Sungho Tae

Effect of Ground Granulated Blast-Furnace Slag on Life-Cycle Environmental Impact of Concrete

To quantitatively evaluate the influence of ground granulated blast-furnace slag (GGBS) as a supplementary cementitious material on the life-cycle environmental impact of concrete, a comprehensive database including 3395 laboratory mixes and 1263 plant mixes was analyzed. The life-cycle assesment studied for the environmental impact of concrete can be summarized as follows: 1) the system boundary considered was from cradle to pre-construction; 2) Korea life-cycle inventories were primarily used to assess the environmental loads in each phase of materials, transportation and production of concrete; and 3) the environmental loads were quantitatively converted into environmental impact indicators through categorization, characterization, normalization and weighting process. The life-cycle environmental impacts of concrete could be classified into three categories including global warming, photochemical oxidant creation and abiotic resource depletion. Furthermore, these environmental impacts of concrete was significantly governed by the unit content of ordinary portland cement (OPC) and decreased with the increase of the replacement level of GGBS. As a result, simple equations to assess the environmental impact indicators could be formulated as a function of the unit content of binder and replacement level of GGBS.

A Study on the Development of an Evaluation System of CO 2 Emission in the Production of Concrete

The main reason of the earth global warming is and the regulation about it in the whole world has been reinforced to reduce emission. It is needed that we should reduce it in the process at the production of concrete generated much of emission as the primary material of construction industry recognized unfriendly environment industry. Based on a concrete, this study was constructed the system to evaluate emission generated in the stage of material production, transportation, manufacture and developed the program to reduce and evaluate it efficiently. As a result, most of emission is generated in the stage of material and it is quantitatively evaluated emission generated in the stage of materials, transportation and manufacture. Moreover, the evaluation system of the volume of emission which has the friendly environment technology about reduction of emission at each stage is suggested for quantitatively evaluation emission generated in the process at the production of concrete and remicon production company could use it to evaluation emission.

A Study on the Requisite Elements of LCCO 2 Evaluation System at Planning Stage of Building

The evaluation programs previously developed in Korea involve limitations in establishing strategies of reducing environmental loads to optimal level in a way to put in materials directly after designing. Therefore, this study has the purpose to extract and propose elements required for the establishment of highly accurate system by counteracting swiftly in a method with high energy efficiency over cost at planning stage. To that end, existing evaluation programs in Korea and abroad were compared and analyzed, and in the planning stage, GEM-21P and Carbon-navigator intended for the establishment of building energy performance improving strategy were selected as the evaluation program for survey. On such basis, after comparison and analysis between calculating methods and system structures of the two programs, elements required for system establishment that can evaluate life-cycle environmental loads of building in planning stage were proposed.

Mixture Proportioning Approach for Low-CO2Lightweight Aggregate Concrete based on the Replacement Level of Natural Sand

The purpose of this study is to propose a mixture proportioning approach based on the replacement level of natural sand for reducing CO2 emissions from artificial lightweight aggregate concrete(LWAC) production. To assess the effect of natural sand on the reduction of CO2 emissions and compressive strength of LWAC, a total of 379 specimens compiled from different sources were analyzed. Based on the non-linear regression analysis using the database and the previous mixture proportioning method proposed by Yang et al., simple equations were derived to determine the concrete mixture proportioning and the replacement level of natural sand for achieving the targeted performances(compressive strength, initial slump, air content, and CO2 reduction ratio) of concrete. Furthermore, the proposed equations are practically applicable to straightforward determination of the CO2 emissions from the provided mixture proportions of LWAC.