tiu chun vit nam

tcvn 6016 : 1995

Xi mng - Phng php th - Xc nh bn Cements - Test methods - Determination of strength ISO 679 - 89(E) 1. Phm vi p dng Tiu chun ny quy nh phng php xc nh bn un v nn ca va xi mng. 2. Tiu chun trch dn TCVN 5884: 1995 (ISO 409 - 1: 1982) , Vt liu kim loi - th cng - Bng cc tr s cng vicker s dng khi th trn mt phng - Phn 1: t HV5 n HV 100. ISO 565: 1983, Sng th nghim Li an bng dy kim loi, ry a v l to hnh bng in - kch thc thng thng ca l. ISO 1101: 1983 Bn v k thut - Dung sai hnh hc - Dung sai hnh dng, hng, v tr v sn phm cui cng. i cng, nh ngha, k hiu, ch dn trn bn v. lSO 1302: 1978 Bn v xy dng - phng php ch dn cu to b mt trn bn v. ISO 2591: 1973 Sng th nghim. ISO S310 - 1: 1982 Sng th nghim - Yu cu k thut v phng php th Phn 1: Sng th nghim c li sng kim loi. ISO 4200: 1985 ng thp u trn c hn v khng mi ni Bng chung v kch thc v khi lng theo chiu di n v. TCVN 5888: 1995 (ISO 65071: 1982), Vt liu kim loi - Th cng - Th Vicker - Phn 1: t HV5 n HVl00 3. Cc c im chnh ca phng php Phng php bao gm cch xc nh bn nn v bn un tng ng ca cc mu th hnh lng tr c kch thc 40mm x 40mm x 160mm. Cc mu ny c c t mt m va do, cha mt phn xi mng v ba phn ct tiu chun theo khi lng vi t l nc/xi mng l 0,5. Ct tiu chun t nhng ngun khc nhau u c th c s dng min l kt qu bn ca xi mng khi s dng ct khng sai khc ng k, so vi kt qu bn xi mng khi s dng ct chun theo ISO (xem iu ll). Va c trn bng my v ln cht trong mt khun nh s dng my dn. Thit b v k thut ln cht khc cng c th dng nhng kt qu khng c sai khc so vi vic dng thit b dn chun (xem iu 11). Cc mu trong khun c bo dng ni khng kh m 24 gi v sau cc mu c tho khun ri c ngm ngp trong nc cho n khi em ra th bn.

n d tui yu cu, mu c vt ra khi ni bo dng, sau khi th un mu b b gy thnh hai na v mi na mu gy c dng th bn nn. 4. Phng th nghim v thit b 4.1. Phng th nghim Phng th nghim ni ch to mu th c duy tr nhit 270C 20C m tng i khng thp hn 50%. TTCXDVN TX 1 tcvn 6016 : 1995

tiu chun vit nam

Phng bo dng mu cn trong khun c duy tr lin tc nhit 270C 10C v m tng i khng thp hn 90%. Nhit ca nc ngm mu duy tr lin tc nhit 270C 10C. Nhit d v m tng i ca khng kh trong phng th nghim v nhit nc ngm mu c ghi li t nht mt ln mi ngy trong gi lm vic. Nhit v m tng i ca phng bo dng m c ghi li t nht 4 gi mt ln. Khi c dy nhit th nhit cn thit cho kim tra s l gi tr trung bnh ca dy. 4.2. Thit b 4.2.1. Quy nh chumg Dung sai nu trong cc bn v rt quan trng cho s vn hnh ng n ca thit b khi th nghim. Khi o kim tra bnh thng m dung sai khng p ng thit b phi loi ra hoc iu chnh li, hay sa cha nu c th. Cn lu gi cc s liu nhng ln o kim tra. Khi nghim thu thit b mi cn o kim tra: khi lng, th tch v cc kch thc nh quy nh ca tiu chun ny, c bit ch ti cc kch thc ti hn ca dung sai yu cu. Trong cc trng hp m vt liu ca thit b c th nh hng n kt qu vt liu y phi c ghi r. 4.2.2. Sng th nghim Sng th nghim l loi sng li an bng dykim loi, ph hp vi yu cu cu ISO 2591 v ISO 8310- l. Kch thc danh ngha ca l sng theo ISO 565 quy nh trong bng 1 (loi R20). Bng 1 Loi

Kch thc danh ngha ca sng, mm

R20

2 1,6 1 0,5 0,16 0,08

4.2.3. My trn My trn (xem hnh 1) ch yu gm: a) Mt ci bng thp khng g, c dung tch khong 5l, c hnh dng chung v kch thc nh trong hnh l, ci c gn vo khung my trn sao cho trong sut thi gian trn an ton c m bo, chiu cao ca ci tng xng vi cnh trn v trong mt chng mc no khong cch gia cnh quay v ci c th vi chnh v c nh c. TTCXDVN TX 1 tcvn 6016 : 1995

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b) Mt cnh trn bng thp khng g c hnh dng chung, kch thc v dung sai ch r trong hnh l. Cnh trn quay xung quanh trc quay ca n v chuyn ng kiu hnh tinh quanh trc ci do mt ng c in c tn s quay kim sot c Hai chiu quay s ngc nhau v tr s gia hai tn s quay s phi l mt s nguyn. Khi s dng nhiu my trn, cc ci v cc cnh trn s c lm thnh b v khng c s dng ln ln.

