scholarly journals Moisture Dry-Out Capability of Steel-Faced Mineral Wool Insulated Sandwich Panels

2020 ◽  
Vol 12 (21) ◽  
pp. 9020
Author(s):  
Kristo Kalbe ◽  
Hubert Piikov ◽  
Targo Kalamees
Keyword(s):  
Moisture Transport ◽  
Sandwich Panel ◽  
Sandwich Panels ◽  
Internal Surface ◽  
Mineral Wool ◽  
Construction Time ◽  
Knowledge Based ◽  
Time Of Wetness ◽  
Dry Out ◽  
Vertical Joint

Moisture dry-out from steel-faced insulated sandwich panels has previously received little attention from researchers. This paper reports the results from laboratory tests and dynamic heat, air, and moisture transport simulations of the moisture dry-out capabilities of a steel-faced sandwich panel with a mineral wool core. Three test walls (TWs) with dimensions of 1.2 m × 0.4 m × 0.23 m were put above water containers to examine the moisture transport through the TWs. A calibrated simulation model was used to investigate the hygrothermal regime of a sandwich panel wall enclosure with different initial moisture contents and panel joint tightening tapes. The moisture dry-out capacity of the studied sandwich panels is limited (up to 2 g/day through a 30-mm-wide and 3-m-long vertical joint without tapes). When the vertical joint was covered with a vapour-permeable tape, the moisture dry-out was reduced to 1 g/day and when the joint was covered with a vapour-retarding tape, the dry-out was negligible. A very small amount of rain would be enough to raise the moisture content to water vapour saturation levels inside the sandwich wall, had the rain ingressed the enclosure. The calculated time of wetness (TOW) on the internal surface of the outer steel sheet stayed indefinitely at about 5500 h/year when vapour-retarding tapes were used and the initial relative humidity (RH) was over 80%. TOW stabilised to about 2000 h/year when a vapour-permeable tape was used regardless of the initial humidity inside the panel. A vapour-permeable tape allowed moisture dry-out but also vapour diffusion from the outside environment. To minimise the risk of moisture damage, avoiding moisture ingress during construction time or due to accidents is necessary. Additionally, a knowledge-based method is recommended to manage moisture safety during the construction process.

scholarly journals Use of Blind Rivets in Sandwich Panels—Experimental Investigation of Static and Quasi-Cyclic Loading

Buildings ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 155
Author(s):  
Robert Studziński ◽  
Katarzyna Ciesielczyk
Keyword(s):  
Experimental Investigation ◽  
Cyclic Loading ◽  
Sandwich Panel ◽  
Tensile Force ◽  
Sandwich Panels ◽  
Core Layer ◽  
Mineral Wool ◽  
Expanded Polystyrene ◽  
Eccentric Load ◽  
Pull Out

In this paper, we present an original experimental investigation on a pull-out test of a blind rivet from the external facing of sandwich panels with various core layer materials (polyisocyanurate foam, mineral wool, and expanded polystyrene). The blind rivets were subjected to an axial and eccentric tensile force introduced as static and quasi-cyclic loading. The statistical sample size was 5. The laboratory results depicted that the core layer of a sandwich panel influenced the load-displacement path of the investigated blind rivet connections, regardless of the nature of the load (static, quasi-cyclic) and the point of the load application (axial, eccentric). It was observed that the blind connection with the polyisocyanurate foam core sandwich panel was characterized by a reduction of both the capacity and the secant stiffness when compared with the blind connection with the mineral wool or the expanded polystyrene core sandwich panels. Moreover, the tested connections demonstrated that the eccentric load gave a higher flexural stiffness than the axial load and that the quasi-cyclic load did not reduce their stiffness and capacity.

scholarly journals Blast Test and Failure Mechanisms of Soft-Core Sandwich Panels for Storage Halls Applications

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 70 ◽  
Author(s):  
Robert Studziński ◽  
Tomasz Gajewski ◽  
Michał Malendowski ◽  
Wojciech Sumelka ◽  
Hasan Al-Rifaie ◽  
...  
Keyword(s):  
Sandwich Panel ◽  
Shear Failure ◽  
Failure Mechanisms ◽  
Sandwich Panels ◽  
Core Layer ◽  
Mineral Wool ◽  
Expanded Polystyrene ◽  
Blast Load ◽  
Steel Columns ◽  
The Core

