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This is an article in the field of ceramics and composites. The changes of resistivity, compressive strength and chloride ion migration coefficient of concrete under different dosages are used to evaluate the durability of concrete. The impermeability, mechanical properties, and chloride ion corrosion resistance of concrete under the action of different iron tailings content and different fly ash content are studied. The effect of adding different proportions of iron tailings and fly ash on the performance of concrete is analyzed.The results show that the compressive strength of concrete reaches the maximum when the content of iron tailings and fly ash is 30%. However, the larger the proportion of fly ash and the smaller the proportion of iron tailings, the worse the compressive strength, impermeability and resistance to chloride ion corrosion of concrete. Therefore, in the actual preparation of concrete, a mixing ratio of a large amount of iron tailing sand and a small amount of fly ash should be used. With the increase in the content of iron tailings and fly ash, the hydration heat release rate and total heat release of iron tailings also show a decreasing trend under the same hydration time. This shows that the addition of iron tailings and fly ash greatly reduces the hydration heat release rate and total heat release of concrete. With the increase in the amount of iron tailings and fly ash, the pore size value corresponding to the peak point of the concrete pore size distribution curve is also increasing, but the increasing amplitude is getting smaller and smaller.

Copyright of Multipurpose Utilization of Mineral Resources / Kuangchan Zonghe Liyong is the property of Multipurpose Utilization of Mineral Resources Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study investigated the flame retardancy of water-based intumescent coatings for plywood by conducting flame retardancy tests by using water-based acrylic resin mixed with various concentrations (1%, 3%, 5%, and 10%) of alkaline lignin. Intumescent coatings containing alkaline lignin demonstrated superior flame retardancy compared with those without additives. At a concentration of 5%, the alkaline lignin promoted the formation of an ideal char layer during combustion. The chemical structure and durability of the phosphorus–carbon structure in the intumescent coatings were investigated through Fourier transform infrared spectroscopy and solid-state nuclear magnetic resonance analysis (13C and 31P). The analysis results reveal that intumescent coatings containing 5% alkaline lignin were more effective in reducing flammability than those containing higher concentrations of alkaline lignin. [ABSTRACT FROM AUTHOR]

In this study, microalgae–bacteria (MB) systems using saline conditions (3 and 5% salinity) were built in order to use waste-activated sludge (AS) as raw material for cultivating lipid-rich microalgae. Algae were observed to be flourishing in 60 days of operation, which totally used the N and P released from the sludge biomass. A prominent improvement of lipid content in MB consortia was obtained under algae growth and salinity stimulation, which occupied 119–136 mg/g-SS rather than a low content of 12.1 mg/g-SS in AS. Lipid enrichment also brought a 3.1–3.3 times total heat release (THR) in the MB biomass. The marine spherical algae Porphyridium, as well as filamentous Geitlerinema, Nodularia, Leptolyngbya were found to be the main lipid producers and self-flocculated to 23.0% (R1) and 33.5% (R2) volume under the effect of residue EPS. This study had a big meaning in not only waste sludge reduction but also in manufacturing useful bioenergy products. HIGHLIGHTS Self-reliant MB consortia systems were built with 3 and 5% of saline water.; MB consortia achieved 119–136 mg/g-SS lipid content.; MB consortia had 3.1–3.3 times the total heat release than AS.; MB consortia could self-flocculate to 23.0–33.5% volume.; Spherical Porphyridium and filamentous Cyanobacteria used N and P from AS.;

A mixture of etherified melamine–formaldehyde and acrylic emulsion resin was designed, with the hybrid resin improving the fire retardancy of indoor plywood as well as the CO and CO2 emissions. The water-based hybrid resin exhibited a single curing peak; the need for solvents was reduced. Compared with pure etherified melamine–formaldehyde resin, the hybrid resin had better flame retardancy and produced less pollution. Scanning electron microscopy and cone calorimetry were conducted, and the analyses revealed that lower binder resin concentrations resulted in improved flame retardancy and better char layer formation. When the binder resin concentrations were increased and CO/CO2 emissions were continued beyond 300 s, the flame retardancy of the intumescent coating was the same as that of the lower binding resin concentrations. Furthermore, the chemical structure and durability of the phosphocarbonaceous structure were verified through Fourier transform infrared spectroscopy and solid-state nuclear magnetic resonance analyses. [ABSTRACT FROM AUTHOR]

