IMHLTIMG G I A I P H A P V A T L I E U V A T H I COIViG
I M H A I V I
IMAIMG CAO K H A IMAIMG CHOIMG T H A M CHO D A P
B E TOIMG DAIVI LAIM DIIMH DIIMH
Nguyin Ngoc Chau^
T O M T A T
Bai viet de cap den cac giai phap vl vat lieu va cong nghe da ap ditng trong thi cong de nang cao kha nang chdng tham cho dap Dinh Binh. Cac giai phap vl vat lieu la b a chon vat lieu thanh phin, sir dung phu gia khoang tro bay bii hat min trong cat, sir dtrng phtr gia giam nuoc va tinh toan thanh phin cap phdi hop ly.
Ben canh cac giai phap ve vat lieu cting da ap dtrng cac bien phap to chiic thi cong tir khau lua chon thiet bi thi cong, tham sd dam chat hgp ly, sir ly tdt khe tiep giap gitra cac lop BTDL, qua trinh bao duong nghiem tuc va quan ly chat lugng thi cong chat che.
Tir khoa: Be tong ddm ldn, chdt phu gia.
LDATVANDE
C6ng trinh dap Dinh Bmh, tinh Binh Diiih dugc fhi c6ng theo cong nghe be t6ng d i m lan (BTDL).
Viec Ip dung cong nghe thi c6ng dim b n cd nhiiu uu viet so vdi be tong tmyin thdng do lugng dung chit kit dmh tblp hon, thdi gian thi c6ng nhanh do Ip dung CO gidi boa tdi da v l rat it su dung vin khu6n trong thi cong. Tuy nhien, c6ng nghe thi c6ng BTDL cung cd nhifng ban c h i do kha nang chdng fham kem hon so vdi be t6ng tmyen thdng cung mlc, mdi hen kit giffa d c ldp BTDL 11 mgt diim ylu d l nudc d l thim qua. Ddng thdi, trong thi cong BTDL d n cd thilt bi miy mdc frang hi hien dai co gidi h o l cao, qua trinh giim sit fhi c6ng va quan ly chat lugng trong thi c6ng BTDL phii tuan fhu nghiem ngat quy trinh ky thuat thi c6ng. Vdi nhiing ly do tren, viec nghien cuu thilt k l fhlnh phin d p phdi BTDL phai ddng thdi dam bao d e yeu d u ky thuat ung vdi d c thilt hi fhi c6ng, phii dam bao d c chi tieu vl tinh chat ca ly, yeu clu thilt k l , giam thilu lugng dfing xi mang. Dap Dmh Binh dugc thilt k l thi cong theo phuong an tudng chdng tham bing be fong cdt tblp tmyIn thdng M250B8 b phia thugng luu, tilp theo 11 ldp BTDL chdng tiiam M200B4 va cudi cfing 11 ldp BTDL frgng lire M150B2. D l nang cao chit lugng cung nhu do chdng thim cua dap BTDL, phai k i t hgp tdt giffa vaf lieu vl thi c6ng. Bai vilt neu kit q u i nghien cuu v l nhifng vin d l tren.
L CM Be\l PHAP VE VAT IfU IWW CAO KHA NAW CHOW THAM Vien Khoa hgc Thuy lgi, nay b Vien KHTL Viet Nam thuc hien nghien cuu giai phap vat lieu v l thi
cong n h l m nang cao chdng tham cho dap be tong d i m lan (BTDL) b tinh Binh Dinh. Trong q u i frinh thilt k l da tham khIo nhiiu phuong phap thilt k l vat lieu BTDL khic nhau cua d c nudc nhu My, Nhat Bin v l T m n g Qudc, k i t hgp dugc nhifrig diim manh, phfl hgp vdi diiu kien Viet Nam.
