A. Shop Drawings and Details for Tests
B. Sound and Impact Test Results Summary
C. Test 1: Sound and Impact Transmission Test - CLT
D. Test 2: Sound and Impact Transmission Test - Concrete Topping
E. Test 3a: Sound and Impact Transmission Test - Marmoleum
F. Test 3b: Sound and Impact Transmission Test - Marmoleum
G. Test 4: Sound and Impact Transmission Test - Carpet
H. Test 5a: Sound and Impact Transmission Test - Luxury Vinyl Plank
I. Test 5b: Sound and Impact Transmission Test - Luxury Vinyl Plank
J. Test 6: Sound and Impact Transmission Test - Mechanical Roof
Timber-concrete composite (TCC) ceilings build on the idea of making use of the advantageous properties of both materials symbiotically. While concrete, as the upper layer, is used to absorb the compression forces, wood is used in the lower layer to absorb the tensile forces. Many systems have been developed with special attention paid to solutions with both a continuous concrete and wood layer. This article introduces a new system developed with the primary focus set on the most efficient material use by introducing a free space between the concrete and the wood layer using special vault shaped moldings. The first part of the paper contains an introduction including a short overview of different embodiments of TCC floor systems. The second part focuses on the design of the new system and gives an overview of the estimated structural performance. In the third part the environmental performance of the new system is discussed in comparison to chosen existing systems focusing at the the whole life-cycle including a re-use (A-D).
Composite structures use the advantages of two materials – timber and concrete – and improve the efficiency of a material application. Especially the concept of timber-concrete-composite ceilings has synergetic effects to achieve an effective ratio of thickness to span with high cost effectiveness simultaneously. Following the systematic...
This paper deals with the possibilities of using coupled timber-concrete structures by means a glued coupling bar. The described process of static reinforcement is particularly suitable for reconstruction of historic timber ceilings and places where it is necessary to prevent damage to non-supporting structures (e.g. ceiling, plaster, stucco decorations, etc.). The method is also employed in those cases where it is necessary to allow traffic-flow in the rooms below the reconstructed ceiling. The article describes the specific technological process that has been examined in the reconstruction of the ceiling structure of a house on Sokolska Street in Ostrava. Following experimental testing in laboratories at the Faculty of Civil Engineering VSB - TU Ostrava the technology of bonded shear bars under static reinforcement of timber ceilings was first applied and successfully tested in construction practice.
Journal of Sustainable Architecture and Civil Engineering
Cross-laminated timber is a structural material, which successfully used for structural purposes during the last years. The material is environmentally friendly and decreases CO2 emissions. Cross-laminated timber possesses a decreased level of anisotropy in comparison with solid and glued timber. It is significant for structural units working in bending. So, cross-laminated timber panels are considered as an object of investigation. Design methodology for cross-laminated timber panels subjected to flexure was presented. The methodology is based on LVS EN1995-1-1 and laminated plate theory. The presented methodology was tested experimentally and analytically. Behavior and mechanical properties of cross-laminated timber are analyzed for case of static loading. Two panels with thickness 95mm consisting from three layers were tested in laboratory. Freely supported panels with span equal to 2m, which is loaded by the uniformly distributed load was a design scheme of considered panels. The panel’s width was equal to 1m. Analytical FEM design method, which is based on the using of computational program ANSYSv14 and RFEM5.0, was checked by the experiment. The comparison of stresses acting in the edge fibers and vertical displacements shows that the considered design methodology can be used for engineering calculations. The result difference changes in limits to 30%.
Project contact is Rokib Hassan at the National Research Council of Canada
Phase two of a four-phased research project, with the overarching goal of developing transparent intumescent coating (TIC) for mass timber construction, which would be technology certified, IP protected and licensed out. The use of TIC would ensure that fire resistance rating requirements are met while reducing the need for encapsulation, resulting in increased overall aesthetics provided by timber. Phase two focuses on demonstrating a proof-of-concept on a small scale and optimizing the TIC formula and coating thickness based on the testing results. Small scale tests will be conducted to measure fire resistance, weatherability and fire toxicity.
