Modern day energy codes are driving the design and multi-layered configuration of exterior wall systems with a significant emphasis on achieving high performance insulation towards improving energy performance of building envelopes. Use of highly insulating polyisocyanurate (PIR) based materials enhanced with eco-friendly lamellar inorganic fillers reinforces energy performance requirements, environmental challenges and cost reduction without compromising the overall building fire safety. The current work assessed the fire behaviour of PIR modified with three layered fillers, namely MgAlCO3 (PIR-LDH1), MgAl Stearate (PIR-LDH2) and Zirconium Phosphate octadecylamine (PIR-ZrP3). For each of the fillers, three loadings (2, 4 and 6 % by weight) were used.Optical analysis by X-ray diffraction patterns (XRD), cone calorimeter (CC), thermogravimetric (TGA) analysis, post-burning morphological evaluation using field emission scanning electron microscope (FESEM) and diffuse reflectance infrared spectroscopy (DRIFT) analysis, were performed. The results indicated that fire reaction properties and thermal stability of foam samples were enhanced with three different types of lamellar inorganic smart fillers. The initial degradation temperature of PIR-layered filler samples was increased, demonstrating that incorporation of flame retardants decelerated the degradation of PIR foam and contributed to significant char formation, from 19.5% in pure PIR samples to 33% in PIR-6%LDH1 samples. Increasing the filler content also resulted in improved char properties and decreased peak Heat Release Rates (HRR) in the cone calorimeter.Due to the development of a stable char layer, samples containing 6% of ZrP3 did not ignite at 20kW/m 2 and a reduction of up to 40% in the peak HRR was achieved in PIR-2%ZrP3 samples.
Green roofs are becoming increasingly common practice of the urban sustainable environment. The growing substrate is the most important part of green-roof technology. The cost of engineering substrates can be reduced by using locally available components. Since green roofs are a relatively new concept in Poland, there is a need to examine substrate compositions and characteristics, including commonly used ingredients as well as alternative recycled/waste materials. The aim of our study was to assess the ability of locally sourced waste materials as roof-growing media amendments. In the greenhouse experiment we tested two grass and herb species mixtures and four waste substrate formulas. The locally disposed waste materials used as components of growing media included silica wastes (byproducts of metallic ferrosilicon alloys), cellulose, foundry sand, and organic waste material removed from the organic horizons of mucky peat. The engineered Si-waste substrates were compared with the commercially available media. The physico-chemical properties of components and substrates, their stability over time, and the influence on plant growth and mineral nutrient status were examined. Particle size distribution, bulk density, mass, water capacity, soil reaction, and total dissolved salt content of Si-waste-growing media were compatible with FLL standards. We found low amounts of available P and K, and high concentrations of Ca, Mg, S, and trace elements (with the exception of B) in Si-waste substrates in comparison with the control media. Silica waste materials have the potential to maintain pH with high buffering capacity. Engineered Si-waste substrates had a positive impact on plant growth and biomass. In general, these results indicate that contaminant elements contained in alkaline Si-waste substrates were not easily available to the root system, and consequently they did not restrict plant growth. We consider Si-wastes to be a valuable and environmentally responsible green roof media amendment.
This work examines the effect of Layered Double Hydroxides (LDHs), Expandable Graphite (EG) and Ammonium Polyphosphate (APP) on the thermal stability and behaviour under fire conditions of polyisocyanurate (PIR) insulation foams. Virgin materials' and char residues' morphologies were analyzed with a variety of experimental techniques including field emission scanning electron and optical microscopy along with Raman spectroscopy. Thermal stability and burning behaviour were examined using thermogravimetric (TGA) coupled with Fourier Transform Infrared (FTIR) spectrometer and cone calorimeter. TGA results suggested a decrease in degradation temperature upon introduction of fillers in PIR samples. FTIR spectra were used to determine the absorbance intensity of the different pyrolysis gases. Cone calorimeter data analysis established a limited effect on reducing the rate of heat release rate and smoke production with the inclusion of LDHs. However, EG or EG + APP addition, caused a considerable decrease in heat release rate, owing to the increased char strength and the release of non-combustible gases. The positive effect of EG or EG + APP in the fire behaviour of PIR foams was further supported by the morphological evaluation of their residual char samples.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.