Through exploring the effects of low pH on the composite system of desulfurization gypsum(DG)enhanced by melamine-formaldehyde resin(MF),it is found that the inducing of sulfate-ion,in contrast to chloride and oxalate...Through exploring the effects of low pH on the composite system of desulfurization gypsum(DG)enhanced by melamine-formaldehyde resin(MF),it is found that the inducing of sulfate-ion,in contrast to chloride and oxalate ions,favors the longitudinal growth of the crystalline form of the hydration product,which was relatively simple and had the highest length to width(L/D)ratio.At the same time,MF can also improve L/D ratio of gypsum hydration products,which favors the formation of hydrated whiskers.Finally,in a composite system composed of hemihydrate gypsum,MF,and glass fibers,when dilute sulfuric acid was used to regulate pH=3-4,the tight binding formed among the components of the composite system compared to pH=5-6.The hydration product of gypsum adheres tightly to glass fiber surface and produces a good cross-linking and binding effect with MF.The flexural strength,compressive strength,elastic modulus,and water absorption of the desulphurized gypsum composite board is 22.7 MPa,39.8 MPa,5608 MPa,and 1.8%,respectively.展开更多
The purpose of this research is to investigate the effect of low-absorbent and reflective building materials(gypsum board)on the acoustic parameters of the room,depending on the type and structure of the cladding.Alth...The purpose of this research is to investigate the effect of low-absorbent and reflective building materials(gypsum board)on the acoustic parameters of the room,depending on the type and structure of the cladding.Although gypsum board(dry cladding system)is widely used in music schools,concert halls,gyms,recording studios,their sound-absorbing properties are generally under-considered,with the main focus on their sound insulation properties.More than 10 types of boards comply with the EN520 standard;each type of board has its own sound-absorbing parameters and is used in different systems.The essence of this study is to evaluate the influence of EN520 plates on the acoustic parameters of the room:Rt;C80 and RASTI.This study does not cover all types of EN520 boards and possible combinations of their applications.This study compared four different wall-cladding systems-single-and double-layer cladding,with and without the use of stone/glass wool in order to determine acoustic properties compliance to function for sport and teaching room space.展开更多
针对相变石膏板和普通石膏板的实际应用热性能进行了实际测试和数值模拟。结果表明:相变石膏板的相变温度为25℃、相变潜热为5 k J/kg时可有效提高室内舒适度,使室内温度波动减少3~5℃,峰值延迟时间为200 min。通过数值模拟得出,相变石...针对相变石膏板和普通石膏板的实际应用热性能进行了实际测试和数值模拟。结果表明:相变石膏板的相变温度为25℃、相变潜热为5 k J/kg时可有效提高室内舒适度,使室内温度波动减少3~5℃,峰值延迟时间为200 min。通过数值模拟得出,相变石膏板搭建的试验箱与普通石膏板相比可节能9.8%,说明相变石膏板具有控温节能的优势。展开更多
文摘Through exploring the effects of low pH on the composite system of desulfurization gypsum(DG)enhanced by melamine-formaldehyde resin(MF),it is found that the inducing of sulfate-ion,in contrast to chloride and oxalate ions,favors the longitudinal growth of the crystalline form of the hydration product,which was relatively simple and had the highest length to width(L/D)ratio.At the same time,MF can also improve L/D ratio of gypsum hydration products,which favors the formation of hydrated whiskers.Finally,in a composite system composed of hemihydrate gypsum,MF,and glass fibers,when dilute sulfuric acid was used to regulate pH=3-4,the tight binding formed among the components of the composite system compared to pH=5-6.The hydration product of gypsum adheres tightly to glass fiber surface and produces a good cross-linking and binding effect with MF.The flexural strength,compressive strength,elastic modulus,and water absorption of the desulphurized gypsum composite board is 22.7 MPa,39.8 MPa,5608 MPa,and 1.8%,respectively.
文摘The purpose of this research is to investigate the effect of low-absorbent and reflective building materials(gypsum board)on the acoustic parameters of the room,depending on the type and structure of the cladding.Although gypsum board(dry cladding system)is widely used in music schools,concert halls,gyms,recording studios,their sound-absorbing properties are generally under-considered,with the main focus on their sound insulation properties.More than 10 types of boards comply with the EN520 standard;each type of board has its own sound-absorbing parameters and is used in different systems.The essence of this study is to evaluate the influence of EN520 plates on the acoustic parameters of the room:Rt;C80 and RASTI.This study does not cover all types of EN520 boards and possible combinations of their applications.This study compared four different wall-cladding systems-single-and double-layer cladding,with and without the use of stone/glass wool in order to determine acoustic properties compliance to function for sport and teaching room space.
文摘针对相变石膏板和普通石膏板的实际应用热性能进行了实际测试和数值模拟。结果表明:相变石膏板的相变温度为25℃、相变潜热为5 k J/kg时可有效提高室内舒适度,使室内温度波动减少3~5℃,峰值延迟时间为200 min。通过数值模拟得出,相变石膏板搭建的试验箱与普通石膏板相比可节能9.8%,说明相变石膏板具有控温节能的优势。