Khong cch gia cnh trn v ci trn hnh l, c kim tra hng thng. Ch thch: Khong cch (3mm 1mm) trong hnh 1 l v tr khi cnh trn trong ci rong v c chnh st vo thnh ci. Dng c o dung sai n gin l dng c o khe" v c dng nhng ch kh o trc tip. My trn vn hnh vi cc tc quy nh trn bng 2. Bng 2 - Tc ca cnh trn trong my trn Gi tr tnh bng vng/pht Chuyn ng quay Tc quanh trc Thp 140 5 Cao 285 10

Chuyn ng hnh 62 5 125 10

4.2.4. Khun Khun (hnh 2) gm c 3 ngn nm ngang sao cho ba mu hnh lng tr c tit din 40mm x 40mm v di 160mm c th c ch to cng mt lc.

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tiu chun vit nam

Khun phi c lm bng thp c thnh dy t nht l0mm. cng Vicker trn b mt ca mt trong khun phi t t nht HV200 (xem ISO 409 - l v ISO 6507 - l). Ch thch: - Gi tr cng Vicker ti thiu HV400 l thch hp. Khun phi c ch to sao cho vic tho mu khi khun c d dng v khng gy h hi. Mi khun phi c mt tm phng bng gang hoc bng thp. Khi lp rp li khun phi kht cht v c nh vo tm . Vic lp rp khng c gy ra vnh hoc khe h. Tm phi tip gip hon ton v chc chn vi mt bn ca my dn khng gy giao ng ph. Mi b phn ca khun phi c nh s tin vic lp rp v m bo ph hp vi cc dung sai quy nh. Cc b phn ging nhau ca cc b khun khc nhau khng c i ln cho nhau. Khun lp rp phi ph hp cc yu cu sau: a) Kch thc bn trong v dung sai ca mi ngn khun theo bn s o i xng phi m bo cc tr s sau: Chiu di: 160mm 0,8mm. Chiu rng: 40mm 0,2mm. TTCXDVN TX 1 tiu chun vit nam tcvn 6016 : 1995

Chiu su: 40,lmm 0,lmm. b) Dung sai phng (xem ISO 1101) trn ton b mi mt trong phi m bo 0,03mm; c) Dung sai v vung gc (xem ISO 1101) ca mi mt trong so vi mt y khun v mt k pha trong lm mt chun l 0,2mm; d) Cu to b mt ca tng mt pha trong s l N8 hoc nh hn (xem ISO 1302). Khun phi c thay khi bt k mt dung sai no quy nh b vt qu. Khi lng ca khun phi ph hp vi yu cu v khi lng tng hp trong 4.2.5. Khi lp rp khun lm sch chun b dng, cn dng mt loi matit thch hp trm kn cc mi ni pha ngoi khun. Mt trong ca khun cn c bi mt lp mng du khun. khun c d dng cn c mt phu rt bng kim loi c thnh cao t 20mm n 40mm. Khi nhn vo s , thnh phu nghing so vi thnh khun khng qu lmm. Thnh ngoi ca phu phi c cch nh v m bo rt ng vo khun. ri v gt bt va cn c hai bay v mt thanh gt bng kim loi vi hnh dng nh hnh 3.

4.2.5. My dn My dn chun (xem hnh 4) c lm theo cc yu cu sau:

TTCXDVN TX

1 tcvn 6016 : 1995

tiu chun vit nam

My gm ch yu mt bn hnh ch nht c gn bng hai tay n nh vo mt trc quay cch tm l 800mm. Bn c gn tm mt di mt vu ni mt trn. Bn di vu ni ny phi c mt cht hm nh c mt trn v tr ngh, ng thng gc chung qua cc im tip xc gia vu v cht hm phi thng ng. Khi vu ni t ln cht hm th mt nh ca bn phi nm ngang sao cho cao trnh ca mt trong bn gc bt k khng chnh qu cao trung bnh l 1mm. Bn phi c kch thc bng hoc ln hn kch thc ca tm khun v mt trn bn phi c bo my. Cn dng kp gn cht khun vi bn. Tng lng ca bn, k c tay n, khun rng, phu v np l 20kg 0,5kg. Cc tay n ni lin vi b lp rp bn vo trc quay phi cng v lm bng ng trn c ng knh ngoi t 17mm n 22mm, v c chn t cc kch thc ng theo quy nh ca ISO 4200. Tng khi lng ca c hai tay n k c lin kt ngang l 2,25kg 0,25kg. Cc gi ca tr quay phi

l loi hnh cu hoc loi con ln v phi c bo v trnh xm nhp ca ct v hi. S dch chuyn ngang khi tm bn do hot ng ca trc quay khng c vt qu 1mm. Vu v cht hm phi lm bng thp ti c tr s cng Vicker t nht bng HV500 (xem ISO 409 - l). vnh ca vu khong 0,0lmm-1. TTCXDVN TX 1 tcvn 6016 : 1995

