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CHNG 1.NHNG TNH CHT C BN CA VLXD
Cu1.Cu trc ca VLXD? nh hng ca cu trc n tnh cht ca VLXD?
+Cu trc ca VLXD c biu th3 mc
-V m:c th quan st bng mt thng: nhn to,cu trc t ong,dng si,dng lp,-Vi m:ch quan st bng knh hin vi.
.Cu trc kt tinh:sp xp theo 1 quy lut nht nh trong khng gian v lin kt thng l lin kt ha hc bn vi mi trng v mt c,l,ha.
.Cu trc v nh hnh(VH):cc phn t vt cht c bn khng sp xp theo 1 quy lut no m sp xp hn ntrong khng gian v lin kt thng l lin kt vt l khng bn,tnh cht km vc,l,ha.
VH ngng t:khi VL b ph v, ghp li vi nhau k hi phc lien kt (VL v c)
VH nh t:khi VL b ph vm c ghp li th hi phc cu trc ban u:nha ng, t st
.Cu trc polime:sp xp theo nhnh,thng,khng gian.ph thuc bn cht polime v s sp xp trong khnggian.
.Cu trc t bo:ph thuc bn cht v sp xp ca t bo,bn cht th ph thuc mi trng hnh thnh lien kt.
VL c cu trc polime c cc tnh cht c,l,ha cao hn VL c tnh cht kt tinh.
-Cu trc trong hay cu to cht:phi dung nhng thit bi hin i quan st v ngin cu nh knh hin viin t,phn tch rn genc trng bng cu to nguyn t,phn t,hnh dng,kch thc ca tinh th,lien kt nib gia chng.Quyt nh cng , cng, bn nhit,
.LK cng ha tr: c hnh thnh ti in t dung chung.
.LK ion: c hnh thnh trong cc tinh th VL m cc nguyn tkhi tng tc vi nhau nhng in t chonhau hnh thnh cc ion m v dng.
.LK phn t: c hnh thnh ch yu trong nhng tinh th ca cc cht c lien kt cng ha tr.
.LK silicat:l lien kt phc tp to ra nhng tnh cht c bit ca VLXD.
+nh hng ca cu trc n tnh cht VLXD:
-VL c cu to rng c cng , chng n mn km hn VL c cng loi,nhng khnng cch nhit cchm li tt hn.Lng l rng,kch thc ,hnh dng, c tnh v s phn b c nh hng ln n tnh cht ca VL.
-VL c cu to dng si c cng , dn nhit v cc tnh cht khc khc nhau theo phng dc thv ngangth.VL c cu to dng thcng c tnh dhng ( tnh cht khc nhau theo cc phng khc nhau) .
-VL ri c cc tnh cht khc v cng dng khc nhau ty theo thnh phn, ln v trng thi b mt ht.
-Cu trc kt tinh bn vi mi trng v mt c,l,ha.
-Cu trc v nh hnh khng bn,tnh cht km vc,l,ha.
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-LK cng ha tr:c cng , cng cao v rt kh nng chy.
-LK ion:c cng v cng thp,khng bn vi nc.
-LK phn t:c nhit nng chy thp ( nc ).
-LK silicat:v lien kt ion yu hn lien kt cng ha tr bn trong mch nn di tc dng ca lc c hc amiangd tch thnh nhng si nh.
Cu 2:Thnh phn ca VLXD? nh hng ca thnh phn n tnh cht ca VLXD?
+Thnh phn ca VLXD :gm 3 loi
-Thnh phn ha hc:biu th bng % hm lng cc oxit c trong VL.Ring i vi kim loi or hp kim th thnhphn ha hc c tnh bng % cc nguyn t ha hc.VD:XMCaO,Al2O3,SiO2,Fe2O3.
-Thnh phn khong vt:l thnh phn nh nht m th hin tnh cht ca VL ,nhm cc oxit.VD:XM-
3CaO.SiO2,2CaO.SiO2,3CaO.Al2O3,4CaO.Al2O3.Fe2O3.
-Thnh phn pha:rn lng kh. a s cc VL khi lm vic u tn ti pha rn.Nhng trong VL lun cha 1 lngl rng,nn ngoi pha rn cn c pha kh ( kh kh) v pha lng ( khm ).
+nh hng ca thnh phn n tnh cht ca VLXD:
-Thnh phn ho hc : khi thay i thnh phn ho hc th t/c ho hc, t/c thuc VLXD thay i rt lnthnh phn ho hc c biu th = % hm cht lng cc oxit c trong VL . N quyt nh hng lot cc t/c ;tnh chu la , bn sinh vt cc c trng c hc v c c tnh tinh th khc ca VL
-Thnh phn khong vt :q tnh cht c bn ca VL. khi thay i thnh phn khong vt th t/c ca VL thay irt ln
VD: C3S gip xi mng c R cao lm xi mng rn nhanh ; C 3A lm xi mng rn rt nhanh ; khong3Al2O32SiO2quyt nh t/c thuc VL gm
-Thnh phn pha gm c : pha rn , pha lng , pha kh , pha nht do ( ho hc btng ) . T l cc pha ny trongVL c nh hng n cht lng : c bit l t/c v m nhit chng n mn , R sthay i thnh phn pha lmcho t/c thuc VL cng thay i
VD: nc cha nhiu trong cc l rng thuc VLnh hng xu n t/c nhit , m ,lm cho VL b nra
Cu 3.Trnh by trng thi cu to rng ca VL? rng v tnh cht l rng nh hng ti cc tnh chtch yu ca VL ntn?
+Trng thi cu to rng ca VL:
-Trng thi rng:gm 2 loi
.Rng kn:nm bn trong VL.khng c khnng TC vi mi trng.
.Rng h:nm bn trn VL.c khnng TC vi mi trng.Gm 2 trng thi:
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Rng hthng nhau:cc l rng nm trong VL v thng v 2 phi ca VL.
Khe rng: xut hin khi tn ti VL ri rc ( ct,si, ) .Rng hthong nhau,h thng khe rng rt ln.
-Kch thc rng:
.V m:quan st bng mt thng (200->300 micromet)..Vi m:khng quan st bng mt thng,c trgip ca dng c quang hc.
-VL c cu to rng c th l nhng VL c nhng l rng ln nh b tong kh,b tong bt,cht do t ong hocnhng VL c cc l rng b ( VL gm dung nc,dung ph gia chy ).
- rng ca vt liu dao ng trong phm vi ln t o -> 98% . Da vo rng c thphn on 1 s t/c thucVL: chu lc ,tnh chng thm ,cc t/c c lin quan ti nhit m .
+nh hng:VL cha nhiu l rng kn th cng cao,cch nhit tt.VL cha nhiu l rng hth ht m tt.VLc rng ln th cng nhnhng cch in m cch nhit tt chng thm km , ht nc thp.
Cu 4.Trnh by v rng ca VL? (nh nga,cng thc tnh ton,cch xc nh v ngha ).
-nh ngha : rng l thtch rng cha trong 1 n v thtch tnhin thuc VL (%).
-CT tnh ton:
Vr : th tch rng
Va: Th tch hon ton c
V0 : th tich t tnhin
: khi lng th tch
; khi lng ring
-Cch xc nh:
Vic xc nh rng ca VL c thc hin thng qua tnh ton theo theo CT v cng c thdng phng phpbo ho hlilng
- ngha:
rng ca VL dao ng trong phm vi kh rng 0-98% . Da vo rng c thphn on c 1 s t/c thucVL : chu lc , tnh chng thm , cc t/c c lin quan n nhit m
VD: VL c rng ln th R nhcch in m tt chng thm km , ht nc thp
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Cu 6.KLR ca VLXD?( nh nga,cng thc tnh ton v n v,cch xc nh,cc yu tnh hng v ngha ).
-nh ngha:KLR l KL ca 1 n v th tch trng thi c hon ton.
- Cng thc v n v:
+Cng thc =
trong :khi lng ring
m: khi lng kh ca VL
:thtch hon ton c ca VL
+n v
: g/ cm3 ,kg/cm3 ,T/ cm3
G : g, kg,T
V0 : cm3 ,m3
-Phng php xc nh:
+i vi VL hon ton c th KLR c xc nh bng cch cn o trc tip mu th nghim.
KL:sy kh ri cn trc tip bng cn
Thtch:dung phng php cht lng ri ch.
+i vi nhng VL c cu to rng
KL:sy kh ri cn trc tip bng cn.
Th tch:nghin VL n cht 3,15 XM pooclang.
+Dng d thit k thnh phn Btng
+C thnh gi s b thnh phn khong ho h s truyn nhit ,tnh ht nc, tnh thm nc
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+KLR ca VL bin i trong 1 phm vi hp c bit nhng loi VL cng loi c KLR tng tnhau do c thdung KLR phn bit nhng loi vt liu khc nhau
+Phn on 1 s tnh cht ca VL
+Tnh ton thnh phn VL trong VL hn hp
Cu 7.Nc trong VLXD v nh hng ca n ti tnh cht ca VLXD?
Da vo mc lin kt gia nc vi VL m nc trong VLXD c chia thnh 3 loi
+ Nc ho hc :
-L nc tham gia vo thnh phn VL c lien kt bn vi VL,nm trong CTHH cu to nn VL .Lin kt hahc.