1. Lua chgn vat heu thanh phan
Vat lieu lua chgn su dung gdm: Xi mang PCB40 - Nghi Son, PCB40 - Bim Son, PCB30 - Bim Son, d t vIng s6ng K6n, d l dam gdc Granit, tro bay Pha Lai, phu gia h o l hgc ciia hang Sika (TM20 v l Pbstimen 96), Cong ty Tu van Thi nghiem Cong trinh giao fh6ngl (PA95vlPA2000).
a. Cdc chi tieu tinh chdt cua PCB - 40 Bim Son (xem trin bdng 1).
Bang 1. Cac chi tieu tinh chat co ly ciia xi mang PCB40-Bim Son
TT 1 2 3 4 5
6 7
Chi tieu thi nghiem Khdi lugng rieng Do min Guong sot tren
sang 0,08) Do am Do deo tieu chuan Thoi gian ninh kit
- Bit diu - Kit thuc Dp dn dinh the tich
Lasatalie Gioi ban ben nen
- 3 ngay - 28 ngay
Don vi (g/cm')
%
%
% h.ph h.ph mm N/mm-
Ket qua 3,07
7,6 0,1 27,2 2hl5 3h20 4,2
27,5 48,0
' Truang Dai hpc Thuy Lgi
Nhdn xet: Xi mang dat tieu chuan Xi mang Poocbng hdn hgp PCB 40 - Theo TCVN 6260 - 1997.
b. Cdc chi tieu, tinh chdt cua cdt (xem tren bdng 2).
KHOA HOC CONG N G H l
Bang 2. Cac chi tieu tinh chat eg ly cua cat
Cac chi tieu KL the tich, g/cm^
KL the tich xdp, k g / m \ Ham lugng biin bui set, %
Ket qua lln 1 2,65 1460 0,81
Ket qua lan 2 2,64 1450 0,91
Ket qua lan 3 2,65 1440 1,12
Kit qua TB 2,65 1450 0,95
Nhdn xet: Modun ctia d t : Mn = 2,8-3,1, cat fhi cong thuoc loai tho, rat if bat min c. Cdc chi tiiu, tinh chdt cua dd ddm ldy tqi Men
tru&ng (xem trin bdng 3).
Bang 3. Cae ehi tieu tinh chat ca ly eua d t
Loai da dam
Co 5x20 mm Co 20x40 mm Co 40x60 mm Co 5x40 mm Co 5x60 mm
KL. the tich xdp,
kg/m^
1400 1413 1450 1440 1480
Ham lupng btii biin set ban, %
1,5 0,34 0,13
Ham lugng hat dai det, %
13,4 21,2 22,3
d. Tinh ndng vdt ly vd thdnh phdn hod cua tro bay nhiet dien Phd Lqi (xem trin bdng 4).
Bang 4. Cae chi tieu tinh chat ca ly ciia fro bay Pha Lai
TT 1 2 3 4 5
6
Chi tieu thi nghiem Khdi lugng rieng Dp min Ougng sot tren sang
0,08) Do am Do deo tieu chuan Thai gian ninh k i t
- Bit dau -Ket thuc Chi sd hoat tinh ddi voi xi
mang tuoi - 7 ngay - 28 ngay
Don vi g/cm3
%
%
% h.ph h.ph
%
Kit qua 2,74
12 0,2 26.1 2h55 4 h l 0
• 78,5 85,0
Phu gia tro bay dat tieu chuan phti gia khoing boat tinb nghiin min diing cho be fong - Theo 14 TCN 105 - 1999. Phu gia hoa hgc dung loai phu gia hda hgc TM-20 cua Hang phu gia Sika cung cap, la phu gia hol deo cho be tong dugc nghien cuu thiet kl dac biet cho BTDL hgp vdi yeu clu c6ng frinh 11 phu gia hoa deo keo dii ninh kit.