tiu chun vit nam

Khi vn hnh bn s c nng ln bi mt cam v c ri t do t cao 15mm 0,3mm trc khi vu p vo cht hm. Cam phi lm bng thp c tr s cng Vicker t nht bng HV 400 v trc ca n phi c lp trn gi bi v c ch to sao cho khi ri t cao 15mm 0,3mm lun gi c tr s ny. C cu ph ca cam phi m bo cho cam t b mn nht. Cam c quay bi mt ng c in khong 250W nh mt hp gim tc vi tc u 1 vng/giy. m bo mi chu k dn l 60 giy 3 giy v chnh xc 60 ln dn, cn c mt b phn c kh kim tra v mt thit b m. V tr ca khun trn bn phi c t sao cho chiu di ca cc ngn khun thng hng vi chiu di ca tay n v vung gc vi trc quay ca cam. d dng nh v c khun sao cho tm im ca ngn gia khun va ng nm trn im p, cn phi c cc du hiu nhn bit thch hp. My c lp rp chc chn trn mng b tng c khi lng khong 600kg v th tch khong 0,25m3 v c kch thc m bo chiu cao lm vic thch hp cho khun. Ton b ca tm b tng c t trn mt m n hi, th d: m bng cao su t nhin, c cch ly hu hiu ngn c cc dao ng bn ngoi nh hng n chc c. B ca my s c gn vo b tng bng cc bu lng neo v mt lp va mng s c ri vo gia lp my v b tng m bo mt tip gip trnh cc dao ng t do v cc nh hng khc. 4.2.6. My th bn un My th xc nh bn un phi chu c ti trng n 10KN vi chnh xc: l% ca ti trng c ghi nm khong bn phn nm pha trn ca di ang dng v vi tc tng ti 50N/s l0N/s. My c hai gi ta dng con ln lm bng thp chu lc ng knh l0mm 0,5mm, t cch nhau 100mm 0,5mm v mt con ln chu tai th ba bng thp c ng knh cng nh trn v

c t chnh gia hai con ln kia. Chiu di ca cc con ln khong t 45mm n 50mm. S b tr ti trng c ch r trong hnh 5. Ba mt thng ng xuyn qua trc ca ba con ln phi c v tr song song vi nhau v phi duy tr c tnh song song, cch u nhau v cng vung gc vi chiu nm ca mu trong lc th. Mt trong cc con ln gi ta v con ln ti trng phi c cn cht t m bo s phn b ng u ca ti trn c chin rng ca mu m khng gy ra ng sut xon. xc nh bn un c th s dng my th bn nn (xem 4.2.7). Trong trng hp ny cn c mt thit b ph hp vi yu cu cho trn. 4.2.7. My th bn nn. My dng xc nh bn nn phi c kh nng thch hp cho vic th nghim:my phi c chnh xc 15% ti trng c ghi nm khong bn phn nm pha trn ca dy ti ang dng v phi m bo c tc tng ti l 2400N/s 200N/s. My phi c ni vi mt b phn ch k, b phn ny c ch to sao cho s bo khi mu b ph hu vn c ghi li trn mt s sau khi my c d ti. Vic ny c th thc hin bng cch dng dng c ch k ti a da trn cch o p sut hoc mt b nh trn mn hin s. Cc thit b TTCXDVN TX 1 tcvn 6016 : 1995

tiu chun vit nam

th thao tc bng tay phi c lp mt dng c o tc d dng kim tra mc tng ti. Trc thng ng ca b phn nn phi trng vi trc thng ng ca b phn my

v trong thi gian nn ti, chiu di chuyn ca b phn nn phi theo phng ca trc my. Mt khc hp lc phi i qua tm ca mu. B mt ca tm p di ca my phi vung gc vi trc my v gi nguyn v tr vung gc sut thi gian cht ti. Tm gi cu ca tm p trn phi nm giao im ca trc thng ng ca my vi b mt di ca tm p trn ca my vi dung sai 1mm. Tm p trn c th t do v thng t theo s tip xc vi mu, nhng trong thi gian cht ti v tr ca tm p trn v di ca my phi c gi c nh. Cc tm p ca my c lm bng thp cng vi cng Vicker (xem ISO 4091) t nht l HV600, hay tt nht l vonfam cacbit. Cc tm p ny phi dy t nht 10mm v rng 40mm - 0,lmm v di t nht 40mm. Dung sai phng cho ton b din tch tip xc vi mu l 0,01mm (xem ISO 1101). Cu to b mt phi ln hn N3 v nh hn N6 (xem ISO 1302). Cng c th dng hai a ph bng thp cng, tt nht bng vonfam cacbit, dy t nht 10mm v ph hp vi yu cu v cc tm p. Tm ca cc a ph phi tng xng vi trc ca h thng truyn ti v khng sai lch qu 0,5mm. Trng hp my th khng c goi cu, hoc gi cu b kt hay ng knh gi cu ln hn 120mm th phi cn mt g nh v theo 4.2.8. Ch thch: 1. Thit b th c th c hai hay nhiu cht ti trng. Gi tr cao nht ca cp ti trng di phi xp x bng mt phn nm gi tr cao nht ca cp ti trong trn k cn. 2. Thit b th tt nht l c thao tc t ng iu chnh tc tng ti vi b phn ghi kt qu. 3. Gi cu ca my cn c tra du d iu chnh tip xc vi mu nhng cng ch trong chng mc khng xy ra chuyn dch ca tm p khi gia ti trng qu trnh th nghim, khng nn dng loi du nhn b nh hng di p sut cao. TTCXDVN TX 1 tcvn 6016 : 1995

