??????(Prestress)???(Loss)

1
??????(Prestress)???(Loss)

• ???????????
• ?? ??

2
?????????

• ??????(PC??????)???????????,????????????.?????????
  ,PC???????????????.
• P(x)Pi-??Pi(x)?Pt(x)?
• ???,
• P(x)??x????????????
• Pi????????????Initial Prestress
• ?Pi(x)????????????????????????
• ?Pt(x)??????????????
• ???????????????????????????????????????????.

Pi
x
P(x)
3
?????????? ??????????
????????
????????
?????????PC??????????????,???,??????????,???,????
?????(?????????????????) ? JIS?,???
???????????????????PC?????????(????????,???,?????
??) ? ???PC?
4
??????????????????????-1

• ???????????(????,??????)
• ??????????,?????????????????????,?????????????
  
• ???????????(??????)
• ???????(???)?????????,????????,???????????????
  ?????

5
??????????????????????-2

• ?????????????(??????)
• ?????????????????????????????? ???ltlt????
• ???
• ?????????????????

6
????????????-1

• ??,????,?????????
• PC???????????(Relaxation)
• ??????????????????????????????????????PC?????????
  ?????????

????
7
????????????-2

• ???????????(Creep)
• ?????????????????????????????????????????????????
  ???????????????(?????????,???????????)
• ?????????(Shrinkage)(????????)
• ???????????????????????(???),?????????(????)??

8
??????????????

• ???????????PC???????spt
• ????????spespt-?spr-?spcs
• ???,?spr?????????????????????
• ?spcs?????????????????????
• ???????????spe/spt(???,?0.8??)
• ???????????(spt),???????(??????????? spe
  )?????????.