Transportation hub 설계방향과 컨셉, 다이어그램들을 수록한 피피티
- 최초 등록일
- 2011.09.01
- 최종 저작일
- 2011.06
- 16페이지/
MS 파워포인트
- 가격 3,000원
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Transportation hub 설계방향과 컨셉, 다이어그램들을 수록한 피피티
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본문내용
CONCRETE IS A MIXTURE OF AGGREGATES (SAND AND GRAVEL), ENTRAINED AIR, CEMENT, AND WATER. A CHEMICAL REACTION BETWEEN THE CEMENT AND THE WATER CAUSES CONCRETE TO HARDEN. THIS REACTION IS KNOWN AS HYDRATION. CONCRETE IS, AT FIRST, A PLASTIC MASS THAT CAN BE CAST OR MOLDED INTO NEARLY ANY SIZE OR SHAPE. WHEN HYDRATED, CONCRETE BECOMES STONE-LIKE IN STRENGTH, DURABILITY, AND HARDNESS. THE STRENGTH OF CONCRETE DEPENDS ON THE WATER-TO-CEMENT RATIO USED IN THE CONCRETE MIXTURE. GENERALLY, THE LESS WATER IN THE MIX, THE STRONGER, MORE DURABLE, AND WATERTIGHT THE CONCRETE. TOO MUCH WATER DILUTES THE CEMENT PASTE AND RESULTS IN WEAK CONCRETE.
GENERAL PROPERTIES
A SACK OF CEMENT REQUIRES ABOUT 2 1/2 GALLONS OF WATER FOR HYDRATION. HOWEVER, MORE WATER WILL IMPROVE THE WORKABILITY OF PLASTIC CONCRETE. NORMALLY, CONCRETE MIXTURES WILL USE 4 TO 7 GALLONS OF WATER PER SACK OF CEMENT.
TABLE G-1 SHOWS THE APPROXIMATE COMPRESSIVE STRENGTHS OF CONCRETE FOR VARIOUS WATER-TO-CEMENT RATIOS. TO CLASSIFY BRIDGES WITH UNKNOWN CONCRETE STRENGTH, ASSUME A COMPRESSIVE STRENGTH OF 3,000 PSI.
CONCRETE IS AMONG THE BEST AND MOST IMPORTANT BUILDING MATERIALS. CONCRETE IS FIREPROOF, WATERTIGHT, COMPARATIVELY ECONOMICAL, AND EASY TO PREPARE. IT OFFERS SURFACE CONTINUITY AND SOLIDITY AND BONDS WITH OTHER MATERIALS. CONCRETE IS USED IN BRIDGING TO MAKE ABUTMENTS, INTERMEDIATE SUPPORTS, COLUMNS, BEAMS, SLABS, DECKS, CURBS, AND HANDRAILS. CONCRETE OFFERS GOOD COMPRESSIVE STRENGTH AND HAS A LONG SERVICE LIFE.
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