2. Thanh phan d p phdi thi cong
Cap phdi BTDL thi c6ng dugc nghien cuu qua hai giai doan: Trong phdng vl hien trudng. Giai doan nghien cuu frong phdng dugc nghien cuu ky bt ca cle chi tieu CO ly cua vaf Ueu vl be fong. Giai doan ngben cuu hieu chmh tai hien trudng dl thu nghiem c6ng nghe thi cong dim nen, thilt hi miy mdc thi c6ng vl diiu chmh d p phdi (chii ylu 11 phu gia hol hgc vl ti le cdt heu) cho phfi hgp vdi cong nghe dam vl thilt hi.
a. Thdnh phdn cdp phdi de xudt sau khi thi nghiim dam nen Men truang
Qua qui frinh nghien cuu frong phdng vl thu nghiem hien trudng dam bao d c ylu td ky thuat, thdi gian bit diu d6ng kit cua BTDL (Tbd) phai ldn ban 12 gid', tinh cong b e Vc frong khoang tu 7-13 s, bl mat dim phii no viia, it ran nut. Vi vay da fang ty le dfing phu gia klo dii thdi gian d6ng kit, tang phu gia khoang boat tinh bu lugng hat min cdn thilu trong d t , kit qui hieu chinh nhu frong bang 5.
Ky hieu M150 M200
Bang 5. Thanh phan d p phdi BTDL M200 va M150
Thanh phan cap phdi cho Im^ be tong XM Bim son
PCB40 (kg) 105 126
Tro (kg) 140 141
CKD (kg) 245 267
N Oit) 122 132
C (kg)
772 746
D(5x20) (kg)
526 852
D (20x40) (kg) 215 468
D (40x60) 0<g) 600 0
Tdng da (kg) 1341 1320
Phu gia (kg) 2,49 2,7
N/CKD 0,50 0,49
C/CL 0,37 0,36
KLTT (kg/m^
2482 2468
Kit qua thi nghiem cho thay, cap phdi be f6ng hieu chinh trong qui frinh dim nen hien tmdng dap ling dugc chi tieu ve tinh c6ng be Vc, cudng do, do chdng fham theo yeu cau dl ra.
Do c6ng be Vc ciia BTDL fai ldp dd nen chgn bing 7 H-13 giay ffiy theo tinh hinh thdi tilt.
b. Thdnh phdn cdp phdi de xudt de cd gidi phdp khdng chi'nhiet trong thi cdng bi tdng ddm ldn
Sau khi thi nghiem dim nin hien tmdng da dl xuat hai cap phdi be f6ng mac M150 vl M200 (bang 5), cudng do be f6ng tmng binh tudi 90 fai bai fhu vl fhuc tl fhi cong diu dat vl vugt mac thief kl, do chdng thim dat tuong ung 11 B2 va B4. Theo tinh toln vl van dl nhiet frong dap BTDL Dinh Binh, C6ng fy Tu vin Thilt kl Xay dung Thuy lgi Viet Nam dua ra bien phap khdng chi nhiet do dl dam bio chat lugng cong tiinh. Dl kip tiin do fhi c6ng c6ng
trinh va dam bao an foln nhiet frong than dap, cin giim lugng dfing xi mang cic d p phdi BTDL xudng mfrc cd fhl chi d n dat chi tieu vl cudng thilt k l . Bg Nong nghiep & PTNT da xem xet thong qua vin d l nly va giao cho Vien Khoa hoc Thuy lgi Viet Nam hieu chmh lai d c cap phdi be fong dim lan tai hien tmdng.
Qui trinh hieu chinh giaim lugng dfing xi mang nhlm giam lugng nhiet thuy h o l frong be f6ng, Vien KHTL da tiin hinh thi nghiem hieu chinh va chgn dugc cap phdi BTDL M150 dat duoc: cac yeu clu ky thuat d l ra. TTilnh phan d p phdi nhu the hien fren bang 6.