tiu chun vit nam

4. Cc thut ng "thng ng", "di", "trn" l dng cho cc thit b th quy c. Tuy nhin, thit b c trc khng thng ng cng vn dng c, min l thit b ny p ng c quy trnh th chp nhn tng ng quy nh trong 11.7 v min l cc yu cu khc u c p ng. 4.2.8. G nh v mu ca my th cng nn Nu cn dng n mt g nh v (hnh 6) th n phi c t vo gia cc tm p ca my truyn ti t my sang b mt nn ca mu va. G nh v c mt m p di v m p c gn vi tm p di ca my. M p trn nhn ti t tm p trn ca my qua mt gi cu trung gian. Gi ny l mt phn ca ton b c cu v c th trt theo chiu thng ng m khng gy ma st ng k trong g nh v theo hng chuyn ng

ca n. G nh v cn phi c gi gn sch s v gi cu phi quay c d dng sao cho tm p khp vi khun mu v sau c c nh trong sut thi gian th. Khi phi s dng g nh v, cn m bo cc yu cu quy nh trong 4.2.7. Ch thch: 1. Gi cu ca g nh v c th c tra du nhng ch va phi trnh s chuyn dch ca cc tm p khi gia ti, trong sut thi gian th. Khng nn dng loi du nhn b nh hng di p sut cao. 2. Tt nht l ton b c cu phi t ng tr v c v tr ban u sau khi ph hng mu. 5. Thnh phn va 5.1. Ct 5.1.1. Quy nh chung Ct tiu chun ISO xc nh bn ca xi mng phi ph hp vi cc vu cu theo iu 5.l.3. Ct tiu chun phi c t chc tiu chun ho quc gia chng nhn t tiu chun ISO. Mt khc t chc ny phi m bo rng ct tiu chun ISO trong cc ln sn xut tip theo vn c gim st lin tc ph hp vi tiu chun ny.

1. vng bi 2. C cu trt thng ng 3. L xo tr v 4. Gi cu ca tm p trn 5. Tm p trn ca my 6. Gi cu ca g nh v 7. M p trn ca g nh v 8. Mu th 9. M p di 10. Mt di ca g nh v 11. Tm p di ca my

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tcvn 6016 : 1995

Do kh khn trong vic quy nh ct tiu chun ISO mt cch y v r rng nn khi chng nhn v th kim tra cht lng cn tiu chun ho ct da vo ct mu ca ISO. Ct mu ISO c m t trong iu 5.1.2. 5.1.2. Ct mu ca ISO Ct mu ca ISO1 l ct thin nhin giu silic, gm tt nht l cc ht trn cnh v c hm lng silic dioxit khng t hn 98%. Cp phi ht nm trong cc gii hn quy nh bng 3. Bng 3 Cp phi ht ca ct mu ISO Kch thc l vung mm 2 1,6 1 0,5 0,16 0,08 0 75 33 5 67 5 87 5 99 1

Vic phn tch sng cho ct c thc hin trn mt mu i din. Tin hnh sng lin tc cho n khi lng ct lt qua mi sng nh hn 0,5g/pht. Hm lng m nh hn 0,2%, c xc nh theo khi lng hao ht ca mu ct i din sau 2 gi sy kh nhit t l050C n 1100C v c biu th bng t l phn trm khi lng ca mu sy kh. 5.1.3. Ct tiu chun ISO Ct tiu chun ISO phi ph hp vi cc quy nh v cp phi v hm lng m nh iu 5.l.2. Trong sn xut ct, s xc nh ny phi c tin hnh t nht mi ngy mt ln. Tuy vy cc yu cu ny vn cha m bo cho ct tiu chun tng ng vi ct mu. S tng ng c m bo qua mt chng trnh th cng nhn bao gm vic so snh ct tiu chun vi ct ca mu ISO. Chng trnh ny v cch tnh ton c m t trong iu 11.6. Ct tiu chun ISO c th c giao nhn theo tng cp phi ring bit hay c trn sn theo tng ti plastic vi khi lng 1350 g 5 g, loi vt liu dng lm ao b khng c gy nh hng n kt qu th cng . 5.2. Xi mng Xi mng th nghim nu phi lu hn 24 gi k t lc ly mu n lc tin hnh th, th phi c lu gi ton b trong thng kn, loi thng khng gy phn ng xi mng. 5.3. Nc Nc ct c s dng cho cc php th cng nhn. Cn i vi cc

th nghim khc, s dng nc ung.

1 Ct mu ISO chnh l ct mu ca CEN (U ban Chu u v tiu chun ho). Mun tm hiu thng tin c c loi ct ny, xin lin h vi hip hi c F.R:DIN Postfach 1107. D 1000 Berlin.30. TTCXDVN TX 1 tiu chun vit nam tcvn 6016 : 1995

6. Ch to va 6.1. Thnh phn T l khi lng bao gm mt phn xi mng (5.2), ba phn ct tiu chun (5. l) v mt na phn l nc (5.3) (t l nc/xi mng =0,5). Mi m cho ba mu th s gm: 450g 2g xi mng, 1350g 5g ct, v 225g 1g nc. 6.2. nh lng m trn Xi mng, ct, nc v thit b c cng nhit phng th nghim (xem 4.l). Xi mng v ct c cn bng cn c chnh xc n lg. Khi thm nc, dng ng ong t ng 225ml , c chnh xc 1ml. 6.3. Trn Dng my trn (4,2,3,) trn mi m va. My trn khi v tr thao tc, cn tin hnh nh sau. nc vo ci v thm xi mng. Khi ng my trn ngay v cho chy tc thp (xem bng 2), sau 30 giy thm ct t t trong sut 30 giy1l. Khi dng cc nhm ht ct ring bit, cho thm s lng cn thit ca tng nhm ht bng cch bt u tun t t nhm ht ln nht. Bt my trn v cho chy tc cao (xem bng 2), tip tc trn thm 30 giy. Dng my trn 90 giy. Trong vng 15 giy u dng bay cao su co va bm thnh ci, y ci v vun vo gia ci. Tip tc trn tc cao trong 60 giy na. Thi gian ca mi giai on trn khc nhau c th c tnh chnh xc n 1 giy. 7. Ch to mu th 7.1. Hnh dng v kch thc Mu th hnh lng tr c kch thc 40mm x 40mm x 160mm 7.2. c mu Tin hnh c mu ngay sau khi chun b xong va. Khun v phu c kp cht vo bn dn. Dng mt xng nh thch hp, xc mt hoc hai ln ri lp va u tin cho mi ngn khun sao cho mi ngn tri thnh hai lp th y (mi ln xc khong 300g) v ly trc tip t my trn, Dng bay ln (hnh 3) ri ng u bay c gi thng ng so vi vai ca n v tip xc vi inh phu v c

