Italian hybrid fire prevention code

Fire safety of residential buildings and activities subjected to fire inspection is a difficult task, especially when the safety targets have to be adopted in built buildings or in activities that are going to be modified into more complex ones. Generally, these circumstances show more constraints and it could be difficult to achieve an acceptable level of fire residual risk by prescriptive based fireregulations. Therefore, the Italian National Fire Rescue and Service in charge for fire safety, in August 2015 issued a new Fire Prevention Code whose design methodology is more oriented to fire performance based design rather than prescriptive fire codes. The flexibility of this new fire design methodology offers a very complex tool to experts in order to design fire safety measures and strategies of buildings and activities subjected to fire inspection. The present paper aims tohighlig hts the contents and the fire safety strategy design methodology of the new Italian Fire Prevention Code

Fire safety of steel wall systems using enhanced plasterboards

Fire safety design is important to eliminate the loss of property and lives during fire events. Gypsum plasterboard is widely used as a fire safety material in the building industry all over the world. It contains gypsum (CaSO4.2H2O) and Calcium Carbonate (CaCO3) and most importantly free and chemically bound water in its crystal structure. The dehydration of the gypsum and the decomposition of Calcium Carbonate absorb heat, which gives the gypsum plasterboard fire resistant qualities. Currently plasterboard manufacturers use additives such as vermiculite to overcome shrinkage of gypsum core and glass fibre to bridge shrinkage cracks and enhance the integrity of board during calcination and after the loss of paper facings in fires. Past research has also attempted to reduce the thermal conductivity of plasterboards using fillers. However, no research has been undertaken to enhance the specific heat of plasterboard and the points of dehydration using chemical additives and fillers. Hence detailed experimental studies of powdered samples of plasterboard mixed with chemical additives and fillers in varying proportions were conducted. These tests showed the enhancement of specific heat of plasterboard. Numerical models were also developed to investigate the thermal performance of enhanced plasterboards under standard fire conditions. The results showed that the use of these enhanced plasterboards in steel wall systems can significantly improve their fire performance. This paper presents the details of this research and the results that can be used to enhance the fire safety of steel wall systems commonly used in buildings

Exploratory study into a safety format for composite columns exposed to fire

Current performance based structural fire engineering approaches evaluate structural behaviour under prescribed fire scenarios. The mechanical properties of the materials, the load conditions and geometric parameters are all however fraught with uncertainty, and there is currently no clear safety format ensuring the reliability of the design solution. In this contribution, a safety format is explored for evaluating the fire resistance of composite columns, following results obtained in earlier studies on uncertainty quantification. Using the safety format, a single nonlinear finite element evaluation of the fire resistance time is combined with a global safety factor, defining its design value. Under the assumptions derived from earlier work, the safety format works well, but additional parameter studies indicate that good performance is limited to relatively low ambient design utilization ratios. The results thus highlight the importance of uncertainty quantification and the limitations of basing a safety format for structural fire design on limited studies. It is concluded that detailed studies into the probabilistic description of the response of composite columns exposed to fire are required to generalize the results to a broadly applicable design rule

Performance analysis of a self-protection system for vehicles in case of WUI fire entrapment

Sheltering inside a civilian vehicle has proved to be a high risk strategy in case of wildfire entrapment. Survival is by no means guaranteed, especially in moderate to high-intensity wildfires. However, vehicles do offer a certain degree of fire protection, which can be reinforced by ad-hoc fire resistant technology. In this paper, we present the experimental performance analysis of a self-protection system that has been designed to protect people’s life in case of fire entrapment. Similar to a firefighter fire shelter, the designed system can be quickly deployed covering the whole vehicle. In case of fire exposure, this fabric provides additional heat protection to the occupants and the vehicle itself. An experimental burning was designed in order to simulate real fire exposure conditions in case of vehicle entrapment in a rural road. An ex-situ 2-m high fuel bed composed of Pinus halepensis fine logging slash was arranged in a 13 m long x 6 m wide area. Fire was ignited at one end of the fuel bed and spread driven by an induced constant air flow (3 m/s midflame wind speed). 2.8 m away from the other fuel bed end, a car covered with the fire protection fabric was placed, parallel to the fire. Data analysis provided mean values of fire rate of spread (2 m/s), fireline intensity (1800 kW/m), flame height (6.5 m), flame tilt angle (30º), flame depth (2 m), flame temperature (800 ºC) and flame emissive power (47.5 kW/m2 ). Maximum air temperatures inside the vehicle ranged around 41-42.5 ºC during a period between 20 min and 35 min after ignition. A thermocouple in contact with the internal side of the driver’s window registered a maximum value of 47.3 ºC. These results evidenced the good performance of the fabric when protecting eventual vehicle occupants against thermal exposure from wildfires of moderate intensity.Peer ReviewedPostprint (author's final draft

