Current environmental crisis calls for sustainable solutions in the building industry. One of the possible solutions is to incorporate timber-framed constructions into designs. Among other benefits, these structures are well established in many countries, originating in traditional building systems. This paper focuses on experimental timber-frame walls. Different wall assemblies vary in thermal insulation materials and their combinations. We investigated ten experimental wall structures that have been exposed to natural external boundary conditions since 2015. The emphasis was on their state in terms of visual deterioration, mass moisture content, and thermal conductivity coefficient. We detected several issues, including defects caused by inappropriate realization, causing local moisture increase. Material settlement in loose-fill thermal insulation was another issue. Concerning was a significant change in the thermal conductivity of wood fiber insulation, where the current value almost doubled in one case compared to the design value determined by the producer.
In the case of existing prestressed concrete structures, information about the actual state of prestressing is an important basis for determining their load-carrying capacity, as well as remaining service lifetime. This is even more important in the case of existing prestressed concrete bridges, which are exposed to a more aggressive environment than the other prestressed concrete structures. The level of prestressing is affected and reduced by prestress losses at a given time. In calculating the internal forces and stresses, required for the assessment of the Ultimate Limit State and the Serviceability Limit State, it is necessary to know not only the prestressing level but also the cross-sectional area of the prestressing steel (wire, strand or cable), which can change in time due to corrosion. In practice, in the case of the pre-tensioned concrete members, it has often happened in the past that cable ducts have been grouted only partially, or not at all, due to poor grouting technology. Experts did not realize what this could cause in the future—the penetration of water with aggressive agents directly into the cable duct and consequently corrosion of the prestressing steel, which means not increased protection of the steel, but rather acceleration of degradation. On the other hand, in many cases, corrosion also occurs in ducts that are not grouted and no water has entered them. This paper deals with this phenomenon—the formation of corrosion of prestressing steel in cable ducts in ungrouted ducts due to moisture. This problem was investigated experimentally and numerically in the simulation program ESP-r. Experimental measurements and numerical simulations have shown that the water vapor condenses in the cable ducts, which can subsequently cause corrosion of the prestressing steel.
High-performance buildings became necessary in terms of the environment and energy consumption. The wooden houses report high efficiency in this regard. This paper contains an analysis of selected lightweight wooden envelope structure designed in the nearly zero-energy demand for heating standard. Evaluated will be the energy and hygrothermal performance of the selected structure. These will be based on results of pavilion measurements (constant interior conditions and real external boundary conditions) and results of measurements in climate chambers during various boundary conditions. Afterwards, the results of numerical simulations will be presented, configured according to experimental measurements.
The advancing times and legislation require constant research of new progressive building envelope structures. Walls based on wooden material are perspective in this regard. These are capable of elimination the wall thickness while providing the required thermal resistance. The pavilion research of KPSU UNIZA laboratory includes this kind of wall structures intended for passive wooden houses. This paper deals with one of the researched wall assemblies in the annual operation. The measurements show that such a construction is suitable for near to zero energy buildings. It also points out that the correct design can eliminate thermal bridges in the area of the load-bearing wooden studs.
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