WVMP SAR Reference 3-19

WVMP SAR Reference 3-19 Response of High Performance to Fire Conditions: Review of Thermal Property Data and Measurement Techniques, NIST Report GCR 99-767, D. R. Flynn, March 1999. RESPONSE OF HIGH PERFORMANCE CONCRETE TO FIRE CONDITIONS: REVIEW OF THERMAL PROPERTY DATA AND MEASUREMENT TECHNIQUES Daniel R. Flynn MetSys Corporation Millwood, VA 22646-0317 NnLSr United States Department of Commerce Technology Administration National Institute of Standards and Technology RESPONSE OF HIGH PERFORMANCE CONCRETE TO FIRE CONDITIONS: REVIEW OF THERMAL PROPERTY DATA AND MEASUREMENT TECHNIQUES Prepared for U.S. Department of Commerce Building and Fire Research Laboratory National Institute of Standards and Technology Gaithersburg, MD 20899 By Daniel R. Flynn MetSys Corporation Millwood, VA 22646-0317 Final Report December 1998 Issued March 1999 #901 OF CO% S0* Notice This report was prepared for the Building and Fire Research Laboratory of the National Institute of Standards and Technology under Contract number 43-NANB-809607. The statement and conclusions contained in this report are those of the authors and do not necessarily reflect the views of the National Institute of Standards and Technology or the Building and Fire Research Laboratory. MetSys Report No. 98-01-101 December 1998 Response of High Performance Concrete to Fire Conditions: Review of Thermal Property Data and Measurement Techniques Daniel R. Flynn MetSys Corporation Millwood VA 22646-0317 This report is based upon work supported by the Department of Commerce/National Institute of Standards and Technology (NIST) under contract No. 43-NANB-809607. Any opinions, findings, and conclusions or recommendations expressed in this publication are those of the author and do not necessarily reflect the views of the Department of Commerce/NIST. iii The NIST Building and Fire Research Laboratory (BFRL) has undertaken a project concerning the effect of fire on high strength concrete. Heating concrete to sufficiently high temperatures results in water of hydration being driven off, with a resultant irreversible loss of concrete strength. In addition, it has been observed that rapid heating of high strength concrete can result in spalling of the concrete. Computer models for prediction of temperature and pore pressure distributions in heated concrete typically include consideration of (1) mass transfer of air and water by diffusion and by forced convection, conversion of liquid water to vapor, and release of water of hydration and (2) heat transfer by conduction, mass diffusion, and forced convection. In order to make valid predictions, the computer models require reliable data as to the physical properties of the concrete. Mass transport properties are being investigated by the Building Materials Division. Thermal transport properties, the subject of this report, are being investigated by the Building Environment Division. The present report addresses (1) identification of material properties critical to prediction of heat and mass transfer in high strength concrete at high temperatures, (2) variation of the thermal properties with temperature, pressure, and thermal history, (3) examination of correlations between concrete composition and thermal properties, (4) identification of appropriate experimental techniques for determination of the thermal properties of high strength concrete, (5) identification of available equipment and testing services for carrying out such measurements, and (6) preliminary design of special -equipment that needs to be constructed for measurement of the thermal conductivity of concrete. iv The Principal Investigator thanks the following organizations for permission to reproduce copyrighted figures and tables: American Society for Testing and Materials NRC Research Press (National Research Council - Canada) Pearson Education Limited (Longman Group Limited) Portland Cement Association The Principal Investigator also thanks Robert R. Zarr, the NIST Contracting Officer's Technical Representative for the contract under which this report was prepared, for his guidance and his review of earlier drafts of the report and James R. Lawson, of NIST, for assisting with the preparation of this report. V I aDIe 01 LOllteltS Page A b stract .. .. ... ... ... .. ... .............. .. ..... ... ... .. ... .. ... .. ... .. ...... iv N omenclature ............................................................... xii 1. Introductio n ................................................................ I 2. Modeling of Simultaneous Heat and Mass Transfer in Porous Media ................... 3 2.1 Overview of Heat and Mass Transfer in Concrete Exposed to Fire .............. 4 2.2 Irreversible Thermodynamics Approach for Diffusion of a Gas ................ 