دانلود رایگان مقاله انگلیسی عملکرد محیطی سازه های چوبی مختلف برای سقف های شیبدار - نشریه الزویر

abstract

The construction industry is one of the most important actors in the global sustainability act, seeing as it is responsible for a significant negative load over the natural environment. In the journey towards minimising these damaging effects, the first key step is understanding the environmental performances of the materials used in this sector. Taking into account that forests have a crucial role in sustaining life, analysing the environmental impact of wood as a construction material represents a necessary task for civil engineers. The present paper aims at evaluating and comparing the environmental performances of three timber structures for pitched roofs: the trestle frame roof structure, the roof structure with collars, and the trussed rafter roof structure. The environmental burdens have been determined by using the cradle-to-cradle Life Cycle Assessment methodology and the GaBi ts software. Upon analysing the results, the authors have concluded that the roof structure with collars has the lowest impact over the Earth's ecosystem. The study also shows that even if the trestle frame is the leading environmentally friendly solution over the pre- and post-operation phases, this structural system is responsible for the highest unfavourable effects over its entire life cycle. The authors argue that by using the roof structure with collars, the damaging load of the construction sector over the natural environment is one step closer to being minimised.

7. Conclusions

Considering that the construction sector has a tremendous role in the efforts towards achieving sustainable development at the global scale, seeing as it is an industry with a significant impact over the Earth's ecosystem, the authors consider that knowing and understanding the environmental effects of building materials represents an important step in the design process of a structure. Taking into account that forests have a critical function in sustaining life, by using wood as a construction material, the natural environment can be substantially influenced in a negative manner. This aspect stood as the primary reason in conducting the presented LCA studies, with the goal of determining the timber roof system with the lowest load over the natural environment by considering a cradle-to-cradle approach.

The performed analyses illustrate that by way of the cradle-togate approach, the roof structure with collars has the most advantageous benefit regarding the amount of CO2 equivalent, this construction system exerting the most significant negative carbon footprint in the case of GWP, including the biogenic carbon parameter; the resulted value is approximately 1.25 and 2.35 times larger than the one resulted in the first and respectively, in the last case study. If we take into account all the considered environmental parameters, we can conclude that the trestle frame roof system is the most environmentally friendly option due to the fact that the ecological influence of this structure is lower than that of the other two considered roof solutions for 11 indicators. In the case of these parameters, the highest difference has been registered for ODP, where the impact in case study no. 1 is approximately 21 times lower than the one resulted in the last case study, while the lowest ecological difference was marked between the first two case studies for the Ecotoxicity for aquatic freshwater indicator, where the impact resulted for the trestle frame roof structure represents approximately 96% of the one exerted by the roof structure with collars.