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1. S.D.M.E. Society’s S.D.M COLLEGE OF ENGINEERING & TECHNOLOGY ( Autonomous Institute affiliated to VTU, Belgaum) Dharwad-580002 PRESENTATION COURSE TITLE: CONCRETE TECHNOLOGY COURSE CODE: 22USCVC405 TOPIC: SELF-COMPACTING CONCRETE SUBMISSION BY , COURSE INSTRUCTOR, DR. SHRUTI KAMBALIMATH MADAM RASHMI PAWAR SHRAVANI SAGAR KADANI SHREENATH MD YUSUF MEERANAIK RAJESHEKARA .S.M SUHAS R.T. SDMCET STAFF & STUDENTS CONSUMERS’ CO-OP. SOCIETY DHARWAD - 580002

2. INDEX INTRODUCTION HISTORY OF SELF-COMPACTING CONCRETE PROPERTIES MATERIALS REQUIRED REQUIREMENTS APPLICATIONS LIMITATIONS MIX DESIGN TEST METHOD CONDUCTED ADVANTAGES AND DISADVANTAGES PRODUCTION AND PLACING CONCLUSION

3. INTRODUCTION: Self-compacting concrete (SCC), also known as self-consolidating concrete, is a type of concrete that flows and compacts under its weight, eliminating the need for external vibration during placement. Self-Compacting Concrete (SCC) is defined as concrete that can flow under its own weight, fill the required space or formwork completely, and produce a dense and adequately homogenous material without a need for vibrating compaction.

4. HISTORY OF SELF-COMPACTING CONCRETE: IN 1983, a concrete crisis in Japan, and concern for the durability of concrete IN 1986: basic concept by prof H. Okamura of Tokyo University In 1988: prototype for field experiment and implementation IN1989 : open experiment IN1991 :Jt . Research project with construction companies IN 1994, high-performance concrete was established HAJIME OKAMURA (18 th SEPTEMBER 1938)

5. At first, SCC is only used in pre-fabricated products and ready-mixed concrete in Japan. Self-compacted concrete has been described as the most revolutionary Development in concrete construction for several decades.

6. Properties: Self-compacting concrete (SCC) is a highly flowable, non-segregating concrete that can spread into place, fill formwork, and encapsulate reinforcement without the need for mechanical vibration. Its properties include: Fresh State Properties: 1. High Flowability: Easily flows into complex shapes and congested reinforcement areas. 2. Self-Leveling: Can spread uniformly without manual effort. 3. Segregation Resistance: Maintains uniformity without separating aggregates and paste. 4. Passing Ability: Can flow through narrow spaces and reinforcement without blockage. 5. Stability: Retains homogeneity during transport and placement.

7. Hardened State Properties: High Strength: Often achieves better compressive and tensile strength than conventional concrete. Durability: Low permeability and high resistance to aggressive environments. Improved Bond Strength: Enhances bonding with reinforcement due to its high paste content. Reduced Shrinkage and Creep: Proper mix design minimizes shrinkage and long-term deformation.

8. MATERIALS REQUIRED: cement Fine aggregates course aggregates water Chemical admixtures such as plasticizers, viscosity modifying agents ( VMS) air entraining agents (AEA) mineral admixtures such as fly ash, GGBFS, silica fume

9. cements: ordinary Portland cements of 43 or 53 grade can be used Aggregates: will be graded, cubical or rounded aggregates are desirable water quality: maintained the same as reinforced concrete chemical admixtures: super plasticizers, particularly Poly-carboxylate either are also used in SCC, VMA AEA are also used minerals admixtures : 1. Fly ash: It improves the quality and durability of concrete. 2. GGBFS: it improves rheological properties (semisolid & liquid state 3. It improves mechanical properties. stone powder: finely crushed limestone. Dolomite, granite may be added to increase powder content.

10. REQUIREMENTS OF SCC: Fresh Properties Requirements (Workability) To ensure self-compaction without segregation:- Filling ability: The ability to flow under its own weight. Passing ability: The ability to flow through tight spaces and around reinforcement without blocking. Segregation resistance: The ability to maintain a uniform composition without separating. These are typically measured by: ‘Slump Flow Test’: 650–800 mm (typical range), ‘V-Funnel Test’: 6–12 seconds, ‘L-Box Test’: Ratio (H2/H1) ≥ 0.8, ‘J-Ring Test’: To assess passing ability. 2. Material Requirements To achieve SCC properties:- Cement: Similar to conventional concrete, but often with a higher powder content. Supplementary Cementitious Materials (SCMs): Fly ash, silica fume, or GGBS to enhance flowability and reduce heat of hydration. Fine Aggregates: Higher proportion to reduce segregation. Coarse Aggregates: Well-graded and typically smaller size (10–20 mm) to avoid blocking. perplasticizers : Essential to enhance flow without increasing water content. Viscosity Modifying Agents (VMA): Optional, used to improve cohesion and reduce segregation.

11. 3. Performance Requirements (Hardened Concrete) Even though SCC focuses on fresh properties, it must still meet structural requirements:- Compressive Strength: As per design, same as conventional concrete (e.g., 30–50 MPa or higher). Durability: Good resistance to permeability, carbonation, and chloride ingress. Shrinkage & Creep: Should be controlled by mix design.

