs - Structures have less weight than RC. - Reduced cracking and deflections - Improved seismic performance Cost Direct - Prices cheaper than 10% of RC (Material cost + Labour cost) Indirect - Save times SPAN 8.00 m FLOOR HT. 3.7m SLAB THK 0.25m AIR DUCT 0.4m CLEAR HT. 2.4m SPAN 8.00 m FLOOR HT. 3.00m SLAB THK 0.2m AIR DUCT 0.4m CLEAR HT. 2.4m Post-tensioned Slab Types Selection Flat Slab Drop Panel Band Beam Span 6-9 m. Span 9-12 m. Span >12 m. Construction Process of Post-Tension System 1. Formwork Installation 2. Bottom Steel Bar Installation - Flat simple formworks are easy and fast to install. Fewer steel reinforcement requires less labor and placing time. 39 Construction Process of Post-Tension System 3. Tendons Lay Out & Anchorages Placing 4. Top Bar Installation 5. Concreting 40 Construction Process of Post-Tension System 6. Stressing 7. Grouting - - - Stressing when concrete strength > G28 (3 days). Floor can carry full load after stressing Grouting mortar mix with expanding agent 41 Post-Tension Slab Construction Typical Cycle Time for Post tension Slab Construction (Floor area 1200 Sq.m.) 12,900 sq.ft 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 Column Construction Formworks Installation FL.1 FL.3 FL.2 Bottom Bars Placing Anchorages Fixing Tendons Installation Formwork Re-Use Top Bars Placing Inspecting Concreting Stressing Formworks Stripping FL.1 FL.2 Grouting (not critical) Fast stripping and reuse of formwork greatly reduce investment cost. 42 Post-tensioned concrete floors system Cost comparison between RC and Post-Tension Slab Post-tensioned concrete floors system Cost comparison between RC and Post-Tension Slab 6.5 Post-tensioned concrete floors system Post-tensioned concrete floors system Post-tensioned concrete floors system 5.3 m Post-tensioned concrete floors system Benefit Conclusion • More Floor Area • Lower Height • More Storey • Flexibility for partition • Cost Saving • Time Saving Structural Reliability • • • • High Quality Materials : Concrete, Steel Reduce Crack : Concrete under compression Less Deflection : Due to Uplift Force Diaphragm plate distribute lateral load to shear wall : Seismic load resistance 48 Agenda Introduction to PostPost-tensioned Slab System Materials, Equipment and Construction Method PostPost-tensioned Slab Design Principle Installation Works Quality Inspection PostPost-Tension Slab Design for Earthquake Building Modification Materials – Post-tensioned Bonded System - Strand ½” Grade 270 (ASTM A 416M-96) - Anchorage Set of 2 and 4 strands(Anchor Block, Guide) - Corrugated Galvanized Steel Sheath - Cement Grouted Materials – Post-tensioned Bonded System Concrete for Post - Tension slab 28 day Compressive Strength 320 ksc (or) 31.5 MPa (Cylinder) 380 ksc (or) 37.5 MPa (Cube) Concrete Strength Before Stressing 240 280 ksc (or) 23.5 MPa (Cylinder) ksc (or) 27.5 MPa (Cube) Materials – Post-tensioned Bonded System (Strand) NORMINAL SIZE : 12.70 mm. or ½ inch GRADE : 270 k TYPE : LOW RELAXATION BREAKING FORCE : 18.73 TONS TRANSFER FORCE : 14.20 - 15 TONS DESIGN FORCE : 10.80 TONS Force-Elongation Diagram of Strand Pressure (%) 80% Total Elongation shall lies between 0.95 to 1.05 of theoretical elongation 77.5% 75.8% (37.9%) 75.8% / 2 A Pressure shall not exceed 80% of fpu 0 A Elongation at 75.8 % Elongation at 77.5 % Elongation at 80 % B C Elongation (mm) Materials – Post-tensioned Bonded System Grouting Materials and Strength Test Portland Cement Type 1 Daratard BLEEDING 2-4 % Aluminum Paste W/C ≤ 0.45 7 Days Strength 17Mpa (175ksc) Grouting Mortar FLUIDITY > 11 SEC. Materials – Post-tensioned Bonded System • Functions of Grouting • 1. Transfer force between tendon and concrete also bond the strands to the duct and surrounding concrete. • 2. Provides a cementitious cover that slows ingress of water and corrosion causing contaminals. • 3. Grout creates a passive environment for steel , inhibiting corrosion. Materials – Post-tensioned Bonded System Bar Chair Agenda Introduction to PostPost-tensioned Slab System Materials, Equipment and Construction Method PostPost-tensioned Slab Design Principle Installation Works Quality Inspection PostPost-Tension Slab Design for Earthquake Building Modification Post-tensioned slab design principle Design Process Select design criteria Make conceptual design Moments & shears analysis Calculate required tendons Calculate required steel rebar Check shear stresses Post-tensioned slab design principle Design Process Select design criteria Make conceptual design Moments & shears analysis Calculate required tendons Calculate required steel rebar Check shear stresses Post-tensioned slab design principle CONCRETE: STRENGTH at 28 days ............................. 