B xy dng

TCXDVN 317-2004

B xy dng cng ho x hi ch ngha vit namS 16 /2004/ Q-BXD c lp - T do - Hnh phc

H Ni , ngy 11 thng 6 nm 2004

Quyt nh ca B trng b xy dng

V vic ban hnh Tiu chun xy dng Vit Nam TCXD VN 317: 2004 '' Blc b tng nh - Phng php th ''

B trng b xy dng

- Cn c Ngh nh s 36/ 2003/ N - CP ngy 04 / 4 / 2003 ca Chnh Ph quy nh chc nng, nhim v, quyn hn v c cu t chc ca B Xy dng.

- Cn c bin bn ngy 21 / 5 / 2004 ca Hi ng Khoa hc k thut chuyn ngnh nghim thu tiu chun '' Blc b tng nh - Phng php th ''

- Xt ngh ca Vin trng Vin Vt liu Xy dng ti cng vn s 449 / VLXD - KHKT ngy 31 / 5 / 2004 v ca V trng V Khoa hc Cng ngh.

Quyt nh

iu 1 : Ban hnh km theo quyt nh ny 01 Tiu chun Xy dng Vit Nam TCXD VN 317 : 2004 '' Blc b tng nh - Phng php th ''

iu 2 : Quyt nh ny c hiu lc sau 15 ngy k t ngy ng cng bo.

iu 3 : Cc ng : Chnh Vn phng B, V trng V Khoa hc Cng ngh , Vin trng Vin Vt liu Xy dng v Th trng cc n v c lin quan chu trch nhim thi hnh Quyt nh ny ./.

Ni nhn :

- Nh iu 3

- VP Chnh Ph

- Cng bo

- B T php

- V Php ch - BXD

- Lu VP&V KHCN

b trng b xy dng

Nguyn Hng Qun

Blc b tng nh - Phng php th

Blocks of lightweight concrete - Method of testing

1 Phm vi p dng

Tiu chun ny quy nh cc phng php xc nh ch tiu k thut cho Blc b tng nh c ch to t hn hp xi mng, ct liu mn, cht to bt hoc cht to kh dng cho cc kt cu chu lc, chu lc cch nhit, cch nhit trong cc cng trnh xy dng.

2 Ti liu vin dn

TCVN 1772 87 - xy dng Phng php xc nh m

TCVN 3113:1993 - B tng nng - Phng php xc nh ht nc

3 Phng php th

3.1 Ly mu

Mu th c ly theo tng l. T l nghim thu ly 15 vin bt k cc v tr khc nhau sao cho mu th l i din cho ton b l sn phm.

3.2 Xc nh kch thc

Dng thc l kim loi o cc chiu vin Blc, chnh xc ti 1mm. Kt qu l gi tr trung bnh cng ca 3 kt qu o ti hai cnh bn v gia ca mt tng ng.

3.3 Xc nh khuyt tt hnh dng

3.3.1 Xc nh vung gc

Sai lch vung gc c xc nh bng thc kim loi c gc 900 v c cnh di 500mm. t cnh thc p st mt cnh vin Blc, dng cc tm dng kim loi c chiu dy chun bit trc o khe h to gia cnh kia ca thc vi mt bn v tr xa nht. Kt qu o l tr s ln nht khi o 2 gc i nhau ca vin Blc. S nguyn l xc nh vung gc c th hin trn hnh 1

Hnh 1. S nguyn l xc nh vung gc (3.3.2 Xc nh cong vnh

p thc thng ln ng cho mt Blc. Dng thc l kim loi o khong h ln nht gia thc thng v b mt ca Blc. S nguyn l xc nh cong vnh c th hin trn hnh 2

Kt qu o l gi tr ln nht ca 2 ln o trn tng b mt ca Blc .

Hnh 2. S nguyn l xc nh cong vnh (3.3.3 Xc nh st gc, cnh

Dng thc cp k thut o chiu su, chiu di cc gc, cnh b st. m s vt nt c chiu su ( 15mm, v chiu di ( 20mm trn Blc.