In this paper, an experimental investigation is presented for sandwich panels with various core layer materials (polyisocyanurate foam, mineral wool, and expanded polystyrene) when subjected to a justified blast load. The field tests simulated the case for when 5 kg of trinitrotoluene (TNT) is localized outside a building’s facade with a 5150 mm stand-off distance. The size and distance of the blast load from the obstacle can be understood as the case of both accidental action and a real terroristic threat. The sandwich panels have a nominal thickness, with the core layer equal 100 mm and total exterior dimensions of 1180 mm × 3430 mm. Each sandwich panel was connected with two steel columns made of I140 PE section using three self-drilling fasteners per panel width, which is a standard number of fasteners suggested by the producers. The steel columns were attached to massive reinforced concrete blocks via wedge anchors. The conducted tests revealed that the weakest links of a single sandwich panel, subjected to a blast load, were both the fasteners and the strength of the core. Due to the shear failure of the fasteners, the integrity between the sandwich panel and the main structure is not provided. A comparison between the failure mechanisms for continuous (polyisocyanurate foam and expanded polystyrene) and non-continuous (mineral wool) core layer materials were conducted.

scholarly journals The blast relief sandwich panel fixing under the explosion energy action

2021 ◽  
Vol 264 ◽  
pp. 02002
Author(s):  
Vladimir Rybakov ◽  
Olga Gracheva ◽  
Mikhail Ogurtsov ◽  
Saydiolimkhon Abdusattarhuzha ◽  
Ikbaloy Raimova
Keyword(s):  
Polymer Coating ◽  
Sandwich Panel ◽  
Sandwich Panels ◽  
Mineral Wool ◽  
Excess Pressure ◽  
Explosion Energy ◽  
Galvanized Steel ◽  
Technical Solution ◽  
The Moment

This article is devoted to the assessment of the efficiency of using wall sandwich panels with mineral wool core, sheathing made of galvanized steel with a polymer coating, used as blast-relief panels. The article presents the developed seating unit for the wall sandwich panel at the moment of the explosion energy influence. As a result of the experiments carried out, when an excess pressure of no more than 3.0 kPa in the room is reached, the safety shut-off devices ensure the discharge of the displaced element, which avoids damage to the main elements of the frame. According to the results of 2 tests, the actual value of the overpressure for opening the displaced element is 2.7 kPa, which allows the discharge of the displaced element to be ensured. In the course of the study, the expediency of using blast-relief panels(BRP) in the form of wall sandwich panels was substantiated, and this technical solution was implemented at the facility with the possibility of a deflagration explosion

scholarly journals A numerical study of the impact perforation of sandwich panels with graded hollow sphere cores

2021 ◽  
Vol 13 (4) ◽  
pp. 168781402110094
Author(s):  
Ibrahim Elnasri ◽  
Han Zhao
Keyword(s):  
Boundary Conditions ◽  
Hollow Sphere ◽  
Sandwich Panel ◽  
Numerical Study ◽  
Sandwich Panels ◽  
Hopkinson Bar ◽  
Core Density ◽  
The Core ◽  
The Impact ◽  
Force Displacement

In this study, we numerically investigate the impact perforation of sandwich panels made of 0.8 mm 2024-T3 aluminum alloy skin sheets and graded polymeric hollow sphere cores with four different gradient profiles. A suitable numerical model was conducted using the LS-DYNA code, calibrated with an inverse perforation test, instrumented with a Hopkinson bar, and validated using experimental data from the literature. Moreover, the effects of quasi-static loading, landing rates, and boundary conditions on the perforation resistance of the studied graded core sandwich panels were discussed. The simulation results showed that the piercing force–displacement response of the graded core sandwich panels is affected by the core density gradient profiles. Besides, the energy absorption capability can be effectively enhanced by modifying the arrangement of the core layers with unclumping boundary conditions in the graded core sandwich panel, which is rather too hard to achieve with clumping boundary conditions.

scholarly journals Construction and insulation of agricultural buildings and structures