320 Ksc (31.5 Mpa) WEIGHT .......................................... 2400.00 (Kg/m3) CREEP factor for deflections..................... 2.00 TENSION STRESS limits (multiple of √(f'c)) Top of external support ......................... 1.590 Top of internal support ......................... 1.590 Bottom of external span ......................... 1.590 Bottom of internal span ......................... 1.590 COMPRESSION STRESS limits (multiple of (f'c)) At all locations ................................ .450 MILD REINFORCEMENT: YIELD strength .................................. 4.00 (T/cm2) Minimum Cover at TOP ............................ 2.50 (cm) Minimum Cover at BOTTOM ......................... 2.50 (cm) POST-TENSIONING: SYSTEM .......................................... BONDED Ultimate strength of strand ..................... 18.60 (T/cm2) Average effective stress in strand (final) ...... 10.80 (T/cm2) Post-tensioned slab design principle Design Process Select design criteria Make conceptual design Moments & shears analysis Calculate required tendons Calculate required steel rebar Check shear stresses Post-tensioned slab design principle DESIGN LOAD SDL (Kg/m2) LL* (Kg/m2) Residential 250 200 Office 200 300 Shopping Center 200 400 0 400 Parking *From EIT and Bangkok Municipal Codes Post-tensioned concrete floors system DESIGN LOAD • SDL, Super Imposed Dead Load, is a load of permanent structures built after slab is complete. For example: loads of floor topping, decoration tiles, walls To calculate SDL, we should select one area of the building that will be mostly present the floor layout • Example of calculation 2.5 m. Calculate total wall load 1.00 m. Unit weight of 1-layer brick wall = 180 kg/m2 SDL = Total wall load/total area Total wall load = (Length × Height) × Unit weight 2.0 m. 2.0 m. = (8×2.8 + 2×2.8 + 2×2.8 + 0.5×8×2.8 + 0.5×7×2.8 + 0.5×7×2.8) × 180 = 64.4 × 180 = 11,592 kg Total Area = 7 × 8 = 56 m2 SDL = 11,592/56 = 207 kg/m2 ∴ Use SDL > 207 kg/m2 Post-tensioned Slab Types Selection Flat Slab Drop Panel Band Beam Span 6-9 m. Span 9-12 m. Span >12 m. Post-tensioned slab design principle Floor Depressed Maximum floor depressed of ‘Post-tensioned Slab’ is 5 cm. There are 2 major methods of floor depressed. 1. Flat slab bottom 2. Keep slab thickness Post-tensioned slab design principle Typical span/depth ratios for each floor type Slab thickness selection factors 1. Loading 2. Span Length 3. Controlled Slab Deflection *Minimum slab thickness of CPAC Post-Tension Slab system is 18 cm. (bonded) Post-tensioned slab design principle Example of conceptual design Post-tensioned slab design principle Example of conceptual design 8.00 m. 8.00 m. BST ลง B- 6.00 m. BB- ลิฟท์ ลง BST 2.00 m. SDL 250 LL 200 B- 6.00 m. Post-tensioned slab design principle Example of conceptual design 8.00 m. PTS. 0.20 BST ลง B- B- 6.00 m. PTS. 0.25 B- ลิฟท์ ลง BST 2.00 m. SDL 250 LL 200 PTS. 0.20 B- 6.00 m. Post-tensioned slab design principle Design Process Select design criteria Make conceptual design Moments & shears analysis Calculate required tendons Calculate required steel rebar Check Shear stresses Post-tensioned slab design principle A FLAT PLATE DESIGN USING EQUIVALENT FRAME METHOD Elastic analysis of a structural frame consisting of column members and slab members Convert 3D frame to 2D frame by taking of stiffness of slabs and beams. Post-tensioned slab design principle Width for EFM analysis, called Design Strip, is a length between the middle of two columns Post-tensioned slab design principle (torsional stiffness of slab), Kt K t = ∑ 9 E cC c l 2 1 − 2 l2 3 where x x3 y C = 1 − 0.63 y 3 This image