y ln pha trc, pha sau dc theo mi ngn khun. Sau ln lp va u bng cch dn 60 ci. thm lp va th hai, dng bay nh (hnh 3) dn u mt va ri ln lp va ny bng cch dn thm 60 ci. Nh nhng nhc khun khi bn dn v tho phu ra. Gt b va tha bng mt thanh gt kim loi (hnh 3) thanh ny c gi thng ng v chuyn ng t t theo kiu ca ngang (hnh 2) mi chiu mt ln. Cng dng thanh gt trn gt bng mt va. Ghi nhn hoc nh du cc khun nhn bit mu v v tr tng i ca chng so vi bn dn. 1 C th s dng thit b o thi gian v thit b t ng kim tra cho thao tc ny. TTCXDVN TX 1 tcvn 6016 : 1995

tiu chun vit nam

8. Bo dng mu th. 8.1. X l v ct gi mu trc khi tho khun Gt b va tha trn ra khun coi nh mt phn ca vic tho d. t mt tm knh kch thc 210mm x 185mm v dy 6mm ln khun. Cng c th dng mt tm thp hoc vt liu khng thm khc c cng kch thc. Ch thch: m bo an ton cn dng cc tm knh c cnh c vut trn. t ngay cc khun nh du ln gi nm ngang trong phng khng kh m hoc trong t (xem 4.l). Hi m phi tip xc c vi cc mt bn ca khun. Khun khng c chng cht ln nhau. Mi khun s c ly khi ni ct gi vo thi im thch. vic tho khun. 8.2. Tho d khun Vic tho d khun phi rt thn trng1. i vi cc php th 24 gi, vic tho d khun mu khng c qu 20 pht trc khi mu c th 2. i vi cc php th c tui mu ln hn 24 gi, vic tho d khun tin hnh t 20 gi n 24 gi sau khi d khun. Ch thch: Vic tho d khun cng c th c chm li 24 gi nu nh va cha c cng yu cu trnh h hng mu. Cn ghi li vic tho khun mun trong bo co th nghim. Mu tho khi khun v c chn th vo 24 gi (hoc vo 48 gi nu d khun mun), c ph bng khn m cho ti lc th. nh du cc mu chn ngm trong nc v tin phn bit mu sau ny, nh du bng mc chu nc hoc bng bt ch. 8.3. Bo dng trong nc Cc mu nh du c nhn chm ngay trong nc ( nm ngang hoc thng ng, ty theo cch no thun tin) nhit

270C 20C trong cc b cha thch hp (xem 4.l). Nu ngm mu nm ngang th cc mt thng ng theo ng hng thng ng v mt gt va ln trn. t mu ln trn li khng b n mn v cch xa nhau sao cho nc c th vo c c su mt mu. Trong sut thi gian ngm mu, khng lc no khong cch gia cc mu hay su ca nc trn b mt mu li nh hn 5 mm. Ch thch Li bng g l khng thch hp. mi b cha , ch ngm nhng mu c xi mng cng thnh phn ho hc. Dng nc my y b ln u v thnh thong thm nc gi cho mc nc khng thay i. Trong thi gian ngm mu khng c php thay ht nc.

1 Khi tho d khun c th s dng ba bng cao su hoc cht do hay dng c c bit khc. 2 kim tra vic trn, to chc c v hm lng kh t vi va, cn tin hnh cn mu sau khi tho khi khun. TTCXDVN TX 1 tcvn 6016 : 1995

tiu chun vit nam

Ly mu cn th bt k tui no (ngoi 24 gi hoc 48 gi khi tho khun mun) ra khi nc khng c qu 15 pht trc khi tin hnh th. Dng vi m ph ln mu cho ti lc th. 8.4. Tui ca mu th bn Tnh tui ca mu th t lc bt u trn xi mng v nc. Khi th bn theo yu cu cc tui khc nhau, cn m bo gii hn sau: 24 gi 15 pht 48 gi 30 pht 72 gi 45 pht 7 ngy 2 gi Bng v ln hn 28 ngy 8 gi 9. Tin hnh th 9.1. Quy nh chung Dng phng php ti trng tp trung xc nh bn un bng thit b quy nh trong iu 4.2.6. Na lng tr gy sau khi th un c em th nn ln mt bn pha tip xc vi thnh khun vi din tch 40mm x 40mm. Khi khng yu cu gi tr bn un th php th ny c th hu b, nhng cc th nghim xc nh bn nn vn c tin hnh trn hai na

u

lng tr b gy nh bin php thch hp m khng gy ng sut c hi cho cc na lng tr. 9.2. Xc nh bn un t mu lng tr vo my th (4.2.6) vi mt mt bn ta trn cc con ln gi ta v trc dc ca mu vung gc vi cc gi ta. t ti trng theo chiu thng ng bng con ln ti trng vo mt i din ca lng tr v tng ti trng dn dn tc 50N/s l0N/s cho n khi mu gy. Cn gi m cho cc na lng tr cho n khi em th bn nn. Tnh bn un, Ru, bng Newtons trn milimet vung (N/mm2), theo cng thc sau: 1,5 F R .1

