Moisture Accumulation in Building Façades Exposed to Accelerated Artificial Climatic Ageing—A Complementary Analysis to NT Build 495

Building façades must endure severe climatic exposure throughout their lifetimes. To prevent damage and expensive repairs, ageing tests are used in durability assessments. The NT Build 495 describes an artificial ageing procedure to address building material and component resistance to ultraviolet (UV) light, heat, water, and frost using a climate simulator. The test has been used for decades to investigate exterior surface materials and façade products but has only recently been adopted for multi-layered systems. This study investigates moisture accumulation in a façade system for retrofitting based on concrete and thermal insulation. Hygrothermal simulations of the façade system subjected to ageing were conducted. Moisture accumulation was considered theoretically for the current test procedure and compared to a modified setup in which the interior climate was controlled at 21 °C. Physical measurements were performed in the climate simulator to determine the boundary conditions. Results showed that moisture accumulation in the thermal insulation was largely affected by the type of concrete, that applying a water-repellent surface treatment reduced moisture accumulation, and that the current setup resulted in less moisture accumulation compared to the modified setup. The latter implicates accelerated degradation with the modified setup.

Download Full-text

Study on Spread of Fire Overflow on Building Facades with Insulation Materials

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.405-408.2438 ◽

2013 ◽

Vol 405-408 ◽

pp. 2438-2442

Author(s):

Yan Feng Li ◽

Cong Cong Xu ◽

Xue Fei Xing ◽

Jin Zhang ◽

Cheng Hu

Keyword(s):

Numerical Simulation ◽

Thermal Insulation ◽

Maximum Temperature ◽

Computational Results ◽

Exterior Wall ◽

Insulation Layer ◽

Insulation System ◽

High Rise ◽

Building Facades ◽

Fire Barrier

Fire overflow on exterior wall with thermal insulation system has been studied by numerical simulation. The spread laws of fire overflow are analyzed through the temperature distribution near the window. The computational results are compared with those of test in the Exterior Insulation Fire Barrier Technical Guidelines (EIFBTG). It has been found that the calculated maximum temperature points is closed to the test on the first floor, the first ceiling, and the points near the above two windows. However, there are differences between two kinds of results above two floors and ceilings, and the points near the first window. It has also shown that when the HHR is 7.5KW, the scope of damage of exterior thermal insulation layer is about 15 square meters near the window. The research would provide reference for fire protection design of exterior wall thermal insulation in the high-rise buildings.

Download Full-text

Performance of wood treated with prospective organic surface protectants upon outdoor exposure: FTIR spectroscopic analysis of weathered surfaces

Holzforschung ◽

10.1515/hf-2011-0247 ◽

2013 ◽

Vol 67 (2) ◽

pp. 227-235 ◽

Cited By ~ 4

Author(s):

Christoph F. Schauwecker ◽

Armando G. McDonald ◽

Jeff J. Morrell

Keyword(s):

Pinus Taeda ◽

Loblolly Pine ◽

Lignin Degradation ◽

Structural Integrity ◽

Uv Light ◽

Outdoor Exposure ◽

Water Repellent ◽

Surface Protection ◽

Alternative Materials ◽

Lignin Depolymerization

Abstract Visual appeal of wood is as important as its structural integrity in outdoor applications. Discoloration and checking of wood favor the utilization of alternative materials for outdoor cladding and decking. Lignin depolymerization is one of the critical processes leading to weathering. In the present paper, the potential of different classes of surface protection agents has been assessed on loblolly pine (Pinus taeda) impregnated with water repellents, organic UV inhibitors, and an organic biocide. The treated samples were exposed to predetermined doses of solar radiation in Eastern Oregon, and the chemical changes occurring on the surfaces were evaluated by FTIR spectroscopy. After 1-year exposure, lignin loss was complete on all surfaces; however, some treatments provided longer term protection than others. Organic UV light inhibitors were most effective in this regard. A petroleum-based water repellent with a melting point of 54–58°C also provided protection against lignin degradation.

Download Full-text

Super Water-Repellent Fractal Surfaces of a Photochromic Diarylethene Induced by UV Light

Japanese Journal of Applied Physics ◽

10.1143/jjap.47.7298 ◽

2008 ◽

Vol 47 (9) ◽

pp. 7298-7302 ◽

Cited By ~ 14

Author(s):

Norikazu Izumi ◽

Takayuki Minami ◽

Hiroyuki Mayama ◽

Atsushi Takata ◽

Shinichiro Nakamura ◽

...

Keyword(s):

Uv Light ◽

Water Repellent ◽

Fractal Surfaces

Download Full-text

Development of Eddy Current Test Procedure for Non-destructive Detection of Fatigue Cracks and Corrosion in Rivets of Air-intake Structures

Defence Science Journal ◽

10.14429/dsj.59.1497 ◽

2009 ◽

Vol 59 (2) ◽

pp. 106-112 ◽

Cited By ~ 11

Author(s):

B. Sasi

Keyword(s):

Eddy Current ◽

Fatigue Cracks ◽

Test Procedure ◽

Eddy Current Test ◽

Current Test ◽

Air Intake ◽

Non Destructive

Download Full-text

Influence of Waste Plastic Aggregate and Water-Repellent Additive on the Properties of Lightweight Magnesium Oxychloride Cement Composite

Applied Sciences ◽

10.3390/app9245463 ◽

2019 ◽

Vol 9 (24) ◽

pp. 5463 ◽

Cited By ~ 6

Author(s):

Martina Záleská ◽

Milena Pavlíková ◽

Ondřej Jankovský ◽

Michal Lojka ◽

Filip Antončík ◽

...

Keyword(s):

Thermal Insulation ◽

High Efficiency ◽

Cement Composite ◽

Thermal Parameters ◽

Silica Sand ◽

Water Vapor Transport ◽

Water Repellent ◽

Cement Composites ◽

Waste Plastic ◽

Magnesium Oxychloride

The aim of the present study is to improve the thermal and hygric performance of magnesium oxychloride (MOC) cement composites by the incorporation of waste plastic-based aggregate and the use of the inner and surface hydrophobic agents. The crushed waste expanded polypropylene particles were used as a full replacement of natural silica sand. The aggregate properties were evaluated in terms of their physical and thermal parameters. The caustic calcined magnesite was studied by SEM, XRF, and XRD spectroscopy. The MOC cement composites were characterized by SEM/EDS, XRD, and FT-IR spectroscopy and measurement of their structural properties, strength parameters, thermal conductivity, and volumetric heat capacity. Assessment of water- and water vapor transport properties was also conducted. The results show significantly improved thermal parameters of MOC cement composite containing expanded polypropylene (EPP) as aggregate and indicate high efficiency of surface hydrophobic agent (impregnation) as a barrier against the transport of liquid and gaseous moisture. The resulting lightweight EPP-MOC cement composite with improved thermal insulation function and suitable mechanical properties can be used to produce thermal insulation floors, ceilings, or wall panels reducing the operational energy demand of buildings.

Download Full-text