1. 2E8 Materials (Civil Engineering Component) Civil Engineering Materials Department of Civil, Structural and Environmental Engineering Trinity College Dublin Dr. Roger P. West (TCD) Mr. Peter Flynn (Arup)

2. 2E8 Materials (Civil Engineering Component) Section A:Concrete A1Basic Materials: A2Fresh Concrete Properties: A3Hardened Concrete Properties: A4Concrete Mix Design: A5Reinforced Concrete: A6Pre-stressed Concrete:

3. 2E8 Materials (Civil Engineering Component) Section A.4Concrete Mix Design 1.Mix Requirements 2.EN206 – Concrete Specification 3.Trial Mixes 4.Cube Variability 5.Characteristic Strength 6.Standard Deviation & Margin 7.Target Mean Strength

4. 2E8 Materials (Civil Engineering Component) 1.Mix Requirements Section A.4Concrete Mix Design

5. 2E8 Materials (Civil Engineering Component) 1.Mix Requirements Section A.4Concrete Mix Design Essential Properties of Hardened Concrete; Strength Durability Other requirements; Satisfactory workability Stiffening time Cohesiveness

6. 2E8 Materials (Civil Engineering Component) 1.Mix Requirements

7. 2E8 Materials (Civil Engineering Component) 1.Mix Requirements Section A.4Concrete Mix Design Strength Defined by the Characteristic Compressive Strength; Defined by the crushing strength of 150mm cubes when 28 days old. Strength below which not more than 5% of test results fall. Generally referred to as 28 day strength Concrete must be designed to have an average strength well in excess of the characteristic strength required.

8. 2E8 Materials (Civil Engineering Component) 1.Mix Requirements Section A.4Concrete Mix Design Strength

9. 2E8 Materials (Civil Engineering Component) 1.Mix Requirements Section A.4Concrete Mix Design Strength Grade (N/mm 2 ) Characteristic Strength (@28days) (N/mm 2 ) Lowest Grade for Compliance with Appropriate Use <7 7.0 Special Purpose (such as energy absorption), Plain Concrete <10 10.0 15 15.0 20 20.0 Reinforced Concrete with Lightweight Aggregates 25 25.0 Reinforced Concrete with normal weight aggregate & Prestressed Concrete with post tensioned tendons 30 30.0 40 40.0 Prestressed Concrete with pretensioned tendons 50 50.0 60 60.0

10. 2E8 Materials (Civil Engineering Component) 1.Mix Design Section A.4Concrete Mix Design Types of Mixes (BS5328 /ISEN206) Designed Mix Performance specified by purchaser Producer is responsible for the design & mix proportions Must conform to ISEN206 Prescribed Mix Mix Proportions are specified by purchaser

11. 2E8 Materials (Civil Engineering Component) 1.Mix Design Section A.4Concrete Mix Design Types of Mixes (BS5328 / ISEN206) Standard Prescribed Mix Admixtures are not permitted Producer is responsible for the design & mix proportions Must conform to ISEN206 Designated Mix Wide-ranging concretes for almost every type of concrete construction Specifications as per ISEN206/BS8500 Third Party QA accreditation – No cube testing on site

12. 2E8 Materials (Civil Engineering Component) 1.Mix Design Section A.4Concrete Mix Design All mix designs require a trial mix The proportions of which may need modification in the light of experience Empirical Approach

13. 2E8 Materials (Civil Engineering Component) 1.Standards