In order to study the effect of moisture content on the combustion characteristics of coal, taking the bituminous coal from Zhujixi Coal Mine as the research object, the method uses cone calorimeter to test the parameters of ignition time, heat release rate, total heat release, smoke generation rate, total smoke release and CO generation rate of coal samples with different moisture content and analyzes the combustion efficiency of coal samples. The experimental results show the following points. ① The ignition time of coal samples decreases first and then increases with the increase of moisture content. The order of moisture content of coal samples corresponding to ignition time from long to short is 17.82%>13.82%>1.82%>5.82%>9.82%. The peak heat release rate of the coal sample decreases first, then increases and then decreases with the increase of water content. The order of moisture content of coal samples corresponding to peak heat release rate from large to small is 9.82%>1.82%>5.82%>13.82%>17.82%. The total heat release, smoke generation rate, and total smoke release of coal samples decrease first, then increase and then decrease with the increase of water content. The order of the moisture content of coal samples corresponding to the total heat release, smoke generation rate, and total smoke release from large to small is 1.82%>9.82%>5.82%>13.82%>17.82%. In the late stage of combustion process, the coal sample with 5.82% moisture content has the lowest CO generation rate, and the coal sample with 17.82% moisture content has the highest CO generation rate. The high moisture content will increase the CO yield. The order of the moisture content of coal samples corresponding to the combustion efficiency from high to low is 9.82%>5.82%>1.82%>13.82%>17.82%. ② Appropriate moisture content can improve the combustion performance of coal. It is suggested to choose the coal with moisture content of 5.82% to 9.82% so as to shorten the coal ignition time, reduce the smoke generation rate, total smoke release and CO generation rate, and improve the heat release rate and combustion efficiency.

The quantitative structure‐property relationship (QSPR) approach has widely been used to predict several physicochemical properties of materials employing the information obtained from their chemical structures (numerical descriptors). In the present work, we have generated three individual QSPR models for three different endpoints for a large number of polymers in order to determine their fire retardant property such as heat release capacity, total heat release, and %Char, using the only two‐dimensional descriptors with definite physicochemical meaning. Relevant subsets of descriptors were selected employing a genetic algorithm approach; subsequently, the selected descriptors were utilised for the identification of the best combination of the variables for the model generation, while the final models were developed employing the partial least squares (PLS) regression algorithm. The generated models were rigorously validated using various internationally accepted internal and external validation metrics. All the models showed promising statistical quality in terms of determination coefficient R2 (0.802, 0.842 and 0.826), cross‐validated leave‐one‐out Q2 (0.759, 0.810 and 0.752) and predictive R2pred or Q2ext (0.810, 0.900 and 0.847) for HRC (nTraining=62, nTest=28), THR (nTraining=64, nTest=21) and %char (nTraining=49, nTest=21) datasets, respectively. All the certified models were used for prediction of flammability characteristics of 37 external set compounds, and further, the quality of prediction was determined by using the PRI software tool. The final models of HRC, THR and %Char formation of polymers may be useful to predict the flammability characteristics of polymers quickly before their synthesis and used as a better alternative approach to the experimental testing of flammability of polymers. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Mine Automation is the property of Industry & Mine Automation Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Summary: Knowledge about the heat release rate (HRR) is essential for studying tunnel fires. The standard method in ISO 9705 is widely applied to calculate the HRR of combustion by measuring the consumption of oxygen in a fire. However, the studies of HRR measurement in full‐scale tunnel fires are rare because of the complication and costs of large experiments. This paper presents a system based on the principle of oxygen consumption calorimetry for the measurement of HRR and total heat release (THR) of full‐scale fires in tunnels. A total of 22 fire experiments are performed in a large‐scale ventilated testing metro tunnel with dimension of 100.0 m × 5.5 m × 5.5 m to validate the reliability and effectiveness of this system. Firstly, four oil spray fire tests are conducted with nozzle flow of 106 L/h at (1 ± 0.1) MW HRR to calibrate the instrumentation. Then, 18 full‐scale fire tests using square diesel pools at five sizes (0.5, 1.0, 2.5, and 5.0 m2) and wood cribs as fire sources are carried out for the measurement of HRR and THR. Results provided by the comparison between the measured HRR and THR values of the fire tests and the theoretically calculated ones show that our system works effectively in the HRR measurement of full‐scale fires in tunnels. [ABSTRACT FROM AUTHOR]

Copyright of Chemistry & Industry of Forest Products is the property of Chemistry & Industry of Forest Products Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Total heat release of a polymer is the heat of complete combustion of the pyrolysis gases per unit its initial mass. Microscale combustion calorimetry, an oxygen consumption technique, identifies the total heat release of polymers that is a key parameter for predicting polymer flammability where their measured data can be confirmed by thermogravimetric analysis (TGA) and derivative TGA (DTG) data. The simplest model is introduced to predict the total heat release of different polymers on the basis of their repeat units that may contain chemical groups/moieties. In contrast to the available quantitative structure–property relationships methodology, the new method simply requires only elemental composition of repeat unit of a desired polymer without using complex molecular descriptors and computer codes where they need expert users. For the measured total heat release of 122 polymers, the predicted results are compared with the calculated data of the latest group additivity methods. The root mean square deviation, mean absolute deviation and maximum of errors of the new model are 4.5, 3.4 and 15.3 kJ g−1, which are lower than those predicted by group additivity method, i.e., 9.0, 5.8 and 35.7 kJ g−1, respectively. [ABSTRACT FROM AUTHOR]