-Nc ho hc chbay hi nhit cao( t0 > 5000) .Nng lng mt i ln 4500. Khi nc ho hc mt i th
t/c thuc VL thay i rt ln ,VL mt i bn cht,cu trc thnh phn ho hc b ph hu.
VD : caolinit ( Al2O3.2SiO2.2H2O) mt nc ha hc s mt tnh do
Amiang ( 3Mgo.2SiO2.2H2O) mt nc ha hc s rt gin,cng gim nhiu.
+ Nc ho l ( nc hp th ) :
-Bm trn b mt VL.
-C lin kt kh bn vi VL = lc ht phn t Vandecvan hoc = lc ht tnh in b mt (nc mng ) . Cnggn b mt lc lien kt cng ln.
- Nu ng knh l rng ln th nc thm vo.Nu ng knh l rng nhth nc khng thm vo l rng vtrong c y nc hp th. Nc ho l chthay i di iu kin ca mi trng ( nhit , m ).
-i vi 1 s VL,khi mt nc c th gy co.
-Mt nc th nng lng mt i
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W = ( ma-mk) / (mk) . 100 % trong ma :KL VL lc m. (g,kg,)
mk : KL VL sau khi sy kh.(g,kg,)
- n v : %.
-Phng php xc
nh: Cn VL c
ma. em sy nhit t 105
0
-> 110
0
C n khi khi lng khng i=> cn VL mk ri tnh ton theo cng thc.
-nh hng ca m ti t/c ca VL :
+ m thay i dn n thay i t/c ca VL c bit l bin dng ( thay i th tch ).
+ m ca VL tng lm xu i tnh cht nhit k thut,gim cng v bn,lm tng th tch ca VL.
- ngha:+xc nh t/c VL trong iu kin m xc nh.
+chuyn i vcc iu kin thc t ca VL
VD: ti thi im Ct, c m Wc,Wd
Ctt=C(1+0.01Wc) tt= (1+0.01Wd)
Xtt=X Ntt=N-0.01(C. Wc+. Wd).
-Cc yu tnh hng:
+Cu trc,cu to v thnh phn ca VL.
+Bn cht VL:Knc hay a nc.
+Rng trong VL:% rng,rng h,hnh dng,kch thc rng. Trong cng 1 iu kin mi trng nu VL cngrng th m ca n cng cao.
+iu kin mi trng:nhit , m tng i.mi trng khng kh khi p lc hi nc tng ( m tngi thuc khng kh tng ) th m thuc VL tng.
Cu 9.Trnh by vht nc ca VLXD?( Khi nim,cng thc,phng php xc nh,cc yu tnhhng ).
-nh ngha: ht nc ca VL l khnng ht nc v ginc ca n n ti a iu kin thng v nhit v p sut.
-Cng thc:
+ht nc theo khi lng ( % )
HP=( mu-mk) / ( mk) . 100 %
+ht nc theo th tch (%)
Hv = ( Vn/ V0 ) .100 % = [( mu- mk) / ( V0 n)] .100%
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Trong n : KLR ca nc ( =1g/cm3)
mu :KL ca mu t sau khi ht nc.
mk :KL ca mu kh.
Vo :th tch t nhin.Vn :thtch nc m VL ht vo.
H0/HP= mk/ (V0 n)=vtc /n=> Hv= (HP. o
tc) /n
ht theo khi lng ca VL rng c th ln hn rng nhng ht nc theo th tch th khng thvt qua rng.
-Phng php xc nh( ht nc ca gch ) phng php ngm t t :
+Chia mu gch lm 4 phn , cn mu c m1
+ t mu vo dng c ngm+ nc n 1/4 vin gch ngm trong 5 pht dng gim lau kh v em cn c m2
+ t gch ngm n 2/4 trong 5pht lm tng tc m3
+ t gch ngm n 3/4 trong 5pht lm tng tc m4
+Ngm ngp vin gch trong 5 pht lm tng tc m5
HP= (m5-m1) /(m1) .100% Hv= (HP. otc) /n
-Cc yu tnh hng :
+Ph thuc vo cu tr c,cu to v thnh phn ca VL.
+ c tnh ca l rng:% rng,rng h,hnh dng,kch thc rng .VL c c ht nc nh,VL rng c htnc nc ln . Cng th tch l rng , nu VL c l rng kn th ht nc nhhn ht nc ca VLc lrng h.
+ Bn cht VL:Knc hay a nc
+iu kin mi trng:nhit , m tng i.
Cu 10.Th no l trng thi bo ha ca VLXD?Phng php lm VL bo ha nc v ngha ca phngphp ?Hy ni skhc bit ca ht nc bo ha vi ht nc thng?
-Khi nim:L trng thi ht nc ti a ca VL trong iu kin cng bc ( bng nhit hay p lc ).
-Phng php lm VL bo ha nc:c 2 phng php
+Phng php nhit : un mu VL trong nc si 4 gi, ngui,ri vt mu ra.
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+Phng php chn khng: ngm mu VL trong 1 bnh kinns ng nc h p lc trong bnh xung 20mmHg chon khi khng cn bt kh thot ra th tr li p lc bnh thng v gi them 2 gina ri vt ra.
-Cng thc:
+ht nc bo ha theo khi lng ( % )
Hbhp=( mbh
u-mk) / ( mk) . 100 %
+ht nc bo ho theo th tch (%)
Hbhv = (Vbh
n / V0 ) .100 % = [(mbh
u- mk) / ( V0 fn)] .100%
Trong fn : KLR ca nc ( =1g/cm3)
mbhu :KL ca mu t sau khi ht nc ti a.
mk :KL ca mu kh.
Vo :th tch t nhin.
Vbhn :thtch nc m VL ht vo.
- ngha :nh gi th tch rng htrong VL, gip xc nh c ht nc bo ho ca VL,t stnh ch s bo ho
Cbh= Hbh
V/r (0
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+Hp: khnng ht nc v ginc ca n n ti a
+ Hbhp: trng thi ht nc ti a ca VL
Cu 12.Nhit dung ca VLXD?( Khi nim,cng thc xc nh,cc yu tnh hng, ngha ).-Khi nim : nhit dung l nhit lng Q (kcal) m VL thu vo khi nung nng.
-Cng thc xc nh:
Q = C.m.(t2-t1)
Trong C: nhit dung ring ca VL (kcal/kg0C)
m :khi lng ca VL (kg)
t2,t1: nhit ca VL sau v trc khi nung nng
Nhit dung nhit l nhit lng cn thit nung nng 1 kg VL ln 10C.
-Cc yu tnh hng:
+Ph thuc vo NDR ca VL thnh phn.
Ch=(p1C1+p2C2++pnCn) / (C1+C2+ +Cn)
p1 , p2, , pn : t l tng thnh phn
+ khi m thuc VL tng th nhit dung ca n tng ln
CW= ( C+ 0,01W) /( 1 + 0,01 W)
C,CW: nhit NDR ca VL kh , VL m.
- ngha:
+ NDR ca VL dng tnh ton nhit lng khi gia cng nhit VLXD.
+ Da vo C la chn VL trong cc trm nhit
Cu 13.Khi nim c bn v tnh dn nhit ca VLXD?Bn cht hin tng dn nhit qua VL?Phn tch ccyu tnh hng ti khnng dn nhit ca VLXD?
-Khi nim:L tnh cht cho nhit truyn qua t mt ny sang mt khc.
+K cn:trong VL c cha phn t vt cht c lien kt cng vi nhau cu thnh nn VL.
+K :phi c s chnh lch nhit 2 pha VL.
Khi ch truyn nhit n nh v VL c dng tm phng th nhit lng Q (kcal) truyn qua
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VL tnh = cng thc :Q=
Trong : Q nhit lng truyn qua VL (kcal)
:h s truyn nhit (kcal/m0C.h) ;
F:din tch ( m2) ; : dy ca kt cu (m)
: chnh lch nhit ; t: thi gian truyn nhit (h)
Thng thng c 3 hnh thc truyn nhit:truyn dn nhit, i lu v bc x.
H s truyn nhit = nhit lng Q truyn qua 1 tm tng c F = 1m2; chiu dy a = 1m trong thi gian t = 1hkhi nhit chnh lnh nhit 2 bn tm tng l 10C.
-Bn cht:l qu trnh truyn NL ca cc phn t vt cht c lien kt cng trong VL khi c s chnh lch nhit v 2 pha ca VL.
-Cc yu tnh hng:
+Loi VL.
+ rng v t/c ca l rng ( h, c).VL cng rng dn nhit cng km ( ch nhit tt ) .VL cng nng ( h sdn nhit cng ln) th dn nhit cng tt.
+ VL m dn nhit tt hn VL kh . Khi nhit bnh qun gia 2 mt tm tng tng th dn nhit cng ln.
+Cu trc VL :cu trc kt tinh truyn nhit tt hn.
+K mi trng:nhit , m.
Cu 14.Bin dng l g?Th no l bin dng do v bin dng n hi?Hy ni r hin tng tbin vtrng ng sut ca VL?
- Khi nim:l t/c ca n c ththay i hnh dng, kch thc di s tc dng ca ti trng bn ngoi
Thc cht:l s chuyn dch tng i of cc phn t v/c cu thnh VL di t/d ca ngoi lc v lm pht sinhtrong VL 1 ng sut c thlm thay i hay ph hoi VL .
