Utvärdering av termiska egenskaper av gipsskivor: Bestämmandet av den termiska konduktiviteten baserade på konkalorimetertester
Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
This study describes an attempt to determine the thermal conductivity of gypsum at higher temperatures with the aim of being able to predict temperatures of for example protected steel structures when exposed to fire by using temperature calculation computer programs. The determination in this study was done by conducting bench-scale trials in the cone calorimeter. The gypsum samples that have been used are named GYPROC GFE 15 PROTECT™ F ERGO which is a fire rated gypsum board provided by the manufacture Gyproc Saint-Gobain. Measured steel temperatures during the trials in the cone calorimeter were retrieved by curve fitting calculations with the finite element computer program TASEF (Temperature Analysis in Structures Exposed to Fire). The conductivity of gypsum was obtained by altering the conductivity in order to get a similar temperature curve as the measured temperatures during the laboratory trials. Meanwhile all other parameters were predefined. In particular the temperature-volumetric enthalpy relation (the temperature integral of the product of the density and the specific heat of the material) was derived from values found in the literature. As gypsum contains a lot of physically and chemically bound water the specific heat has great spikes to consider the latent heat of evaporating water. This may cause numerical problems which, however, is overcome by using the enthalpy curve as input as in TASEF. The achieved conductivity of gypsum at various temperatures was then used as input to finite element calculations for comparison with temperatures of insulated steel structures as published by the manufacturer Gyproc Saint-Gobain.Measured steel temperatures in the cone calorimeter shows almost identical trends in presented temperature-curves, i.e. measured and calculated temperatures using determined properties were almost the same. The suggested method of determining thermal properties of gypsum plaster boards has shown reliable results. It is cheap, simple and consists of bench-scale tests in the cone calorimeter. More tests are however required in the cone calorimeter at higher incident heat fluxes to determine the conductivity at higher temperatures, and in particular analyses of additional full scale furnace tests are needed to validate the method and determine its accuracy.
Place, publisher, year, edition, pages
2016. , 52 p.
Teknik, Gips, termisk konduktivitet, TASEF, finita elementmetoden, konkalorimeter, adiabatisk yttemperatur, specifika volymetriska entalpi
IdentifiersURN: urn:nbn:se:ltu:diva-46356Local ID: 3fd6ef92-8756-41c2-8a24-87e4d7b97763OAI: oai:DiVA.org:ltu-46356DiVA: diva2:1019670
Subject / course
Student thesis, at least 15 credits
Fire Protection Engineer, bachelor's level
Validerat; 20160620 (global_studentproject_submitter)2016-10-042016-10-04Bibliographically approved