bài giảng thí nghiệm vật liệu xây dựng tác giả: ncs. ngô tấn dược, ths. lê...
TRANSCRIPT
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7/27/2019 Bi ging Th nghim vt liu xy dng Tc gi: NCS. Ng Tn Dc, ThS. L c Hin Trng H Tn c Thng, 2011
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GiGingng VinVin::
NCS.NCS. NgNg TTnn DDccThSThS.. LLcc HiHinn
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I. KHI LNG RINGII. KHI LNG THTCH
III. RNG CA VT LIU
IV. M -HT NC CA VT LIU
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I. KHI LNG RING (KLR)
Khi lng ring l khi lng ca mt n vthtch vt liutrng thic hon ton.
CNG THC TNH: (1.1)
Trong:G Khi lng mu vt liutrng thi kh (g).
VaThtch mu V.liutrng thi hon tonc(cm3)
aa
VG=
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CCH XCNH:
Ty theo tng loi vt liu m c nhng phngphp xcnh khc nhau:
- Phng php Bnhttrng
- Cn, sng- Bnh chngm
Phng php Bnh t
trng
Vt liu ri
(ct -xi mng)
- Bnh ttrng- Cn, sng
Nghin(cht < 0.2mm).
P.php Bnh ttrng
Vt liu rng (gch)
-Cn
- Thc thp, kpCn -o mu
Vt liu hon ton
c (thp, knh)
DNG CTHNGHIM
PHNG THCTH
NGHIMC IM CA
VT LIU
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a. Mu knh phng (ty chn)
b. Mu st hnh tr- hnh khi (ty chn)
c. Mu ghnh khi.
A. VT LIU HON TONC
Cn
Thc thp, thc kp.
Cn o
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Ly 30g ct sau khi sng qua sng c kch
thc l5mm.Synhit105 -110o n KL khngi.
B. VT LIU RI
Bnh Khi Lng Ring (KLR),
Cn kthut (chnh xc 0.01g),Bnh htm, tsy.
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a. Cn bnh KLR sau khi sy kh -m1b. mu thvo bnh KLR, cn -m
2c. nc ct vo bnh KLR (khong 2/3), lcu
d. Ht ht khng kh bng bnh chn khng
e. thm nc vo bnh n vch c nh -1000.Cn bnh cha ct +nc, m3
f. mu thra, ra sch bnh -> nc vonvch -1000, cn bnh + nc, m4.
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( )
( ) ( )231412
mmmm
mm n
=
(1.2)
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II. KHI LNG THTCH(KLTT)
L khi lng ca mtn vthtch vt liutrng thi tnhin
CNG THC TNH: (1.3)
Trong:G Khi lng mu vt liutrng thi kh (g).VoThtch mu V.liutrng thi tnhin(cm3)
0
0VG=
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Ly 5 vin gch - dng bn chi qut sch mu
thv sy khn KL khng i [1]. nguinnhitphng.
A. GCH XY
Cn cchnh xc 0.1g.Thc thp cchnh xc 0.5mm
o chiu di -rng- dy bng thc thp, mi kch
thco 03 ln, ly trung bnh - sau cn mu.
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Ly trung bnh cng ca 05 mu th
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a mu vmt trong bn trng thi:a. Mu sy khn KL khngi (ging gch)b. Kh t nhin trong khng kh, t nht 7 ngy m
(dng trng hp ny)c. mu trong 20 ngy, to =27+/-2, m 90-95%d. Bo ho nc
B.B TNG NNG
Ly 03 vin mu (15x15x15cm) - dng bn chi
qut sch mu thv sy kh n KL khng i. nguin nhitphng.
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Cn cchnh xc 0.1g.Thc thp cchnh xc 0.5mm
o chiu di -rng- cao bng thc thp, mi mu
o 4 cnh, ly trung bnh - sau cn mu.
Ly trung bnh cng ca 03 mu th
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Khi lng th tch ca tng vin mu () ctnh bng kG/m3 theo cng thc:
Trong:
m Khi lng ca vin mu, tnh bng gram.V Thtch ca vin mu, cm3
Khi lng thtch ca b tng (kg/cm3
), chnh xcn 10kg/m3 l trung bnh cng ca ba kt quthtrnba vin mu.