Project contact is Mark Weaver at Karagozian & Case
Buildings for the U.S. Department of State (DOS) and U.S. Department of Defense (DOD) often have to meet blast as well as forced entry / ballistic resistance (FE/BR) design requirements to mitigate the hazardous effects associated with terrorism. Historically, DOS and DOD buildings exposed to these threats have been constructed using concrete and steel. However, the emergence of cross-laminated timber (CLT) presents an opportunity to provide a sustainable building material alternative to owners and architects developing such structures. Several wood characteristics (i.e., propensity to rupture in a brittle fashion upon being overstressed, relatively low penetration resistance) serve to limit CLT’s effectiveness in resisting blast and FE/BR threats. The proposed effort seeks to address these limitations by investigating the possibility of incorporating commercial off-the-shelf (COTS) building materials into CLT panel designs in order to meet DOS/DOD blast and FE/BR design requirements. Particular emphasis will be placed on ensuring the developed panel designs are cost competitive to facilitate their inclusion in actual buildings. The project team includes an American CLT manufacturer to quickly assess the cost impacts of incorporating COTS materials into CLT panel layups. Additionally, representatives from the DOS, DOD, and an architecture firm routinely involved with the design of DOS buildings will be consulted to ensure programmatic, aesthetic, and detailing issues are considered during candidate panel design development.
Timber-concrete composite (TCC) solutions are not a novelty. They were scientifically referred to at the beginning of the 20th century and they have proven their value in recent decades. Regarding a TCC floor at the design stage, there are some assumptions, at the standard level, concerning the action of concentrated loads which may be far from reality, specifically those associating the entire load to the beam over which it is applied. This naturally oversizes the beam and affects how the load is distributed transversally, affecting the TCC solution economically and mechanically. Efforts have been made to clarify how concentrated loads are distributed, in the transverse direction, on TCC floors. Real-scale floor specimens were produced and tested subjected to concentrated (point and line) loads. Moreover, a Finite Element (FE)-based model was developed and validated and the results were collected. These results show that the “loaded beam” can receive less than 50% of the concentrated point load (when concerning the inner beams of a medium-span floor, 4.00 m). Aiming at reproducing these findings on the design of these floors, a simplified equation to predict the percentage of load received by each beam as a function of the floor span, the transversal position of the beam, and the thickness of the concrete layer was suggested.
An experimental study of the influence of an exposed combustible ceiling on compartment fire dynamics has been performed. The fire dynamics in compartments with combustible cross-laminated timber ceilings vs non-combustible reinforced concrete ceilings in otherwise identical compartments with three different ventilation factors were investigated. The experimental results are compared against predictions from two theoretical models for compartment fire dynamics: (a) the parametric fire model given in EN 1991-1-2, and (b) a model developed at Technische Universität Braunschweig, which are the parametric fire models currently used in Germany. It is confirmed that the introduction of a combustible timber ceiling leads to higher temperatures within the enclosure, both under fuel-controlled and ventilation-controlled scenarios. It is also demonstrated that the theoretical models considered in this article require refinement in order to adequately represent all relevant scenarios when combustible ceilings are present. A refinement of the German model, by adding the fuel from the combustible ceiling to the occupancy fuel load, was shown to not adequately capture the response for the ventilation-controlled fires.
Cross-laminated timber (CLT) is an engineered wood product made up of layers of structurally graded timber, where subsequent layers are oriented orthogonally to each other. In CLT, the layers oriented in transverse direction, generally termed as cross-layer, are subjected to shear in radial–tangential plane, which is commonly known as rolling shear. As the shear modulus of cross-layers is significantly lower than that in other planes, CLT exhibits higher shear deformation under out-of-plane loading in contrast to other engineered wood products such as laminated veneer lumber (LVL) and glue laminated timber (GLT). Several analytical methods such as Timoshenko, modified gamma and shear analogy methods were proposed to account for this excessive shear deformation in CLT. This paper focuses on the effectiveness of Timoshenko method in hybrid CLT, in which hardwood cross-layers are used due to their higher rolling shear modulus. A comprehensive numerical study was conducted and obtained results were carefully analyzed for a range of hybrid combinations. It was observed that Timoshenko method could not accurately predict the shear response of CLTs with hardwood cross layers. Comprehensive parametric analysis was conducted to generate reliable numerical results, which were subsequently used to propose modified design equations for hybrid CLTs.