This study aims to develop a system for assessing the impact of the substances discharged from concrete production process on six environmental impact categories, i.e., global warming (GWP), acidification (AP), eutrophication (EP), abiotic depletion (ADP), ozone depletion (ODP), and photochemical oxidant creation (POCP), using the life a cycle assessment (LCA) method. To achieve this, this study proposed an LCA method specifically applicable to the Korean concrete industry by adapting the ISO standards to suit the Korean situations. The proposed LCA method involves a system that performs environmental impact assessment on the basis of input information on concrete mix design, transport distance, and energy consumption in a batch plant. The Concrete Lifecycle Assessment System (CLAS) thus developed provides user-friendly support for environmental impact assessment with specialized database for concrete mix materials and energy sources. In the case analysis using the CLAS, among the substances discharged from the production of 24 MPa concrete, those contributing to GWP, AP, EP, ADP, ODP, and POCP were assessed to amount to 309 kg-CO2 eq/m3, 28.7 kg-SO2 eq/m3, 5.21 kg-PO43− eq/m3, 0.000049 kg-CFC11 eq/m3, 34 kg/m3, and 21 kg-Ethylene eq/m3, respectively. Of these six environmental impact categories selected for the LCA in this study, ordinary Portland cement (OPC) was found to contribute most intensely to GWP and POCP, and aggregates, to AP, EP, ODP, and ADP. It was also found that the mix design with increased prop proportion of recycled aggregate was found to contribute to reducing the impact in all other categories.

An optimization system that supports the production of concrete while minimizing carbon dioxide (CO 2 ) emissions or costs is presented that incorporates an evolution algorithm for the materials' mix design stage, a trigonometric function for the transportation stage, and a stochastic model for the manufacturing stage. A case study demonstrates that applying the optimization system reduced CO 2 emissions by 34% compared to the standard concrete production processes typically used. When minimizing the cost of concrete production was prioritized, the cost dropped by 1% compared to the cost of conventional concrete production. These findings confirm that this optimization system helps with the design of the concrete mix and the choice of a material supplier, thus reducing both CO 2 emissions and costs.

This study assessed the environmental effects and cost of the Industrial Waste addictive Blast Furnace Slag (W-BFS) using Life Cycle Assessment (LCA) and compared it to general BFS. The environmental impacts of W-BFS were as follows: 1.12ˆ10´1 kg-CO 2 eq/kg, 3.18ˆ10´5 kg-Ethylene eq/kg, 4.79ˆ10´4 kg-SO 2 eq/kg, 7.15ˆ10´4 kg-PO 4 3´e q/kg, 7.15ˆ10´4 kg-CFC 11 eq/kg and 3.94ˆ10´3 kg-Antimony eq/kg. Among the environmental impact category, GWP and AP were 9.28ˆ10´2 kg-CO 2 eq/kg and 3.33ˆ10´4 kg-SO 2 eq/kg at a raw material stage, accounting for 80% and 70% of total environmental impact respectively. In EP, POCP and ADP, in addition, raw material

Studies which reduce cement usage, develop an alternative by partial replacement of cement with blast-furnace slag, fly ash, or such industrial byproducts, and evaluate the environmental load and economic value of concrete mixed with such are in high demand. In this study, A-BFS (Activator Blast Furnace Slag), which is mixed with an activator in order to induce early-age strength manifestation of BFS mixed concrete was used to execute a physical property evaluation of concrete. This study first conducted physical property tests for compression strength of concrete that partially replaced OPC (ordinary Portland cement) with A-BFS and executed a comparison/analysis with 100% OPC. It was thought that if concrete early strength is manifested through this process when applied to RC (Reinforced Concrete) building, at most a three to four day construction cycle would be possible, according to which the economic value of the construction period reduction was evaluated. For this evaluation, general apartment houses (Case 1) were taken as the evaluation subject, and for comparison, Cases 2, 3, and 4 were set up by the mix ratio of A-BFS, and the economic value evaluation range was established. As a result, it was found that Case 2 had no change from Case 1, while Case 3 saved about 106,654,762 KRW (Korea Won) and Case 4 saved about 159,982,143 KRW.

Abstract:In each country in the world, there is a strong need for all industries to reduce CO 2 emissions for sustainable development as a preparation for climatic change. The biggest issue in many developed countries, including the United States, is to reduce CO 2 emissions for the upcoming implementation of Carbon Emissions Trading. The construction industry, in particular, which accounts for up about 30% of CO 2 emissions, will need studies on the amount of CO 2 emissions. The purpose of this study is to present the most environmentally friendly and economical apartment house plan types according to the increasing number of layers by evaluating the amount of CO 2 emissions and economic efficiency. The results indicated that flat and Y-shaped types are more eco-friendly and economical in lower levels of less than 20 stories. However, the L-shaped type is more highly eco-friendly and economically efficient in higher levels of more than 20 stories. The results of this paper would help to make a decision on the building types and the number of stories in the early stages of construction.

The importance of environmental consequences due to diverse substances that are emitted during the production of concrete is recognized, but environmental performance tends to be evaluated separately from the economic performance and durability performance of concrete. In order to evaluate concrete from the perspective of sustainable development, evaluation technologies are required for comprehensive assessment of environmental performance, economic performance, and durability performance based on a concept of sustainable development called the triple bottom line (TBL). Herein an assessment method for concrete eco-efficiency is developed as a technique to ensure the manufacture of highly durable and eco-friendly concrete, while minimizing both the load on the ecological environment and manufacturing costs. The assessment method is based on environmental impact, manufacturing costs, and the service life of concrete.

The purpose of this study is to construct of database for greenhouse gas (GHG) emission reduction technologies through the analysis of domestic and foreign green building certifications, as part of inventory study of greenhouse gas reduction technologies. For this purpose, analyzing G-SEED, LEED, BREEAM, CASBEE cert3ifications, derived the three categories associated with GHG reduction technologies and investigated the technologies related to standards of the three categories. As a result, commercially available GHG reduction domestic technologies database was constructed based on GHG reduction technology groups. After analyzing domestic and international environment-friendly building certifications (G-SEED, LEED, BREEAM, CASBEE), three categories (ecological environment, materials & resources, energy) associated with GHG reduction technology were derived. The certification standards by category and GHG reduction technologies were analyzed, and GHG reduction technology group was classified. Based on the list of the classified GHG reduction technologies, GHG reduction technologies commercialized in the Republic of Korea were kept as database.