Vm=1000 (1.4)
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C. CT XY DNG(Xcnh KLTT xptrng thi khng nn cht)
Ly 5-10Kg ct - sau khi sng qua sng c kchthc l5mm, synhit105 -110 n KL khngi
ngong 1lt (s4 -Dx h =108 x108).
Cn kthut, tsy.Thc l kim loi v Sng #5mm
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Cnngong, m1ct t cao 10 cm vo ng ong cho n
khi to hnh chp trn ming ng, dng thc Kimloi gt phng.Cnng + ct, m2
Tin hnh hai ln ly trung bnh cng.V
m2 m1= (1.5)
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rng c
(1.6)
Trong:
v: KLTT xp, kG/m3.
: KLR , g/cm3
%100
1000
10
=
vX
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III. M HT NC CAVT LIU
Li lngnh gi lng nc c tht trongvt liu, ti mt thiim no.
CNG THC TNH:
(1.7)
Trong:mk Khi lng mu vt liutrng thi kh (g).mu Khi lng mu vt liutrng thit (g).
( )%100
=k
ku
mmm
W
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Ly > 0.5kg ct sau khi sng qua sng cng
knh l5mm.
A. CT XY DNG XCNHHTM
Khay cha ct.Cn cchnh xc 0.1g v tsy
mu thvo khay, (m1) .
Sy khn KL khngi. Cn khay ( m2).
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Tin hnh hai ln ly trung bnh cng
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Ly5 vin gch - dng bn chi qut sch mu thv sy khn KL khngi.
nguin nhitphng.
B. GCH XY XCNHHT NC
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Cn mu sau khi sy, m1Cho mu ngm ncnhitphng
Ngm trong 48 gi, theo chiu thngngCn mu sau khi ngm, m2
Tin hnh trn 5 mu thly trung bnh cng.m1
m2 m1=W (1.8)
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I. XCNHDO TIU CHUNII. XCNH LNG NC TIU CHUN
III. THI GIANNG KT.
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I. XCNHDO TIU CHUN
Hxi mngm bocm su ca kim Vi ca (kimln) cm su t36+/-1mm --> Hcdo tiu chun.
Cn cchnh xc 0.1g.ngong, c vch chia.
My trnDng cVicatng h
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M tDng cVicat
C hai kim:Kim to (10 +/-0.05).
Kim nh(1.13+/-0.05).Khi lng phn chuynng: 300g.
Vnh khu:Lm bng cao su rn, dng hnh nn ct, cao
40mm+/-0.2mm. ng knh trong y 80mm vnh 70mm (+/-5mm). Vnh khu phicng vtln tmbng thp.
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Trn HXi MngCn 500g XM + 125ml nc; vo ci trn (nc
trc sauttXM vo ci trn). Thi gian
khng t hn 5sec v khng nhiu hn 10sec. Ly thiim kt thc l thiim 0.
Khi ng ngay my trn vi tc thp trong
90sec. Dng myvt hxung quanh trong 15sec. vtrn tip trong 90sec.vo vnh khu
Bi trn tm knh mt lp du. y vo khu, khng nn, rung qu mnh. Gt
phng vnh khu.
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Th LnHkim to vo chm tm, chnh kim chvch
skhng.Chuyn khu v tm vo dng c Vica. Hkim t tsao cho va chm vo mt vnh khu.
Thiim thkim to pht th4, tnh tthiim 0.cln sau 30sec hoc lc kim ngng ln.
Ghi li s c, trs c biu thkhong cchgiau kim to vi tm. ng thi ghi li lngnc (tnh theo % khi lng XM). Lau kim saumi ln th.
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Th Ln
Nu khong cch gia kim to v tml 6mm +/-1th vatdo tiu chun, nu cat th ta lp liphp th t u vi lng nc mi ln iu ch l
.05% chon khitc gi trquynh.II. XCNH LNG NC TIU CHUN
Lng nc tiu chun :l lng ncto hcdo tiu chun
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III. XCNH THI GIANNG KT
Thi gian btu ninh kt:L khong thi gian
btu nho trn vi ncn khi kim Vi-ca cm su36+/-1mm (va xi mng btu mt tnh do)
Thi gian ninh kt xong:L khong thi gian bt
u nho trn vi ncn khi kim Vi-ca cm su 0.5mm(va xi mng hon ton mt tnh do).