Bang 6. Thanh phan d p phdi BTDL M150 Ky
hieu M15
Thanh phan cap phdi cho Im'' be tong XM
0<g) 70
Tro bay O^g)
175 N Oit) 110
C (kg)
772
D(5-20) (kg)
531
D (20-40) 0<g) 219
D (40-60) 0<g)
605
PG TM20 Oit) 1,47
PG P-96 (lit) 0,42
KLTT Oig/m')
2484 d p phdi BTDL sau khi hieu chmh da giam dugc
30 kg xi mang so vdi cap phdi ban diu, giim nhiet thuy hol ldn frong bin than BTDL, tao diiu b e n tdf cho thi c6ng m l kh6ng d n sii dung .din d c bien phip tdn kem nhu Ilm lanh cdt lieu, ha nhiet do hdn hgp BTDL bing nudc da lanh, hay klo dii thdi gian thi c6ng.
III. CAC BIEN P H A P VE THI CONG NANG CAO KHA NANG CHONG THAM
Nghien cuu lua chgn bien phip thi c6ng hgp ly phfl hgp vdi trinh do trong nudc 11 mgt van d l quan trong, vfra nang cao chit lugng BTDL ddng thdi mang lai lgi ich kinh t l .
1. Thilt hi thi cong BTDL cong trinh Dinh Binh Thilt hi thi cong bao gdm d c thilt hi trgn be tong, van chuyen be t6ng, san be t6ng, dam be t6ng vl bao duong be t6ng.
Thilt bi van chuyin sir dung loai xe Kamaz 65115, Huyndai 15 tdng trgng b i 15 b n tu dd de van chuyen BTDL tfr tram trgn d i n khdi do, d c loai xe nly diu tu dd, xe van chuyin vfra lien k i t su dung xe chuyin frgn Kraz cd dung tich thung 6 m^.
- Thief hi san BTDL sti dung may ui chuyen dung Komasu T41, ngoai ra cdn su dung d c dung cu nhu xeng, trang xuc be t6ng v l rai vira.
- Thilt bi d i m sfr dung loai hai trdng hien dai BOMAG cua Diic: Loai ldn BW161/^-4: tir frgng 10,1 b n , luc mng 12,8 T/m6i trdng, tan sd m n g (40- 50) Hz, bien do m n g (0,39-0,93) mm; loai nhd BW100/U3-4: tir trgng 2,4 b n , luc mng 4,2 T/mdi trdng, b n sd m n g (40-50) Hz, bien do m n g 0,53 mm;
miy dam cdc Mikasa.
- Thief hi thi c6ng be t6ng biln tiili : MIy frgn khuay hd, miy d i m cdc, miy dim diii, dim chfim, v.v...
- CIc thilt hi khac phuc vu qua frinh fhi cong:
MIy phun suong, m i y bom nia xe, may phun nudc ap lire cao d l danh xom b l mat, v.v...
2. Tham sd dam chat
CIc y l u td tri sd Vc, chieu dly d i m chat, sd lln dam clu fhlnh nen fham so d i m chat cua BTDL.
Tham sd d i m chat tuong ung vdi mgt nang lugng dam nhd nhlt, m l dat dugc do chat fhilf k l , dd 11 tham sd d i m chat tdi uu. Tri sd tinh c6ng b e hon hgp BTDL Vc phai dam bao cho d c thilt bi thi c6ng nhu 6 t6, m i y gat di chuyin, van h i n h tren b l mat tuong ddi d l ding, tuy nhien v l k h i nang d i m chat lai phai d l ding, vi fhl tri so Vc khong nen q u i ldn v l ciing khong nen q u i nho. Ddi vdi mgt hdn hgp BTDL da chgn, thilt hi da chgn thi chilu dly ldp d i m tinh cho nang lugng dam la nhd nhat d l dat dugc do chat thilt k l . Ddi vdi c6ng trinh Dmh Binh, tham sd dim chat dugc lua chgn thong qua thi nghiem d i m nin hien tmdng, tham sd d i m chat tdi uu fhl hien o bang 7.
