{"id":{"repo_id":"reykjavik","oai_identifier":"oai:skemman.is:1946/25603"},"canonical_url":"https://search.dev.ndltd.org/etd/reykjavik/oai:skemman.is:1946/25603","repository":{"repo_id":"reykjavik","name":"Reykjavík University","base_url":"https://skemman.is/oai/request"},"display":{"title":"Glulam beams strengthened with pre-stressed basalt fibres","abstract":"Timber has throughout history played an important role in all kinds of construction work where its properties are very sought after. Engineered timber products such as glulam have managed to increase these properties even more with stronger and stiffer material. In recent years new ways have emerged that enhance these properties even further by strengthening it with materials that have more tensile strength and higher modulus of elasticity. To study the effect of gluing basalt fibres on the tension zone of glulam beams an experiment was conducted in the structural laboratory (Sel) of Reykjavik University. 12 glulam beams 3,2 m long, 65 mm wide and 167 mm high in strength class GL30c were randomly divided into 3 groups with 4 beams in each group. For each group the beams were either reinforced with slack basalt fibres, pre-stressed basalt fibres or with no reinforcement for comparison. The reinforcement ratio of the basalt fibres was about 0,45% of the beams cross section for both slack and pre-stressed beams. The pre-stressing was done with cambering where the beam was cambered to the point where the stresses in the timber reached 90% of authorized stresses according to the standard EN 14080:2013. The beams were then tested in a four-point bending test. Results of the experiment showed a 37% increase in moment capacity for the slack reinforced beams and 64% for the beams reinforced with pre-stressed fibres. The modulus of elasticity also increased but not as much as the moment capacity or 11% for the slack reinforced beams and 19% for the pre-stressed beams. When the experimental results were compared with values estimated by calculations to predict the pre-stress in the fibres and the moment capacity, an apparent difference was found in the values where the calculations under estimated the moment capacity and overestimated the pre-stress. Keywords: Strengthened glulam, Basalt fibres, Pre-stressed glulam, Cambering","abstract_html":"Timber has throughout history played an important role in all kinds of construction work where its properties are very sought after. Engineered timber products such as glulam have managed to increase these properties even more with stronger and stiffer material. In recent years new ways have emerged that enhance these properties even further by strengthening it with materials that have more tensile strength and higher modulus of elasticity. To study the effect of gluing basalt fibres on the tension zone of glulam beams an experiment was conducted in the structural laboratory (Sel) of Reykjavik University. 12 glulam beams 3,2 m long, 65 mm wide and 167 mm high in strength class GL30c were randomly divided into 3 groups with 4 beams in each group. For each group the beams were either reinforced with slack basalt fibres, pre-stressed basalt fibres or with no reinforcement for comparison. The reinforcement ratio of the basalt fibres was about 0,45% of the beams cross section for both slack and pre-stressed beams. The pre-stressing was done with cambering where the beam was cambered to the point where the stresses in the timber reached 90% of authorized stresses according to the standard EN 14080:2013. The beams were then tested in a four-point bending test. Results of the experiment showed a 37% increase in moment capacity for the slack reinforced beams and 64% for the beams reinforced with pre-stressed fibres. The modulus of elasticity also increased but not as much as the moment capacity or 11% for the slack reinforced beams and 19% for the pre-stressed beams. When the experimental results were compared with values estimated by calculations to predict the pre-stress in the fibres and the moment capacity, an apparent difference was found in the values where the calculations under estimated the moment capacity and overestimated the pre-stress. Keywords: Strengthened glulam, Basalt fibres, Pre-stressed glulam, Cambering","abstract_has_math":false,"creators":["Guðmundur Ingi Hinriksson 1981-"],"institution":null,"degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":["Háskólinn í Reykjavík"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2016,"date_issued":"2016-08-02","date_published":"2016-08-02","updated_at":"2026-07-27T20:43:09Z","subjects":["Byggingarverkfræði","Meistaraprófsritgerðir","Timbur","Burðarþol","Tækni- og verkfræðideild","Civil