My trn +ng hDng cVicat
Cn cchnh xc 0.1gngong, c vch chia.
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Ththi gian btung kt(Sdng kim nh)HCch vn hnh dng cVica nhTN trn.
Ghi li cc s c trn thang s, s c biu thkhong cch gia u kim to vi tm . ng thighi li thi gian tnh t im khng.
Lp li php thtrn cng mt mu vi cc vtrkhc nhau (khng nhhn 10mm ktra hoc tln trcn ln sau. TN lp li vi cc khong thigian cch nhau (10pht).
H XM c gi l ng kt khi kim cch ykhu 4mm+/-1. Ghi li thi gian tnh t im 0.
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Xcnh thi gian kt thcng kt.Lt p khu ln tmca n.
Lp kim nhv tin hnh nhtrn, nhng khong
thi gian lu hn (30pht).Ghi li thi giano (chnh xcn 15pht), tnh t
im 0.
Thi gian kt thcng kt khi kim chln 0.5mm.
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I. XCNH THNH PHN HT
II. XCNH M-UNLN
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I. XCNH THNH PHN HT
Thnh phn ht l gi?Xcnh thnh phn ht l g ?
CNG THC TNH:
Trong:Mi Khi lng st li trn sn thi (g).
M Khi lng mu vt liu (g).
( )%100=MMiai
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Thnh phn ht l hm lng cc cht cln khc nhau trongt, c biu din bng tl% so vi tng khi lng t kh (?) m phn
tch thnh phn ht
Xc nh thnh phn ht l phn chia t
thnh tng nhm cc cht gn nhau v ln vxcnh hm lng phn trm ca chng.
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Cn kthut + TsyBli sng c kch thc mt sng:
10, 5, 2.5, 1.25, 0.63, 0.315, 0.14mm.
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Bry c np vy
My sng
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Ly 2kg ct, sy kh 105 -110C n khi lngkhngi.Sng qua sng c kch thc mt sng 10 & 5mm.
Cn khi lng cn li trn sng (M10 v M5).Tnh tlphn trm lng ht si cha trong ct ccht 5 -10mm (S5) v ln hn 10mm (S10):
M10(g): Khi lng si cn li trn sng 10mmM5- khi lng si cn li trn sng #5mm.
M Khi lng mu (g).
1001010 =M
MS 10055 =MMS
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Ly 1000g ct di sng c kch thc 5mm xc
nh thnh phn ht khng c si.Sng mu th c chun b trn qua bsng.
C thsng bng tay hoc bng my. Thi gian cxc nh bng cch t tgiy xung di mi lisn, ri sng u. Nu khng c ct lt qua sng thkhng sng na.
Cn lng ct cn li trn mi sng, chnh xc n1%;
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( )%100= MM
iai
Lng st ring (ai) trn sng c mt (i) ctnh bng %, theo cng thc:
Trong:
Mi Khi lng st li trn sn thi (g).
M Khi lng mu vt liu (g).Lng st tch ly(Ai) trn sng c kch thc i l tng
lng st trn sng c kch thc mt sng ln hn n vphn st trn n. Lng st tch ly bng (%) theo cngthc: Ai= a2.5 + a1.25+ + ai
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MM--ununLLnn
M-unln ca ct (M), tnh theo cng thc
100
14.0315.063.025.15.2AAAAA
M
++++
=Kt quxcnh thnh phn htc ghi vo bng
sau, v vln biu:
Lng st tch ly, Ai
Lng st ring, ai
0.140.3150.631.252.5
Lngct qua
sng
0.14mm
Kch thc mt sng, mmPhnc n li trn
sng (%)
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Kt QuBiuthnh phn ht:
0
20
40
60
80
100
0.14 0.315 0.63 1.25 2.5 5
Kch thc mt sng
Phn
cn
litrn
sng
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I. PHNG PHP TH ST.II. LY MU - CHTO V BO DNG MU
III. XCNH CNGNN.
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I.PHNG PHP TH ST (TCVN 3106-1993)
do ca hn hp b tng mi trn l chtiu kthut biu thkhnng bin dng do ca hn hp btng vc biu thbng haii lng ty theo trangthi ca h2 b tng khi xcnhdo:do tnh haydong.