Foam composite structures

The need to include fire resistant foams into state of the art aircraft interior paneling to increase passenger safety in aircraft fires was studied. Present efforts were directed toward mechanical and fire testing of panels with foam inclusions. Skinned foam filled honeycomb and PBI structural foams were the two constructions investigated with attention being directed toward weight/performance/cost trade-off. All of the new panels demonstrated improved performance in fire and some were lighter weight but not as strong as the presently used paneling. Continued efforts should result in improved paneling for passenger safety. In particular the simple partial filling (fire side) of state-of-the-art honeycomb with fire resistant foams with little sacrifice in weight would result in panels with increased fire resistance. More important may be the retarded rate of toxic gas evolution in the fire due to the protection of the honeycomb by the foam

Fire design in safety engineering: likely fire curve for people’s safety

The present study analyses fire design settings according to Fire Safety Engineering (FSE) for the simulation of fire in civil activities and compares these simulations developed using natural and analytic fire curves. The simulated Heat Rate Release (HRR) curve, appropriately linearized, allows for the estimation of a Likely Fire Curve (LFC). The analytic curves have been introduced for the purpose of evaluating the strength and integrity of the structure, and the adoption of these curves in the fire safety engineering was made following the assumption that the phenomena of major intensity ensure the safe approach of fire design. This argument describes the method adopted for determining a likely fire model that guarantees a greater adherence of the virtualized phenomenon with respect to the potential event. The study showed that the analytic curve, adopted in order to verify the structural strength, in the beginning phases of fire produces fields of temperature and toxic concentrations lower than those obtained by simulation of the Likely Fire Curve. The assumption of the Likely Fire Curve model safeguards exposed people during self-rescue and emergency procedure. The programs used since 2011 for the simulation are FDS (Fire Dynamic Simulator v. 5.4.3) and Smokeview (5.4.8). Comparative analysis was developed using thermo-fluid dynamic parameters (temperature and heat release rate) relevant to the safety of the exposed persons; the case study focuses on children and employees of the nursery. The main result shows that the safety criterion, implicitly included in the analytical fire curves - normally used for fire resistance - doesn’t have the same applicability of a performance based approach on safety evaluation involving people. This paper shows that the Likely Fire Curve assumption involves a thermo-chemical stress more relevant to assessing the safety of exposed people

Evaluation of WRF-Sfire Performance with Field Observations from the FireFlux experiment

This study uses in-situ measurements collected during the FireFlux field experiment to evaluate and improve the performance of coupled atmosphere-fire model WRF-Sfire. The simulation by WRF-Sfire of the experimental burn shows that WRF-Sfire is capable of providing realistic head fire rate-of-spread and the vertical temperature structure of the fire plume, and, up to 10 m above ground level, fire-induced surface flow and vertical velocities within the plume. The model captured the changes in wind speed and direction before, during, and after fire front passage, along with arrival times of wind speed, temperature, and updraft maximae, at the two instrumented flux towers used in FireFlux. The model overestimated vertical velocities and underestimated horizontal wind speeds measured at tower heights above the 10 m, and it is hypothesized that the limited model resolution over estimated the fire front depth, leading to too high a heat release and, subsequently, too strong an updraft. However, on the whole, WRF-Sfire fire plume behavior is consistent with the interpretation of FireFlux observations. The study suggests optimal experimental pre-planning, design, and execution of future field campaigns that are needed for further coupled atmosphere-fire model development and evaluation

Flight parameters and vehicle performance for project fire flight 1, launched april 14, 1964

Flight parameters and spacecraft performance for Fire project flight