Text of Thong So Vat Lieu Cua TCVN, BS, ACI, EUROCODE-draft1
TIU CHUN VIT NAMCNG B TNG THEO TCVN 356-2005 (MPa)Trng thi B1 B1.5 B2 B2.5 B3.5 B5 B7.5 B10 B12.5 B15 B20 B25 B30 B35 B40 B45 B50 B55 B60
MC M50 M75 M100 M150 M150 M200 M250 M350 M400 M450 M500 M600 M700 M700 M800Rb (TNH TON) 2.1 2.8 4.5 6.0 7.5 8.5 11.5 14.5 17.0 19.5 22.0 25.0 27.5 30.0 33.0
Rbt (TIU CHUN) 2.7 3.6 5.5 7.5 9.5 11.0 15.0 18.5 22.0 25.5 29.0 32.0 36.0 39.5 43.0
E 9500 13000 16000 18000 21000 23000 27000 30000 32500 34500 36000 37500 39000 39500 40000Gi tr cng ca Cp bn b tng trong bng ny l Cng lng tr
THNG S CA B TNG
Gi tr cng ca Mc b tng trong bng ny l Cng lp phng
Tng quan gia cp bn chu nn ca b tng v mc b tng theo cng chu nn Cch thit lp cc gi tr trong bng ca TCVN Cng trung bnh ca mu th tiu chun
B10
B12.5
B15 Cp bn chu nn (gii thch con s sau B)
B20
B22.5
B25 83.48
M500
M600
Cp bn chu nn
Cng trung bnh ca mu th tiu chun MPa
Mc theo cng chu
nn12.84
16.05
19.27
25.69
28.90
32.11
B40
B45
B50
B55
B60
M150
M150
M200
M250
M300
M350
51.37
57.80
64.22
70.64
M700
M700
M800
M900
vi ni l s lng mu th tiu chun c cng tng ng khi nn (ko) l Bi (Gi tr ny c th xem l Mc b tng )
Cp bn chu nn
Cng trung bnh ca mu th tiu chun MPa
Mc theo cng chu
nn
B65
77.06 l h s bin ng ca cng cc mu th tiu chun, ph thuc vo cng ngh sx b tng, =0.135 cho BT chu nn, =0.165 cho BT chu ko (con s ny lm trn chnh l
B ) S 1 64 i t b 95%
= ni
n
ii
m
n
BnB
1
1
( )64.11= mBB
B27.5
B30 Cng tiu chun v nn Rbn (TCXDVN 356:2005) Rnc (TCVN 5574:1991)
B35
Cng thc chnh xc xc inh Rbn (mu lng tr) t B
Cng tnh ton v nn Rb (TCXDVN 356:2005) Rn (TCVN 5574:1991)
bc l h s tin cy ca b tng, =1.3
EUROCODE 4
CNG B TNG THEO EUROCODE 4 (N/mm2 ~ MPa) CNG TIU CHUN CA B TNG THEO THI GIAN CNG TNH TON CA B TNG
89.90
96.33
B70
B75
B8044.95
M400
35.32
38.53
M350
M1000
M1000M450
M900
102.75 An l h s chuyn i t cng chu nn ca mu lp phng sang mu lng tr , ly t 0.700 n 0.765
con s sau B ) S 1.64 ng vi xc sut m bo 95%
BARR nncbn =
bc
bnb
RRR =
( )BBRbn 001.077.0 =
( ) Lp bn C20/25 C25/30 C30/37 C35/45 C40/50 C45/55 C50/60 Cng chu nn c trng ca b tng tui th t Cng tnh ton chu nn
fck 20.0 25.0 30.0 35.0 40.0 45.0 50.0 vi 3
TNG QUAN GIA TCVN & EUROCODETiu chun C20/25 C25/30 C30/37 C35/45 C40/50 C45/55 C50/60 Cch thit lp cc gi tr trong bng
Bc 1: Tnh h s quy i =fcuk/fcu
B25 B30 B35 B45M350 M400 M450 M600
69.6
Bc 2: Tnh cng trung bnh ca mu chu nn (fcm) ca b tng tui 28 ngy cho mu lp phng fcm(cu) =fcuk/fcu * fcm(c)
Bc 3: So snh cc gi tr cng trung bnh ca cac mu th theo TCVN v ca EUROCODE 4 mt cch gn ng ta c cc con s ca bng bn.
