This paper investigates the influence of temperature and wind conditions on ventilation of the air cavity beneath the roofing in a full-scale pitched wooden roof construction.The potential for condensation in the air ...This paper investigates the influence of temperature and wind conditions on ventilation of the air cavity beneath the roofing in a full-scale pitched wooden roof construction.The potential for condensation in the air cavity is studied.The relevant roof construction is equipped with 81 thermocouples and four air velocity measurement devices.A weather station at the site records outdoor temperature and wind conditions.Five periods between 2016 and 2018 are investigated.The findings show distinct periods of below-ambient temperature and positive condensation potential in the ventilated air cavity of the roof.A relation between low wind speed and positive condensation potential is shown.Difference in size of periods with below-ambient temperature and periods with positive condensation potential implies that the materials in the roof regulate the humidity in the air cavity.Large negative peaks in the condensation potential indicate dry-out of the construction.展开更多
The SINTEF Building Research Design Guides are a series of Norwegian building technical recommendations.The design guides are highly reputed and widely used in the Norwegian construction sector,serving as a link betwe...The SINTEF Building Research Design Guides are a series of Norwegian building technical recommendations.The design guides are highly reputed and widely used in the Norwegian construction sector,serving as a link between the technical regulations and the design process of the individual construction project.This paper examines the element of risk in the use of multiple design guides to extract information about a topic not explicitly covered by any single guide,using the example of blue-green roofs.The research has been conducted in the form of a document study.While the advice given in the design guides is both valid and coherent,the amount of information presented is likely to be overwhelming for industry professionals.There are great degrees of awareness of quality risk present in the individual design guides,but an overall risk picture is not presented.Input from the fields of project management and psychology can help develop risk awareness strategies.The design guides may benefit from an aggregate level of information,where main technical challenges are grouped into super-level categories.展开更多
Geotechnical classification is vital for site characterization and geotechnical design.Field tests such as the cone penetration test with pore water pressure measurement(CPTu)are widespread because they represent a fa...Geotechnical classification is vital for site characterization and geotechnical design.Field tests such as the cone penetration test with pore water pressure measurement(CPTu)are widespread because they represent a faster and cheaper alternative for sample recovery and testing.However,classification schemes based on CPTu measurements are fairly generic because they represent a wide variety of soil conditions and,occasionally,they may fail when used in special soil types like sensitive or quick clays.Quick and highly sensitive clay soils in Norway have unique conditions that make them difficult to be identified through general classification charts.Therefore,new approaches to address this task are required.The following study applies machine learning methods such as logistic regression,Naive Bayes,and hidden Markov models to classify quick and highly sensitive clays at two sites in Norway based on normalized CPTu measurements.Results showed a considerable increase in the classification accuracy despite limited training sets.展开更多
文摘This paper investigates the influence of temperature and wind conditions on ventilation of the air cavity beneath the roofing in a full-scale pitched wooden roof construction.The potential for condensation in the air cavity is studied.The relevant roof construction is equipped with 81 thermocouples and four air velocity measurement devices.A weather station at the site records outdoor temperature and wind conditions.Five periods between 2016 and 2018 are investigated.The findings show distinct periods of below-ambient temperature and positive condensation potential in the ventilated air cavity of the roof.A relation between low wind speed and positive condensation potential is shown.Difference in size of periods with below-ambient temperature and periods with positive condensation potential implies that the materials in the roof regulate the humidity in the air cavity.Large negative peaks in the condensation potential indicate dry-out of the construction.
基金This research was funded by the Research Council of Norway,grant number 237859.The authors gratefully acknowledge the financial support by the Research Council of Norway and several partners through the Centre of Research-based Innovation“Klima 2050”(www.klima2050.no).
文摘The SINTEF Building Research Design Guides are a series of Norwegian building technical recommendations.The design guides are highly reputed and widely used in the Norwegian construction sector,serving as a link between the technical regulations and the design process of the individual construction project.This paper examines the element of risk in the use of multiple design guides to extract information about a topic not explicitly covered by any single guide,using the example of blue-green roofs.The research has been conducted in the form of a document study.While the advice given in the design guides is both valid and coherent,the amount of information presented is likely to be overwhelming for industry professionals.There are great degrees of awareness of quality risk present in the individual design guides,but an overall risk picture is not presented.Input from the fields of project management and psychology can help develop risk awareness strategies.The design guides may benefit from an aggregate level of information,where main technical challenges are grouped into super-level categories.
基金the CONICYT Programa Formacion de Capital Humano Avanzado/Master Becas Chile(No.2017-73180687)。
文摘Geotechnical classification is vital for site characterization and geotechnical design.Field tests such as the cone penetration test with pore water pressure measurement(CPTu)are widespread because they represent a faster and cheaper alternative for sample recovery and testing.However,classification schemes based on CPTu measurements are fairly generic because they represent a wide variety of soil conditions and,occasionally,they may fail when used in special soil types like sensitive or quick clays.Quick and highly sensitive clay soils in Norway have unique conditions that make them difficult to be identified through general classification charts.Therefore,new approaches to address this task are required.The following study applies machine learning methods such as logistic regression,Naive Bayes,and hidden Markov models to classify quick and highly sensitive clays at two sites in Norway based on normalized CPTu measurements.Results showed a considerable increase in the classification accuracy despite limited training sets.
