Cac phUcfng phap xuf ly vet nuTt be tong san trong thi cong xay dUng cong trinh dan dung
Treatment methods for cracking concrete floors in the work of civilian constructions
Ngay nhan bar 13/3/2017 Le A n h D u n g , Ngay sCBbai: 12/4/2017 Le Van Nam Ngay chap nhan dang: 5/5/2017
T6M TAT
Trong qua trinh thi c6ng cac cong trinh co Icit cau san be tong cdt thep, mcft so nha thau da ap dung nhiing phiicing phap bao dddng m6i nhil dung nifdc da de tr6n ht tong, Iche co gian, sCf dung bao nylon, dap bao tai, dap cat, tddi nddc... nhung van kho tranh khoi hien tUdng be tong bi niJt, nhat la nhflng vet niit co kem theo ro ri nit6c nhii san sSn thU^ng, san tang ham.. .khi€n cdc chu diu td, cic nha tit van xay diing phai lo lang. NhGng vet ntlt nay tgo tam ly khong an toan cho ngiidi sfl dung. Vi the, mot so cong trinh co xuat hien vet niit da phai tam ngflng de chef kiem dmh lai va tim phiidng phap siSa chfla, ch6ng nflt be tong, cung co nhflng vSt nflt phai dap bo do khong hi^u bilt vi vit nflt, dan tdi lang phi thcli gian va them ton k^m chi phi do c6ng trinh ch^m difa vao sil dung. Nghien cflu cac phitong dn x i ly vet nflt san b l tflng thudng dflng trong thi cong xay diing cong trinh de tim ra dU0c phfldng an tfli flu nhat de tao Iflp liin ktft chac v6i be tong vfla giflp bit kin vet nflt, d6ng thdi gia cfl lai bi tong de dat cfldng do thilt kl.
Tii khoa: PhflOng phap xfl ly vet nflt be tflng sin, be tong.
ABSTRACT
In the course of construction work based on reinforced concrete floor, some contractors have applied new maintenance methods such as using ice to mbc concrete, expandable joints, plastic bags, sack covering, sand filling, watering,..But still can't avoid the cracking concrete issue, especially the cracks that are accompanied by water leaks. For example on Terrace or Basement's floor, which makes the investors and the construction consultants worried. Also, these cracks can create the unsafety feeling for the users.
In that case, a number of works that have appeared cracks had been suspended to await testing and finding methods to repair, to find a way to make the concrete unbreakable. Or some of them might even get concealed as a result of lack of knowledge. All of these leads to time wasting and additional costs because the constructions are not completed on time. The research of normally used methods to deal with the concrete floor cracks are being held to find the most posible way to create a steady concrete- linked layer, and also to fix the cracks and reinforce the concrete for the best result.
Keywords: Treatment methods for cracking concrete fIoors,concrete.
PGS. T S U Anh Dung Trudng D^i hpc K\in Tnic Hd Nfli.
T h . s u van Nam
Trfldng Dai hoc Kiln Tnic Ha Nfli
1 . Oat van de - Vet nflt cong ngfie do co ngot b^ tdng, do mflc do dam viJa be V^t nflt trong ket cau san be tong v^ sSn be tong cot thep do nhieu tong k^m, chung bip be tdng khong deu, do che do nhiet-am, bSo nguyen nhan gay ra do tac dong cfla lUc, bien phap thi cong, do flng dUdng be tong;
suat nhiet v& flng suat co ngot [1], [2]... - V i t nut hinh thanh do cdt thep bi an mon va m 6 t s 6 nguy§n nhan Thong thu6ng phan ioai vet nflt [5] nhUsau: phu khic...
a.Theo nguyin nhdn xuSt hiin: b. Theo mdc do nguy hi4m-
- V i t nflt do t^c dong cua ngoai luc trong quS trinh sCf dung; - V^t niJt tie dong nguy h i l m d i n khS nang lam vi^c cila k i t du, - Vet nflt do tic dSng cOa cdt thep flng lUc ttudz len be tong; (cin gia cd k i t cau be tong trudc);
0 5 . 2 0 1 7 fiWniFiiai 4 3
- v i t nflt lam tang d6 tham nUflc cfla be tdng {d tUdng tang ham, san mai...);
- Vet nflt l&m gi^m tudi tho ket cau do cdt thep hoac be tong bi an - V i t nflt thudng, v i t nflt loai nay khdng gay nguy h i l m cho ket cau ( b l rdng vet nflt thudng khdng vUot qua gia tri gidi han cho ph^p cfla tieu chu^n);
HiSn nay tr§n thi trudng cd r i t nhieu phUOng 5n dUOc sfl dyng de xfl ly vet nflt trong be tdng scin. Trong bai bao nay tac gia gidi thieu 2 phuang phap xfl 1^ v i t nflt loai thudng trong bi tdng san gdm'
- Xfl lybSng may bOm keo Epoxyap lflc cao;
- Xfl ly v i t nflt bSng he thdng xi lanh bom keo Epoxy (cdn goi ia phuong phSp bum ^p luc thiip).