-Ngi ta chia bin dng thnh 2 loi : bin dng do v bin dng n hi
+ Bin dng n hi l phn bin dng hon ton mt i khi loi b nguyn nhn gy bin dng( thng l titrn bn ngoi ).Xy ra khi ti trng tc dng b v ngn hn. K: ngoi lc t/d cha vt qu lc tng tc giacc cht im.Cng ca ngoi lc s sinh ra ni nng.Khu b ngoi lc ni nng li sinh cng a VL v v tr banu.
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+ Bin dng do ( bin dng d ) l bin dng khng mt i khi loi b nguyn nhn gy bin dng. Xy ra khingoi lc t/d di v ln. K: ngoi lc t/d vt qu lc tng tc gia cc cht im,ph vcu trc caVL,lm cc cht im c s dch chuyn tng i.Mt mt NL nhit
-Hin tng tbin:
+L hin tng bin dng tng theo thi gian khi ngoi lc khng i tc dng lu di nn VL rn.L hin tngmt dn theo thi gian
+Nguyn nhn:Cu trc VL b li.Khi c t/d lc s hon chnh li cu trc,c s sx li phn t.
S chuyn ha v cu trc VHkt tinh
- Hin tng chng ng sut :
+Khi nin:l hin t ng nu gi cho bin dng khng i di tc dng ca ngoi lc , ng sut n hi sgim dn theo thi thi gian.
+Nguyn nhn:do 1 phn VL c bin dng n hi dn dn chuyn sang bin dng do . Nng lng n hi
chuyn thnh nhit v mt i.
Cu 15.Cng ca VL?( Khi nim,phng php xc nh, ngha ).Phn tch cc yu tnh hng ncng ca VLXD?
-Khi nim: l khnng ca VL chng li s ph hoi ca ng sut xut hin trong VL do ngoi lc hoc K mitrng.
-Phng php xc nh:2 phng php.
+Phng php ph hoi:ch to ra mu,bo dng trong iu kin tiu chunem mu i nn,un,tc dng lc
tui no .
uim:chnh xc, n gin.
Nhc im:tn km VL,nhn cng.Mt thi gian.
p dng vi cng trnh sp sa, ang hoc b ph hy nhng khng p dng vi cng trnh ang s dngnhng khng lu mu.
+Phng php khng ph hoi:phng php ny rt tin li cho vic xc nh cng ca kt cu hoc cu kincng trnh . Trong cc phng khng ph hoi phng php khng ph hoi dng rng ri nht , cng ca VLc nh gi gin tip qua tc truyn sng siu m ca n . i vi VL hn hp ( btng ) ngi ta hay dng
phng php siu m.1 s thit b thtrn cc cng trnh c nghim thu v ang s dng:sung bt ny,sium.
u im:khng tn km VL,nhn cng,nhanh.
Nhc im:khng c chnh xc nh phng php ph hoi mu.
p dng vi VL bit trc. Thng ch p dng vi b mt VL kh ( nh hng K mi trng ).
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- ngha : da vo cng ca VL ta c th bit khnng chu ti trng la chn VL ph hp vi kt cu cngtrnh.
-Phn tch cc yu tnh hng:
+Bn thn cu to VL v thnh phn ca VL : VL c cu to c ,cu ta dng tinh th lin kt cng ho tr th R
cao , VL c cu to rng c lin kt ion th R thp.Khi c cu to rng th quan tm n gi tr,hnh dng,kch thcv s tp trung phn b rng.
+Kch thc mu : cng 1 loi VL kch thc ln th R b , kch thc b th R ln hn.
+Tc ti trng : nu tc tng ti trng nhanh hn tiu chun th kt qu th nghim R stng do bin dngdo khng tng kp vi stng ti trng
+B mt mu : nu b mt mu gip th khi th nghim th s khng gip cho kt qu th nghim c chnh xc ;b mt mu nhn cng th nghim gim 50%
+Nhit : nhit cao c R cao v khi trng VL nra , lnh VL co li
+K ch to mu : nh hng rt nhiu ti cng k ch to mu thun li VL c tnh ng nht cao R ln
Cu 16.H s mm v h s phm cht ca VLXD? ng dng thc t ca cc h s ny?
-H s mm : dc trng cho bn nc ca VL ngi ta dng h s mm kmthng qua cng cc mu boho nc Rbhv cng ca mu kh Rk.. y l h snh gi s suy gim R VL khi bo ho nc.
km=Rbh/Rk ( khng th nguyn ).
i vi cng trnh thy cng km >0.75
km =1 VL c hon ton hoc VL c rng kn.
km =0 VL b phn r khi gp nc.VD: y st.
-H s phm (kpc) hay l h s cht lng kt cu ca VL l 1 i lng c trng = t s gia cng tiu chunRtc (kG/cm2)v KL th tch tiu chun tcv (kg/m3).L 1 chtiu tng i tng qut . i vi VL bnh thng khicng cao th KLTT ln nng ,cc tnh cht v nhit v m km ,kpc nh. Cn VL mun c kpc ln th n phiva c khnng chu lc tt ,va phi nh ,cc t/c v m nht tt.
kp =/ tc
v
kp
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Chng 5: Cht kt dnh v c
Cu 1. Khi nim v phn loi cht kt dnh v c?
Tr li:
1. Khi nimCKD v c l vt liu c ngun gc v c khi nho trn vs dung mi th chuyn sang loi h do v
qua cc qu trnh ha l th chuyn sang trng thi rn.CKD c c im:+ Trn vs dung mi thc hp to thnh hn hp do, c khnng kt sau 1 thi gian th rn chc v c
cng cao+ C khnng gn kt cc ht ri rc thnh 1 khi c khnng chu lc
2. Phn loi (gm 3 loi)+CKD rn trong kk nhng cht c khnng ng rn v gik cng lu di trong kk. Theo thnhphn ha hc chia lm 4 loi:
- Vi (caxit) : ch yu vi CaCO3- Vi Magie : olomit MgCO3.CaCO2. nhit phn to thnh MgO + CaO- CKD thch cao ( cha CaSO4)- Thy tinh lng : silicat natri ( Na2O.mSiO2) or silicat kali (K2O.mSiO2)
Thy tinh lng c td: chng thm, chu la, chu nhit.
+ CKD rn trong nc l cht rn c khnng rn chc v gicng lu di ko nhng trong kk mcn ctrong mi trng nc
C lin kt phc tp, ch yu ca 4 oxit: CaO, MgO, Al2O3, Fe2O3 gm: - Xi mng pooclang ( 20-25% st)
- Xi mng aluminat : khong ch yu l canxi aluminat- Vi thy 8-12% st- Xi mng La m 12-20% st
+ CKD rn trong octocla l nhng cht c khnng rn trong mi trng hi nc bo ha hnh thnhra xi mng. Thnh phn ch yu l CaO-MgO.
Cu 2. Cc chtiu nh gi cht lng vi rn trong kk??
1. hot tnh ca vi
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a. Khi nim L t l ca Cao+MgO c trong vib. Phng php xc nh: Phng php trung ha dd HClc. Cch xc nh:
- Ly m (g) vi em th nghim, cho vi vo bnh tam gic ri 1lng nc xc nh vo bnh,lc u.
- Cho 1 vi git phenolphatalein vo bnh, ta thy dd chuyn sang mu hng.- Cho dd HCl kM t t vo dd trn, lc u, n khi dd chuyn thnh ko mu th dng li, tip
tc lc bnh, thy dd tip tc chuyn hng (do lng CaO cha p ht, tip tc p to Ca(OH)2- Cho tip HCl vo tip n khi mt mu, tnh k lng HCl tham gia p l V(L).
Cc pt p: CaO + H2O Ca(OH)2Ca(OH)2 + 2HCl CaCl2 + 2H2O
Cng thc xc nh: x =
(%)
Vi c hot tnh cao khi x 80%2. Tc ti v nhit ti
a. Khi nim- Tc ti l thi gian (pht) tkhi cho 1 lng vi tc dng vs 1 lng nc nht nh n khi
t k nht cao nht.- Nhit ti l nhit cao nht t k trong qu trnh ti vib. Phng php xc nh: pp ti vi tiu chunc. Cch xc nh- Ly 10g vi cho vo bnh ti vi tiu chun, vo bnh 20ml nc.- C30s c nhit trn thang nhit k 1 ln, ghi kt qu, n khi nhit ko tng hoc gim
theo thi gian th k nhit cao nht, l nhit ti- Thi gian ti < 10p th l ti nhanh, trung bnh l 10-20p, >20p l ti chm
Kt lun: Vi c cu trc hp l v hot tnh ln th s c tc ti nhanh v nhit ti cao.
3. Sn lng vi nhuyna. Kn: l th tch vi nhuyn ly k khi ti 1kg vi sngb. Phng php xc nh: ti vic. Cch xc nh:
- p nh vi cho vo ca c khi lng m1, nc ngp vi, khuy u cho vi ti nhanh.- Khi vi ti ko si na cho ln bp un cho nc bay hi ht n lc b mt vi xut hin vt nt
chn chim th dng li. Cn ca +vi k khi lng m2- y nc vo ca, cn ca+vi+nc k khi lng m3- Ra sch ca, cn ca y nc k khi lng m4
Cng thc xc nh: =
Sn lng vi nhuyn bng 5 ln
Kt lun: Vi nhuyn
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- nh tan vi nhuyn thu k, ln sng 0,63mm- Ra tri ht vi ti, thu li cc ht st sng, cn k khi lng m
Cng thc xc nh: H= (
) .100%
Kt lun: H nh th kt lun vi tt
Ngoi ra nh gi cht lng ca vi ta cn xc nh cc chtiu nh hm lng MgO, hm lng CO2, hmlng mt khi nung, mn ca vi bt, m.