Bang 7. TTiam sd dam chat BTDL STT
1 2 3 4
Chi sd
Chieu day lop BTDL sau dam, cm
Dp cong tac, Vc (sec) Sd lan dam
Dp chat hien tnrong, K
BTDL M150 30 7^13
12 0,96^1
BTDL M200 30
7H-13
12 0,96^1 3. l i e n k i t giira eke lap BTDL
Giiia d c ldp BTDL teo fhlnh khe thi c6ng n l m ngang, viec xii ly khe fhi c6ng tdt se tao lien k i t tdt giifa d c ldp BTDL b m tang k h i nang chdng fhim va giff nuoc cua dap. Dien tich khe thi c6ng d n xu ly trong dap BTDL 11 rat ldn, gap 2 - 3 lln so vdi dap be fong fmyin thdng. Khe fhi cong dugc phan fhlnh hai loai khe ndng vl khe lanh. Khe ndng dugc tao ra khi ldp BTDL tilp theo dugc fhi c6ng khi ldp be fong frudc chua bat diu d6ng kit. Khe lanh dugc tao ra khi ldp BTDL tilp theo dugc thi cong khi ldp be tong trudc da kef fhiic dong k i t v l cd cudng do ban diu
KHOA HOC CONG N G H l
du de d c phuong tien thi cong khong bm anh hudng din qui frinh phlf trien. Ddi vdi khe ndng, khi dim ldp be tong fren, ldp dudi chua dong kit ban diu cd the bm cho ldp dudi tang them do chat, ddng thdi bm cho cdt lieu ldp fren vl ldp dudi xen ke vio nhau, vat lieu kef dinh fham nhap vio nhau bm tang lien kit giiia hai ldp, fang kha nang chdng thim mat ldp vl cho toan dap.
Ddi vdi khe lanh fhi xti ly rii mgt ldp viia mdng cd do linh dong cao hoac dfing ldp be tong tmyIn thdng nhiiu d t de gin kit.
Ddi vdi c6ng trinh Dinh Binh dl tang tinh lien kit giiia d c ldp BTDL Ip dung vdi d khe ndng vl
Bang 8. TTilnh phan d p phdi viia hen kit
khe lanh. Tang cac mdi lien kef ndng bing viec sir dung phu gia keo dai thai gia.n dong kef BTDL vl dd lien tuc tao thanh nhiing khdi cd chieu cao ldn tdi 1,8 m. De thuc hien viec nay ap dung thi cong theo cac phuong In dd len diu, dd bac thang, dd nghieng de phfl hgp vdi dien tich, kich thudc vl dac diim cua mdi khoanh dd.
CIc lien kit lanh ban chi tdi da va dugc xfr ly bing ldp dinh dly 1-2 cm, giau chat kit dinh vl diiu chinh thdi gian dong kit tuong duong vdi thdi gian dong kit cua hdn hgp BTDL vl cd cudng do cao ban cudng do BTDL mgt d p (5 Mpa), fhlnh phin cap phdi vira the hien tren bang 8.
STT 1 2
Mac vua (MPa)
25 20
Thanh phan cap phdi cho Im^ vOa lien kit XM
(kg) 580 512
Tro bay (kg)
200 170
CKD 0<g)
780 682
Cat (kg) 978 1092
Nuac 0) 370 360
Dp luu dpng (cm)
22 21
KLTT 0<g/m^
2128 2134
Cuong dp nen (MPa) R7
23,5 20,0
R28 31,0 24,8 4. Bao duang BTDL
Sau khi BTDL dugc fhi cong xong d n phii bao duong va bao ve gidng nhu be t6ng truyin thdng. Bl mat be t6ng phii giii dugc trong m6i trudng am hoac it nhat cung kh6ng dugc de bl mat be tong mat am.
Trong qui trinh thi cong, bl mat be t6ng da dam nen dugc giii trong tinh trang am udt nhung khong cd vung nudc dgng. Ldp BTDL cudi cung nen dugc bio duong tren 14 ngly. Ddi vdi cong trinh Dinh Binh c6ng viec bao ve, bio duong BTDL dugc thuc hien mgt d c h nghiem ngat vl dly dii:
Trong qui trinh fhi c6ng khi trdi ning, cd he thdng phun suong bm giim nhiet do khong khi vl chdng lai su mat hoi nudc cua hdn hgp BTDL.
