Towards a fragility assessment of a concrete column exposed to a real fire – Tisova Fire Test

Fires can cause substantial damage to structures, both non-structural and structural, with economic losses of almost 1% GDP in developed countries. Whilst design codes allow engineers to design for the primary design driver, property protection is rarely, if ever, designed for. Quantification and design around property protection has been used for some time in the seismic community, particularly the PEER framework and fragility analyses. Fragility concepts have now started to be researched predominantly for steel-composite structures, however, there has been little to no research into the quantification of property protection for concrete structures, whether in design or in post-fire assessments of fire damaged structures. This paper presents selected results from the thermal environment around, and the thermal response of, a concrete column from a large scale structural fire test conducted in Tisova, Czech Republic, inside a four-storey concrete frame building, with concrete and composite deck floors. From the results of the fire test, assessments of the fire intensity are made and used to model the potential thermal profiles within the concrete column and the implications that high temperature might have on the post-fire response of the concrete column. These thermal profiles are then used to assess the reduction of the columns cross-sectional area and are compared to a quantified damage scale for concrete columns exposed to fire. This analyses presented herein will also show that common methods of defining fire intensity through equivalent fire durations do not appropriately account for the complexities of the thermal and structural response of concrete columns exposed to a travelling fire

Impacts of land use change to short rotation forestry for bioenergy on soil greenhouse gas emissions and soil carbon

Short Rotation Forestry (SRF) for bioenergy could be used to meet biomass requirements and contribute to achieving renewable energy targets. As an important source of biomass it is important to gain an understanding of the implications of large-scale application of SRF on the soil-atmosphere greenhouse gas (GHG) exchange. This study examined the effects of land use change (LUC) from grassland to SRF on soil fluxes of methane (CH4), nitrous oxide (N2O) and carbon dioxide (CO2), and the important drivers in action. Examining soils from a range of sites across the UK, CO2 emission potentials were reduced under SRF with differences between coniferous and broadleaved transitions; these changes were found to be related to changes in soil pH and microbial biomass. However, there were limited effects of SRF tree species type on CH4 and N2O fluxes. A detailed study at an experimental SRF site over 16 months demonstrated a reduction in CH4 and net CO2 emissions from soils under SRF and revealed intriguing temporal dynamics of N2O under Sitka spruce and common alder. A significant proportion of the variation in soil N2O fluxes was attributed to differences between tree species, water table depth, spatial effects, and their interactions. The effects of microtopography (ridges, troughs, flats), and its interactions with water table depth on soil GHG fluxes under different tree species was tested using mesocosm cores collected in the field. Microtopography did not significantly affect soil GHG fluxes but trends suggested that considering this spatial factor in sampling regimes could be important. N2O fluxes from Sitka spruce soils did not respond to water table depth manipulation in the laboratory suggesting that they may also be determined by tree-driven nitrogen (N) availability, with other research showing N deposition to be higher in coniferous plantations. An N addition experiment lead to increased N2O emissions with greatest relative response in the Sitka spruce soils. Overall, LUC from rough grassland to SRF resulted in a reduction in soil CH4 emissions, increased N2O emissions and a reduction or no change in net CO2 emissions. These changes in emissions were influenced both directly and indirectly by tree species type with Sitka spruce having the greatest effect on N2O in particular, thus highlighting the importance of considering soil N2O emissions in any life cycle analysis or GHG budgets of LUC to SRF for bioenergy. This research can help inform decisions around SRF tree species selection in future large-scale bioenergy planting

FENDS - a model to investigate growth and nitrogen dynamics in managed stands of Pinus nigra var. maritima (Ait.) Melville

SIGLEAvailable from British Library Document Supply Centre- DSC:DX170985 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

What Are Perfect Places, Anyway?: Exploring the New Zealand Government\u27s Approach to Youth Suicide Prevention

This study utilizes New Zealand as a case study in exploring government suicide prevention strategies for youth. As the OECD country with the highest youth suicide rate, it is a unique case, as the World Happiness Report has consistently ranked it one of the world’s happiest countries. This study seeks to understand what makes New Zealand stand out from other countries in its youth suicide rate, as well as how youth perceive the government’s efforts to prevent suicide among their age cohort. It explores how the population’s relationship with the state has evolved over time with changes in economic structure, discussing how suicide prevention models have necessarily shifted in tandem. It also discusses youth opinions of the New Zealand government’s most recent suicide prevention efforts, analyzing how they see the state’s role in promoting mental wellbeing. The study finds that youth do not see the social processes that contribute to mental distress addressed in government prevention strategies. While they understand the main reasons for suicide to be structural and cultural in nature, the government frames suicide prevention as an issue of interpersonal responsibility, rendering it useless to their age demographic because their perceptions are not reflected in prevention efforts. Future suicide prevention strategies that are aimed towards youth must reflect a notion of hope and working towards societal change in order for them to be most effective

Testing and analysis of catenary action in unprotected steel beams subjected to fire

The use of unprotected steel beams in sprinkler-protected office buildings has been increasing in Australia over the past ten years. This has been justified using performancebased assessments, taking into account firstly the high reliability of the sprinkler system and secondly the robust performance of the floor system in fire resulting from the interconnection between the elements of structure. In this context, quantification of the catenary action developed in the steel beams is of interest, and a study of this mode of support has been commenced. Two fire tests have been conducted on steel beams supported in catenary action. A numerical analysis program has been written, based on moment-curvature methods. The material model for steel used in this analysis was that proposed by Poh. This model includes an explicit calculation of creep strain. Experimental and analytical results were compared. Reasonable agreement was obtained for Test 1, but in Test 2 the observed strength was greater than that calculated. Further investigation of this difference will be undertaken