2020 ◽  
Vol 164 ◽  
pp. 02030
Author(s):  
Boris Efimov ◽  
Oleg Rubtsov ◽  
Igor Bessonov ◽  
Andrey Medvedev
Keyword(s):  
Residential Buildings ◽  
Sandwich Panels ◽  
Mineral Wool ◽  
Internal Environment ◽  
Excessive Heat ◽  
Protection Systems ◽  
Insulation Systems ◽  
Weather Impacts ◽  
Storage Facilities

The article covers different application aspects of the products made of polyethylene foam within the scope of insulation systems of framed and frameless constructions used in the quality of storage premises, logistic objects, agricultural storage facilities and livestock facilities as well as framed residential buildings. Agricultural storage facilities, livestock facilities, covered parking areas for agricultural machinery and some types of storage premises represent the agricultural construction facilities which require the established protection systems against excessive heat losses as well as monitoring of the state of the internal environment - its temperature and humidity. These structures are built based on one of three schemes: frameless type, framed type with a rigid coating and framed type with a tent coating. The insulation of buildings constructed before 2010 is predominantly characterized by usage of mineral wool plates (with a protective facade covering) or sandwich panels. The main problem of suchlike coverings is the impossibility of creating an insulating coating without joints, seams or gapless junctions to the base. Mineral wool plates, in case of destruction of the waterproof coating, contact with water and firstly lose their thermal and physical properties, and then – come to the destruction themselves. Sandwich panels are more resistant to weather impacts, but create a coating with huge quantity of cold bridges and paths of convective air transfer through gaps or openings.

Prediction of Sound Transmission Loss for Finite Sandwich Panels Based on a Test Procedure on Beam Elements

2013 ◽  
Vol 135 (6) ◽  
Author(s):  
Zhongchang Qian ◽  
Daoqing Chang ◽  
Bilong Liu ◽  
Ke Liu
Keyword(s):  
Sandwich Panel ◽  
Transmission Loss ◽  
Test Procedure ◽  
Sandwich Panels ◽  
Sound Transmission ◽  
Expansion Method ◽  
Bending Stiffness ◽  
Sound Transmission Loss ◽  
Modal Expansion ◽  
Beam Elements

An approach on the prediction of sound transmission loss for a finite sandwich panel with honeycomb core is described in the paper. The sandwich panel is treated as orthotropic and the apparent bending stiffness in two principal directions is estimated by means of simple tests on beam elements cut from the sandwich panel. Utilizing orthotropic panel theory, together with the obtained bending stiffness in two directions, the sound transmission loss of simply-supported sandwich panel is predicted by the modal expansion method. Simulation results indicated that dimension, orthotropy, and loss factor may play important roles on sound transmission loss of sandwich panel. The predicted transmission loss is compared with measured data and the agreement is reasonable. This approach may provide an efficient tool to predict the sound transmission loss of finite sandwich panels.

scholarly journals SANDWICH PANELS – BEHAVIOR IN FIRE BASED ON FIRE RESISTANCE TESTS

2016 ◽  
Author(s):  
Paweł Roszkowski ◽  
Paweł Sulik
Keyword(s):  
Thermal Insulation ◽  
Fire Resistance ◽  
Temperature Rise ◽  
Sandwich Panel ◽  
Sandwich Panels ◽  
And Behavior ◽  
In Fire ◽  
Resistance Tests ◽  
Building Elements

<p>Sandwich panel is the material that is easy and quickly to install. Basing on a great experience in the area of determination of the fire resistance class of construction building elements the authors describe the properties and behavior of building elements made of the sandwich panels exposed to fire. The article presents the results of fire resistance tests carried out in accordance with EN 1364-1 non-bearing walls made of sandwich panels with use of different cores.</p>The following parameters were analyzed: temperature rise on unexposed side (I – thermal insulation), integrity (E) depending on the orientations and on the width of the sandwich panels, deflection depending on the thickness of the boards. Conclusions were made on the base of the analysis from fire resistance tests.

scholarly journals Laboratory tests and modelling of mineral wool insulated steel sandwich panels

