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Selecting an appropriate flooring system is essential for structures. Flooring system design has traditionally focused on weight loss and minimizing costs. However, in recent years, the focus of this sector has changed to include improving the environmental performance of building materials and construction systems. This paper illustrates a knowledge-based expert system as a tool to assess of flooring systems such as block joisted (BJ), steel-concrete composite (SCC), composite steel deck (CSD) and concrete slab (CS) based on sustainability criteria that are further divided into twenty sub-criteria. Analytical hierarchy process (AHP) is utilized as a multi-criteria decision making technique that helps to compute weights and rankings of sustainability criteria. For this purpose, some questionnaires completed by construction industry experts in order to compare criterions and sub-criteria in addition to assessment of optimized flooring systems. Then, results of the questionnaires are ranked by AHP and the most significant alternative is selected. The AHP results indicate that CSD system 47.9%, CS; 29.8%, SCC; 12.7% and BJ system 9.6% are the most and the least efficient systems, respectively.

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The global population growth and the subsequent surge in housing demand have inevitably led to an increase in the demand for concrete, and consequently, cement. This has posed environmental challenges, as cement factories are significant contributors to carbon dioxide emissions. One promising solution is to incorporate pozzolanic materials into concrete production. This study investigates the effects of using travertine sludge as a partial substitute for cement. Seven different mix designs, along with a control mix, were created and compared. The primary variable was the ratio of travertine sludge to cement weight, considered in intervals of 10%, 15%, 20%, 25%, 30%, 35%, and 40% of the cement's weight. Various tests were conducted, including compressive strength and flexural strength at ages of 7, 28, and 90 days, as well as a permeability test at 28 days. The findings revealed interesting patterns. At the 7-day mark, as the percentage of travertine sludge increased, there was a decrease in compressive strength. However, by the 28-day mark, the concrete displayed a varied behavior: using up to 30% travertine sludge by weight reduced the strength, but exceeding 30% resulted in increased strength. At the 90-day mark, an overall increase in strength was observed with the rise in travertine sludge percentage. Such pozzolanic effects on compressive strength were somewhat predictable. Additionally, based on the flexural strength tests, travertine sludge can be deemed a viable substitute for a certain percentage of cement by weight. This research underscores the potential of sustainable alternatives in the construction industry, promoting both professional development and personal branding for those engaged in eco-friendly practices.