engineering","Timber","Strength of materials","School of Science and Engineering"],"languages":["en"],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/1946/25603","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Háskólinn í Reykjavík"]},{"key":"dc:creator","label":"Author","values":["Guðmundur Ingi Hinriksson 1981-"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2016-08-02T11:19:54Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2016-08-02T11:19:54Z"]},{"key":"dc:date.issued","label":"Date","values":["2016-08-02"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Byggingarverkfræði","Meistaraprófsritgerðir","Timbur","Burðarþol","Tækni- og verkfræðideild","Civil engineering","Timber","Strength of materials","School of Science and Engineering"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/1946/25603"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Timber has throughout history played an important role in all kinds of construction work where its properties are very sought after. Engineered timber products such as glulam have managed to increase these properties even more with stronger and stiffer material. In recent years new ways have emerged that enhance these properties even further by strengthening it with materials that have more tensile strength and higher modulus of elasticity. To study the effect of gluing basalt fibres on the tension zone of glulam beams an experiment was conducted in the structural laboratory (Sel) of Reykjavik University. 12 glulam beams 3,2 m long, 65 mm wide and 167 mm high in strength class GL30c were randomly divided into 3 groups with 4 beams in each group. For each group the beams were either reinforced with slack basalt fibres, pre-stressed basalt fibres or with no reinforcement for comparison. The reinforcement ratio of the basalt fibres was about 0,45% of the beams cross section for both slack and pre-stressed beams. The pre-stressing was done with cambering where the beam was cambered to the point where the stresses in the timber reached 90% of authorized stresses according to the standard EN 14080:2013. The beams were then tested in a four-point bending test. Results of the experiment showed a 37% increase in moment capacity for the slack reinforced beams and 64% for the beams reinforced with pre-stressed fibres. The modulus of elasticity also increased but not as much as the moment capacity or 11% for the slack reinforced beams and 19% for the pre-stressed beams. When the experimental results were compared with values estimated by calculations to predict the pre-stress in the fibres and the moment capacity, an apparent difference was found in the values where the calculations under estimated the moment capacity and overestimated the pre-stress. Keywords: Strengthened glulam, Basalt fibres, Pre-stressed glulam, Cambering","Timbur hefur í gegnum tíðina spilað mikilvægt hlutverk í alls konar byggingarframkvæmdum þar sem efniseiginleikar þess hafa verið eftirsóknarverðir. Verkfræðilega hannaðar timbur afurðir eins og límtré hafa náð að auka þessa eiginleika enn frekar svo útkoman verði sterkara og stífara efni. Á síðustu árum hafa komið fram á sjónarsviðið nýjar aðferðir til að auka þessa efniseiginleika enn frekar með því að styrkja límtré með efnum sem hafa meira togþol og hærri fjaðurstuðul. Til að rannsaka áhrif þess að líma basalt trefjar á togbrún límtrésbita var tilraun framkvæmd á rannsóknarsetri Háskólans í Reykjavík í mannvirkjahönnun (SEL). Tólf límtrés bitum, 3,2 m löngum, 65 mm breiðum og 167 mm háum í styrkleikaflokki GL30c var skipt af handahófi niður í 3 hópa þar sem voru 4 bitar í hverjum hóp. Allir bitarnir í hverjum hópi voru annað hvort styrktir með slökum basalt trefjum, forspenntum basalt trefjum eða voru hafðir óstyrktir til viðmiðunar. Styrkingarhlutfall basalt trefjanna var um 0,45% af þversniði bitans bæði fyrir slöku og forspenntu bitana. Forspenna trefjanna var framkvæmd með yfirspennu þar sem bitinn var yfirspenntur þar til spennan í timbrinu hafði náð 90% af leyfilegri spennu samkvæmt staðlinum EN 14080:2013. Bitarnir voru svo prófaðir í fjögurra punkta álags prófi. Niðurstöður rannsóknarinnar sýndu 37% aukningu á vægisþoli fyrir bitana sem styrktir voru með slökum basalt trefjum og 64% aukningu fyrir bitana styrkta með forspenntum basalt trefjum. Fjaðurstuðullinn jókst einnig en þó ekki jafn mikið og vægiþolið eða um 11% fyrir bitana styrkta með slökum trefjum og 19% fyrir forspenntu bitana. Þegar niðurstöður tilraunarinnar voru bornar saman við reiknuð gildi sem áætluðu forspennu í trefjunum og væntanlegt vægiþol, kom fram greinilegur munur þar sem reikningarnir vanáætluðu vægiþolið og ofáætluðu forspennukraftinn. Lykilorð: Styrkt