Round-Robin Test on Creep Behaviour in Cracked Sections of FRC: Experimental Program, Results and Database Analysis: State-of-the-Art Report of the ... 261-CCF (RILEM State-of-the-Art Reports, 34)

The book presents the work of the RILEM Technical Committee 261-CCF, which organized the challenging International Round Robin Test (RRT) on the creep behaviour of Fibre Reinforce Concrete (FRC) cracked specimens. Although different creep test methodologies have been developed in recent years, the absence of a standardised creep methodology hindered general comparisons. Therefore, the RILEM TC 261-CCF launched an ambitious international RRT program to improve the knowledge on long-term behaviour of cracked sections of FRC and assess all the different testing methodologies, assuming the big variability of testing criteria among the scientific community. The participation of 19 laboratories across 20 institutions in 14 countries all over the world enabled the realisation of the largest experimental campaign on creep in the cracked state. As a result of the RRT, an extensive database of creep test results was created containing comprehensive information from 124 cracked FRC specimens tested using different creep testing procedures in agreed conditions. The book will benefit academics and practitioners interested in the long-term behaviour of FRC since it served as basis for the recently published RILEM Recommendation on creep testing procedure and represents the current knowledge on creep in cracked FRC specimens. RILEM Technical Committee 261-CCF (Creep behaviour in Cracked Sections of Fibre Reinforced Concrete) Members Chairman Secretary Members Preface Acknowledgements RILEM Publications RILEM Proceedings (PRO) RILEM Reports (REP) Contents Symbols 1 Introduction and Background 1.1 Objectives 1.2 Limitation of the RRT 1.3 Structure of the Document 1.4 Participants 2 Round-Robin Test Program and Execution 2.1 Materials 2.1.1 Concrete Matrix 2.1.2 Fibres 2.2 Production and Delivery 2.3 Schedule of RRT 3 Fibre Reinforced Concrete Characterization 3.1 Compressive Strength and Elastic Modulus 3.2 Flexural Residual Strength 3.2.1 Characterisation at 7 and 28 Days 3.2.2 Characterisation at T1, T2 and T3 3.3 Shrinkage Test 3.4 Creep in Compression Test 3.4.1 Compressive Creep Test Delayed Deformations 3.4.2 Compressive Creep Test Parameters Analysis 4 General Procedure of Creep Test 4.1 Flexural Creep Tests Procedure on Prismatic Specimens 4.1.1 Pre-cracking Stage 4.1.2 Creep Stage 4.1.3 Post-creep Failure Test Stage 4.2 Direct Tension Creep Tests Procedure 4.2.1 Pre-cracking Stage 4.2.2 Creep Stage 4.2.3 Post-creep Failure Test Stage 4.3 Square Panel Creep Tests Procedure 4.3.1 Pre-cracking Stage 4.3.2 Creep Stage 4.3.3 Post-creep Failure Test Stage 4.4 Round Panel Creep Test Procedure 4.4.1 Pre-cracking Stage 4.4.2 Creep Stage 4.4.3 Post-creep Failure Test Stage 5 Equipment and Procedure Description 5.1 Description of Equipment/Procedures: LAB-01 5.1.1 Description of Creep Frames 5.1.2 Support Conditions 5.1.3 Measuring System and Data Acquisition 5.1.4 Creep Test Procedure 5.2 Description of Equipment/Procedures: LAB-02 5.2.1 Description of Creep Frames 5.2.2 Support Conditions 5.2.3 Measuring System and Data Acquisition 5.2.4 Creep Test Procedure 5.3 Description of Equipment/Procedures: LAB-03 5.3.1 Description of Creep Frames 5.3.2 Support Conditions 5.3.3 Measuring System and Data Acquisition 5.3.4 Creep Test Procedure 5.4 Description of Equipment/Procedures: LAB-04 5.4.1 Description of Creep Frames 5.4.2 Support Conditions 5.4.3 Measuring System and Data Acquisition 5.4.4 Creep Test Procedure 5.5 Description of Equipment/Procedures: LAB-05 5.5.1 Description of Creep Frames 5.5.2 Support Conditions 5.5.3 Measuring System and Data Acquisition 5.5.4 Creep Test Procedure 5.6 Description of Equipment/Procedures: LAB-06 5.6.1 Description of Creep Frames 5.6.2 Support Conditions 5.6.3 Measuring System and Data Acquisition 5.6.4 Creep Test Procedure 5.7 Description of Equipment/Procedures: LAB-07 5.7.1 Description of Creep Frames 5.7.2 Support Conditions 5.7.3 Measuring System and Data Acquisition 5.7.4 Creep Test Procedure 5.8 Description of Equipment/Procedures: LAB-08 5.8.1 Description of Creep Frames 5.8.2 Support Conditions 5.8.3 Measuring System and Data Acquisition 5.8.4 Creep Test Procedure 5.9 Description of Equipment/Procedures: LAB-10 5.9.1 Description of Creep Frames 5.9.2 Support Conditions 5.9.3 Measuring System and Data