2. Xfl ly vet nflt bang mdy btfm keo Epoxy ap lflc cao 2.1. Uu va nhitcfc d i l m vi pham vi ap dung
• Pham VI 3p dung: Xfl li? cac vet nflt cd dd rong nhd (<0.5 mm) hoSc nhflng v i t nflt cd do sSu Idn (a 200 mm) ma cac phuang phap kh^c khong the bom vat lieu vao den noi 3uac. Cic vet nflt li^n quan tdri k i t cau nhu Ifln nflt dat nen. rung dap ket cau, lun do tcii trong, thudng
ic vet nut gay Idn.
Hirh21 Vetniltiandtraiiconglrinh Hiiih2.3 GaytrEin,vetnutuu6ngg6ctran
•:* Lfu diem:
- Khdng he bi co ngot trong qua trinh sfl dung do trong th^nh p h i n khdng bao gdm cac chat bay hoi,
- Cd kh3 nSng tao liSn k i t gifla cac v i t nflt nhanh k l c3 trong trudng hap be mat bi am Udt;
- Cdc hop chat keo Epoxy cd the de dang len ldi vao tan sau ben trong c^c v i t nflt;
- Khdng tUOng tac vdi nudc vi dc mdi tcudng chUa hda c h i t khde
• Nhugc diem: Thdi gian thi cdng keo dai, hao tdn nhieu nhan cdng, gi^ thSnh cao hon cac phuong phap khac.
2.3. Dung cu thi cdng
- Ban chai s^t, chdi, bay, may due, m^y mSi, m i y thdi b i i i .
yf^
- Keo tram TC - 1401 {hoic cac loai keo khac cd tinh chat tu'ong duong) cd tdc dung de gSn kim bom keo va t r i m kfn cdc dfldng nflt de khi bom khdng bi chdy keo bom ra ngoai
Kmh 2.5. Mmh hoa cho vat lieu siidung 2.5. Quy trinh thi cdng a. Chudn bi be mat
Hmh 2 6 Chuan bl be mat
- Khoanh vung cac vet nflt, s f dyng mSy mai cha doc theo dudng - Thoi sach cac dUdng nflt bSng may chuygn dung, ban chdi s3t, co quet
b. Ddnh ddu dUdng ndt
- Oanh dau vet nflt be tdng bang vach dau c^c vi tri quan trong de xfl ly v i t nflt;
- Danh dau cac vi tri trong yeu de khoan gan kim bom
Hmh 2 7, fianh dau duong nut c. Khoan vd g&n kim bam keo
- Dung may khoan vao cac VI tri da danh dau Khoan lo tai vi tri each vet nflt t f l 2,0cm - 5,0cm, khoan xeo 45 dd vao dUdng nflt, chieu sSu mui khoan t f l 7 - 20cm (tuy theo ehieu sau vet nflt, mui khoan phSi cat vet nut) Cac vi tri khoan each nhau 15 - 20cm. Ve sinh Id khoan bang may thdi bui,
Hmh 2 3. May bom tang ap Hinh 2.4. Kim bam keo - Kim bOm keo (hay cdn goi la ty bOm), m^y khoan, cac phu kien di kfem;
- Thiet bj quan trong n h l t trong phuong phap bom ap lUc cao la may bom keo ip lUc cao M^y bOm keo ap iUc cao cd ap lue toi da len tdi 10.000 PSI {tuong duong 750 kg/em2), i p luc binh quan t f l 1500^2500 PSI (tuong duong 105^175 kg/cm2).
