200-HTC : Mechanical concrete properties at high temperature - Modelling and applications
Technical Committee 200-HTC
The RILEM Committee TC 129 "Test methods for Mechanical Properties of Concrete at High Temperatures" has prepared 10 drafts for technical recommendations concerning the test methods for relevant mechanical properties of concrete at high temperature. The draft recommendations comprise the following papers and publications: Part 1: Introduction (not completed and will not be published) Part 2: Stress-Strain-Relationship (to be published 2000) Part 3: Compressive Strength (publ. 1995) Part 4: Tensile Strength (publ. 2000) Part 5: Modulus of Elasticity (to be publ. 2000) Part 6: Thermal Strain (publ. 1997) Part 7: Transient Creep (publ. 1998) Part 8: Steady State Creep and Creep Recovery (publ. 2000) Part 9: Shrinkage (publ. 2000) Part 10: Restraint (to be published 2001) Part 11: Relaxation (to be published 2001) The life time of the TC 129 MHT lasted eight years and will come to an end in the autumn 2000.
Terms of reference
A life time of three years for the new TC is proposed.
Detailed working programme
The new committee intends to compile the technical knowledge of the recommendations mentioned above within an all encompassing State of the Art updated document. This document will be the umbrella of all 10 recommendations including their appropriate applications. Based on the data obtained the committee will extent its work in the direction of practical application of the material data. This comprises the development of a material model for concrete at for high temperatures especially under the consideration of nonsteady temperature conditions. The material model will be based on former models developed by Dr. Anderberg, Dr. Khoury, Dr. Fransen/ Mr. Morita and Prof. Schneider, and Prof. Majorana. The existing model for concrete structures according to the EURO-Code will be taken into consideration as well as the effect of spalling of concrete due to rapid heating up connected with the development of high pore pressures. In detail the work program contains the following items: 1. It defines and summarises the general context of concrete and temperature behaviour. 2. It defines precisely the environment for service and accident conditions of structural concrete at high temperatures. 3. It presents a basic list of defined symbols and specific definitions. 4. It specifies the different mechanical properties which are measured or derived from uni-axial tests according to the results of TC-129 MHT. 5. Drafting a State of the Art report concerning the testing and modelling of concrete at high temperatures. In the document the methods and general recommendations for the use of concrete properties in the structural analysis will be presented.
The new TC is a successor of the following RILEM Committees: TC 44-PHT Properties of Materials at High Temperatures TC 74-THT Test methods for High Temperature properties TC 129-MHT Test methods for Mechanical Properties of Concrete at High Temperatures
The direct benefit from the TC reports concerns the applicability and reproducibility of materials datas derived in complex experiments and applied in complicated calculations of concrete structures. The TC report will describe the state of the art for materials properties and modelling of concrete structures exposed to high temperature environment.
Group of users
The target group or organisations for the indented report are universities, civil engineers and material test laboratories which are involved in high temperature experimental research or calculation methods. ISO and CEN may also have benefit of it.
Specific use of the results
The results may be used directly in the field of fire design of concrete structures and in the evaluation of structured concrete behaviour in nuclear power plants, especially in case of a severe accident. Further use can be made in material test laboratories as similar national or international conventions with respect to temperature testing and evaluating of concrete are not at hand.