Cone th st (m t).Thanh thp trn trn (16), di 600mm.Phuhn hp.Thc l, bng kim loi
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Phng php ly mu hn hp B tngt cone ln nn m, cng, phng. ng ln gi t
chngicone c nh trong qu trnhm vm hnhp b tng.
hn hp b tng vo cone thnh 3 lp. Dng thanhthp chc u trn ton bmt txung quanh vo gia.
Mi lp chc 25 ln (cone N1). Lp th nht chc htchiu cao lp va, lp hai v ba xuyn vo lp trc 2-3cm.
Nhc cone trong thi gian 5 -10sec.t cone sang cnh v o st (khong cch giaming cone vnh ca khi to hnh.
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II.LY MU - CHTO V BO DNG
Hn hp b tng nng l hn hp c nho trn
ng nht theo mt tlhp l ca cc vt liu. Baogm: cht kt dnh, nc, ct liu ln, ct liu nhvphgia (nu c).
Cn kthut
ngong, c vch chia.My trn My rungBkhun mu - Chym
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Phng php ly mu hn hp B tngLy ti hin trng hoc chun bti phng TN
Mu cn ly gp 1.5 ln tng thtch cc vin mu,khng t hn 20lt.Thi gian ly mu khng qu 15 pht.
Phng phpc mu B tngKhi hn hp c st di 10cm: hn hp b
tng thnh mt lp (chiu cao mu di 150mm). Khihn hp b tng cst ln hn 10, thnh hai lp.Sau dng thanh thp trn, chcu tnglp
Phng php c mu B tng
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Phng phpc mu B tng
Khi hn hp c st di 10cm: hn hp btng thnh mt lp (chiu cao mu di 150mm). Khihn hp b tng cst ln hn 10, thnh hai lp.
Sau dng thanh thp trn, chcu tnglp.t mu ln bn rung v rung cho ti khi thot ht
bt kh v hxi mng ni u. Dng bay gt phng
mu.Cc vin mu c trong khun, sau khi m c
lm phng mt nhsau: trn hxi mngc (N/X =
0.32-0.36). Sau khong 2-4 gi, chcho mu se, phlp hmng ti mc tia v dng tm thp phng lphng mt mu.
Bo dng mu B tng
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Bo dng mu B tng
Mu kim tra Mac thit kcp phi b tng, cph m trong khun nhit phng. Sau ly rabo dng trong phng dng h.
Thi hn gi mu trong khun 16 -24 gi.
Cc mu phi ghi k hiumt khng chu ti.
III. PHNG PHP XC NH CNG
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III. PHNG PHP XC NH CNG
NN B TNG(TCVN 3118-1993)
Cngchu nn ca b tng sau khi rn chc
c xcnh bng phng php thph hai trn muth nghim trong cciu kin tiu chun vkch thcmu, hnh dng mu, phng php c m, iu kin
bo dng v tui mu.
My nn mu.Thc l, bng kim loi
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Chun bmu B tngBa vin (mt tmu).Mu phic bong theo TCVN 3105 -1993.
Kch thc mu, 150 x 150x 150Trnh tp mu B tngXcnh din tch chu lc ca mu (o chiu di cc
cp cnh song song ca hai mt chu nn vung gc vinhau tng i mt din tch chu nn l din tch trungbnh ca hai mt).
Xc nh ti trng ph hoi mu: chn thang lc camy, sao cho ti ph hoi mu t 20 -80% ti trng cci.
Trnh t p mu B tng
-
7/27/2019 Bi ging Th nghim vt liu xy dng Tc gi: NCS. Ng Tn Dc, ThS. L c Hin Trng H Tn c Thng, 2011
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Trnh tp mu B tng
t mu vo my nn, sao cho mt chu nn nmngtm ca tht. Hpittng ttsao cho mt tht trn chmnhvo mu.
Tng ti 4-6daN/cm2/sec, chon khi ph hoi mu.c kt qu.
Cngnn tng vin mu (R):
Trong:
P Ti trng ph hoi mu.F din tch chu nn; v-hstnhi (=1)
PR
F
=