Trong : u b 3 Fu: L ti trng t ln gia lng tr khi mu b gy, tnh bng Newtons; l: L khong cch gia cc gi ta, tnh bng milimet; b: L cnh ca tit din vung ca lng tr, tnh bng milimet. 9.3. Xc nh bn nn Th bn nn cc na lng tr trn cc mt bn pha tip xc vi thnh khun bng thit b quy nh iu 4.2.7 v iu 4.2.8.

TTCXDVN TX

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tiu chun vit nam

t mt bn cc na lng tr vo chnh gia cc tm p vi sai lch khng qu 0,5mm, v t nm ngang sao cho mt cui ca lng tr nh ra ngoi tm p hoc m p khong l0mm. Tng ti trng t t vi tc d 2400N/s 200N/s trong sut qu trnh cho n khi mu b ph hoi. Nu tng ti trng bng tay th cn iu chnh chng li khuynh hng gim tc tng ti khi gn ti ti trng ph hu. Tnh bn nn, Rn bng newtons trn milimet vung (N/mm2), theo cng thc sau:

Trong : R Fn u A F: L ti trng ti a lc mu b ph hoi, tnh bng Newtons; A: L din tch tm p hoc m p, tnh bng milimet vung (40mm x 40mm =1600mm2) 10. Th tnh thch hp i vi xi mng 10.1. Quy nh chung Phng php xc nh bn xi mng bao gm hai mc ch p dng chnh, l th s ph hp v th chp nhn. Mc ny m t vic th s ph hp bng cch nh gi xi mng theo yu cu v bn nn. Th chp nhn c quy nh mc 11. 10.2. nh ngha kt qu th Kt qu th l gi tr trung bnh s hc ca su ln xc nh bn nn trn mt b ba mu lng tr. Nu mt kt qu trong s su ln xc nh vt l0% so vi gi tr trung bnh th loi b kt qu v ch tnh gi tr trung bnh ca nm kt qu cn li. Nu mt trong s nm kt qu ny vt qu l0% gi tr trung bnh ca chng th loi b ton b kt qu. 10.3. Tnh ton kt qu th. T cc kt qu bn ring bit thu c qua cc na lng tr, ly chnh xc n 0,lN/mm2, tnh gi tr trung bnh theo iu l0.2 v ly chnh xc n 0,1N/mm2 10.4. Bin bn th Ghi li tt c cc kt qu ring bit. Bo co gi tr trung bnh tnh ton v bt k mt kt qu loi b no theo l0.2. 10.5. chnh xc ca phng php th chnh xc ca phng php c o bng lp li (xem 11.5) v ti lp ca n (xem l0.6) chnh xc ca phng php th i vi php th s ph hp c tnh theo ti lp.

TTCXDVN TX

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tiu chun vit nam

chnh xc ca phng php th i vi php th chp nhn v cho mc ch kim tra sn xut, c tnh theo lp li. 10.6. ti lp ti lp ca phng php xc nh cng nn l mt biu thc nh lng ca sai s lin kt vi cc kt qu th thu c t nhng mu m trn danh ngha ging ht nhau vi mt loi xi mng, v cc cn b th nghim

khc nhau trong cc phng th nghim khc nhau vo cc thi im khc nhau c s dng ct chun t ngun gc khc nhau v cc b thit b khc nhau. i vi vic xc nh bn nn tui 28 ngy, ti lp theo cc iu kin trn gia cc phng th nghim giu kinh nghim, c th hin bng h s bin thin, v nh hn 6%. iu c ngha l s khc nhau gia hai kt qu th tng ng thu c t cc phng th nghim khc nhau c th c ly (chc chn 95%) nh hn khong 15%. 11. Th nghim chp nhn i vi ct v thit b thay th 11.1. Quy nh chung Nh nu r trong mc 8, vic th xi mng theo ng tiu chun ny khng th ch da trn vic dng mt loi ct duy nht, c ngun gc c nh, v vy cn thit c sn nhiu loi ct th m tt c u phi t ct tiu chun ISO. Tng t nh vy, tiu chun ny khng yu cu phng th nghim phi dng mt (loi thit b ln cht ring bit. Chnh v mc ch t do la chn m thut ng cc vt liu thay th v cc thit b thay th c nu ra. Do , mt trong nhng c im c bn ca tiu chun ny l ct v thit b thay th phi c a vo mt chng trnh th nghim bo m rng cc kt qu bn thu c trong th nghim chp nhn khi c dng ct v thit b thay th khng sai khc so vi vic s dng ct mu v thit b mu. Chng trnh th nghim chp nhn bao gm th nghim chng nhn khi c ct v thit b mi xin thay th theo yu cu ca tiu chun v th nghim thm tra m bo rng th nghim chng nhn vn ph hp vi tiu chun ny. Vic th nghim ct v thit b ln cht thay th c m t trong cc iu 11.6 v 11.7 v cc th nghim tng ng vi cc nguyn tc chung ca th nghim chp nhn. 11.2. Xc nh kt qu th nghim Kt qu th nghim c xc nh bng trung bnh s hc ca su php th bn nn trn ba mu lng tr ca mt m. 11.3. Tnh ton kt qu th Xem iu 10.3. 11.4. chnh xc ca phng php th chnh xc ca phng php th i vi php th chp nhn v phc v mc tiu sn xut c o bng lp li ca php th (v ti lp, xem iu 10.6. 11.5. lp li lp li ca phng php th bn nn l mt biu thc nh lng ca sai s lin kt vi cc kt qu th thu c trong mt phng th nghim ca cc mu ging ht nhau trn danh ngha t mt loi xi mng trong cc iu kin nh nhau (nh cng TTCXDVN TX 1