Acquisition 5.9.4 Creep Test Procedure 5.10 Description of Equipment/Procedures: LAB-11 5.10.1 Description of Creep Frames 5.10.2 Support Conditions 5.10.3 Measuring System and Data Acquisition 5.10.4 Creep Test Procedure 5.11 Description of Equipment/Procedures: LAB-12 5.11.1 Description of Creep Frames 5.11.2 Support Conditions 5.11.3 Measuring System and Data Acquisition 5.11.4 Creep Test Procedure 5.12 Description of Equipment/Procedures: LAB-13 5.12.1 Description of Creep Frames 5.12.2 Support Conditions 5.12.3 Measuring System and Data Acquisition 5.12.4 Creep Test Procedure 5.13 Description of Equipment/Procedures: LAB-15 5.13.1 Description of Creep Frames 5.13.2 Support Conditions 5.13.3 Measuring System and Data Acquisition 5.13.4 Creep Test Procedure 5.14 Description of Equipment/Procedures: LAB-16 5.14.1 Description of Creep Frames 5.14.2 Support Conditions 5.14.3 Measuring System and Data Acquisition 5.14.4 Creep Test Procedure 5.15 Description of Equipment/Procedures: LAB-17 5.15.1 Description of Creep Frames 5.15.2 Support Conditions 5.15.3 Measuring System and Data Acquisition 5.15.4 Creep Test Procedure 5.16 Description of Equipment/Procedures: LAB-18 5.16.1 Description of Creep Frames 5.16.2 Support Conditions 5.16.3 Measuring System and Data Acquisition 5.16.4 Creep Test Procedure 6 Data and Parameter Definition 6.1 Data Collection Definition 6.1.1 Pre-cracking Stage 6.1.2 Creep Stage 6.1.3 Post-creep Stage 6.1.4 Complete Creep Test Curve 6.2 Round-Robin Creep Test Parameter Definition 6.2.1 Reference Pre-crack Opening Level 6.2.2 Reference Residual Strength 6.2.3 Specimen or Batch Average Reference Load 6.2.4 Creep Index (Ic) or Stress Level 7 Round-Robin Test Results 7.1 Flexural Tests 7.2 Direct Tension Tests 7.3 Square Panel Tests 7.4 Round Panel Tests 8 Analysis of the RRT Results 8.1 Analysis of the Main Variables of the RRT 8.1.1 Samples Tested on Creep Test by Laboratory and Methodology 8.1.2 Environmental Conditions During Creep Test 8.1.3 Pre-crack Level Reached on Pre-cracking Tests 8.1.4 Mechanical Properties: Residual Strengths in Flexure 8.1.5 Creep Index Ic 8.2 Analysis of Different Methodologies 8.2.1 Flexural Creep Test 8.2.2 Direct Tension Creep Test 8.2.3 Square and Round Panel Creep Test 8.3 Influence of Differences in Procedure and Equipment 8.3.1 Load Configuration and Notch Influence in Flexural Creep Tests 8.3.2 Multi-specimen Configuration 8.3.3 Support Boundary Conditions 8.3.4 Load Application System in Frame 8.3.5 Time in Which Load Is Applied 8.3.6 Environmental Conditions During Creep Test 8.4 Analysis of Creep Coefficient Parameter 8.4.1 Influence of Instantaneous and Short-Term Deformation Definition 8.4.2 Statistical Analysis of the Effect of Test Conditions and Mechanical Parameters 8.5 Analysis of the Crack Opening Rate (COR) Parameter 8.6 Influence of Fibres in the Cross Section: Fibre Counting 8.7 Correlation Between Different FRC Specimens 8.7.1 Member Thickness 8.7.2 Friction and Supports 8.7.3 Fibre Alignment 8.7.4 Notch 8.7.5 Variability 8.8 Influence of Ageing of Concrete Matrix on FRC Characterization Test and Creep Tests 8.8.1 Embrittlement 8.8.2 Corrosion 9 Statements and Conclusions 9.1 Statements 9.2 Conclusions Appendix A Specimens Production Index Appendix B Characterization Test Batch M-B1 Characterization Test Results Batch M-B1 Compressive Strength Test Results Batch M-B1 Flexural Test Results Batch M-B2 Characterization Test Results Batch M-B2 Compressive Strength Test Results Batch M-B2 Flexural Test Results Batch S-B1 Characterization Test Results Batch S-B1 Compressive Strength Test Results Batch S-B1 Flexural Test Results Batch S-B2 Characterization Test Results Batch S-B2 Compressive Strength Test Results Batch S-B2 Flexural Test Results Batch S-B0 Characterization Test Results Batch S-B0 Compressive Strength Test Results Batch S-B0 Flexural Test Results Appendix C Database and Parameter Definition Global Data Obtained for Each Specimen Until Failure: Section 1 Data for the Analysis Calculated Form Creep Test Data: Section 2 Complementary Data for Analysis: Section 3 Appendix D Creep Coefficients Results Creep Coefficients Referred to Creep Stage Flexural Tests Direct Tension Tests Square Panel Tests Round Panel Tests Creep Coefficients Referred to Origin of Deformations Flexural Tests Direct Tension Tests Creep Coefficients Analysis Annex Appendix E Crack Opening Rate (COR) Results Flexural Tests Direct Tension Tests Square Panel Tests References