3.4 Xc nh cng nn

3.4.1 Nguyn tc

Xc nh lc nn ln nht lm ph hu mt n v din tch chu lc ca mu

3.4.2 Dng c v thit b th

- My ct

- My nn c thang lc thch hp khi nn, ti trng ph hu mu, nm trong khong t 20% - 80% ti trng ln nht ca thang lc nn chn. Sai s lc o khng ln hn 2%.

- Bay, cho; trn h ximng

- Thc l kim loi, c vch chia ti 1mm

- Cc ming knh hnh vung c chiu di cnh khng nh hn 150mm

- T sy 3000C c b phn iu chnh v n nh nhit .

3.4.3 Chun b mu th

Mu th l 5 vin hnh lp phng c kch thc mi cnh: 100(4mm, c ct t 5 vin Blc ly theo iu 3.1. Trn h ximng c do tiu chun, trt ln 2 mt chu nn ca vin mu, dng ming knh l phng c 2 mt sao cho khng cn vt lm v bt kh. Chiu dy lp trt khng ln hn 3mm. Hai mt trt phi phng v song song vi nhau. Sau khi trt, mu c t trong phng th nghim khng t hn 72gi ri tin hnh th.

Khi cn th nhanh, c th dng ximng ng rn nhanh hoc thch cao khan trt mt mu. Sau mu c t trong phng th nghim khng t hn 16 gi ri tin hnh th.

3.4.4 Tin hnh th

o kch thc hai mt chu nn ca mu th, chnh xc ti 1mm. t mu th ln tht di ca my nn, tm mu th trng vi tm ca tht nn. Tc tng ti bng 0,06N/mm2(0,02N/mm2 trong1giy n khi mu b ph hu, ghi ti trng ph hu ln nht.

Sau khi mu b ph hu, chn 3 mnh v c th tch t 40 cm3 n 80 cm3 xc nh m theo TCVN 1772 - 1987 xy dng Phng php xc nh m. 3.4.5 Tnh kt qu

Cng nn (Rn) ca vin mu c tnh bng N/mm2 theo cng thc

Trong :

Pn: l lc nn ph hu mu, tnh bng Niutn

S: l din tch chu nn ca vin mu, tnh bng mm2 (: l h s tnh i kt qu th nn cc vin mu b tng c m khc m chun (10%). Gi tr ( c qui nh trong bng 1

Bng 1 - Gi tr h s (Gi tr m, %H s (Gi tr m, %H s (

00,8151,05

50,9201,10

101,0Trn 251,15

Ch thch: Khi m ca mu th khc vi cc gi tr m trong bng 1 th c th dng phng php ni suy tnh.

Tnh trung bnh cng cc kt qu th. Loi b gi tr c sai lch ln hn 15% so vi gi tr trung bnh.

Kt qu cui cng l gi tr trung bnh cng ca cc gi tr cn li, lm trn ti 0,1N/mm2.

3.5 Xc nh khi lng th tch kh

3.5.1 Nguyn tc

T khi lng mu kh v th tch c xc nh qua kch thc 3 cnh, tnh khi lng ca mt n v th tch mu th.

3.5.1 Dng c v thit b th

T sy 3000C c b phn iu chnh v n nh nhit .

Thc l kim loi 500mm, c vch chia ti 1mm

Cn k thut 20kg chnh xc ti 1g

3.5.2 Chun b mu th

Mu th l 3 vin Blc nguyn hoc c ct t 3 vin Blc ly theo iu 3.1 ph hp vi kch thc t sy.

Sy mu nhit 1050C(50C n khi lng khng i (chnh lch khi lng gia 2 ln cn lin tip cch nhau 2 gi, khng vt qu 0,2% khi lng mu). Tc nng nhit khng ln hn 400C/gi.

ngui mu n nhit phng th nghim, ri tin hnh th.

