Training and findingon high value concrete,non destructive testing,structural health monitoring and pile testing
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The document summarizes a training attended by the author on structural health monitoring using smart materials, deep foundation testing through modern instrumentation, non-destructive evaluation of concrete, and high-performance concrete. Key findings from each session include how different non-destructive testing techniques can be used for structural health monitoring, how latest foundation testing technology can determine pile depth and strength, how to evaluate different types of concrete cracks, and how high-performance concrete can reduce costs and improve durability through the use of materials like fly ash and silica fume. The document also provides details on reactive powder concrete/Ductal mixes and properties that allow it to achieve very high strengths and durability.
Training and findingon high value concrete,non destructive testing,structural health monitoring and pile testing
- 1. Training and Finding On dated 11/09/13,we 1.Mr.K.J.Anand and 2.Mr.Abhishek Ganguli participated the training organized by IIT Delhi at Delhi. Subject is as under- 1.Structural health monitoring using smart materials by Dr.Suresh Bhalla 2.Deep Foundation Testing Through Modern Instrumentation by Dr.Brent Robinson,GRL Engineer 3.Non-Destructive Evaluation of Concrete by Prof.B.Bhattacharjee,IIT 4.High-Performance Concrete by Dr.S.K.Dhawan,IIT The findings is given below
- 2. 1.Structural health monitoring using smart materials Dr.Bhalla describes this subject. Finding is as under 1.Common NDT techniques include ultrasonics,magnetic- particle,dye penetration,radiography,eddy-currents etc. 2.SHM may use any one or more NDE techniques.SHM,however,emphasises on continous evaluations.wide group of analysis techniques used in science and industry to evaluate the properties of materials, components or system without causing damage, these aided in SHM 3.SHM can facilitate monitoring of external loads, stress distribution,deflections,design validation,understanding structural behaviours.
- 3. 2.Deep Foundation Testing Through Modern Instrumentation Dr.Brent Robinson describes the new technique with new technology to test the deep foundation. It also includes foundation testing. Two PPT is 1.High strain testing 2.NDT for Structural Integrity Findings 1.How latest technology is helpful find out depth of pile,quality of concrete, steel and strength. 2.How latest technonology is useful for collect actual data of structure to re-design or maintenance.
- 4. 3.Non –Destructive Evaluation of Concrete This chapter is described by prof.B.Bhattacharya Findings. 1.Different types of cracks and defects in concrete is discussed and evaluation technique is described. 2.To find the correct result for NDT it needs to calibrate locally with locally used material.
- 5. 4.HIGH VALUE CONCRETE High value concrete is described by Dr.S.K.Dhawan FINDINGS Their findings is really useful for every part of life to reduce the cost and durability of the concrete, hence complete presentation is attached here with in PPT Uses- Existing Batching plant may become research centre for high value concrete to utilize in city construction or important construction in state and we can utilize our highly qualified personnel. High-Value Concrete
- 6. High-Value Concrete BASICS High performance concrete can be made to have strengths in excess of 30,000-40,000 psi.(200-275Mpa) All concrete is of high value! Cost of concrete Involves Cost of material (small) Cost of placement (significant) Cost of Replacement (HIGH) 4 Types of Concrete Low Strength (<2000psi)/15Mpa Normal (2000-6000psi)/(15-40Mpa) High Strength (HPC) (>6000psi)/40mpa Ultra High Strength (UHPC/RPC) (>40000psi)/200Mpa (ultra high performance concrete/rapid powder concrete)
- 7. High-Value Concrete High value generally associated with High-Performance What is High-Performance? High-Early Strength Concrete High-Strength Concrete High-Durability Concrete Self-Consolidating Concrete Reactive Powder Concrete/Ductal What is high value concrete
- 8. High-Value Concrete Characteristics of High-Performance Concretes High early strength High strength High modulus of elasticity High abrasion resistance High durability and long life in severe environments Low permeability and diffusion Resistance to chemical attack High resistance to frost and deicer scaling damage Toughness and impact resistance Volume stability Ease of placement Compaction without segregation Inhibition of bacterial and mold growth
- 9. High-Value Concrete Materials Used in High- Performance Concrete Material Primary Contribution/Desired Property Portland cement Cementing material / Durability Blended cement Cementing material / Durability / High strength Fly ash / Slag / Silica fume Calcined clay/ Met kaolin Calcined shale HRWR(High range water reducer)/Super plasticizers Flow ability High-range water reducers Reduce water-cement ratio Hydration control admix. Control setting
