In this study, we evaluated the chemical and physical properties of structural steel, which is the most basic material for steel structures and reinforcement concrete structures in modern period. We theorized the technical data for the research of technical history of modern heritage structures by analyzing the product system and its quality control of structural steel used in modern historical heritages. The results of this study are as follow; first, the rounded bars were used in most of modern heritage structures. But in the case of Waegwan railroad bridge, the deformed bars were used in spit of not using in Japan after the great earthquake of Kantou. Second, the structural steel was good in terms of quality control, but It has brittle properties because it was not manufactured by heat treatment process.

Abstract
1. 서 론
2. 조사대상 건축물 개요 및 실험항목
    2-1. 조사대상 건축물
    2-2. 실험방법 및 측정
3. 근대 강재의 재료적 특성
    3-1. 근대 철근의 형태
    3-2. 근대 강재의 화학 성분
    3-3. 근대 강재의 미시조직
    3-4 근대 강재의 강도 및 강성
4. 맺음말
References

• 안재철(동아대학교 건축학과 조교수) | Ahn Jae-Cheol
• 송종목(建展地엔지니어링 대표) | Song Jong-Mok Corresponding Author