Cu 3. Qu trnh rn chc ca vi rn trong kk??
- Gm3 giai on- G 1: ti vi
Cho cht phn tn ( vi) vo mi trng phn tn (nc) th c p xy ra CaO + H2O Ca(OH)2 Khi lng Ca(OH)2 nhiu ln th mi trng phn tn gim xung to thnh 1 hkeo phn tn
- G 2: ha keoMi trng phn tn gim na do nc tham gia p, bbay hi lm cho nng Rn/ Lng tng
ln nn Ca(OH)2 chuyn t trng thi keo sang trng thi ngng keo v kt tinh- G 3: giai on kt ta
Cacbonat ha vi di s td ca kh CO2 trong kk theo pCa(OH)2 + CO2 CaCO3 + H2O
CaCO3 hnh thnh xen k vs Ca(OH)2 lm cho va c chc, cc tinh th lin kt vsnhau to thnh mng tinh th rn chc
Ngoi ra khi t hp vi vs silicat th va cn rn chc theo qu trnh
Ca(OH)2 + SiO2 nCaO .mSiO2.pH20
Cu 4. Nguyn liu v qu trnh sx vi rn trong khng kh ? Cc bin php nng cao cht lng vi
trong qu trnh sdng?
a. Ngun liu: Cc loi giu canxit (CaCO3) nh: phn, vi lomit , lomit vs hm lng st
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Ch : Trong qu trnh nung m chnung n 900 th lp trong ca nguyn liu ko chn sinh ra hin tng nonla (CaCO3). Cn nu nhit cao qu th CaO sau khi to thnh s td vs st to thnh mng keo silicat bc ly htvi lm vi kh thy ha, cc ht ny gi l ht gi la.
3. Bin php nng cao cht lng vi khi nung- V y l p thun nghch: p thun xy ra ta lm thng thong l cho CO2 d thot ra, dng
CaCO3 c kch thc hp l, sp xp vi sao cho p d xy ra- m bo nhit nung lin tc: 900- 1100 trnh tnh trng to ra cc ht non la v gi
la.-
Cu 5. Cc phng php sd vi trong xd?Phn tch u nhc im ca tng pp v khnng ng dng can???
1. Vi bt sng k to thnh khi em vi cc nghin nh, mn kh caoUd: - Dng k 100% lng vi, loi bk ht gi la
- Vi ny khi dng th rn chc nhanh, cho cng cao hn vi chn do tn dng dk lng nhitta ra khi ti vi
- .Nd: - Tn nng lng nghin
- Khi sn xut v s dng nh hng n sc khe ca cng nhn- Kh bo qun do d ht m, lm gim cht lng vi- ..
ng dng: dng rng ri trong xy dng lm va trt, qut trn, tng Vi bt cn dngtrong nng nhip kh chua ca t
2. Vi chn l vi sau khi k ti chnTy vo slng nc cho tc dng vs vi s c 3 loi vi chn thng gp
- Bt vi chn: k to thnh khi lng nc va p vs vi, khong 32,14% so vs lng vi- Vi nhuyn: k to thnh khi lng nc a td nhiu hn n mc to ra 1 loi va st cha
khong 50% nc v 50% Ca(OH)2.Khi bo qun vi nhuyn ta phi cch li vi vs khng kh (tip xc vs CO2 th vi li b binthnh CaCO3 ) bng cch ngm trong hsu c ct or nc ph bn trn dy 10-20cm
- Vi sa: l vi c lng nc nhiu hn so vs vi nhuyn, hn 50% ncu im khi bo qun: Bo qun n ginNhc im: Cng chu lc thp, kh hn chk tc hi ca cc ht gi la, khi sd phi lcht sn..
Cng dng: Vi sa v vi nhuyn thng k dng trong xd v dnh sn xut va xy, trt cc cng trnh vicn dng lm gch silicat, qut trn, tng.. Cn bt vi chn ch yu dng trong y hc v nng nghip
Cu 6. Cc c tnh c bn ca cc khong vt chnh c trong xi mng poolang? V p thy ha cachng????
Clinke c 4 khong vt chnh nh sau :
- Alit : silicat tricanxi : 3CaO.SiO2 ( vit tt l C3S). Ngoi ra cn cha cc oxit nh MgO,Al2O3, P2O5v cc tp cht khc.Chim hm lng 45 - 60% trong clinke.
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Alit l khong quan trng nht ca clinke, n quyt nh cng , tc rn chc, s tanhitca xi mngc tnh c bn: Ta nhiu nhit khi trn, cng tng nhanh, cng cui cng cao, tc ng rn nhanh, dbi n mn (n mn ha tan ).
Phn ng thy ha: 2(3CaO.SiO2) + 6H2O 3CaO.2SiO2.3H2O
- Blit : silicat icanxi 2CaO.SiO2 (vit tt l C2S).Chim hm lng 15-45% trong clinke. Blit l khong quan trng th hai ca clinkec im: Rn chc chm nhng t cng cao tui mun, ta nhit t, t bn mn
Phn ng thy phn: 2(2CaO.SiO2) + 4H2O 3CaO.2SiO2.3H2O
- Aluminat tricanxi : 3CaO.Al2O3 (vit tt l C3A ).Chim hm lng 7-15 % trong clinke.c im: Ta nhit rt ln, qu trnh ng rn rt nhanh nhng cng cui cng thp, khnng bn mn sunfat ln nht trong cc khong nn ngi ta thng phi khng ch khongny trong xi mng.
Phn ng thy phn: 3Cao.Al2O3 + H2O 3CaO.Al2O3.6H2O
- Feroaluminat tetracanxi : 4CaO.Al2O3.Fe2O3 ( vit tt l C4AF ). Chim hm lng 10 - 18%trong clinke.c im: Tc rn chc, cng chu lc, nhit lng ta ra v khnng chng n mnu trung bnh.
Phn ng thy ha: 4CaO.Al2O3.Fe2O3 + mH2O 3CaO.Al2O3.6H2O + CaO.Fe2O3.nH2O.
Ngoi cc khong vt chnh trn trong clinke cn c mt s thnh phn khc nh CaO; Al2O3; Fe2O3;MgO; K2O v Na2O, tng hm lng cc thnh phn ny khong 5-15% v c nh hng xu n tnh cht ca ximng nh nu lng MgO >5%, CaO>1% th lm mt tnh n nh th tch ca xi mng, nhiu oxit kim c th gynt ncho b tng. Khi hm lng cc khong thay i th tnh cht ca xi mng cng thay i theo.
V d: Khi hm lng C3S nhiu ln th xi mng rn cng nhanh, cng cng cao. Nhng nu hm lng C3Atng th xi mng rn rt nhanh v d gy nt cho cng trnh.
Cu 7. Lng nc tiu chun, thi gian ninh kt v tnh n nh th tch ca xi mng pooclang??????
1. Lng nc tiu chuna. Khi nim l i lng bng t lnc/xi theo % khi lng xi mngb. Phng php xc nh: phng php th dn bng dng cvicac. Cc xc nh
- Th nghim bng dng c vica c D=10mm, l=50mm, m=300g, cho, bay tiu chun, thcthp, ng h, ng ong..
- Trn 500g xi mng vs 1 lng nc k coi l tiu chun ( 25-32% khi lng xi mng), trntrong vng 3p ta k hxi mng
- Cho vo cn tiu chun, dng thc thp gt h xi mng bng vs mt cn, tin hnh o cmsu ca kim vica trong vng 30s.
- Nu cm su kim vica vo hxi mng khong 34mm hay cch y 5-7mm th lng ncnho trn k xc nh l lng nc tiu chun..
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Ch : cm su cch y >7mm th b tng qu cng, < 5mm th nho qu, nu k kt qu thnghim nh th th lm li tu vs lng nc tiu chun iu chnh 0,5%
d. Yu tnh hng- Ph thuc vo mn, din tch tip xc ca xi mng, xi mng cng mn th tnh cng tc ca b
tng tng, nh hng n lng nc tiu chn- Ph thc thnh phn khong ca xi mng, nu xi mng nhiu C3S or Ca3A th xi mng c rn
chc nhanh, nhiu C2S th rn chc chm t nh hng n lng nc tiu chun ca ximng.
- Hm lng phgia: xi mng c nhiu phgia nh phgia gip b tng nhanh ng rnth nhhng n lng nc tc..
- iu kin bo qun xi mng, thi gian lu khoe. ngha dng xc nh cc ch tiu khc ca xi mng nh thi gian ninh kt, n nh.2. Thi gian ng kt xi mng
a. Khi nim Thi gian bt u ng kt l khong thi gian k tkhi xi mng trn vs nc n khi h ximng bt u mt tnh do
Thi gian kt thc ng kt l khong thi gian khi xi mng nho trn vs nc n khi hxi mngmt ht tnh do.
b. Phng php xc nh: pp th dn bng dng c vicac. Cch xc nh- Dng kim vica th (d=1,13mm, l=50mm, m=300g)- Tin hnh trn 500g xi mng vs lng nc tiu chun nh th nghim trn v vo khun.