8 2.3 Heat Transfer and Diffusive Mass Transfer ............................... 11 2.4 A hm ed M odel ...................................................... 14 3. Existing Data on Thermal Properties of Concrete and Its Constituents ................. 16 3.1 Mass, Volume, and Density .............. ....................... 16 3.2. Enthalpy, Specific Heat, and Heats of Reaction ............................ 32 3.3 Thermal Conductivity and Thermal Diffusivity ............................ 37 4. Correlations and Prediction, of Thermal Properties ........ .................... 55 4.1 Mass, Volume, and Density ..................................... 56 4.2 Enthalpy, Specific Heat, and Heats of Reaction ............................ 58 4.3 Thermal Conductivity and Thermal Diffusivity ......................... 59 5. Experimental Techniques for Determination of Thermal Properties ................... 71 5. *Mass, Volume, and Density ....................................... 71 5.2 -Enthalpy, Specific Heat, and Heats of Reaction ................. ........... 72 5.3 Thermal Conductivity and Thermal Diffusivity ............................. 72 5.3.1 Steady-State Methods . ............. 74 5.3.2 Transient Methods ..................................... 77. 6. Availability of Apparatus and Testing Service ... ........................... 86 7. Design of New Apparatus for High-Temperature Thermal Conductivity Measurements ... 90 8. R eferences .................... ........................................... 99 vi AppenflxGix. ,-mnaysls rroceaures tur 1 raISICnL riut-VV ie Ur riUVe I eM;ciiques for Thermal Conductivity Measurement ............................. A-I A .I Ideal Line Heat Source ............................................. A-1 A .2 Finite-Diam eter Probe ............................................. A-2 A .3 N um erical Results ................................................ A-7 A .4 R eferences ..................................................... A -12 Appendix B. Analysis Procedures for Transient Plane-Source Techniques for Thermal Conductivity Measurement .............................. B-I List of Figures Figure 1. Thermogravimetric and dilatometric curves for Cement Paste C .............. 18 Figure 2. Typical relationships between weight loss, corresponding length change, and temperature for Portland cement paste ............................... 19 Figure 3. Weight loss of calcareous and siliceous aggregates and concretes caused by heating ................................................... 20 Figure 4. Weight loss as a percentage of initial weight for various concretes caused by heating ................................................... 20 Figure 5. Mass loss of various concrete types as a function of temperature .............. 21 Figure 6. Mass loss of high strength concrete at elevated temperatures (heating rate of 2 K/m in) ............................................. 23 Figure 7. Mass loss of high strength concrete at elevated temperatures (heating rate of 20 K/m in) ............................................ 24 Figure 8. Mass loss of high strength concrete at elevated temperatures (heating rate of 50 K/m in) ............................................ 25 Figure 9. Change of weight with temperature of concrete containing silica fume ......... 26 Figure 10. Length change of Portland cement paste specimens at various temperatures ..... 26 Figure I1. Dilatometric curves for the ten rocks described in Table 3 ................... 27 Figure 12. Dilatometric curves for three normal-weight concretes and three lightweight concretes. Aggregates: LI, limestone; SI siliceous rock; AD, andesite; SG, expanded shale; CL, expanded clay; PU, pumice ........... 28 vii Figure 13. Linear thermal expansion of concretes made with various conventional aggregates, as a function of temperature ((a) quartzite; (b) sandstone; (c) limestone; (d) basalt; (e) expanded slag .............................. 28 Figure 14. Thermal expansion, as a function of temperature, of the three concrete types described in Table I ..................................... 29 Figure 15. Correlation between the coefficient of thermal expansion of the aggregate and that of the concrete ................................... 29 Figure 16. True density (pt), bulk density (pp), and porosity (PPt) of Cement Paste C (calculated) .......................................... 30 Figure 17. Effect of temperature on density of concrete made with limestone aggregate .... 30 Figure 18. Effect of temperature on mass density of concretes made with quartzite, bauxite, and expanded shell aggregates ...................... 31 Figure 19. Density versus temperature curves used in the Ahmed model ................ 31 Figure 20. Computed specific heat of Model Pastes A, B, and C ....................... 33 Figure

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