Trong qui trinh dang thi c6ng nlu gap trdi mua, filn hinh ngfmg thi c6ng vl dung bien phap che phu kh6ng cho nudc mua tham nhap vio be t6ng dang thi c6ng chua xong vl ddi vdi BTDL vfra thi cong xong.
Viec bao duong dugc tiin hanh ngay sau khi thi
suong bao duong ngay sau khi vfra dim xong. Sau khi RCC kit thuc dong kit thi phu bao tai am hoac phun nudc bao duong, fhdi gian bio duong 1128 ngly.
5. Quan ly chat lugng
Cdng nghe thi cong BTDL cd filn do thi c6ng nhanh, mat bang thi cong rgng, ap dung nhiiu thilt hi thi cong khic nhau. Vi vay viec quan ly thi c6ng d n phii dly du vl chat che. Cong trinh Ip dung dly du d c bien phip quan ly vl vat lieu dau vio, quin ly chat lugng BTDL, quan ly chat lugng thi c6ng tai hien trudng, khdng chi nhiet do frong thi c6ng. CIc loai vat lieu dau vio: Xi mang, phu gia, cdt lieu diu dugc bao quin frong kho dim bao diing tieu chuan quy dinh cho tfmg loai, rieng ddi vdi dl dam cdn dugc ha nhiet do bing d c h bd tri he thdng phun nudc trudc khi frgn be t6ng. Qui trinh thi nghiem kiem tra chat lugng vat lieu dau vio dugc thuc hien nghiem ngat theo diing b n xuat quy dinh. Vat lieu BTDL tei tram frgn dugc kilm tra chat che vl chat lugng, the hien tren bang 9.
cong BTDL xong, frong tmdng hgp frdi nang thi phun
Bang 9. Tan xuat kilm fra thong sd ehinh BTDL tai fram frgn TT
1 2 3 4
Chi tieu kiem tra Tinh cong tac, tri sd Vc (giay)
Nhiet do hdn hop BTDL Cuong do nen BTDL Dp chdng tham BTDL
Tin xuat kiem tra 2 gio mpt lan 2 - 4 gio mpt lan
300 - 500m'^ mot td mlu, 1 ca it nhat mpt td mlu 300 - 500m^ mot to mlu, 1 ca it nhat mpt td mau
Cong tec kiem tra chat lugng BTDL tei dap ciing dugc kilm fra giim sat chat che theo ten xuat, the hien tren bang 10.
B i n e 10. T i n xuat kilm fra thong sd chinh BTDL tei hien tmdng TT
1 2 3 4 5
Chi tieu kiem tra Tinh cong tac, tri sd Vc (giay)
Nhiet do hon hop BTDL Su phan li cdt lieu
Thoi gian dan each cua hai lop BTDL He sd dam chat hien tnrong
Tan xuat kiem tra 2 gio mpt lan 2 - 4 gio mot lln
Khdng che trong ca qua trinh thi cong Khdng che trong ca qiia trinh thi cong
100-200 m^ kiem tra 1 diem, mdi khdi dd kiem tra it nhat 1 diem, moi lop dd it nhat mpt diem kiem tra.
IV. KET LUAN - KIEN NGH|
1. Kit b a n
(1). Dap BTDL Dinh Binh 11 c6ng trinh diu tien trong nglnh thuy lgi ap dung c6ng nghe BTDL, mac du vay frong q u i trinh fhi c6ng ciing da I p dung d c bien phap v l vat lieu v l fhi cong de nang cao chat lugng vl kha nang chdng thim cho dap.
