# Proposal for the Evaluation of Eco-Efficient Concrete
## 3 Proposed Assessment Method for the Eco-Efficiency of Concrete
### Eco-Efficiency Assessment Method of Concrete
#### 3.4.1 Environmental Performance (EP)
The classification of abiotic depletion potential (ADP) based on the standards provided by Guinee (1995) [23], takes into account a total of 89 resource items including crude oil, natural gas, and uranium (U). Acidification potential (AP) varies widely according to regional characteristics and atmospheric environments, and we applied the AP index presented by [PERSON] et al. and [PERSON] [24] applicable to all regional types. A total of 23 inventory items linked to acidification category, including sulfur dioxide (SO\({}_{2}\)), hydrogen sulfide (H\({}_{2}\)S), and hydrogen fluoride (HF), are expressed in terms of their standard substance SO\({}_{2}\). Likewise, the index proposed by [PERSON] et al. and [PERSON] was applied for the classification of the eutrophication potential (EP), with phosphate (PO\({}_{4}\)\({}^{3-}\)) used as the standard substance for a total of 11 inventory items including phosphate (PO\({}_{4}\)\({}^{3-}\)), ammonia (NH\({}_{3}\)), and nitrogen oxides (NO\({}_{x}\)). For the ozone depletion potential (ODP), we applied the ODP index specified in the World Meteorological Organization (WMO) [25] for a total of 23 inventory items, including CFC-11, Halon-1301, and CFC-114, with trichloro-fluoro-methane (CFC-11) as the standard substance. For the photochemical oxidant creation potential (POCP), a total of 128 inventory items were considered, including ethylene, NMVOC, and ethanol, with ethylene being the standard substance, thereby applying the POCP index proposed by [PERSON] et al. [26] and [PERSON] [27]. Characterization is a process of quantifying the environmental impact of inventory items itemized for each category in the classification step. In the classification step, inventory items are assigned to their respective environmental impact categories, but there is a limitation in quantifying the potential impacts of inventory items in common metrics due to different impact potentials. Category indicator results, i.e., characterization values, are calculated in the characterization step where the environmental impact (=inventory data) of each inventory item is multiplied with the characterization factor (=impact potential) unique to the impact category concerned, and the resulting environmental impact thus converted into impacts are aggregated within each impact category to yield the overall environmental impact of that category (Equations (3)-(8)). Global Warming Potential (GWP) \[=\] Environmental impact  
\[\times\]  
Characterization factor for GWP (3) Ozone Depletion Potential (ODP) \[=\] Environmental impact  
\[\times\]  
Characterization factor for ODP (4) Acidification Potential (AP) \[=\] Environmental impact  
\[\times\]  
Characterization factor for AP (5)_Abiotic Depletion Potential (ADP)_ = Environmental impact \(\times\) Characterization factor for ADP (6) _Photochemical Oxidant Creation Potential (POCP)_ = Environmental impact \(\times\) Characterization factor for POCP (7) _Eutrophication Potential (EP)_ = Environmental impact \(\times\) Characterization factor for EP (8)  
(3) Damage assessment  
Environmental cost, shown by Equation (9), converts the damage done to human beings and the ecosystem by the production of concrete into an economic value. Environmental cost is calculated by multiplying the damage factor of each safeguard subject and the economic value of each damage indicator for influential substances that belong to an environmental impact category (Figure 6). \[D_{k}\,=\,\sum(Load_{ij}\times DF_{k,ij}\times K_{c}) \tag{9}\]  
Here, \(Load_{ij}\) is the environmental load of influential substance \(j\) that belongs to impact category \(i\), \(DF_{k,ij}\) is the damage factor for the damage caused by influential substance \(j\) that belongs to impact category \(i\) on safeguard subject \(k\), and \(K_{c}\) is the economic value (KRW) of safeguard subject \(k\). (a) Safeguard subject  
From the viewpoint of environmental ethics, the environment is mainly divided into the human environment and the ecosystem.