Dissertations / Theses on the topic 'Intumescent fire retardant coatings'

Baigiamajame magistro darbe nagrinėjamas priešgaisrinės išsipučiančios dangos porėto ir nedegių liekanų termiškai stabilaus sluoksnio sudarymo principai. Aprašomi užpildai bei kiti komponentai gerinantys dangos termoizoliacines savybes. Taip pat pateikta įvairių užpildų įtaką sudarant apsauginį dažų sluoksnį. Be to, darbe yra aprašyti minimalaus priešgaisrinės dangos sluoksnio, reikalingo plieno konstrukcijoms gaisro metu apsaugoti, skaičiavimai. Metodinėje-tiriamojoje darbo dalyje pateikta priešgaisrinės dangos bandymo atlikimo tvarka ir įranga, šilumos laidumo skaičiavimo metodika. Išnagrinėta koreliacinės-regresinės analizės vertinimo metodika. Praktinėje darbo dalyje analizuojamos priešgaisrinės dangos šilumos laidumo ir dangos termoizoliacinio sluoksnio padidėjimo priklausomybė nuo skirtingai didėjančių gaisro temperatūrų. Taip pat gautiems šilumos laidumo rezultatams atliekama koreliacinė-regresinė analizė. Darbą sudaro 5 dalys: įvadas, analitinė dalis, metodinė-tiriamoji dalis, išvados, literatūros sąrašas.<br>In the analytical part of this Thesis, the principals of fire resistance intumescent coatings foam and thermally stable char layer forming is presented. The fillers and other components for improving surface thermal properties are discussed. As well as a variety of fillers influence the protective coating analyses. In addition, the work is described the minimum fire protection coating layer of steel structures required for fire protection calculations. In the project part of this Thesis, the procedures and equipment, the heat conduction calculation is given. Moreover, the Thesis fire surface thermal conductivity and thermal insulation coating layer increases dependence on the different ways of rising temperatures in the fire analyses. It is also obtained the result of heat conduction by correlation-regression analysis. Structure: introduction, analytical part, the research part, conclusions and references.

Cette étude s’intéresse aux comportements de 4 peintures intumescentes développées pour protéger des plateformes offshores et susceptibles de résister aux « jet-fires ». Un jet-fire peut intervenir sur un site pétrochimique suite à une fuite d’hydrocarbures sous pression et causer de sérieux dommages de part la chaleur dégagées et surtout la quantité de mouvement générées. Les aspects physiques et chimiques de ces formulations ont été développés permettant de mettre en avant les effets du pentaérythritol sur le comportement viscoélastiques et le processus d’intumescence. Par diffraction des rayons X et par RMN à l’état solide, nous avons montré les interactions entre ammonium et polyphosphate et différentes sources de carbones (pentaérythritol, dipentaérythritol, réseau époxyde) permettant la formation d’un char. Les résidus phosphorés réagissent ensuite avec TiO2 pour former une structure cristalline TiP2O7 suspectées d’améliorer la résistance au feu et la résistance mécanique du char. Des tests feu ont confirmés ces améliorations. Dans un dernier chapitre nous avons développé un test permettant de reproduire à l’échelle laboratoire les phénomènes radiatifs et convectifs du jet-fire. Les premiers résultats ont montré de bonnes corrélations entre les observations faites à grande échelle et celles réalisées au laboratoire<br>The aim of this study is to understand and to explain behaviours exhibited by four epoxy based intumescent formulations used on offshore platforms facing to jet-fire. A jet-fire is a turbulent diffusion flame resulting from the combustion of a fuel continuously released with some significant momentum. It represents a significant element of the risk on offshore installations. Regarding the formulation studied, we have developed three approaches. Firstly, the visco-elastic behaviour and mechanical resistance of the formulations have been investigated. The results show that pentaerythritol causes a viscosity decrease at lower temperature that appears as prejudicial to maintain efficient char on steel substrate. In a second part, chemical evolutions of the intumescent formulation have been determined thanks to solid-state NMR and X-Ray diffraction. Interactions between ammonium polyphosphate and respective carbon sources present in formulations have been assumed, yielding to the formation of char and production of phosphorus residues. Then these phosphorus residues react at high temperature with TiO2 to form a crystalline structure TiP2O7 suspected to enhance mechanical properties and flame retardant performance. In a last part, furnace fire tests confirm this enhancement. Furthermore a new small-scale experimental setup is developed mimicking large scale jet-fire resistance test in order to obtain rapidly and at low cost reliable behaviours of a large number of formulations facing to high load mixing radiative heat and flame impact. First results have been correlated with the large-scale ones and different geometries have been considered