Ghi li thi im trn xi mng vs nc.- Cho hvo khun t trn tm knh ca dng c, h kim xung mt h v vn cht vt hm sau
mvt hm cho kim cm vo, ghi kt qusau 10p, khi kim cch y khong 4mm th ghi lithi gian, l thi im bt u ng kt
- Thay 1 kim nh khc, lt p mu xc nh thi gian kt thc ng kt. c 30p cho kim cm 1ln,n khi kim ch cm vo hxi mng 0,5mm th ghi li thi gian, l thi im kt thcng kt.
d. Cc yu tnh hng- Ph thuc loi xi mng- Ph thuc mn, thnh phn khong xi mng, vd nh xi mng ch nhiu khong C3S or C3A
th xi mng ng rn nhanh, nhiu khong C2S th xi mng rn chc chm- Ph thuc cc ph gia thm vo- iu kin bo qun xi mng
e. nghaKhi thi cng b tng v va cn phi bit thi gian bt u ng kt v thi gian kt thc ng ktca hxi mng nh ra k hoch thi cng hp l v vy cn phi xc nh ch tiu ny.
3. n nh th tcha. Khi nim l thay i th tch ca hxi mng sau khi trn xi mng vs nc. Nguyn nhn ch yu
l do s tip xc ca hxi mng vs mt.
b. Phng php xc nh: pp bnh a xi mngc. Cch xc nh- Trn 500g xi mng vs lng nc tiu chun- chia hxi mng thnh 4 phn bng nhau, nn mi phn thnh mt vin bi, t mi vin bi ln
mt tm knh lau bng du nhn ri rung tm knh cho n khi cc vin to thnh hnh trndt nh cc bnh a (bnh trng) c ng knh 7-8cm, b dy ch gia chng 1 cm. Dng daom mit t cnh vo gia mp mu mng v nhn mt.
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- t cc mu vo thng gi mu ri y np kn v gi trong 24 2 gik t lc to mu.Sau ly ra khi thng v tch mu ra khi tm knh. t 2 mu trn li thp trn, 2 mu trnli thp di ca thng chng v luc mu.
- Sau khi xp mu, un si nc trong thng 4 gilin, thi gian tlc un n lc si khngqu 30 - 40 pht. mu ngui trong thng n nhit trong phng ri ly ra quan st.
- Khi quan st nu thy mu th b cong vnh v c nhng vt nt chy xuyn tm ra n mpth xi mng c coi khng n nh th tch Nu cc mu khng b cong vnh khng c vtnt hoc ch c cc chm nh v mt vi vt nt gia mu khng chy ra n mp, th xi mngc coi l c tnh n nh th tch
d. Yu tnh hng- Loi xi mng dng, thnh phn xi mng, mn- Ph gia khong thm vo- Thi gian bo qun mu, luc mu.
e. ngha: kim tra tnh n nh ca hxi mng trong lc thc hin cc cng trnh..Cu 8. Cng v phng php t mc cho xi mng???
1. L cng chu nn () ca ximng vi cc iu kin:- Kch thc mu th 4x4x16cm- Mu th l hn hp ximng ct bng 1 : 3.- Dng h28 ngy trong iu kin tiu chun: t=20, W > 95%
Dng c th nghim
- Khun c mu kch thc 4x4x16cm.- Chy m c kch thc mt y 3,5x3,5cm.- Cn k thut chnh xc 0,1g.- Cho hnh chm cu v bay.- My un v p mu, tm m p.2. Cch tin hnha. To mu
- Cn lng ximng X = 450g v ct C = 1350g m bo t lX/C = 1/3. Ct dng y l cttiu chun (cht t 0,51 mm).
- T lnc/ximng: X/N = 0,5 N = 225g.- Cho lng ximng v ct c lau sch bng vi m, trn u. Sau 1 pht dng bay moi
thnh hc gia, cho lng nc trn vo tip tc trn u.- Bi du vo khun (4x4x16cm).- Hn hp va trn xong cho vo mi mu trong khun theo 2 ln, ln 1 cho va vo khong
hn chiu cao ca khun, m 20 chy qua li dc theo chiu di khun.Ln 2 tip tc chova vo y khun v cng m qua li 20 chy.
- Gt bng mt khun v mit mt va cho nhn. Dn 2 u khun t 57 ci nc ximngphn bu trnh r mt mu th.
- Dng h mu 1 ngy trong khun sau ly ra ngm nc 27 ngy.
b. Xc nh cng chu nn
Sau khi dng h 28 ngy, ly mu ra lau ro mt v th cng ngay khng chm qu 10 pht.
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Tin hnh th nghim un mu, mi mu th b gy thnh 2 na. Sau tin hnh th nghim xc nhcng chu nn vi 6 na mu tng ng.
Gi trcng chu nn c tnh ton:
(kg/cm2)
P (kg): lc nn ng vi mi na mu,
F = 16 cm2: tit din chu lc ca mi na mu.
- Mc ximng l tr s trung bnh ca 4 kt qu gn nhau nht trong 6 kt qunn c.
= = /4
Cu 9. Hin tng n mn xi mng v cc bin php bo v??
Nguyn nhn:
- Ch quan: Bn thn xi mng c l rng hth khnng ht nc ln, cu trc ca ,thnh phn khongvt, ha hc cha nhiu cht dn mn, xi mng ngoi thnh phn pha rn cn c pha lng v phakhnh hng ln n sn mn ca xi mng.
- Khch quan: xy ra hin tng trao i cht, cht c hi t mt xy nhp vo xi mng gy ra cc p chi, lm bin i thnh phn, cu trc ca xi mng. S phn r cc thnh phn ca xi mng, s ha tan v ra tri hyroxit canxi To thnh cc mui dtan do hyroxit canxi v cc thnh phn khc ca xi mng tc dng vi cc
cht xm thc v s ra tri cc mui (n mn axit, n mn magiezit). S hnh thnh nhng lin kt mi trong cc l rng c th tch ln hn th tch ca cc cht tham gia
phn ng to ra ng sut gy nt b tng (n mn sunpho-aluminat).
Cc loi n mn c th:
- n mn ha tan: cht mt xm nhp vo xi mng gy ra cc p thy ha, Do s tan ca Ca(OH)2 xy ranhanh mnh di s tc dng ca nc mm (cha t cc cht tan) nh nc ngng t, nc ma, ncsnglm pH gim, t cc sp bn ca xi mng( vd C3S2H3 bn pH=13) s b phn hy lm chtlng xi mng gim
C3S3H3 + H2O Ca(OH)2 + C2S2H3, C2S2H3 li tip tc phn hy to Ca(OH)2, Khi hm lngCa(OH)2 c trong xi mng ti15 - 30% thcng ca xi mng gim n 40 - 50%.
- n mn trao i: cc cht ngoi mt xm nhp vo xi mng thc hin cc p trao i, nh cc loi muicha magie trong nc bin, nc ngm, nc cha mui khong tc dng vi Ca(OH)2 to ra cc snphm d tan (CaCl2; CaSO4.2H2O) hoc khng c khnng dnh kt [Mg(OH)2] :
MgCl2 + Ca(OH)2 CaCl2 + Mg(OH)2 .
MgSO4 + Ca(OH)2 CaSO4.2H2O + Mg(OH)2 .- n mn do trng n: c c im l s tch t cc cht sinh ra t stng tc ca cc sn phm thy ha
vi cc cht tan trong nc thm vo b tng, sinh ra sn phm ha hc mi lm tng th tch nhiu, gyni ng sut ln, ph hoi cu trc ca xi mng v b tng. Tc nhn chyu l cc mui sunphatthng c trong nc ngm, nc thi cng nghip (sn sut phn bn, m, than cc ) v c nhiu trongnc bin dng SO4
2- . Tuy nhin loi n mn ch xy ra ng k khi nng SO42-> 250 mg/l. u tin
mui sunphat phn ng vi Ca(OH)2nh sau:
MgSO4 + Ca(OH)2 + H2O CaSO4.2H2O + Mg(OH)2
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Na2SO4 + Ca(OH)2 + 2H2O CaSO4.2H2O + 2NaOH
Sn phm CaSO4.2H2O c hnh thnh, tng th tch gp 2,34 ln so vi th tch ca Ca(OH)2. Tuy nhinCaSO4.2H2O li tip tc tng tc vi 3CaO.Al2O3.6H2O to thnh 3CaO.Al2O3.3CaSO4.31H2O ettringit nthtch ln 4,8 ln theo phn ng sau:
3CaO.Al2O3.6H2O + 3(CaSO4.2H2O)+19H2O 3CaO.Al2O3.3CaSO4.31H2O
Ettringit nth tch nhiu ln s ph vi cu trc xi mng v b tng lm xut hin cc vt nt to iu kin chonc v khng kh i vo trong b tng gy n mnct thp bn trong.
Phng php bo v:
- Ngn cch b mt xi mng vs mt bng cch thc hin cc bin php nh: sn ph b mt bng snchng thm, chng m, p vt liu chng n mn bn ngoi,.
- Lm nhn b mt xi mng, tng tit din chu lc- Tng c chc trong kt cu xi mng bng cch tnh ton thnh phn hp l,tnh cp phi ht, ph gia,
xi mng nghin mn-
Gim thnh phn khong d bn mn, thm ph gia chng n mn vo xi mng, gim sn phm thu haCa(0H)2, tng gc siliccat (SiO2)- .