cannot currently be display ed. X = shorter over-all dimension of a rectangular part of a cross section Y = longer over-all dimension of a rectangular part of a cross section Isometric view of a slab-column junction ที่มา : http://nptel.iitm.ac.in/courses/IIT-MADRAS/PreStressed_Concrete_Structures/pdf/9_Special_Topics/Section9.3.pdf Post-tensioned slab design principle Moment & Shear ที)มา : http://www.pretex.com/pdf/mgreg-14.pdf Post-tensioned slab design principle Results of analysis Post-tensioned slab design principle Design Process Select design criteria Make conceptual design Moments & shears analysis Calculate required tendons Calculate required steel rebar Check Shear stresses Post-tensioned slab design principle Calculate required tendons P Mc Pec σ= ± ± A I I TENSION STRESS limits (multiple of √(f'c)) Top of external support ......................... 1.590 Top of internal support ......................... 1.590 Bottom of external span ......................... 1.590 Bottom of internal span ......................... 1.590 COMPRESSION STRESS limits (multiple of (f'c)) At all locations ................................ .450 Post-tensioned slab design principle Design Process Select design criteria Make conceptual design Moments & shears analysis Calculate required tendons Calculate required steel rebar Check Shear stresses Post-tensioned slab design principle Calculate required steel rebar MU = 1.4MDL+1.7 MLL+1.0MSEC a − Apsfs dp − φ 2 As = fyz 2 MU Post-tensioned slab design principle Design Process Select design criteria Make conceptual design Moments & shears analysis Calculate required tendons Calculate required steel rebar Check Shear stresses Post-tensioned slab design principle What is Punching Shear From: ACI 318-05 Post-tensioned slab design principle Punching Shear Check From Axail Load From Moment Post-tensioned slab design principle SHEAR STIRRUP 83 Post-tensioned slab design principle Punching Shear Check From: ACI 318-05 Agenda Introduction to PostPost-tensioned Slab System Materials, Equipment and Construction Method PostPost-tensioned Slab Design Principle Quality Inspection Inspection Installation Works Quality PostPost-Tension Slab Design for Earthquake Building Modification Installation works quality inspection Quality Inspection for Installation Installation works quality inspection Strands/Tendons Installation Vertical Tolerance = + 5 mm (1/5 in.) Bar-chair Spacing Tolerance = + 20 cm (8 in.) Tendon Horizontal Bending Tolerance = 1:12 (From flexibility of strands) Bar-chair Spacing Bar-chair Height Installation works quality inspection Strands/Tendons Formation 1. Both Uniformly Distributed 2. Uniform + Column Strip 3. Both Column Strip Installation works quality inspection 1. Uniformly Distributed for Both Directions UNIFORM DIRECTION UNIFORM DIRECTION Installation works quality inspection 2. Uniformly Distributed and Column Strip (Banded) BAND DIRECTION BAND DIRECTION UNIFORM DIRECTION Installation works quality inspection 3. Column Strip (Banded) in Both Directions COLUMN STRIP MIDDLE STRIP COLUMN STRIP Installation works quality inspection Banded Uniform Installation works quality inspection Tensioning Process 1.Tensioning 50% of Banded Tendons (Except Extra Tendons) 2.Tensioning 100% of Uniformed Tendons (Except Extra Tendons) 3.Tensioning 50% of Banded Tendons Left 4.Tensioning Extra Banded Tendons 5.Tensioning Extra Uniformed Tendons Installation works quality inspection Concrete Strength Test Before Stressing Cylinder Test Cube Test 23.5MPa (240ksc ) 27.5MPa(280ksc) 28 days strength Cylinder Test Cube Test 31.5MPa (320ksc ) 37.5MPa(380ksc) Installation works quality inspection Formworks Installation Install formworks during construction, pouring concrete and do not remove formwork before tensioning After finish tensioning, supporting formworks can be removed (some formworks should be re-installed to support construction loads) Do not remove formworks until block-out area gains designed strength Installation works quality inspection Formworks Installation Slab thickness 25 cm. 100 % under construction floor 50 % the lower under the construction floor Agenda Introduction to