RILEM Technical Committee 195-DTD Recommendation for Test Methods for AD and TD of Early Age Concrete

This report presents the Round-Robin (RR) program and test results including a statistical evaluation of the RILEM TC195-DTD committee named Recommendation for test methods for autogenous deformation (AD) and thermal dilation (TD) of early age concrete. The task of the committee was to investigate the linear test set-up for AD and TD measurements (Dilation Rigs) in the period from setting to the end of the hardening phase some weeks after. These are the stress-inducing deformations in a hardening concrete structure subjected to restraint conditions.

The main task was to carry out an RR program on testing of AD of one concrete at 20 °C isothermal conditions in Dilation Rigs. The concrete part materials were distributed to 10 laboratories (Canada, Denmark, France, Germany, Japan, The Netherlands, Norway, Sweden and USA), and in total 30 tests on AD were carried out. Some supporting tests were also performed, as well as a smaller RR on cement paste. The committee has worked out a test procedure recommendation which is reported separately and submitted acceptance as a RILEM method.

Prepares the reader for design of test rigs for measuring autogenous shrinkage of concrete, as well as reliable execution of testing autogenous shrinkage Uncovers the pitfalls in preparing a Round Robin program on concrete Includes an overview of test rigs for measuring of autogenous shrinkage of concrete Includes supplementary material: sn.pub/extras

Inhalt

****1.Introduction and background.- 2. RR-participants.- 3. Brief description of the Dilation Rigs.- 4, Round-Robin tests, plan and execution.- 4.1 Materials.- 4.2 Mortar tests.- 4.3 Cement paste tests.- 5 Mortar test results.- 5.1 Fresh properties and 28-days strength.- 5.2 Supporting test results.- 5.3 Dilation Rig results, autogenous deformation.- 6 Statistical evaluation of the Dilation Rig results.- 6.1 Prerequisites, Objectives and procedure.- 6.2 A concept for the estimation of candidates of outliers from unbiased samples.- 6.3 Analysis of the data - Calculation of outliers.- 6.4 Statistical attributes of AD and AS.- 6.5 Summary and conclusions.- 7 Cement paste test results.- 7.1 Supporting test results.- 7.2 Dilation Rig test results.- 8 Summary and conclusions.- 9 References.- APPENDIX 1 Cement analyses.- APPENDIX 2 Sand grading curve.- APPENDIX 3 Data sheet, superplasticizer.- APPENDIX 4 Description of equipment, made by the participants.