The combustion and thermal characteristics of fire retardant-treated pine (Pinus densiflora) were evaluated according to the KS F ISO 5660-1 (2003) standard, using a cone calorimeter. The specimens were treated with fire-retardant chemical compounds using pressure-impregnation equipment to reliably impregnate the compounds inside the wood. The heat release rate value of the fire retardant-treated wood specimens showed that the heat release time was delayed. A reduction of the total heat release value can indicate that fire was prevented from igniting in the materials during combustion. The microstructures of natural specimen and treated fire-retardant chemical compounds specimen were determined by scanning electron microscopy. It also confirmed that the pressureimpregnation processing method was effective in comparison to the other treatment methods. [ABSTRACT FROM AUTHOR]

PET laminated photovoltaic modules present a high level of fire hazard, with varying levels of risk in complex external environments. This paper presents the experimental results of the ignition and combustion behavior of a PET laminated photovoltaic panel using the Fire Propagation Apparatus. The ignition time, heat release rate, combustion equivalent ratio, and total heat release were measured at different external heat flows and ventilation levels. The ignition time was determined as a function of the external radiant heat flow and the ventilation volume, respectively. The experimental results showed that the ignition time was sensitive to the change of external heat flow under different experimental conditions, but at lower external heat flow, the increase of ventilation had a great contribution to the shortening of the ignition time. The oxygen consumption method was used to determine the heat release rate under multiple boundary conditions, the value of which depends on the close coupling effect of external radiant heat flow and ventilation and is positively correlated with both. The immediate effect of boundary conditions on combustion efficiency was analyzed by equivalence ratios. For the total heat release, the external radiant heat flow directly plays a decisive role, but the ventilation volume can play a great role in promoting, especially under the low external heat flow. • Combustion tests of PET laminated photovoltaic panels using FPA. • Data analysis of fire hazard assessment under multi boundary conditions. • The influence of ventilation rate on ignition time and heat release rate is concerned. • Analysis of the coupling effect of boundary conditions on combustion efficiency. [ABSTRACT FROM AUTHOR]

Composite materials like FRPs offer the advantages of the high strength and stiffness with their low density and highly flexible shaping, thus, their potential in replacing conventional materials such as aluminium and steel for prefabrication of modular residential and office applications. The main limitation of fibre reinforced polymer composites (FRPCs) is their relatively poor fire performance. In this study, two CFD models using the modified Mc Grattan and the modified Coats Redfern – Kissinger method were developed to mimic the testing conditions of thermo-gravimetric analysis and cone calorimeter. Validation with experiments proves that the models can realistically predict the fire growth index (FIGRA) and total heat release (THR) of the organoclay/glass fibre reinforced polymer (GFRP) laminates. Two other CFD models were also developed to predict the behaviour of GFRP façade panel, where GFRP laminates are sandwiched with the foam core and undergo ISO 9750-1:2013 conditions in a typical office defined by the National Construction Code, Australia and a city office building in Netherlands. In the first case, 5% organoclay in GFRP prevents flash-over from happening and also the flame from spreading in the horizontal direction. In the second case, organoclay/GFRP panel is tested with different configurations. FIGRAs and THRs in all the selected configurations were found to be well below the thresholds required for building environment. [ABSTRACT FROM AUTHOR]

The compatibility and coating ratio between flame retardant materials and expanded polystyrene (EPS) foam is a major impediment to achieving satisfactory flame retardant performance. In this study, we prepared a water-based intumescent flame retardant system and methylene diphenyl diisocyanate (MDI)-coated expandable polystyrene microspheres by a simple coating approach. We investigated the compatibility, coating ratio, and fire performance of EPS- and MDI-coated EPS foam using a water-based intumescent flame retardant system. The microscopic study revealed that the water-based intumescent flame retardant materials were successfully incorporated with and without MDI-coated EPS microspheres. The cone calorimeter tests (CCTs) of the MDI-coated EPS containing water-based intumescent flame retardant materials exhibited better flame retardant performance with a lower total heat release (THR) 7.3 MJ/m2, peak heat release rate (PHRR) 57.6 kW/m2, fire growth rate (FIGRA) 2027.067 W/m2.s, and total smoke production (TSP) 0.133 m2. Our results demonstrated that the MDI-coated EPS containing water-based intumescent flame retardant materials achieved flame retarding properties as per fire safety standards. [ABSTRACT FROM AUTHOR]