Chng3: Vt liu gm
Cu 1. Khi nim, phn loi vt liu gm xy dng????
a. Khi nim l loi vt liu nhn to k sn xut t nguyn liu chnh l t st bng cch to hnh vnung nhit cao
u in: bn v tui th cao, nguyn liu a phng, cng nghsx n gin, gi thnh h,Nhc im: gin, d v, tng i nng, kh c gii ha xd, xs nhiu cn lm gim din tch t nngnghip..
b. Phn loi- Theo cng dng: Vt liu xy : Cc loi gch c, gch 2 l, gch 4 l.
Vt liu lp : Cc loi ngi.Vt liu lt : Tm lt nn . lt ng, lt va h.Vt liu p : p tng nh, p cu thang, p trang tr.Sn phm k thut v sinh : Chu ra, bn tm, b x.Sn phm cch nhit, cch m : Cc loi gm xp.Sn phm chu la : Gch samt, gch i n
-Theo cu to vt liu gm c chia ra :Gm c : C rng r 5% nh gch p, lt, ng thot nc. Gm rng : C rng r > 5% nh gchxy cc loi, gch l nem.
- Theo phng php sn xut vt liu gmc chia ra:Gm tinh: thng c cu trc ht mn, sn xut phc tp nh gch trang tr,s v sinh.Gm th: thng c cu trc ht ln, sn xut n gin nh gch ngi, tm lt, ng nc.
Cu 2. Khi nim, phn loi, thnh phn t st ch to gm xy dng???
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a. Khi nim: t st l loi trm tch a khong, khi nho trn vs nc n trthnh hn hp do cth to hnh thnh cc hnh khc nhau, sau khi gia cng nhit n bin thnh trng thi .
b. Thnh phn ca t st gm cc thnh phn ha, khong v ht- Thnh phn ha
Al2O3 8-22% c phn tn cao, kh nungnn c khnng chu nhit tt.SiO2 lin kt: 40-60% tham gia vo qu trnh to khong mi thng qua qu trnh nung
SiO2 t do 15-30% gim,co th tch khi sy gy mt n nh th tch khi nungFe2O3 1-7% tnh cht nhum mu, gim nhit kt khiMgO, CaO, K2O,Na2O 0,5-4,5% gim kt khi
- Thnh phn khongThnh phn chnh ca t st l cc khong alumsilict ngm nc (nAl2O3.mSiO2.pH2O) chng cto thnh do fenspt b phong ha.Ty theo iu kin ca tng mi trng m cc khong to ra c thnh phn khc nhau, vd trong mtaxit(pH=6-7) to khong caolinit 2SiO2.Al2O3.2H2O, trong mt kim (pH= 7,3-10,3) to khongmontmrilonit 4SiO2.Al2O3.nH2O. hai khong quyt nh nhng tnh cht quan trng ca t st nh do, co, phn tn, khnng chu la v.v...Ngoi ra trong t st cn cha cc tp cht v c v hu c nh thch anh (SiO2), cacbonat (CaCO3,
MgCO3), cc hp cht st Fe(OH)3, FeS2, tp cht hu c dng than bn, bi tum v.v... cc tp cht unh hng n tnh cht ca t st.- Thnh phn ht
Ht ct: 0,14-5mm c tnh ht nc kmHt bi: 0,05-0,14mmHt st: 28%, co: 10-15%t st do trung bnh: Nyc 20- 28%, co: 7-10% do km: Nyc
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- Khi n nhit 450-700-900 metacaolinit phn hy thnh Al2O3 v Sio2. Mn li tinh th cakhong t st hon ton b ph hy cng sn phm gim. 700 Fe2O3 nng chy,y l in nngchy u tin trong qu trnh nung, nhit bt u kt khi
- 900-1200-900 y l nhit kt khi, ton bt st chy lng nhng vn gik hnh dng. yAl2O3 bin thnh Al2O3 khong silimanit c to thnh
Al2O3 + SiO2 Al2O3. SiO2Khong cacbonat b phn hy
CaCo3 CaO + CO2Trong nhit 1000 -1200 ch yu l s to thnh khong silimanit v khong mulit bt u dc hnh
thnh:Al2O3. SiO2 3 Al2O3 .2SiO2
Nhit cng tng s chuyn ha silimanit thnh mulit cng cao v chuyn ha hon thnh mulit 1370 -1420 . khong mulit l khong quan trng nht, lm cho sp c cng cao v bn vs mt.
- 900-700 lm ngui chm- 700-200 lm ngui nhanh
Cu 5. Cc chtiu nh gi cht lng gch, ngi t st?? Nu ngha thc tin ca cc chtiu v phng
php xc nh chng????1. Gch- Ngoi hnh
HCN: 220x105x60mm, sai lch ko qu: chiu di 6mm,chiu rng 4 mm,chiu dy 3mmMu sc: gch tt: mu ti, mu en: qu la, vng c:nonm thanh: trong:tt, c:non, anh:gi, r:ntCong vnhNt, tch: chiu cao, chiu rng, chiu su vt nt
Nu ko tha mn cc tc ngoi hnh th loi, ko kim tra nhng tc sau na
- Cc ch tiu vt l: = 1,6-1,9g/, = 2,2-2,6g/, = 8-15%- Cc ch tiu chu lc Gii hn bn khi nn v un
Ngoi sx gch c ngi ta cn sx gch xp, gch nhiu l rng ngha: ta cn xc nh cc chtiu ny loi bngay nhng vin gch ko t cht lng, gy nhhng n cng trnh xy dng, n cn gip ta xc nh mc ch ca tng loi gch dng u thch hp,mt no dng tt
2. Ngi- Ngoi hnh: c 3 loi chnh: 22 vin/1, 13/1, 16 vin/1. B mt nhn, ko k nt, tch, cong vnh,
mu sc ti, u, m thanh trong, vang, chng thm, xp kht- Ch tiu vt l = 1,9-2,1g/, = 2,2-2,6g/, ht nc Hp
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CHNG 6: VA XY DNG
CU 1: Va xy dng
- Khi nim: Va xy dng l vt liu nhn to nhn c do s cng ha ca hn hp bao gm cht ktdnh, nc, ct liu nh v ph gia
- c im: Lun trng thi dn mng, ch yu dng truyn lc v trang tr Khng c ct liu ln do ln hn HHBT Cng khng cn cao: Mac khong 50-75-100 Din tch tip xc vi mi trng ln nn d mt nc
- Phn loi: Theo cng dng: va xy, va trt, va chn mi ni, va c bit Theo khi lng th tch: Va nng ( > 1500kg/cm3); va nh((
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CU 3: Cng va xy dng? Skhc nhau gia va xy trn nn c v nn xp?
- Cng va xy dng Khi nim: l khnng chng li s ph hoi ca va bi cc yu t ngoi lc Cc yu tnh hng: loi cht kt dnh, lng cht kt dnh, t l N/X, cht lng ct, iu kin bo
dng v thi gian cng rn
Cng tng theo thi gian do cng xi mng tng v tun theo quy lut hm Logarit nh sau:CT:
=
; n= 3 - 90 ngy, khng s dng ph gia
Va hn hp ph thuc lng vi hoc st s dngTc pht trin cng ph thuc nhit
Cch xc nh: Xc nh gii hn chu nn ca cc mu lp phng kch thc (7,07x7,07x7,07 cm)VD: Va xi mng, khun t trong mi trng m trn 90%, nhit trong thi gian 24-48h..sau khi tho khun tip tc bo qun trong mi trng tng t..Sau thi gian bo dng mang 3mu ra th ri ly trung bnh cng..sai s khng qu 15%. Nu 2 trong 3 mu khng t th lm li.
- So snh va xy nn c v nn xp
Va xy trn nn c Va xy trn nn xp
X : lng xi mng, T/ctK: h s ph thuc cht lng ct
Cng ph thuc cng xi mng, ph thuc
vo gi tr
Cng ph thuc lng dng xi mng, khng
ph thuc
nc sau khi b nn ht cn li hu nh
bng nhau
CU 4: So snh cc yu cu v tnh cht ca va xy v va trt?- Do v tr v cng dng ca va trt nn n c mt s yu cu khc vi va xy: nho hn v c khnngginc tt hn ( phn tng tt nht 1-2mm). C th vt liu ch to va trt cn t nhng yu cu:
Vi phi ti k, lc k Ct phi mn hn: lp d b v lp m , lp trang tr C th dng thm ph gia nng cao do
CHNG 7: VT LIU G
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CU 1: Vt liu gxy dng? Cu to ca g?
1. Vt liu g xy dng- G: l vt liu thin nhin c s dng rng ri trong xy dng v nhiu lnh vc- u im:
Cng cao nhng kh nh..VD: Lim , Xoan ,
Phong ph v mu sc v kiu dng, vn g c gi trm thut cao Cch m cch nhit tt Ti trng va p tt,dca x.
- Nhc im: Cu to v tnh cht c l khng ng nht, thng thay i theo tng loi g, tng cy v tng phn
trn thn cy. (tnh dhng)
D ht v nhhi nc lm sn phm b bin i th tch, cong vnh, nt tch( d bnh hng bimi trng)
D b su nm, mc mi ph hoi, d chy. C nhiu khuyt tt lm gim khnng chu lc v gia cng ch bin kh khn
- Phn loi: Theo khi lng th tch: Rt nh - Nh - NngNng vaRt nng Theo 1 s ch tiu khc
2. Cu to ca g: g c cu to phc tp- Cu to th: gm 6 lp
V c chc nng bo v g khi b tc dng c hc. Libe l lp t bo mng ca v, c chc nng l truyn v d tr thc n nui cy. Lp hnh thnh gm mt lp t bo sng mng c kh nng sinh trng ra pha ngoi sinh ra v v
vo pha trong sinh ra g.