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tcvn 6016 : 1995

ngi thao tc, cng loi thit b, cng mt loi ct, trong cng mt khong thi gian.v.v i vi vic xc nh bn nn tui 28 ngy, lp li trong nhng iu kin ny mt phng th nghim c nhiu kinh nghim, c biu th di dng h s bin thin, t 1% n 3%. 11.6. Ct tiu chun ISO 11.6.1. Th chng nhn ct. Ct c dng lm ct th -theo tiu chun ny phi c chng nhn v sau c gi l ct tiu chun ISO. Vic th nghim chng nhn trong thi k sn xut u tin (t nht l 3 thng) i vi ct ngh c l ct tiu chun ISO l rt cn thit chng minh cho s ph hp ca n (ngoi ra, m bo tnh n nh cht lng di hn, cn phi c th nghim xc minh hng nm - xem 11.6.2). Th nghim chng nhn da trn mt quy trnh chun so snh ct ngh l ct tiu chun ISO vi ct mu ca ISO, quy nh trong iu 11.6.3. Th nghim chng nhn da trn vic th bn nn tui 28 ngy, tin hnh trong cc phng th nghim c c quan tiu chun ho quc gia chp nhn cho mc tiu ny. Cc phng th nghim chng nhn s c nhng hot ng hp tc quc t v tham gia trong cc h thng th nghim hp tc m bo rng c tnh ct tiu chun ca cc nh sn xut t cc nc khc nhau u so snh c vi cc ch tiu chp nhn quc t. 11.6.2. Th thm tra ct Trnh t thm tra ct chng nhn li hng nm, bao gm mt th nghim nm trn mt mu ct ly ngu nhin do c quan chng nhn thc hin v mt cuc thanh tra ca c quan ny v cc s liu th nghim kim tra cht lng ct ca c s sn xut. Chng trnh th thm tra c cng nguyn tc nh th chng nhn, c m t trong iu 11.6.4. Cc th nghim kim tra cht lng ca c s sn xut ct c phng th nghim ca c s sn xut hoc phng th nghim dch v thc hin u n (mi thng mt ln nu sn xut lin tc). Cc s liu v kt qu ca cc th nghim kim tra cht 1ng trong vng ba nm cui phi c sn sng cung cp cho c quan chng nhn thanh tra v coi l mt phn ca trnh t thm tra. 11.6.3. Phng php th chng nhn ct tiu chun ISO 11.6.3.1. Quy nh chung Trong thi k sn xut ban u, t nht l ba thng, cn ly ba mu ct c lp th chng nhn l ct tiu chun ISO v vic ly mu do c quan chng nhn thc hin. Th nghim so snh vi ct mu ca ISO c tin hnh trn tng mu ca ba mu ct, dng mt trong ba loi xi mng m c quan chng nhn chn cho mc ch .

Nu tng mu ring bit trong cc th nghim i chng ti 28 ngy, u chp nhn c th ct ngh c th chp nhn c l ct tiu chun ISO. TTCXDVN TX 1 tcvn 6016 : 1995

tiu chun vit nam

11.6.3.2. Tiu chun chp nhn Tiu chun ny da trn mt chun mc chp nhn l mt loi ct m trong mt thi gian di c s chnh lch v cng nn tui 28 ngy khong 5% so vi loi ct mu ca ISO, th loi b ct c kh nng t nht l 95% b loi b. 11.6.3.3. Trnh t cho mi ln th so snh S dng mu xi mng chn lc cho th nghim ny ch to 20 cp m va, c s dng ct ngh tiu chun ISO cho mt m cn m kia th dng ct mu ca ISO. Chun b hai m mi cp theo th t ngu nhin, m n k tip m kia, theo tiu chun ny. Sau 28 ngy bo dng, tin hnh th cng nn c su mu lng tr ca mt cp m v tnh ton kt qu cho mi loi ct theo ng iu l0.3, ly x ch ct ngh l ct tiu chun ISO v y l ct mu ca ISO. 11.6.3.4. nh gi mi ln th so snh Tnh ton cc thng s sau: a) bn nn trung bnh, Y , cho tt c 20 m chun b bng ct mu ca ISO; b) bn nn trung bnh, X , cho tt c 20 m chun b bng ct ngh l ct tiu chun ISO. nh gi D = l00 X Y / Y , ly chnh xc n 0,1 khng k du. 11.6.3.5. X l gi tr ngoi l Nu xut hin mt sai lch ngoi l ng ng th phi tnh cc thng s sau: a) chnh lch i s = x - y, gia mi cp kt qu th. b) Chnh lch gia gi tr trung bnh ca kt qu = X - Y; c) lch chun ca cc chnh lch, S; d) Gi tr ca 3S; e) Chnh lch s hc gia gi tr cao nht ca , tc l max v , v gia gi tr thp nht ca , tc l min v . Nu mt trong cc chnh lch ny ln hn 3s th loi b gi tr lc (max hoc min) v tnh ton li trn 19 chnh lch cn li. 11.6.3.6. Yu cu chp nhn Ct ngh l ct tiu chun ISO c coi l ct t tiu chun ISO nu mi gi