Cette étude s’intéresse aux comportements de 4 peintures intumescentes développées pour protéger des plateformes offshores et susceptibles de résister aux « jet-fires ». Un jet-fire peut intervenir sur un site pétrochimique suite à une fuite d’hydrocarbures sous pression et causer de sérieux dommages de part la chaleur dégagées et surtout la quantité de mouvement générées. Les aspects physiques et chimiques de ces formulations ont été développés permettant de mettre en avant les effets du pentaérythritol sur le comportement viscoélastiques et le processus d’intumescence. Par diffraction des rayons X et par RMN à l’état solide, nous avons montré les interactions entre ammonium et polyphosphate et différentes sources de carbones (pentaérythritol, dipentaérythritol, réseau époxyde) permettant la formation d’un char. Les résidus phosphorés réagissent ensuite avec TiO2 pour former une structure cristalline TiP2O7 suspectées d’améliorer la résistance au feu et la résistance mécanique du char. Des tests feu ont confirmés ces améliorations. Dans un dernier chapitre nous avons développé un test permettant de reproduire à l’échelle laboratoire les phénomènes radiatifs et convectifs du jet-fire. Les premiers résultats ont montré de bonnes corrélations entre les observations faites à grande échelle et celles réalisées au laboratoire<br>The aim of this study is to understand and to explain behaviours exhibited by four epoxy based intumescent formulations used on offshore platforms facing to jet-fire. A jet-fire is a turbulent diffusion flame resulting from the combustion of a fuel continuously released with some significant momentum. It represents a significant element of the risk on offshore installations. Regarding the formulation studied, we have developed three approaches. Firstly, the visco-elastic behaviour and mechanical resistance of the formulations have been investigated. The results show that pentaerythritol causes a viscosity decrease at lower temperature that appears as prejudicial to maintain efficient char on steel substrate. In a second part, chemical evolutions of the intumescent formulation have been determined thanks to solid-state NMR and X-Ray diffraction. Interactions between ammonium polyphosphate and respective carbon sources present in formulations have been assumed, yielding to the formation of char and production of phosphorus residues. Then these phosphorus residues react at high temperature with TiO2 to form a crystalline structure TiP2O7 suspected to enhance mechanical properties and flame retardant performance. In a last part, furnace fire tests confirm this enhancement. Furthermore a new small-scale experimental setup is developed mimicking large scale jet-fire resistance test in order to obtain rapidly and at low cost reliable behaviours of a large number of formulations facing to high load mixing radiative heat and flame impact. First results have been correlated with the large-scale ones and different geometries have been considered

Epoxy intumescent coatings are fire protection systems for steel structural elements that are widely used in applications that protection from severe hydrocarbon fires is required, such as oil and gas facilities. These polymer coatings react upon heating and expand into a thick porous char layer that insulates the protected steel element. In the typical fire scenarios for these applications, the intumescent coatings must resist very high heat fluxes and highly erosive forces from ignited pressurised gases. Hence, continuous fibre reinforcement is embedded in the thick epoxy coating during installation, so as to ensure the integrity of the weak intumesced char during fire exposure. This reinforcement is typically in the form of a bidirectional carbon and/or glass fibre mesh, thus under normal service conditions a fibre-reinforced intumescent coating (FRIC) is essentially a lightly fibre-reinforced polymer (FRP) composite material. This thesis examines the impacts of embedded high strength fibres on the tensile behaviour of epoxy intumescent materials in their unreacted state prior to fire exposure, and the potential enhancements that arise in the structural performance of elements protected with FRICs. An experimental programme is presented comprising tensile coupon tests of unreacted intumescent epoxies, reinforced with different fibre meshes at various fibre volume fractions. It is demonstrated that the tensile properties of FRICs can be enhanced considerably by including increasing amounts of carbon fibre reinforcement aligned in the principal loading direction, which can be tailored in the desired orientation on the coated structural members to enhance their load carrying capacity and/or deformability. An experimental study is presented on coated intact and artificially damaged I-beams (simulating steel losses from corrosion) tested in bending, demonstrating that FRICs can enhance the flexural response of the beams after yielding of steel, until the tensile rupture of the coatings. An analytical procedure for predicting the flexural behaviour of the coated beams is discussed and validated against the obtained test results, whereas a parametric analysis is performed based on this analytical model to assess the effect of various parameters on the strengthening efficiency of FRICs. The results of this analysis demonstrate that it is feasible to increase the flexural load capacity of thin sections considerably utilising the flexural strength gains from FRICs. Finally, a novel application is proposed in this thesis for FRICs as a potential system for structural strengthening or retrofitting reinforced concrete and concrete-encased steel columns by lateral confinement. An experimental study is presented on the axial compressive behaviour of short, plain concrete and concrete-encased structural steel columns that are wrapped in the hoop direction with FRICs. The results clearly show that epoxy intumescent coatings reinforced with a carbon fibre mesh of suitable weight can provide lateral confinement to the concrete core resisting its lateral dilation, thus resulting in considerable enhancements of the axial strength and deformability of concrete. The observed strengthening performance of the composite protective coatings is found to be at least as good as that of FRP wraps consisting of the same fibre reinforcement mesh and a conventional, non-intumescent epoxy resin. The predictive ability of existing design-oriented FRP confinement models is compared against the experimental results, and is found to be reasonably precise in predicting the peak strength of the tested columns, hence existing models appear to be suitable for design and analysis of column strengthening schemes with the proposed novel FRIC system. The research presented herein shows clearly that FRICs have a strong potential as alternative systems for consideration in the field of structural strengthening and rehabilitation, since they can provide substantial enhancements in the load carrying capacity for both applications considered. At the same time FRICs can thermally protect the underlying structural elements in the event of a fire, by intumescing and charring, thus potentially eliminating the need for additional passive fire protection that is common with conventional fire-rated FRP wrapping systems. Although this thesis provides a proof-of-concept for use of the proposed novel FRICs as structural strengthening materials, considerable additional research is particularly required to study their fire protection performance when applied to concrete substrates, to make use of the proposed hybrid functionality with confidence.