CHARRING DEPTH OF FIRE PROTECTED STUDS IN TIMBER FRAME WALL ASSEMBLIES EXPOSED TO FIRE
Journal Title: Вісник Національного університету "Львівська політехніка". Серія "Теорія та практика будівництва" - Year 2019, Vol 0, Issue 912
Abstract
The present standards do not consider cases for timber elements covered with fire- resistant penetrating coatings and jointed claddings simultaneously. This article is focused on the influence of such combined fire protection on charring depth of studs in timber frame wall assemblies exposed to fire. A key idea was to investigate rather common in local building types of wall assemblies. Wood panels with rabbet joints as cladding with commercially available fire-coating were used for the frame specimens with loose-fill mineral wool filling. The studs were protected also with timber laths which carried the panels forming an air gap between the cladding and insulation material. Two furnace model scale fire tests were performed in the fire test laboratory of LPNU. Temperature analysis was conducted at control points inside wall assemblies. The calculations according to EN 1995-1-2 are introduced to compare with experimental results. Studies show the impact of investigated coating on the charring rate for studs (150×50 mm), but not for 12 mm wood cladding. Also, using loose-fill mineral wool for insulating tends to char accelerating for the lateral side of studs. The experimental residual cross-section shape considers a faster recession of the wide side surface due to heat transfer through the insulation. Otherwise, timber laths reduce charring of bottom surface exposed to fire. Therefore, residual cross-section shape is different than the predictable traditional form respectively EN. Despite that, this conservative design approach covered experimental data for residual cross-section of unprotected studs. For fire-coating protected studs, experimental results charring depth is smaller against traditional calculations. That reveals the necessity of further improving computational methods. Wood cladding with rabbet joints fell off almost at the same time (unprotected and protected as well). Possible reasons could be insufficient fire-resistant coatings penetrating in the joint area (covering was performed in-situ), air gaps between wood panels due to the geometry tolerance, air gap between the cladding and insulation material (increasing heat transfer after local fall-off), etc. These issues need to be investigated additionally.
Authors and Affiliations
S. S. Bula, T. M. Shnal
Keywords
Related Articles
- EP ID EP673305
- DOI -
- Views 95
- Downloads 0
Застосування вдосконаленого методу розрахунку похилих перерізів залізобетонних балок
The priority task for researchers of building structures is developing methods of calculation, which would allow performing constructions calculations with higher accuracy, preserving the reliability of the design. This...
ВИРОБНИЦТВО, ВЛАСТИВОСТІ І ЗАСТОСУВАННЯ ГАЗОБЕТОНУ НЕАВТОКЛАВНОГО ТВЕРДНЕННЯ
One of the priorities of modern construction industry is to increase the heat-shielding properties enclosing structures and reduce construction costs. Solving these problems is possible through the use in the manufacture...
EFFECT OF COMPONENT COMPOSITION ON PROPERTIES OF ENGINEERED CEMENTITIOUS COMPOSITES
The application of engineering cementitious composites (ECC) – a specially developed class of cement-based material reinforced with fibers – allows to enhance the loading capacity, stability under static and dynamic infl...
Heat pump heating systems and low potential heat sources
This paper focuses on the application of renewable energy resources in the form of heat pumps and their use in heating systems. As the energy prices are constantly rising, the energy management is currently a very import...
МІЦНІСТЬ ЗАЛІЗОБЕТОННИХ БАЛОК, ПІДСИЛЕНИХ ПОПЕРЕДНЬО НАПРУЖЕНОЮ АРМАТУРОЮ
This article describes strengthening normal cross-section of reinforced concrete beams with prestressed reinforcement under load. The samples of RC beam with 2100 mm. length, 100 mm width, and 200 mm height was tested. A...