límtré, Basalt trefjar, Forspennt límtré, Yfirspenna"]},{"key":"dc:title","label":"Title","values":["Glulam beams strengthened with pre-stressed basalt fibres"]}]}],"canonical_facts":{"dc:contributor":["Háskólinn í Reykjavík"],"dc:creator":["Guðmundur Ingi Hinriksson 1981-"],"dc:date.accessioned":["2016-08-02T11:19:54Z"],"dc:date.available":["2016-08-02T11:19:54Z"],"dc:date.issued":["2016-08-02"],"dc:description.abstract":["Timber has throughout history played an important role in all kinds of construction work where its properties are very sought after. Engineered timber products such as glulam have managed to increase these properties even more with stronger and stiffer material. In recent years new ways have emerged that enhance these properties even further by strengthening it with materials that have more tensile strength and higher modulus of elasticity. To study the effect of gluing basalt fibres on the tension zone of glulam beams an experiment was conducted in the structural laboratory (Sel) of Reykjavik University. 12 glulam beams 3,2 m long, 65 mm wide and 167 mm high in strength class GL30c were randomly divided into 3 groups with 4 beams in each group. For each group the beams were either reinforced with slack basalt fibres, pre-stressed basalt fibres or with no reinforcement for comparison. The reinforcement ratio of the basalt fibres was about 0,45% of the beams cross section for both slack and pre-stressed beams. The pre-stressing was done with cambering where the beam was cambered to the point where the stresses in the timber reached 90% of authorized stresses according to the standard EN 14080:2013. The beams were then tested in a four-point bending test. Results of the experiment showed a 37% increase in moment capacity for the slack reinforced beams and 64% for the beams reinforced with pre-stressed fibres. The modulus of elasticity also increased but not as much as the moment capacity or 11% for the slack reinforced beams and 19% for the pre-stressed beams. When the experimental results were compared with values estimated by calculations to predict the pre-stress in the fibres and the moment capacity, an apparent difference was found in the values where the calculations under estimated the moment capacity and overestimated the pre-stress. Keywords: Strengthened glulam, Basalt fibres, Pre-stressed glulam, Cambering","Timbur hefur í gegnum tíðina spilað mikilvægt hlutverk í alls konar byggingarframkvæmdum þar sem efniseiginleikar þess hafa verið eftirsóknarverðir. Verkfræðilega hannaðar timbur afurðir eins og límtré hafa náð að auka þessa eiginleika enn frekar svo útkoman verði sterkara og stífara efni. Á síðustu árum hafa komið fram á sjónarsviðið nýjar aðferðir til að auka þessa efniseiginleika enn frekar með því að styrkja límtré með efnum sem hafa meira togþol og hærri fjaðurstuðul. Til að rannsaka áhrif þess að líma basalt trefjar á togbrún límtrésbita var tilraun framkvæmd á rannsóknarsetri Háskólans í Reykjavík í mannvirkjahönnun (SEL). Tólf límtrés bitum, 3,2 m löngum, 65 mm breiðum og 167 mm háum í styrkleikaflokki GL30c var skipt af handahófi niður í 3 hópa þar sem voru 4 bitar í hverjum hóp. Allir bitarnir í hverjum hópi voru annað hvort styrktir með slökum basalt trefjum, forspenntum basalt trefjum eða voru hafðir óstyrktir til viðmiðunar. Styrkingarhlutfall basalt trefjanna var um 0,45% af þversniði bitans bæði fyrir slöku og forspenntu bitana. Forspenna trefjanna var framkvæmd með yfirspennu þar sem bitinn var yfirspenntur þar til spennan í timbrinu hafði náð 90% af leyfilegri spennu samkvæmt staðlinum EN 14080:2013. Bitarnir voru svo prófaðir í fjögurra punkta álags prófi. Niðurstöður rannsóknarinnar sýndu 37% aukningu á vægisþoli fyrir bitana sem styrktir voru með slökum basalt trefjum og 64% aukningu fyrir bitana styrkta með forspenntum basalt trefjum. Fjaðurstuðullinn jókst einnig en þó ekki jafn mikið og vægiþolið eða um 11% fyrir bitana styrkta með slökum trefjum og 19% fyrir forspenntu bitana. Þegar niðurstöður tilraunarinnar voru bornar saman við reiknuð gildi sem áætluðu forspennu í trefjunum og væntanlegt vægiþol, kom fram greinilegur munur þar sem reikningarnir vanáætluðu vægiþolið og ofáætluðu forspennukraftinn. Lykilorð: Styrkt límtré, Basalt trefjar, Forspennt límtré, Yfirspenna"],"dc:identifier.uri":["http://hdl.handle.net/1946/25603"],"dc:language.iso":["en"],"dc:subject":["Byggingarverkfræði","Meistaraprófsritgerðir","Timbur","Burðarþol","Tækni- og verkfræðideild","Civil engineering","Timber","Strength of materials","School of Science and Engineering"],"dc:title":["Glulam beams strengthened with pre-stressed basalt fibres"],"dc:type":["Thesis"]},"updated_at":"2026-07-27T20:43:09Z"}