Lp g ba (gic) mu nht, cha nhiu nc, d mc nt, mm v c cng thp. Lp g li mu sm v cng hn, cha t nc v kh b mc mt. Li cy (ty cy) nm trung tm, l phn mm yu nht, d mc nt.- Cu to vi m: T bo ca g gm c t bo chu lc, t bo dn, t bo tia li v t bo d tr. T bo chu lc (t bo th) c dng hnh thoi di 0,3 - 2mm, dy 0,02 - 0,05 mm, thnh t bo dy, ni
tip nhau theo chiu dc thn cy. T bo chu lc chim n 76% th tch g .
T bo dn hay cn gi l mch g, gm nhng t bo ln hnh ng xp chng ln nhau to thnh ccng thng sut. Chng c nhim v dn nha theo chiu dc thn cy.
T bo tia li l nhng t bo xp nm ngang thn cy. Gia cc t bo ny cng c l thng nhau. T bo d tr nm xung quanh mch g v c l thng nhau. Chng c nhim v cha cht dinh
dng nui cy.- Qua quan st cu trc, g th hin r l vt liu khng ng nht v khng ng hng, ci thg ch xp
theo mt phng dc, phn lp r rt theo vng tui. Do vy tnh cht ca g khng ging nhau theo v trv phng ca th.
CU 2: Cc loi nc trong g? nh hng ca chng n tnh co nv cng ca g?
- Cc loi nc trong g Nc tdo: nm trong ng dn, rut t bo. S bin i ca nc t do nh hng n tnh cht ca
g
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Nc hp ph: nm trong rut hoc khong trng t bo nn nh hng trc tip n tnh cht ca glm v t bo nra khi thm nc v xp li khi nhnc dn n sthay i th tch, gim s linkt gia cc t bo nh hng n khnng chu lc ca g
Nc lin kt ha hc: nm trong cu to ha hc cu thnh nn g- S co ngt xy ra khi sy kh g dn n gim thtch. Nc tdo bay hi khng lm co ngt m nguyn
nhn l do sbay hi ca nc hp ph chiu dy v t bo gim i, cc mixen xch li gn nhau gim th tch
- Strng nxy ra khi ght nc vo thnh tbo lm tng kch thc v th tch. Thc t, gtrngnkhi ht nc t n gii hn bo ha th( ch cha nc hp ph)
- S bin i cc loi nc dn n xy ra s co nlm thay i kch thc v th tch thay i tit dinchu lc v lin kt gia cc thtrong gnh hng n khnng chu lc ca g.
CU 3: Phn tch nh hng ca m ti cc tnh cht c l ca g? T xc nh mi quan h gia m vi cc i lng ny bng cng thc tnh ton?
- Do nh hng ca m, nc hp ph mt i lm chiu dy cc t bo gim, cc mixen xch li gn nhaudn n g b co
Mc co th tch y0 (%) c xc nh da theo th tch ca mu gtrc khi sy kh (V) v sau khisy kh (V
1) theo cng thc:
H s co th tch K0
(i vi g l kim: 0,5, g l rng: 0,6) c xc nh theo cng thc:
Vi W l m ca g, - Khi lng th tch ph thuc vo rng v m ca g.-
l khi lng th tch iu kin chun v m W
l h s co th tch- G cu to dhng nn tnh cht c hc khc nhau theo cc phng v ph thuc vo nhiu yu t..trong
quan trng l m.
l h siu chnh mW l m ca g,
CU 4: Cc chtiu m ca gv ngha ca chng?
m ca g c 3 loi
- m cn bng: l m khi vt liu gt trng thi cn bng v nhit , m khi t trong 1 mitrng nht nh (thng t 2-18%)
- m bo ha th: l trng thi khi g ch cha nc hp phm khng c nc t do. Cc tnh chtca g chthay i khi m ca g> m bo ha th
- m tiu chun: l m so snh tnh cht ca cc vt liu g vi nhau (18%) Chuyn khi lng th tch m bt k v khi lng th tch m tiu chun
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l khi lng th tch m tiu chun v m W l h s co th tch
m cng nh hng n cng ca g
l h siu chnh m
W l m ca g
CU 5: Tt bnh ca g? Cc bin php bo v g?
- Khuyt tt ca g c th do nhiu nguyn nhn: Khuyt tt do cu to khng bnh thng : Dng khuyt tt ny kh ph bin bao gm: lch tm, vn
th, trc lp, hai tm v.vCc khuyt tt ny u lm gim cht lng ca g.
H hi do nm: Nm c th lm g b bin mu, b mc v gim tnh cht c l. Nm c th ph hoingay khi cy gcn ang sng, cy g cht xung hoc tip tc ph hoi g ngay trong kt cucng trnh.
H hi do cn trng: Dng khuyt tt ny xy ra khi cy gang ln v cy g cht xung cn ticng nh kh. Mi mt l nhng h hi su bn trong g. Khuyt tt ny lm gim cht lng cag rt nhiu, lu dn s ph hoi nghim trng, nh hng n tui th ca cc kt cu g.
- Cc bin php bo v g Phng chng nm v cn trng: bin php ny nhm ko di tui th ca g bng cc bin php sn
hoc qut (m,sn hoc du trng hp); ngm chit kim(tch nha cy bng cch ngm nc hocth b tri sng) v ngm tm cht ha hc
Phng chng h:+ Dng g cng hoc qunh lm h kh c hoc snha khng bm vo+ nguyn v cy hoc bc kim loi, xi mng bn ngoi+ Dng ha cht nh hoc creozot..
Sy g l bin php lm gim m ca g, ngn nga mc nt, tng cng , hn ch sthay ikch thc v hnh dng trong qu trnh s dng, cc bin php phi sy gc s dng l sy tnhin, sy phng,sy in, sy trong cht lng un nng. Trong sy t nhin v sy phng l chyu.+ Sy tnhin n gin, khng tn km tuy nhin ph thuc thi tit v hiu qu khng cao+Sy phng i hi trang thit b,tn chi ph v nhn lc tuy nhin tin tng l tuyt i
CHNG 8: CHT KT DNH HU C
CU 1: Cht kt dnh hu c? (Khi nim,phn loi, thnh phn, cu trc)
- Khi nim: l nhng cht dng cng,qunh, lng c thnh phn ch yu l cc Hidrocacbon cao phn tc khnng trn ln v dnh kt cc vt liu khong to thnh vt liu nhn to c nhng tnh cht vt lv c hc ph hp
- ng dng: lm ng, lm vt liu lp, cch nc bo v kim loi v b tng- c tnh k thut:
D lin kt vi vt liu khong bng lp mng mng bn v n nh nc.
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C nht nht nh, nh m trong thi gian thi cng n bao bc quanh vt liu khong cntrong thi k lm vic n gn kt nhng vt liu khong thnh mt khi ng nht, to ra cng cn thit.
Tng i n nh kh quyn, t thay i tnh cht trong qu trnh s dng. Ha tan t trong nc v trong axit v c, ha tan nhiu trong dung mi hu c.
- Phn loiCn cvo cc c im sau phn loi cht kt dnh hu c.
Theo thnh phn ha hc, chia ra : Bitum v gurng. Theo ngun gc nguyn liu chia ra:
+ Bitum du m l sn phm cui cng ca du m.+ Bitum du l sn phm khi chng du.+ Bitum thin nhin l loi bitum thng gp trong thin nhin dng kt tinh hay ln vi cc loi .+ Gurng than l sn phm khi chng kh than .+ Gurng than bn l sn phm khi chng kh than bn.+ Gurng g l sn phm khi chng kh g.
Theo tnh cht xy dng chia ra:+ Bitum v gurng rn: nhit 20 - 25
o
C l mt cht rn c tnh gin v tnh n hi, nhit 180 -
200
o
C th c tnh cht ca mt cht lng.+ Bitum v gurng qunh: nhit 20 - 25
o
C l mt cht mm, c tnh do cao v n hi khng lnlm.
+ Bitum v gurng lng : nhit 20 - 25o
C l mt cht lng v c cha thnh phn hyrcacbon d bayhi, c khnng ng c li sau khi thnh phn nhbay hi v sau c tnh cht gn vi tnh cht ca bitum vgurng qunh.
+ Nh tng bitum v gurng: l mt h thng keo bao gm cc ht cht kt dnh phn tn trong mitrng nc v cht nh ha.
- Thnh phn: Cht kt dnh hu c l h thng phn tn ca cc cht hircacbon khc nhau (thm CnH
2n-
6,naftalin C
nH
2nv m tan C
nH
2n+2) v cc mch d vng ca cc hircacbua c trng lng phn ttng
i cao. Cc nhm cu to ch yu
Nhm cht du gm nhng hp cht c phn tlng thp (300-600), khng mu, khi lng ringnh (0,91-0,925). Nhm cht du lm cho CKDHC c tnh lng. Nu hm lng nhm ny trongCKDHC tng ln s lm cho tnh qunh gim.Trong bi tum nhm cht du chim 45-60%; tronggurng than 60-80%.