- 10. High-Value Concrete Materials Used in High- Performance Concrete Material Primary contribution/Desired property Retarders Control setting Accelerators Accelerate setting Corrosion inhibitors Control steel corrosion Water reducers Reduce cement and water content Shrinkage reducers Reduce shrinkage ASR inhibitors Control alkali-silica activity Improve workability/reduce paste Polymer/latex modifiers Optimally graded aggr. Durability
- 11. High-Value Concrete Selected Properties of High- Performance Concrete Property Test Method Criteria that may be specified High Strength ASTM C 39 70-140 MPa @ 28 to 91 days H-E Comp. Strength ASTM C 39 20-30 MPa @ 3-12 hrs or 1-3 days H-E Flex. Strength ASTM C 78 2-4 MPa @ 3-12 hrs or 1-3 days Abrasion Resistance ASTM C 944 0-1 mm depth of wear Low Permeability ASTM C 1202 500 to 2000 coulombs Chloride Penetration AASHTO T 259/260 Less than 0.07% Cl at 6 months Low Absorption ASTM C 642 2% to 5% High Mod.of Elast. ASTM C 469 More than 40 GPa
- 12. High-Value Concrete High-Early-Strength Concrete Type III or HE high-early-strength cement High cement content 400 to 600 kg/m3 (675 to 1000 lb/yd3 ) Low water-cementing materials ratio (0.20 to 0.45 by mass) Higher freshly mixed concrete temperature Higher curing temperature Chemical admixtures Silica fume (or other SCM) Steam or autoclave curing Insulation to retain heat of hydration Special rapid hardening cements May be achieved by —
- 13. High-Value Concrete High-Strength Concrete 90% of ready-mix concrete 20 MPa - 40 MPa (3000 – 6000 psi) @ 28-d (most 30 MPa – 35 MPa) High-strength concrete by definition — 28 day – compr. strength ≥ 70 MPa (10,000 psi)
- 14. High-Value Concrete High-Strength Concrete Materials 9.5 - 12.5 mm (3/8 - 1/2 in.) nominal maximum size gives optimum strength Combining single sizes for required grading allows for closer control and reduced variability in concrete For 70 MPa and greater, the FM of the sand should be 2.8 – 3.2. (lower may give lower strengths and sticky mixes) Supplementary Cementing materials - Fly ash, silica fume, or slag often mandatory Dosage rate 5% to 20% or higher by mass of cementing material Aggregates —
- 15. High-Value Concrete High-Strength Concrete Materials Use of water reducers, retarders, HRWRs, or super plasticizers — mandatory in high-strength concrete Air-entraining admixtures not necessary or desirable in protected high-strength concrete. Air is mandatory, where durability in a freeze-thaw environment is required (i.e.. bridges, piers, parking structures) Recent studies: w/cm ≥ 0.30—air required w/cm < 0.25—no air needed Admixtures —
- 16. High-Value Concrete High-Strength Concrete Delays in delivery and placing must be eliminated Consolidation very important to achieve strength Slump generally 180 to 220 mm (7 to 9 in.) Little if any bleeding—fog or evaporation retarders have to be applied immediately after strike off to minimize plastic shrinkage and crusting 7 days moist curing Placing, Consolidation, and Curing-
- 17. High-Value Concrete High-Durability Concrete 1970s and 1980s focus on — High-Strength HPC Today focus on concretes with high durability in severe environments resulting in structures with long life — High-Durability HPC
- 18. High-Value Concrete High-Durability Concrete Abrasion Resistance Blast Resistance Permeability Carbonation Freeze-Thaw Resistance Chemical Attack Alkali-Silica Reactivity Corrosion rates of rebar Durability Issues That HPC Can Address
- 19. High-Value Concrete Cement: 398 kg/m3 (671 lb/yd3 ) Fly ash: 45 kg/m3 (76 lb/yd3 ) Silica fume: 32 kg/m3 (72 lb/yd3 ) w/c: 0.30 Water Red.: 1.7 L/m3 (47 oz/yd3 ) HRWR: 15.7 L/m3 (83 oz/yd3 ) Air: 5-8% 91d strength: 60 MPa (8700 psi) High-Durability Concrete Confederation Bridge, Northumberland Strait,Confederation Bridge, Northumberland Strait, Prince Edward Island/New Brunswick, 1997Prince Edward Island/New Brunswick, 1997
- 20. High Durability concrete A Researched Mix Proportion for IIT Delhi for M40 and M70 is written below. Ingredient Proportion(In kg) M40 M70 Cement 1 1 Fine aggregate 1.96 1.37 Coarse aggregate 1.65 1.05 Fly Ash 0.319 0.459 Silica Fumes 0.05 0.024 Super plasticizer 0.02 0.024High-Value Concrete
- 21. High-Value Concrete Self-Consolidating Concrete Developed in 1980s — Japan Increased amount of Fine material (i.e. fly ash or limestone filler) Super plasticizers Strength and durability same as conventional concrete Self-consolidating concrete (SCC) also known as self-compacting concrete —flows and consolidates on its own
- 23. High-Value Concrete Portland cement (Type I) 297 kg/m3 (500 lb/yd3 ) Slag cement 128 kg/m3 (215 lb/yd3 ) Coarse aggregate 675 kg/m3 (1,137 lb/yd3 ) Fine aggregate 1,026 kg/m3 (1,729 lb/yd3 ) Water 170 kg/m3 (286 lb/yd3 ) Superplasticizer ASTM C 494, Type F (Polycarboxylate-based) 1.3 L/m3 (35 oz/yd3 ) AE admixture as needed for 6% ± 1.5% air content SCC for Power Plant in Pennsylvania—Mix Proportions
- 24. High-Value Concrete Reactive Powder Concrete Qinghai-Tibet Railway Sherbrooke pedestrian bridge, in Canada. Shawnessy Light Rail Transit Station in Iowa (2004) First UHPC Bridge in U.S.