2.4. vat ll^u sfl dung [4],
- Keo epoxy TC -1400, keo Epoxy Sikadur 752 (hoac cae loai keo khae cd tinh c h i t tuong dUong nhU: Dd nhdit thap, lien k i t manh vh khdng co rflt) dUdc sfl dung de bom vao vet nflt. Cd tac dung li§n k i t c h i c vdl be tdng, bjt kin v i t nflt dong thdi gia cd be tdng di tao thSnh khoi ddng n h i t ;
- Dung kim bdm keo dat v i o c i c vi trf Id khoan sau dd s i l t ch%i lai;
JL
- Tram keo TC - 1401 (hoac tUong duong) doc theo v i t nflt, muc dieh de keo se khdng bj chiy khi bom;
- Chd khodng 03 gid cho keo khd thi t i l n hanh bom keo.
d. Qud trinh bom keo
- Trdn keo 2 thanh phan theo dflng ti le, gan may bom v i o kim bdm;
.KsmK-r Bdm keo vSo v i t nflt bSng m i y i p luc cao TC-500/ TC-600 cho tdi
^ K k e o day trong vet nflit va tr&o len tren thi diing (gifl Ap iUc binh quan
"Wi50a§-25Q0P5I),
2.6. K i l m tra chat IflOng
Tien hanh khoan mau hien trudng tai vi tri bom keo, sau do dem di nen mau be tdng theo tieu chuan, neu vi tri p h i hoai m i u n i m n g o i i pham vi bom keo la dat yeu cau [3],[6].
2.7. Hi/flng x f l l y vet nut san a. Vet ndt mat tren sdn vd khdng xuyen thdu - HUdngxfllytfltrenxuong du6i.
Hinh 2.8, Qua trinh bam keo
- Khi keo khd t i l n h i n h t h i o kim bom keo;
f, ... Riil vur I chit! J m ftititf huy l^p Iqi ui
\ kiti liAa vM'i lis kttb houn llii^n bi mtll
^-^V
u^
Hinh 211 Hu6ng td ly vet nift mat tren san khong xuyfn thau b. Vetndtmgt dUdi sdn vd khdng xuyin thdu - Xfl ly tuong tU nhu each xfl iy mat tren san, c. Vet ndt mat xuyen sdn
- Xfl ly t u dUdi len hoac t f l tren xudng tfly thudc vi tdng.
WTi:
Hinh29 Ihaokim bom keo
- T r i m Id khoan b i n g vfla tron phu gia Sika latex (hoac tUong dfldng);
- Ve sinh be mat v i khu vUc sfla chfla: Khi cdng viec bom keo hoan t h i n h , sau mdt grd cd t h i g d c i c kim bdm keo mot chieu ra, I i m phang va ve sinh sach lai be mat ciia diem bom keo,
Hinh 211. Hu'dng xil ly vet nut mat xuyen san
3. X f l l y vet nflt b^ng he t h o n g xi lanh d l b o m keo Epoxy 3 . 1 . l/u va nhflorc dJem va p h a m vi ap dung
•:• Pham vi ap dung: Phuong phap xy lanh ap dung eho tat e i cae ioai v i t nut
• l/u d l l m . Tuong t u nhu tren. Tuy nhien Sfl dung phuong p h i p nay thi keo se vao deu, t f l t f l hdn so vdi phuong phap bom b i n g may bam ap luc va se han che duac v i t nflt xuat hien trd lai sau khi bdm.
•:• Nhuoc diem- Thdi gian thi cdng keo dai, hao tdn nhieu nhan cdng, g i i t h i n h cao hon c i c phuang phap bdm apluc cao.
3.2. Dung cu thi cong
- Ban chil sat, choi, bay. b i t nhUa, due, xy lanh .
- Dung cu hoac t h i l t bi khic cho cdng t i e ehdng tham d nhung noi can thiet.
ifflnh 2.10, Ve sinh be mai $au khi bam keo
CYlMDBt SrSTBt
Hinii 31 Xy lanh bam keo 3.3. Vat lieu sfldung [4]
- Tuong t u nhu phuang p h i p ban keo Epoxy i p iUc cao.
3.4. Quy trinh thi cdng a. Chudn bi b4 mat:
- Tuong t u nhu phUdng p h i p bon keo Epoxy ap lUc cao.
b. Ddnh ddu dudng ndt
- Tuong t u nhu phuong p h i p bon keo Epoxy i p iUc cao.