Nhm cht nha gm nhng hp cht c phn t lng cao hn (600-900), mu nu sm, khilng ring xp x 1. N c thha tan trong benzen, etxng, clorofooc. Nhm cht nha trung tnh(t l H/C=1,6-1,8) lm cho CKDHC c tnh do. Nu hm lng nhm ny trong CKDHC tng lns lm cho tnh do tng. Nhm cht nha axit (t l H/C=1,3-1,4) lm tng tnh bm dnh caCKDHC vi vt liu khong. Trong bi tum du m nhm cht nha chim 15-30%; trong gurngthan 10-15%.
Nhm asfalt rn gm nhng hp cht c phn t lng ln (1000-6000), mu nu sm hoc en,khi lng ring 1,1-1,15). Nhm ny khng b phn gii khi t. nhit ln hn 300
o
C th bphn gii ra kh v cc. Nhm asfalt rn c t l H/C=1,1. N c th ha tan trong clorofooc,
ttracloruacacbon (CCl4), khng ha tan trong. te, du ha v axtn (C3H5OH). Tnh qunh v sbin i tnh cht theo nhit ca CKDHC ph thuc ch yu vo nhm ny. Nu hm lngnhm ny trong CKDHC tng ln s lm cho tnh qunh v nhit ha mm ca CKDHC cngtng ln.Trong CKDHC nhm ny chim 10-38%.
Ngoi 3 nhm c bn trn, trong thnh phn ca CKDHC cn c cc nhm ha hc khc nh nhmcacben v cacbit, nhm axit asfalt v cc anhirit, nhm parafin. Cc nhm ny c nh hng nhtnh n tnh cht ca CKDHC.
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- Cu trc : Cht kt dnh hu c l mt h thng keo phc tp c cu trc c bn l cu trc mixen. Mimixen l mt h thng phc tp bao gm mt slng ln cc phn tlng nh bao quanh mt tinh thbng nhng lc tng h. Khi lc tng h ln th mi mixen coi nh 1 nt mng.
CU 2: Tnh do v tnh qunh ca Bitum du m? (Khi nim, cc yu tnh hng, phng php xcnh v ngha thc t)
- Tnh do: Khi nim: c trng cho khnng bin dng ca bitum di tc dng ca ngoi lc Yu tnh hng: nhit v thnh phn nhm. Nhit tng th tnh do tng v ngc li nhit
gim bitum trnn gin
Cch xc nh: nh gi qua ko di L(cm) ca mu tiu chun v c xc nh bng dng co ko di. Mu c c trong khun tiu chun sau c mang ra ko vi nhit ,tc ko 5cm/pht. ko cng ln, do cng cao.
ngha thc t:- Tnh dnh qunh:
Khi nim: Yu tnh hng: Hm lng nhm cu to v nhit mi trng. Khi hm lng nhm atfan
tng v nhm cht du gim th qunh tng. Nhit tng, qunh gim.
Cch xc nh: Dng chtiu cm su ca kim( m=100g, d=1mm) vi dng c tiu chun vobitum trong 5s. K hiu P l kim ln ( o bng , 1 = 0,1 mm). P cng nh tnh qunhcng cao
ngha thc t:CU 3: Cc tnh cht k thut ca Bitum du m?
- nht: Yu tnh hng: thnh phn cc nhm ha hc v t l gia lng cht lng v rn dng pha
long. Bitum cha nhiu nhm cht rn cht nha, t cht du th nht tng
Cch xc nh Dng nht k, o thi gian 50ml Bitum lng chy qua ly ca dng c cd=5mm nhit
- Phn ct Slng v cht lng phn ct l ch tiu gin tip biu th tc ng c ca Bitum lng. Nu
cha cng nhiu v chng c nhit si thp th qu trnh ng c cng nhanh Cch xc inh: ct cc nhit khc nhau . Tnh cht cu phn cn li sau
cng s quyt nh tnh cht Bitum khi s dng.- Yu cu k thut
CU 4: Trnh by v B tng Arphan?
- Khi nim: BT Atphan l sn phm nhn c khi lm c chc hn hn BT Atphan gm: dm, ct, btkhong v bitum theo 1 t l hp l c nho trn v gia cng thnh hn hp ng nht
- c im: Cng , de, n nh nc ph thuc vo nhit v hi nc( nhit cng caocng cng gim, BT cng gin..), c khnng chng n mn tt hn BTXM.
- Phn loi:
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Theo mc ch cng trnh: BT thy cng, BT ng. Theo nhit thi cng
+ Hn hp nng: ri v bt u lm c nhit + Hn hp m: thi cng nhit + Hn hp lnh: dng bitum qunh 70/130, c ri nhit v c ginhit thng
Theo c ( rng cn d): 2-7%: c; 5-12% : rng; 12-18%: rt rng Theo ln ca ct liu: loi ln: ; loi trung bnh v loi nh
Theo t l gia dm v ct: Theo cng dm v cht lng bt khong: BT loi I, II, III
- Cu trc: Cu trc BT ph thuc vo t l vt liu thnh phn v c ca hn hp. Cu trc BT Atphanc 2 loi
Loi c khung: H s lp y l rng gia cc ht ca bkhung ct, dm bng cht kin ktatphan l
Loi khng c khung: H s lp y . Cng v kt dnh ca cu trc gim khi chu nhitthng dn n bin dng do
- Cc tnh cht: Cng :
+ K/n: Biu th khnng chu lc cc nhit khc nhau ca BT+ Yu tnh hng: Ph thuc t l thnh phn vt liu c bit l bitum v thnh phn khong( t lthun vi qunh), cng ngh lm BT, nhit v tc bin dng+ Cch xc nh: Nn nghing cc mu nn
Tnh bin dng:+ BT Atphan l vt liu n hi- chy do. S xut hin tnh cht no ty vo trng thi ng sut viu kin bin dng+ c trng c hc BT Atphan th hin qua 2 chtiu: M un n hi v nht. y l cc yu tquan trng quyt nh chlng ca BT
mi mn+ K/n:l c tnh gim khi lng/ 1 b mt khi chu tc dng ti trng, va p v mi mn (dotc dng ca lc ma st)+ Yu tnh hng: cng v cng vt liu khong vt, c ca hn hp
n nh nc+ L khnng gic trng thi ban u ca BT khi t trong mi trng m. Thng BT trong mi trng m lu ngy c th b ph hoi cc lin kt cu trc ca vt liu.+ Yu tnh hng: thnh phn khong vt, c v sn nh ca s dnh bm
+ Cch xc nh: H sn nh nc
,
rng: Khng nh s hp l v thnh phn BT, nh hng ln n cht lng BT Tnh d to hnh: m bo cho cng tc vn chuyn v yu cu thi cng.Yu tny c trng bi
do ca hn hp nh gi da trn thi gian v lc ko mu kim loi hnh nn chun ra khi hnhp
- Vt liu ch to dm hay si
+ Vai tr: to b khung ct liu+ Cht lng ca dm hay si (cng , tnh ng nht, hnh dng, trng thi b mt, thnh
phn khong vt,) c nh hng rt ln n cht lng ca b tng asfalt
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+ Cc ch tiu cht lng ca dm hay si ch to b tng asfalt cng c xc nh nh khich to b tng xi mng nng.+ dm dng ch to b tng asfalt c thl dm sn xut t thin nhin, dm ch tot cui, cng nh dm ch to t xl cao, nhng phi ph hp vi cc yu cu ca quy phm.Khng cho php dng dm ch to t vi st, sa thch st v phin thch st.+ dm cn phi lin kt tt vi bitum. V mt ny th cc loi vi, lmit, iaba tt hn cc
loi axit. Nu dng loi lin kt km vi bitum phi gia cng bng cht ph gia hot tnhnh vi, xi mng hoc cho thm cht ph gia hot ng b mt vo bitum.
+ cn phi, sch lng ngm cht bn khng c ln hn 1% theo khi lng.
Ct+ Vai tr: chn k hgia cc ct liu ln, tng c ca hn hp+ Cc chtiu k thut ph hp nh khi ch to b tng nng+ i vi ct thin nhin ch dng ct ln ( M
l/2,5 ) v ct va ( M
l= 2 42,5). Nu khng c ct
ln c th dng ct ht nh theo nguyn tc cp phi khng lin tc. Ct cn sch, hm lng bi,st khng c ln hn 3%. Ct nhn to c thc nghin t cc loi (khng phi l vi) c
cng khng thp hn 1000kG/cm2
Bt khong
+ Vai tr: L thnh phn quan trng trong hn hp BT Atphan, nht y l rng gia cc ct liu ln hntng c ca hn hp, lm tng din tch tip xc, lm mng Bitum trn mt ht khong mng dn nlc tng tc gia chng tng >> cng BT tng+ Hm lng bt khong cn gii hn, nu qu nhiu lm Bt gin v tng tc ha gi+ Bt khong cn phi kh v xp, khi trn vi BT khng vn cc, thng s dng bt mn t vi v lmt. Cng chu nn ca . Vt liu ch to bt khong cn sch, khng cha cccht bn v st qu 5%.
Bitum+ Trong xy dng ng thng dng loi bitum du m loi qunh v loi lng.
+ tng tnh n nh nhit cho b tng c th dng hn hp bitum - cao su, bitum - polyme. Ccloi ph gia hin c trn thtrng nc ta lm cho b tng tng n nh nc v chng kh bmt, m bo tc khai thc.