2020 ◽  
Vol 172 ◽  
pp. 17006 ◽  
Author(s):  
Anssi Laukkarinen ◽  
Juha Vinha ◽  
Kristo Kalbe ◽  
Jyrki Kesti ◽  
Targo Kalamees ◽  
...  
Keyword(s):  
Vapour Pressure ◽  
Sandwich Panels ◽  
Mineral Wool ◽  
Water Vapour Pressure ◽  
Limiting Factor ◽  
Insulation Layer ◽  
Water Leakage ◽  
Monitoring Method ◽  
New Radio ◽  
Moisture Conditions

This study presents results from laboratory measurements of mineral wool insulated steel sandwich panels. The purpose of the work was to have a better understanding on the heat and moisture conditions inside sandwich panels and to study how the structure behaves in water leakage situation. The tests were done by sealing the structure from all sides and regulating the temperature on one side of the test structure while measuring the temperature and relative humidity conditions inside the structure. Water leakages were created by injecting liquid water onto the insulation layer. According to the results, water vapour pressure differences stayed relatively small both in stationary and dynamic conditions. This implies that the limiting factor for moisture source was the evaporation rate from the water leakage and that the vapour pressure throughout the insulation layer is determined strongly by the vapour pressure at the possible condensation layer. The paper discusses also the determination of sensor accuracy and impacts of a thermal bridge from the probe itself. Also, measurement results from a new radio wave monitoring method are presented.

Influence of interior layer properties to moisture dry-out of CLT walls

2019 ◽  
Vol 46 (11) ◽  
pp. 1001-1009 ◽  
Author(s):  
Villu Kukk ◽  
Annegrete Külaots ◽  
Jaan Kers ◽  
Targo Kalamees
Keyword(s):  
Moisture Content ◽  
Laboratory Test ◽  
Simulation Model ◽  
Initial Moisture Content ◽  
Mineral Wool ◽  
Test Results ◽  
Interior Layer ◽  
Cross Laminated Timber ◽  
Simulation Results ◽  
Dry Out

The objective of this study was to determine the maximum allowable initial moisture content (MC) for cross-laminated timber (CLT) walls having both exterior and interior thermal insulation. A laboratory test was conducted, for which four test walls with two different insulation solutions and two different MCs were built. Based on the test results, a simulation model was configured and simulations using the model were completed. The simulation results determined that the maximum allowable initial MC of the CLT panels was 17% for walls insulated additionally from inside with mineral wool and 15% for CLT wall assemblies insulated with polyisocyanurate (PIR). Based on these results, it was concluded that the allowable MC ranges between 8% and 16% for construction timber, and therefore, using a PIR board as interior insulation for CLT walls should be undertaken with caution given the very small margin for error in MC.

Dynamic Crushing of All-Metallic Corrugated Panels Filled With Close-Celled Aluminum Foams

2015 ◽  
Vol 82 (1) ◽  
Author(s):  
B. Yu ◽  
B. Han ◽  
C. Y. Ni ◽  
Q. C. Zhang ◽  
C. Q. Chen ◽  
...  
Keyword(s):  
Aluminum Foam ◽  
Sandwich Panel ◽  
Dominant Role ◽  
Sandwich Panels ◽  
Rate Sensitivity ◽  
Aluminum Foams ◽  
Foam Filling ◽  
Plastic Hardening ◽  
Insight Into

Under quasi-static uniaxial compression, inserting aluminum foams into the interstices of a metallic sandwich panel with corrugated core increased significantly both its peak crushing strength and energy absorption per unit mass. This beneficial effect diminished however if the foam relative density was relatively low or the compression velocity became sufficiently high. To provide insight into the varying role of aluminum foam filler with increasing compression velocity, the crushing response and collapse modes of all metallic corrugate-cored sandwich panels filled with close-celled aluminum foams were studied using the method of finite elements (FEs). The constraint that sandwich panels with and without foam filling had the same total weight was enforced. The effects of plastic hardening and strain rate sensitivity of the strut material as well as foam/strut interfacial debonding were quantified. Three collapse modes (quasi-static, transition, and shock modes) were identified, corresponding to different ranges of compression velocity. Strengthening due to foam insertion and inertial stabilization both acted to provide support for the struts against buckling. At relatively low compression velocities, the struts were mainly strengthened by the surrounding foam; at high compression velocities, inertia stabilization played a more dominant role than foam filling.

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