PostPost-tensioned Slab System Materials, Equipment and Construction Method PostPost-tensioned Slab Design Principle Quality Inspection Inspection Installation Works Quality PostPost-Tension Slab Design for Earthquake Building Modification Post-Tension Design for Earthquake Lateral loads Reduced seismic forces and overturning moments which result from the reduced floor height and weight compared with non-prestressed concrete members. PTS resist diaphragm loads as a elastic system with less cracking than non-prestressed concrete structures Where : Cs = Seismic Respond Coefficient W = Weight of Building Post-Tension Design for Earthquake Punching Shear Failure By Earthquake Post-Tension Design for Earthquake Story Drift (%) is an deformation index of one structure that indicate how much that structure can deform beyond elastic limit without losing its strength Post-Tension Design for Earthquake From study, maximum story drift of flat slab is 2%, but required story drift for Bangkok’s earthquake condition is 4%. So, improvement in design is needed. Post-Tension Design for Earthquake Factors for choosing slab types Required Rebar Type 1 > Type 2 > Type 3 Story Drift (%) Type 1 < Type 2 < Type 3 More story drift = more distance slab can be moved and more resistance to earthquake Post-Tension Design for Earthquake Calculate steel rebar for two-way flat slab in earthquake condition (USD) Compressive Term Post-Tension Term Tension Term Post-Tension Design for Earthquake Post-Tension Design for Earthquake Calculated steel rebar from column transferred flexural moment (Ms) must put inside effective width Agenda Introduction to PostPost-tensioned Slab System Materials, Equipment and Construction Method PostPost-tensioned Slab Design Principle Quality Inspection Inspection Installation Works Quality PostPost-Tension Slab Design for Earthquake Building Modification Building Modification Example of slab cutting 1-Span Length (with a cantilever) Building Modification • Modification Process* • 1. Install Formworks/Scaffolds under sawing area 1-Span Length (with a cantilever) • *This modification can be done only with bonded system which has cement grouted to transfer force along strands’ length. Building Modification • 2. Grouted fullness checking Building Modification 3. Re-grouting tendons with void/gap (if any) Grout tube Tendon Building Modification 4. Saw post-tension slab along required line Building Modification Chisel dimension = 40x50cm (1.3x1.65ft) Building Modification Chisel concrete around tendons Building Modification block guide jaws tendon Install an anchorage set Building Modification dowel Install dowel steel rebar Building Modification Pour non-shrink mortar with strength more than 4500 psi (320 ksc) (In Hand and Follow Up Projects in Myanmar) In Hand Project Follow Up Project 1. Min Dama Condo D 1. xxxx 2. Yaw Min gyi (GMP) 2. xxxx 3. Hotel &Diagnostic Center Service Apartment (GMP) 3. xxxx 4. Thiri Yadana Hotel (GMP) 4. xxxx 5. A1,Kabaraye Executive Residence (KER) 5. xxxx 6. KT project 6. xxxx 7. Kandawlay Shopping mall 7. xxxx 8. LSK Residence 8. xxxx 9. Yankin Residence 9. xxxx (Referenced Projects in Oversea) CENTARA GRAND MIRAGE PATTAYA SCG Head Office 3 VIEWTALAY CONDOMINIUM PATTAYA (Referenced Projects in Myanmar) Hotel & Diagnostic Center Thiri Yadanar Hotel (Referenced Projects in Myanmar) Kabar Aye Executive Residence (KER) Mindama Condo D First , PostPost-Tension Seminar in Myanmar Myanmar Engineering Society In Yangon( MES ) AM Construction Company Yangon City Development Committee(YCDC) Second , PostPost-Tension Seminar in Myanmar MES In Mandalay MES In Mandalay Control Quality High-Rise Building Project (CQHP) PostPost-Tension Seminar at University At Thanlyin Technological University At Mhawbi Technological University At West YangonTechnological University Contact Information • MYANMAR CPAC SERVICE CO., LTD. (MCS) • No. 56/59 , Mingalardone Industrial Zone • Zay Kabar Garden Compound, Mingalardone Township, Yangon. • Contact Person • Aung Chit Moe (Engineer) Aung Phone Myint (Engineer) • Mobile No. (+95-9) 422542466 Mobile No. (+95-9) 73027698 • Email: aungchit@scg.co.th Email: pmyint@scg.co.th • 12 5