3.5.3 Tin hnh th

Xc nh kch thc mu th theo iu 3.2

Cn khi lng mu th, chnh xc n 1gam.

3.5.4 Tnh kt qu

Khi lng th tch ((v) ca vin mu, tnh bng kg/m3 theo cng thc:

Trong :

m: l khi lng mu sau khi sy kh, tnh bng gam

l, b, h: l chiu di, rng;, cao mu th, tnh bng milimt

Kt qu l gi tr trung bnh cng ca 3 mu th, lm trn ti 10kg/m3

3.6 Xc nh co ngt kh

3.6.1 Nguyn tc

Co ngt kh ca Blc b tng nh l s thay i kch thc khi gim m, c xc nh bng cch o s thay i kch thc ca mu th m 35% v 5% theo phng php th.

3.6.2 Dng c v thit b th

Cn k thut 1000g, chnh xc ti 0,1g

My ct

T sy 3000C c b phn iu chnh v n nh nhit .

Bnh ht m c ng knh khng nh hn 300mm

Kalicacbonat khan (K2C03)

inh tn ng knh 5mm, di 10mm c ch to bng ng hoc thp khng r. Trn u inh tn c vt lm, su 1mm, ng knh 1mm.

Vt iu chnh inh tn ng knh 6mm, di 10mm

Dng c o chiu di v thanh chun (hnh3)

+ ng h micromet c chnh xc 0,001mm

+ Thanh chun c lm bng thch anh, hp kim hoc cc vt liu c n nhit nh hn 0,001mm/m

3.6.3 Chun b mu th

Mu th l 3 vin hnh lng tr c ct t 3 vin Blc ly theo iu 3.1, c kch thc: chiu di (l) bng 160mm(1mm, chiu rng (b) bng chiu cao (h) bng 40mm(1mm.

Dng keo epoxy gn inh tn vo tm 2 u mu th. Sao cho trc ca inh tn trng vi trc ca mu th.

3.6.4 Tin hnh th

Ngm ngp mu trong nc nhit phng th nghim trong 3 ngy. Vt mu v t vo bnh ht m c nc di, sau 3 ngy cn khi lng (m0) v o chiu di mu (l0). Trc khi o mu dng thanh chun kim tra v chnh kim ng h v v tr s ''khng''. Sau t mu vo bnh ht m khc c cha 600(10g K2C03 di. C sau 7 ngy thay K2C03 mi. Trong 4 tun u, c 3 ngy cn khi lng (mi) v o chiu di mu (li). Sau , c 7 ngy cn v o li cho ti khi khi lng gia hai ln cn lin tip khng i.

Sy mu nhit 1050C(50C ti khi lng khng i (mk). Tc nng nhit khng ln hn 400C/gi.

3.6.5 Tnh kt qu

co ngt ca vin mu ((i), tnh bng mm/m, theo cng thc:

Trong :

l0: l chiu di mu trng thi bo ho, tnh bng milimt

li: l chiu di mu ln th i, tnh bng milimt

L: l chiu di ban u ca mu th trng thi kh, tnh bng milimt

m vin mu (wi) ng vi mi ln o tnh bng phn trm (%) theo cng thc:

Trong :

mi: l khi lng mu cn ln th i, tnh bng gam

mk: l khi lng mu c sy kh, tnh bng gam

Dng th biu din mi quan h gia co ngt ((i) v m (wi) c dng nh hnh 4

Hnh 4. th biu din co ngt kh

T th xc nh co ngt kh m 5% v 35%.

co ngt kh (() ca vin mu, tnh bng mm/m, theo cng thc sau:

( = (5 - (35

Trong :

(5: l thay i chiu di ng vi m 5%, tnh bng mm/m

(35: l thay i chiu di ng vi m 35%, tnh bng mm/m

Kt qu l gi tr trung bnh cng ca 3 mu th, lm trn ti 0,01mm/m

3.7 Xc nh ht nc

Th theo TCVN 3113-93: B tng nng - Phng php xc nh ht nc

3.8 Xc nh h s dn nhit

3.8.1 Nguyn tc

Xc nh dng nhit n nh truyn qua mt n v chiu dy mu th khi c s chnh lch nhit .