c. Gdn ddu bam (Bdt nhUa)
- Gan dau bom vao diem can bom da x i c dinh truoc. Nen dat vao gifla d l l m can bam v S c d d i n h b i n g vat li&u b i m dinh (sfldung keoTC - 1401 hoac tuong dUdng);
- Khoang each gifla c i c vi tri tfl 15 em d i n 20 cm, tuy theo dd rdng v i t nflt;
- Tram kin be mat vet nut bang vat lieu b i m dinh de ngan keo khdng tran ra ngoai khi bom
Hmh 3,3. Bom Iteo bang xy lanh e, Thdo thiet bi bam va hodn thien b4mgt
- Khi vat lieu bom vao v i t nflt da du cflng (khoing 3 gid) thi cd t h i gd bo ndp ong bdm xi lanh;
- Sau khi gd bd nap dng bdm xi lanh, mai bd nhutig vat lieu cdn dinh lai trin bi mat va hoan thi§n b l mat;
- Ve sinh kliu vUc da tiii cdng.
f l_ ••_'; _ i
Hin!i3 4,HoSnthi^nbem3t 3.5. Hfldng xflly v i t nflt san a. V4t ndt mat tren sdn - H u d n g x f l i y t f l t r e n x u d n g d U d i ,
Hmh 3.2 GSn bat nhua va tram keo doc uet niH d. Bam keo
- Sau khoang t f l 3 den 5 gid Idp bam dinh da khd cflng h o i n t o i n , hut keo epoxy vao xy lanh va gdn xy lanh len cic dau bom da dinh vi tfl trudc;
- Bcfm t f l t f l cho den khi keo khdng vao nfla, de tang g i i m i p lUe trong khi bdm chi don gidn i i tang hay g i i m sd lUang d i y cao su vao xi lanh;
- Khi keo da day trong v i t nut v i t r i o ra ngoai thi ngUng;
HUdng bonr t f l dUdi len.
Hinh 3 5, Hirflng xflly wt mit mat tren san b. Vet ndt mat du& sdn - Hudng xflly t f l dudi l§ntr§n.
46,
vf NUT
•- XIUANH
Hinh 3.6. Hudng xfl ly vet nflt mat du6i san 3.6. K i l m tra chat IflOng [3], [6]
- Tuong t u n h u phuong p h i p bon keo Epoxy ap lUe cao.
4 . Ket luan
Vdl dae diem khi hau khde nghiet 6 Viet Nam, nhung ran nflt cfla be tdng x i y ra r i t nhieu nen can chu trong ngay t f l khi do be tdng de dat chat lUdng d i m b i o nhat.
ViSc nflt san be tdng g i y i n h hudng r i t Idn d i n k i t eau efla ngdi n h i , d i e biet l i v i n di chdng tham khi da bi nflt s i n b§ tdng
Oe viec x f l ly v i t nflt be tdng dat hieu qua tot, trUdc khi thi cdng c i n k h i o sat hien trang, d i n h gia v i dua ra phuong phap x f l ly thich hop.
Vi§c x f l ly v i t nut can xem set den cac yeu t d n h u . c h i l u rdng, chieu sau vet n f l t , thiet bj va loai keo Epoxy thi cdng...
Hien nay cd rat nhieu eac phuang phap x f l l y vet nflt, n h u n g d l d i m b i o n h d t e i n c d n g t y c h u y e n siu v l linh vuc nay.
Do han c h l v l mat thdi gian nen tac gia mdi chl nghien cflu c i c g i i i p h i p xfl ly vet nut be tdng s i n ddi vdi cdng trinh d i n dung. T i c g i i k i l n nghi t i l p tue nghien cflu va hoan thien cac g i i i p h i p xfl 1;/ v i t nflt cho eie c i u kien khac va cho cdng trinh cdng nghiep, giao thdng, thiiy lOi...
TAIUEU THAM KHAO
1, TCVN 9345-Z012 Ket COU be tong va be tong col thep - Hudng dan phong chong niit dddi tdc dong cua khi hdu nong am.
2, TCVN 571S1993 Mai m san be tong cdt thep trong xdy dilng. Yeu cdu kylhudt chong tham nudc.
3, TCVN3118'2012 Bl t6ng nong-Phiiang phdp xac dmh cmg 3d nin.
i.KWidllOOfi. Vdt lieu chdng thdm trang xdy dung-Phdn loai.
5. Nguyen Quang Phich, Bui Van Oflc, Le Tuan Anh, Pham Ngoc Anh(2013)- Ndtni trang bi tdngximdng.nguyennhdnvdmdlsogidiphdpphdnglrdnh,l(hdcphuc'\ipdtif.iK\M(>-ilt3diS\
6.'iOm}7Um6:NghiemthudidtlUdngthicdngcdngtnnh
05.2017HDn]¥[|H3i 4 7