- 25. Basics of RPC RPC is able to obtain its improved properties by using a very dense mix, consisting of fine particles and fibers. Low w/cm ratio : 0.16 to 0.24 (as low as 0.13) Portland cement-II (no C3A less HoH) Silica fume (25% by weight) Water High dosages of Superplasticizer Fine quartz sand (150-600μm) (SG=2.75) Steel fibers (2.5-10% by volume) for toughening No rebar needed! Cured in steam bath for 48 hrs @ 190ºF (88ºC) after initial set, placed under pressure at the molding stage High-Value Concrete
- 26. High-Value Concrete Reactive-Powder Concrete (RPC) Properties: High strength — 200 MPa (can be produced to 810 MPa) Very low porosity Properties are achieved by: Max. particle size ≤ 300 µm Optimized particle packing Low water content Steel fibers Heat-treatment
- 27. High-Value Concrete Mechanical Properties of RPC Property Unit 80 MPa RPC Compressive strength MPa (psi) 80 (11,600) 200 (29,000) Flexural strength MPa (psi) 7 (1000) 40 (5800) Tensile strength MPa (psi) 8 (1160) Modulus of Elasticity GPa (psi) 40 (5.8 x 106 ) 60 (8.7 x 106 ) Fracture Toughness 103 J/m2 <1 30 Freeze-thaw RDF 90 100 Carbonation mm 2 0 Abrasion 10-12 m2 /s 275 1.2
- 28. DUCTAL INNOVATION AND SALIENT POINT 1 . Compressive Strength- up to 30000 psi(200MPA) 2. Flexural Strength - up to 6000 psi(40MPA) 3. Direct Tension - up to 1450 psi(10MPA) 4. Ductility - Greater capacity to deform and support flexural and tensile loads, even after initial cracking's Abrasion Resistance - Similar to natural rock Impermeability - Almost no carbonation or penetration of chlorides. Cost -Reducing Global construction cost High-Value Concrete
- 29. High-Value Concrete Cement Sand Silica quartz Silica fume Micro-Fibers - metallic or poly-vinyl acetate Mineral fillers - Nano-fibres Superplasticizer Water Raw Material Components ® uctal
- 30. High-Value Concrete What is the typical Ductal® mix ? 230 kg/m3 710 kg/m3 210 kg/m3 40 - 160 kg/m3 13 kg/m3 140 kg/m3 1020 kg/m3 Cement Silica fume Crushed Quartz Sand Fibres Superplasticizer Total water No aggregates ! ® uctal
- 31. High-Value Concrete What is the typical Ductal® mix ? 9 – 10% 28 - 30% 8.5 – 9% 1.7 – 6.5% 0.6% 5.5 – 6% 42 –43% Cement Silica fume Crushed Quartz Sand Fibres Superplasticizer Total water No aggregates ! ® uctal w/c = 0.20
- 32. COMMENTS
Editor's Notes
- #9: Fig. 17-1. High-performance concrete is often used in bridges. (70017)
- #10: Table 17-1. Materials Used in High-Performance Concrete
- #11: Table 17-1. Materials Used in High-Performance Concrete
- #12: Table 17-2. Selected Properties of High-Performance Concrete
- #13: High-early-strength can be obtained by using one or a combination of the following, depending on the age at which the specified strength must be achieved and on job conditions.
- #14: Explosive nature of high-strength concrete upon failure when tested in compression. (53272)
- #20: The Confederation Bridge across the Northumberland Strait between Prince Edward Island and New Brunswick has a 100-year design life. This bridge contains HPC designed to efficiently protect the embedded reinforcement. The concrete had a diffusion coefficient of 4.8 x 10-13 at six months (a value 10 to 30 times lower than that of conventional concrete). The electrical resistivity was measured at 470 to 530 ohm-m, compared to 50 for conventional concrete. The design required that the concrete be rated at less than 1000 coulombs. The high concrete resistivity in itself will result in a rate of corrosion that is potentially less than 10 percent of the corrosion rate for conventional concrete
- #22: Total content of particles finer than 160 μm sieve has to be high (usually 520 – 560 kg/m3 ) HRWRs based on polycarboxylate ethers typically used to plasticize the mix. Very sensitive to fluctuation in water content therefore stabilizers such as polysaccarides are used
- #23: Fig. 17-6. Examples of materials used in regular concrete and self-compacting concrete by absolute volume.
- #24: Project: Seward Power Plant, New Florence, Pa.
- #25: Fig. 17-9. The Sherbrooke footbridge in Quebec, built in 1997, is North America’s first reactive-powder concrete structure. (68300)
- #27: Fig. 17-8. Freshly-mixed reactive-powder concrete.
- #28: Table 17-6. Typical Mechanical Properties of Reactive Powder Concrete (RPC) compared to an 80-MPa Concrete (Perry 1998).