tr trong ba gi tr ca D tnh theo 11.6.3.4. u nh hn 5. Nu mt hoc nhiu hn gi tr tnh D bng hoc ln hn 5, th ct khng c chp nhn. 11.6.4. Phng php th thm tra ct tiu chun ISO 11.6.4.1. Th nghim hng nm ca c quan cp chng nhn C quan chng nhn tin hnh ly mt mu ngu nhin theo iu 11.6.2. v em th theo quy trnh quy nh trong iu 11.63, c dng n mt loi xi mng do c quan chng nhn chn cho mc ch ny. Nu gi tr D tnh ton theo iu 11.6.3.4, nh hn 5 th mu c coi l ph hp vi cc yu cu th thm tra. Nu gi tr D bng hoc ln hn 5, th phi th tip ba mu chn ngu nhin theo ng quy trnh th chng nhn quy nh trong iu 11.6.3. 11.6.4.2. Th hng thng i vi c s sn xut ct TTCXDVN TX 1 tcvn 6016 : 1995

tiu chun vit nam

Th nghim hng thng do c s sn xut ct tin hnh theo ng cch thc nh th thm tra quy nh trong iu 11.6.4.1, nhng cn tin hnh t nht 10 php so snh, bng cch so snh mt mu ct chn ngu nhin sn xut ra trong thng vi mt mu ct chng nhn l ct tiu chun ISO. Dng mt loi xi mng do c quan chng nhn chn cho mc ch ny. Nu gi tr D tnh ton theo iu 11.6.3.4. ln hn 2,5 v xut hin hn hai ln trong s 12 ln th so snh hng thng lin tc, th cn thng bo cho c quan chng nhn tin hnh mt th nghim chng nhn ton din trn ba mu ly ngu nhin theo quy nh 11.6.3. 11.7. Th chp nhn i vi thit b ln cht thay th 11.7.1. Quy nh chung Khi c yu cu th nghim chp nhn cho thit b ln cht thay th, c quan chng nhn s chn ly ba b thit b c bn sn, a n phng th nghim ca c quan chng nhn bn cnh b thit b chun ph hp iu 4.2.5. Thit b cn th phi c km theo: Vn bn m t k thut y v thit k v cu to, Bn ch dn vn hnh, Mt danh mc kim tra bo m vn hnh ng, Vn bn m t y trnh t ln cht. C quan chng nhn tin hnh so snh cn thn cc c tnh k thut ca thit b cn th vi cc vn bn k thut km theo. Sau tin hnh lm ba th nghim so snh mi thit b dng mt trong ba loi xi mng do c quan chng nhn chn cho mc ch ny v dng ct mu ca ISO. Nu mi ln ca c ba ln th u chp nhn c cho thit b thay th th thit b ln cht ngh c coi l chp nhn c. 11.7.2. Th nghim thit b thay th 11.7.2.1. Tiu chun chp nhn Tiu chun ny da trn mt chun mc chp nhn l mt loi thit b m

khi s dng theo phng php ln cht trong mt thi gian di c s chnh lch v bn nn tui 28 ngy khong 5% so vi phng php quy nh trong tiu chun ny th thit b c kh nng t nht l 95% b loi b. 11.7.2.2. Trnh t mi ln th so snh. Dng mu xi mng chn ch to 20 cp m va v tin hnh lm chc c mt m theo quy trnh ngh cn m kia lm theo quy trnh chun. Hai m ca mi cp c chun b theo th t ngu nhin, ci n k tip ci kia. X l mu lng tr sau khi ln cht tin hnh theo ng tiu chun ny. Sau 2,8 ngy bo dng, tt c su lng tr ca mt cp m s c th cng nn v kt qu ca tng phng php lm chc c s c tnh ton theo iu l1.3 trong x l phng php ln cht ngh thay th v y l lm theo bn dn tiu chun. 11.7.2.3. nh gi mi ln th so snh Tnh ton cc thng s sau: a) bn nn trung bnh, y, ca 20 m c lm trn thit b chun; TTCXDVN TX 1 tcvn 6016 : 1995

tiu chun vit nam

b) bn nn trung bnh, x, ca 20 m c lm trn thit b ngh ln cht thay th. nh gi D = l00 X Y / Y , ly chnh xc n 0,l khng k du. 11.7.2.4. X l gi tr ngoi t Xem 11.6.3.5. 11.7.2.5. Yu cu chp nhn thit b ngh thay th Thit b thay th c coi l chp nhn nu mi gi tr trong ba gi tr D, tnh theo 11.7.2.3, nh hn 5. Trong trng hp m t k thut ca thit b s c ly lm ph lc cho thit b ch r trong 4.2.5, v m t trnh t ln cht s c ly lm ph lc cho quy nh trong iu 7.2. Nu c mt gi tr D tr ln, bng hoc ln hn 5 th thit b ngh thay th khng c chp nhn.

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