12. Application of SCC: High-Rise Buildings Bridges Precast Concrete Elements Industrial Floors Tunnels Marine Structures Parking Structures Architectural Concrete

13. Limitations of SCC: Higher Construction Costs: SCC typically costs more to produce than conventional concrete due to the need for specialized admixtures, higher cement content, and more complex mix designs.  Stringent Material Selection: SCC requires careful selection of materials, including cement, aggregates, and admixtures, to ensure proper flowability and stability.  Increased Trial Batches and Lab Tests: Designing and producing SCC requires more extensive testing and trial batches to ensure the desired properties are achieved.  Precision in Measurement and Monitoring: The quality control of SCC requires more precise measurement and monitoring throughout the construction process to maintain its properties.  Lack of a Globally Accepted Mix Design Standard: There is no universally accepted test standard for SCC mix designs, leading to variations in approaches and potentially inconsistent results. Limited Availability and Experience: Not all contractors or plants are familiar with SCC, and ‘lack of experience’ can lead to poor application or failures.

14. MIX DESIGN: The mix design procedure for self-compacting concrete is based on Indian Standard 10262-2008: A mix design for ‘M30 SCC’ (30 MPa strength) is provided below. The mix proportions may vary depending on material properties and specific requirements. Step 1: Selection of Materials: Cement: Ordinary Portland Cement (OPC 43/53 grade). Fine Aggregate: River sand, well-graded. Coarse Aggregate: 12.5 mm downsize crushed aggregate. Mineral Admixture: Fly ash (for better flowability). Chemical Admixture: Superplasticizer (high-range water reducer), Viscosity Modifying Agent (VMA). Water: Potable clean water Step 2: Target Mix Proportioning:

15. Water/Cementitious Ratio: 0.36 Slump Flow Target:650–750 mm L-Box Test Passing Ratio: ‘≥ 0.8’ V-Funnel Test Flow Time: ‘6–12 sec’ Step 3: Mix Procedure: Dry Mix: Mix cement, fly ash, fine and coarse aggregate for 30 seconds. Add Water & Admixtures: Gradually add water while mixing. Superplasticizer Addition: Add superplasticizer (and VMA if needed) while mixing. Mixing Duration: Continue mixing for ‘4–5 minutes’ for uniform consistency. Workability Testing: Conduct Slump Flow, V-Funnel, and L-Box tests. Adjustments: If ‘flowability is low’ → Increase superplasticizer. If ‘segregation occurs’ → Reduce water or add VMA. If ‘passing ability is poor’ → Adjust aggregate proportions.

16. Step 4: ‘Performance Testing’ Perform the following tests before finalizing the mix:- Slump Flow Test: Target ‘650–750 mm’. L-Box Test: Ensure ‘passing ratio ≥ 0.8’. V-Funnel Test: Flow time should be ‘6–12 sec’. Compressive Strength Test: Ensure ‘30 MPa at 28 days’

17. Tests conducted on scc: Several specialized tests are used to evaluate the properties of Self-Compacting Concrete (SCC), ensuring its workability, flowability, passing ability, and resistance to segregation. These tests are categorized based on different properties: Flowability Tests: (Filling Ability) ‘These tests assess the ease with which SCC spreads under its own weight’: Slump Flow Test T50 Slump Flow Test V- Funnel Test 2. Passing Ability Tests: ‘These tests determine SCC's ability to pass through reinforcements and tight spaces’: L-Box Test U-Box Test J-Ring Test 3. Segregation Resistance Tests: ‘These tests ensure SCC remains uniform and does not separate during flow’: GTM Screen Stability Test Column Segregation Test

18. Advantages and disadvantages: Advantage: (1) eliminating the need for vibration ; (2) decreasing the construction time and labour cost; (3) reducing the noise pollution; (4) improving the filling capacity of highly congested structural members (5) improving the interfacial transitional zone between ... disadvantage : The construction cost of high-performance concrete structures is higher than that of traditional concrete. The precise measurement and monitoring required for the SSC construction. The SCC design mix requires more trial and testing.

19. PRODUCTION AND PLACING: Proportions of materials are taken based on volume rather than by mass aggregates: should come from the same source mixing: it should be done for a longer time when compared to conventional concrete Placing: Some rules need to be followed while placing the concrete 1. Limits of vertical fall distance to 5m 2. Each layer should be at a height of 500mm 3. Horizontal flow should not exceed 10m curing : Early curing is necessary for SCC

20. CONCLUSION: Self-Compacting Concrete (SCC) represents a significant advancement in concrete technology, offering superior flowability, stability, and ease of placement without the need for mechanical vibration. Its ability to fill complex formworks and encapsulate reinforcements ensures enhanced structural performance, improved surface finish, and increased durability. Although SCC may involve higher initial material costs, these are often offset by reduced labor, faster construction times, and better long-term performance. Overall, SCC is a sustainable and efficient solution for modern construction challenges. Self-curing can be a possible solution for improper curing problems. The High-Performance Concrete undergo sizeable self-desiccation and autogenous shrinkage due to its low water-cement ratio which can be reduced by adopting self-curing techniques.