(2). Ve vat lieu: Qua frinh lira chgn vat lieu thanh phin d l c h i teo be t6ng d i m lan dung thi c6ng dap Dinh Binh d i m bio d c yeu clu v l fhlnh phin vaf lieu vl su dung d c vaf lieu khai thac d t , d l dam tei dia phuong; teng lugng dung phu gia khoing boat tinh bd sung lugng hat min frong d t de teng k h i nang chdng thim v l chit lugng BTDL 11 rit hgp ly;
trong q u i frinh hieu chinh d p phdi BTDL n h l m giam lugng dung xi mang phfi hgp vdi giai p h i p khdng c h i nhiet frong thi cong, da su dung them phu gia giam nud'c trong fhlnh phin be tong ngoai phu gia cham dong k i t d l giam ty le N/CKD teng cudng do va do chdng thim 11 mgt giii p h i p hay.
(3). VI fhi cong, da fhuc hien tdt d c bien p h i p td chiic thi c6ng tfr khau lua chgn fhilf hi thi c6ng, tham sd d i m chat hgp ly, xu ly tdf diim ylu khe tiep gilp giifa cic ldp BTDL, q u i trinh bao duong nghiem ttic vl quan ly chit lugng thi c6ng chat che.
2. Kiln nghi
Chat lugng cong trinh Dinh Binh dat yeu d u , tuy nhien vin cdn mgt sd ban c h i d n khic phuc.
1. VI vat lieu su dung: D l bd sung lugng hat min
ngay tai c6ng frudng se dem lai hieu q u i kinh t l v l ky thuat, do hot d l fro nen khong cd phan iing vdi xi mang khong phin ung sinh nhiet. Cd the diiu chinh fhlnh phin hat cua bgt d l phfi hgp nhlm giim lugng dung nudc trong hon hgp be fong v l do nghiin tei chd nen se dn dinh vl ngudn cung cap v l giam phi van chuyen. CIc b i lieu cua T m n g Qudc ciing da d l cap d i n d c nghien cuu ve vin d l nly va khuyin d o nen Ip dung; ngoli phu gia khoang boat tinb tro bay can nghien cuu them phu gia khoing boat tinh Puzolan de phong phii them ngudn vaf lieu, frinh dgc quyen v l dem lai hieu qua kmh t l cho c6ng trmh.
(2). Vl thi cong: Trong q u i frinh san va d i m cd hien tugng nudc frong ndi fren b l mat BTDL do cd du nudc trong fhlnh phin BTDL. Hien tugng nly b m giam cudng do ldp mat ciing nhu kha nang lien k i t vdi ldp tilp theo. Vi vay frong q u i trinh thi cong can xu ly bang d c h miic hoac fham bd; d n chii y khi cudng do BTDL dat 2,5 Mpa trd' len mdi cho thilt hi van chuyen di qua, khi di phai trinh di chuyin nhieu lln qua mgt vi tri m l phai din theo nhiiu hudng.
TAI UEU THAM KHAO
[1] Vien Khoa hgc Thuy lgi Viet Nam. Bdo cdo nghien cuu thdnh phdn bi tdng dam ldn dap Dinh Binh. 2006.
[2] Vien Khoa hgc Thuy lgi Viet Nam 2009. Bdo cdo kiem dinh chdt lug'ng bi tdng ddm ldn dap Dinh Binh. 2009.
[3] Trudng Dai hgc Thuy lgi nam 2008. Hdi thdo ndng cao chdt lugng xdy dung dap be tdng ddm ldn.
trong cat cd t h i nghien cfru su dung hot d l nghiin
/yPUCATTON OF MATERL^L/ySID TECHNICAL MEASUEES TO REINFORCE IMPERMEABLE RESISTANCE OFTHE DINH BINH D/\M WITH TAMPED AND ROLLED CONCRETE
Nguyen Ngoc Chau Summary
The article mention to material solutions and technology which were applied to construction in order to improver waterproof ability of RCC Dinh Binh dam. Material solutions concern to choice of material proportion and intergrade with fly ashley additive to redeem fine agrregate in sand, use water reduced additive and work out optimum proportion. Also, construction methods is full organized by choosing equipments, compaction parameter, treating interval slide in beetween concrete layer, controlling strickly maintainance and quality.
Keywords: RCC -Roller compacted concrete, additive.
Ngudi phan bien: PGS. TS. Le Minh
