Accuracy and completeness of embodied energy,
EE, analysis is dependant on the method used. This paper demonstrates that by
understanding how energy is consumed in each constituent part and manufacturing
processes of reinforced concrete, designers can significantly reduce the
overall embodied energy structures. Embodied energy of products can vary from
country to country. Therefore, to accurately estimate the embodied energy of RC
structures, data specific to the country where they are being constructed must
be used. This paper presents the assessment of embodied energy in typical
reinforced concrete building structures in Ireland.
The most common methods used to calculate EE
are evaluated in this paper and the most suitable method was applied to
reinforced concrete. The EE of a typical 30MPa concrete mix in Ireland is
calculated to be 1.08 MJ/kg. Notably cement is credited with 68% of the total
EE. The major contributors of energy consumption are identified and it is
envisaged that this will aid in the development of techniques to minimise
energy consumption and optimise efficiency.
A case study is presented which compares the EE
of a typical reinforced concrete structure in Ireland using two concrete mix
designs. The first uses Ordinary Portland Cement, while the second uses ground
granulated blast slag (GGBS) replacing half of the cement content. When
compared, the outcomes are as predicted; the EE of the GGBS mix is
significantly lower (30%) than that of its counterpart. Making the assessment
of embodied energy mandatory will aid in the development of techniques to
minimise energy consumption and optimise efficiency, thus significantly
benefitting the environment.