3.8.2 Dng c v thit b

- T sy 3000C c b phn iu chnh v n nh nhit .

My ct

My mi mu

Cn k thut 1000g, chnh xc ti 0,1g

Thc cp 300mm chnh xc 0,1mm

n p

Bin p t ngu

Thit b xc nh h s dn nhit nh hnh 5

3.8.3 Chun b mu th

Mu th l 6 vin c kch thc (150(1)x(150(1)x(20(1)mm c ct t 6 vin Blc ly theo iu 3.1 , b mt mu phi c lm phng v sch.

3.8.4 Tin hnh th

Mu c sy kh n khi lng khng i v c lm ngui n nhit phng th nghim.

t mu vo thit b o (theo nguyn l nh hnh 5). Tm truyn nhit c cp nhit thng qua dy nung in tr bng cch iu chnh dng in nh bin p t ngu.

Theo di nhit ti b mt bn trong mu (t1) v bn ngoi mu (t2). Khi chnh lch nhit (t = t1 t2 t n gi tr khng i th ghi kt qu A, V, t1, t2 v ngng o.

1. Dy in tr

2. Tm truyn nhit bng nhm (Al) dy 2mm

3. Mu th 150x150x20mm

4. Vt me p mu

5. Cp nhit in6. Lp bo n dy 50mm

7. Gi

8. Vn k: 0 30V

9. Am pe k: 0 30A

Hnh 5. S thit b xc nh h s dn nhit

3.8.5 Tnh kt qu

Khi chnh lch nhit (t = t1 t2 t n gi tr khng i. Cng sut nhit (Q) ca thit b c tnh theo cng thc sau:

Q = UxI

Trong :

Q: l cng sut nhit pht ra t ngun in, tnh bng wat (W)

U: l hiu in th ca ngun in, tnh bng von (V)

I: l cng dng in, tnh bng ampe (A)

Mt dng nhit (q) c tnh theo cng thc sau:

q = Q/2F

Trong :

q: l mt dng nhit truyn qua mt n v din tch b mt truyn nhit, tnh bng W/m2 .

Q: l cng sut nhit pht ra t ngun in, tnh bng wat

F: l din tch b mt mu, tnh bng m2H s dn nhit (() ca vin mu ,tnh bng W/m0C, theo cng thc sau:

Trong :

q: l mt dng nhit, tnh bng W/m2(: l chiu dy mu th nghim, tnh bng mt

(t : l chnh lch nhit bch phn trung bnh ca 3 im o, tnh bng 0C

Kt qu h s dn nhit l gi tr trung bnh ca 6 mu th (3 ln th) lm trn ti 0,01 W/m0C.

EMBED Equation.3

EMBED Equation.3

Hnh 3. S dng c o chiu di

1. Gi

2. ng h micromet

3. Vt iu chnh

4. Thanh chun

EMBED Equation.3

EMBED Equation.3

(5

(35

EMBED Equation.3

_1147560563.dwg

_1147564038.dwg

_1147564237.dwg

_1147564872.xlsChart1

1

0.6

0.39

0.32

0.3

0.27

0.23

0.18

0.11

0.09

0.05

0

m, %

co ngt kh i , mm/m

Sheet1

01

20.6

50.39

100.32

150.3

200.27

250.23

300.18

350.11

400.09

450.05

500

Sheet1

0

0

0

0

0

0

0

0

0

0

0

0

m, %

Co ngt kh, mm/m

Biu co ngt kh ca mu c KLTT 610Kg/m3

Sheet2

Sheet3

_1147563914.dwg

_1146847513.unknown

_1146952014.unknown

_1141902760.unknown

_1141902788.unknown

_1141902586.unknown