Sustainability of reinforced concrete frame structures – a case study

Abstract

Traditionally, the engineering education is aiming to establish quantifiable, measurable units, and after that comparing those to utilise the unit considered more suitable. When thinking about sustainability of structures, traditional mentality has to be set aside, as comparing different structural systems is becoming a complex task. Choosing different materials for the same reinforced concrete structure has immediate comparable impact on the environment. Reinforced concrete structures are using excessively the limited limestone and other resources and, in the same time, a large quantity of energy for producing the rebar, the clinker and the structural concrete, having negative impact on the environment. Even if reinforced concrete structures are not generally known as the most sustainable solutions for several structural queries, reinforced concrete structural solutions are preferred for most of the situations due to the other advantages presented by these structures. Hence, considering that specific building indispensable for the society, the aim of obtaining sustainable buildings becomes equivalent to decrease their negative impact on the environment while still taking full advantage of their strength. This target can be achieved by judicious choose of the built-in materials. For a given multistorey reinforced concrete frame building, the scope is to establish the concrete and the reinforcing steel classes in such a way that the impact of these materials on the environment to be kept at the lowest possible level. This paper presents a study on an ordinary reinforced concrete frame structure designed using two different concrete classes (C16/20 and C30/37) and two different reinforcing bar classes (PC52 and S500), obtaining four different possibilities for the same solution. Different combinations of built-in materials are resulting different economic and environmental impacts. The environmental impact for the whole life cycle of the studied solutions, using different material qualities, is estimated using Athena Impact Estimator for Buildings, taking into consideration weighted life-cycle analysis indicators (total energy used, the quantity of solid emissions in air and water, the required natural resources consumed -especially the non-renewable ones -the impact owed to the depletion of the natural resources, human health and the impact on the ecosystems). Besides the environmental impact estimation, realisation cost is also evaluated for each structural solution, obtaining a relationship between the cost (as the major decision influencer) and the sustainability of the studied solutions.

Transformative role of machine learning in design optimization of reinforced concrete frames

“…The restrictions and elements that must be taken into account while developing and optimizing a concrete building frame are referred to as constraints in RC frame optimization [79]. These limitations cover a wide range of topics, such as structural specifications [80], material qualities [81], adherence to building standards [82], economic variables [83], aesthetics [84], safety [85], environmental considerations [86], and geotechnical elements [65]. A cost-effective and structurally sound design that satisfies project objectives and regulatory requirements must strike a balance between these restrictions.…”

Some Properties of Self-Compacting Concrete with Optimum Percentages of Cement Replacement Materials

“…It was firstly developed in Japan in 1980 (EFNARC, 2005). It can be considered as a sustainable material due to the ability of decreasing cement content using alternative materials which might increase its compressive strength (Puskas & Moga, 2015). It has many benefits compared to conventional concrete, such as eliminating vibration, high workability, and good pumpability.…”