Lp bn
Mu hnh tr 43383328
Mu lp
phn
fcm (Mpa)
48 53 58
35.0 46.0 46.7 55.0
EUROCODE
TCVN
60.0 64.7
BS8110Cch k hiu ca BS8110: C30 c ngha l fcu=30 MPa
TNG QUAN GIA TCVN V TIU CHUN ANH BS8110Tiu chun B15 B20 B25 B30 B35 B40 B45TCVN 8.5 11.5 14.5 17.0 19.5 22.0 25.0
BS8110 19.0 25.7 32.5 38.1 43.7 49.3 56.0
ACI
CNG V M UN N HI CA B TNG
Cp bnRb
fcu(quy i)
Cng thc gn ng quy i t cng tnh ton chu nn Rb (TCVN) sang gii hn chy f”c (ACI)
in-pound (psi) Xut pht t vic ng b 2 cng thc tnh din tch ct dc A s ca cu kin chu un (t ct n)
3000 y c:
3500
4000 v l h s gim cng , ly theo ACI, =0.9
4500
5000
T y rt ra c 2 iu:
(1) Cng thc gn ng quy i t cng tnh ton chu ko Rs (TCVN) sang gii hn chy fy (ACI)
SI (MPa)
Cng f”c M un Ein-pound (psi) SI (MPa)
27800
29600
21(20.7)
24(24.1)
28(28.1)
31(31.0)
35(34.5)
22900
24500
26500
3150000
3400000
3460000
3860000
4070000
( )
=
2adf
MAACI
y
us
( )
=
20xhR
MATCVN
s
ghs
( )bf
MddaACI
c
u
“2
85.02= ( )
bR
MhhxTCVN
b
gh2200 =
0hdMM ghu
==
yys ffR 9.0==(2) Cng thc gn ng quy i t cng tnh ton chu nn Rb (TCVN) sang gii hn chy f”c (ACI)
TIU CHUN VIT NAMCNG CT THP THEO TCVN 356-2005 (MPa)
Cng chu ko tiu chun ca ct thp Rsn
CI, AI 1.05 1.00
CII, AII 1.05 1.00
AIII 1.10 1.00
Cng chu ko
225
K hiu Ghi ch
Trng thi gii hn 1 Trng thi gii hn 2
6-8mm
Nhm thp thanh
175
225
185
Ct thp dc Rs Ct thp ngang Rsw225
280
355
280
355
THNG S CA CT THP
H s tin cy
TTGH1 TTGH2 ym l gi tr trung bnh ca gii hn chy khi th
nghim, l ng sut vi bin dng d l 0.2%
l h s bin ng (th hin ng nht ca ct thp) =0.05-0.08 (H s ny kh ln VN l do trn th trng tn ti nhiu sn phm c ng nht thp)
Gi tr Rsn v Rs,serCng chu nn Rsc
235
295
390
( ) 64.11= mysnR
CIII, AIII 1.07 1.00 Cng chu ko tnh ton ca ct thp RsCIV, AIV 1.15 1.00 s l h s tin cy
AV 1.15 1.00
AVI 1.15 1.00
ATVII 1.15 1.00C kin sot gin di v ng
sut
10-40mm 290
405
545
650
785
365
510
680
815
980
490
450
390
360
200
200
500
500
365
450
500
540
540
1.10
1.20
1.00
1.00
390
590
788
980
1175
Ch kim sot gin di
AIIIB
s
sns
RR =
MT S LOI THP THNG DNG-BNG NY P DNG CHO THP THNGp dng vic quy i theo Gii hn chy thc t , loi thp Thp cacbon cn nng