12 research outputs found

    A sensitivity study of parameters used in shrinkage and creep prediction models

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    Over the last 15 years, there have been numerous models put forward for the prediction of the time-dependent behaviour of concrete and consequently concrete structures. The development of these models from a number of different sources has meant that the engineer now has a choice to make when undertaking creep and shrinkage prediction and it is difficult to know which is best suited for this purpose. Some are considerably more complex than others requiring greater amounts of input focusing on material data, concrete properties, environmental conditions, specimen geometry and loading conditions. The study reported here focuses on the sensitivity to change, in both the short term and over time, of the individual parameters that comprise the input and whether one model is more appropriate in any given situation. It has been found that for each model certain parameters are more sensitive than others. It is suggested that for any given model, the parameters that do not reflect the expected behaviour when changed counterbalance each other, cancelling out any errors. This further suggests that when deciding on which model to use when predicting shrinkage and creep strains it is prudent to look at the specific conditions that prevail, assess the relevant input parameters for which data are available, assess the sensitivity level of each of these parameters and then make a decision as to the most appropriate model to use

    Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

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    Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

    SFRC arch ribs for bridges and earth retaining structures

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    Effect of conditioning temperature on the strength and permeability of normal- and high-strength concrete

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    In order to evaluate the effect of the conditioning temperature on strength and permeability properties of concrete a series of compressive, indirect tensile and permeability tests were performed on concretes (designed to have 28-day compressive strengths of 40 and 100 N/mm2) conditioned at temperatures of 85 and 10

    A state of the art review of HPFRCC

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    Report for Sub-Task 15, Sustainable Advanced Materials for Road Infrastructure (SAMARIS

    A review of permeability test methods

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    Report for Sub-Task 15, Sustainable Advanced Materials for Road Infrastructure (SAMARIS

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