Composite Constructions of Timber and High-Performance Concrete

Abstract

Currently Timber-Concrete Composite (TCC) Constructions are often applied for strengthening existing timber beam slabs. The load bearing capacity of the composite construction is primarily affected by the material properties of the timber beam and the concrete slab. But the type of bond between both parts is also of high importance. The concrete slab has to perform several tasks, not only in load carrying direction of the ceiling but also perpendicular to the direction of span or for stiffening the whole building. These tasks will be pointed out in this paper. Furthermore the working process (easy workable mixture and exchange of conventional reinforcement) and the dead load of the construction are of particular interest in the field of redevelopment. Several innovative concretes have been verified for the use in TCC constructions. Regarding their fresh and hardened concrete properties, they all can be described as High Performance Concretes (HPC). In this paper Self Compacting Concrete (SCC), Fiber Reinforced Concrete (FRC), Structural Lightweight Concrete (SLWC), High Strength Concrete (HSC) or combinations of them will be focused. Especially the advantages but also the disadvantages of innovative concretes for the use in TCC will be presented as well as the results of some experimental investigations.

The predictive model for strength of inclined screws as shear connection in timber-concrete composite floor

“…They are most commonly used as floor systems. Mechanical fasteners are typically used and there are a number of different types of connectors available with varying effectiveness, price and labour requirement (Kieslich & Holschemacher 2010). Fasteners include nails, screws, spikes, shear keys and proprietary devices.…”

“…TCCs benefit from the composite action, resulting in a significant improvement in strength and stiffness compared to the timber and concrete acting independently (Clouston et al 2005). The level of this benefit depends on the stiffness of the connector, and can range from no connection to rigid connection, with the boundaries of structural efficiency determined by these theoretical limits (Clouston et al 2005;Kieslich & Holschemacher 2010). The literature review of existing theoretical model and experimental investigation indicates that the inclination of The predictive model for strength of inclined screws as shear connection in timber-concrete composite floor F. Moshiri, C. Gerber, H.R.…”

The Effect of Interlayer on the Structural Behavior of Timber Concrete Composite Utilizing Self-Compacting and Conventional Concretes

“…There are only few investigations to study the effect of concrete properties on the structural behavior of TCC system. With the advance in high performance concrete, concrete mixes can be designed to new requirements of strength and serviceability such as self-compacting concrete (SCC), light-weight concrete (LWC) and fiber reinforced concrete (FRC) [3]. The fresh properties of concrete are in retrofit of old timber floor as The authors are with University of Technology, Sydney, Australia (e-mail: farzad.moshiri@student.uts.edu.au, Rijun.Shrestha-1@uts.edu.au, Keith.Crews@uts.edu.au).…”

“…Moreover, concrete needs to be pumpable as some locations, particularly in retrofits may not be able to be reached by crane [3].…”

“…SCC has been used increasingly for more than two decades in pre-cast concrete technology whilst its application in TCC provides a potential development to enhance the workability and flow ability of concrete without the need for an external vibration [3], [4]. The components of SCC and NC are identical consisting of cement, water, aggregates, admixtures, and mineral additions but the composition of the mixture, fresh and hardened properties are different.…”