15.Trinh bay cau tao san betong cot thep toan khoi

1. Dac diem:

San betong cot thep toan khoi la loai san duoc ap dung pho bien trong xay dung

kien truc dan dung va cong nghiep.

Uu diem:

• Cau tao don gian ben chac co do lon cung.

• Kha nang chong chay tot, khong muc nat, it phai bao tri, de thoa man cac yeu

cau ve ve sinh.

• Vuot duoc khau do tuong doi lon, dien tich rong.

Nhuoc diem:

• Sua chua ,cai tien kho.

• Kha nang cach am khong cao, can co bien phap cach am cho san theo yeu cau.

• Ton van khuon va suc lao dong, thoi gian thi cong cham va chiu anh huong cua

thoi tiet.

• Tai trong ban than lon., co the che tao bang be tong nang hoac betong nhe (

nhu betong keramzit, betong xi, betong peclit.v.v..)

2. Phan loai:

1. San betong cot thep hinh thuc ban:

San betong cot thep ban ke hai canh: la loai toan khoi don gian nhat . Ban chiu

luc theo mot phuong, voi chi so chieu dai lon hon hay bang hai lan chieu rong. Nhip

cua ban san nen lay trong khoang 2000-3000mm , san co be day 60-100mm, duoc gac

sau vao tuong toi thieu #120mm. Loai san nay thich hop cho hanh lang, san nha ve

sinh hay cac phong co khau do nho.

San betong cot thep ban ke bon canh: la loai san ma ban san chiu luc theo hai

phuong, ty so chieu dai nho hon hai lan chieu rong, nhip cua ban san nen lay 4000-

5000mm san co be day khoang 80-120mm duoc gac sau vao tuong toi thieu #120mm.

Loai san nay thich hop cho san nha co mat bang gan vuong.

2. San betong cot thep hinh thuc san suon :

- San ban dam toan khoi

La loai san co suon gom cac ban va he dam tao thanh tren mat bang nhung o hinh

chu nhat voi ty so giua 2 canh >2

Hinh thuc ban dam duoc ap dung trong truong hop nhip cua san tuong doi lon, neu

dung hinh thuc ban thi thi do day cua ban se lon khong tinh te, do do phai them cac

dam de giam bot chieu dai nhip cua ban.

Voi san co ket cau theo hinh thuc ban dam se dat duoc hieu qua kinh te khi san co

nhip trung binh.Tuy nhien se ton go van khuon hon loai san thinh thuc ban. Mat duoi

cua san khong bang phang va phai lam tran treo khi co yeu cau

Theo hinh thuc chiu luc co the phan thanh 2 loai : San 1 he thong dam va San 2 he

thong dam

San mot he dam: Ap dung khi mat bang san hep. Can chon phuong chiu luc de co

nhip cua dam ngan nhat voi khoang cach giua cac dam tu 1m den 2.5m. Khi khoang

cach giua hai dam lien ke < 1,2m thi nguoi ta goi do la san day suon.

San hai he dam :Ap dung khi mat bang san rong, so do ket cau duoc xem nhu la

ban ke len dam phu, dam phu goi len dam chinh, dam chinh dat len cot hoac tuong.

Phuong cua he dam duoc chon tuy thuoc vao su bo tri chung cua ngoi nha va cac

yeu cau khac.

Khi dat dam chinh theo phuong doc nha , tran nha va ca gian nha duoc chieu sang

tot hon nhung co the phai ke mot so dam phu len phan tuong tren o cua o tuong doc,

luc do can dat lanh to khoe de chiu luc tu mut dam phu truyen xuong. Trong truong

hop dat dam chinh theo phuong ngang nha lam tang do cung ngang cua nha. Khoang

cach giua cac dam chinh tu 4m den 6m.

Ngoai ra khi bo tri cot de do dam trong nha can quan tam den nhung yeu cau su

dung ngoi nha nhu su sap xep day chuyen san xuat viec su dung khong gian cua

phong oc.

Trong pham vi moi nhip cua dam chinh co the bo tri mot, hai hoac ba dam phu , va

nen xep dat dam phu the nao cho co mot dam phu dat theo truc cot. Khoang cach giua

cac dam phu tu 1,5m den 3m.

Kich thuoc tiet dien dam va ban :

Dam chinh :Chieu cao dam lay bang 1/8-1/12chieu dai dam

hdc = (1/8-1/15)ldc ; bdc = (1/2-1/3)hdc

Dam phu :Chieu cao dam lay bang 1/15-1/20 chieu dai dam

hdp = (1/15-1/20)ldp ; bdp = (1/2-1/3)hdp

Ban : Chieu day ban 6-10 cm tuy theo khau do ban nho hay lon , 5cm doi voi san

mai.

Khi san ke truc tiep len tuong, doan ke le tuong gach la : 120mm doi voi ban,

220mm doi voi dam phu , 340mm doi voi dam chinh. Neu be day tuong khong du thi

lam them bo tru. Mut dam chinh phai duoc duc lien toan khoi voi cot be tong cot thep

dat o trong tuong hoac sat tuong.

- San o co (ket song):

Co hai loai san o co: kieu ban ke bon canh va kieu luoi o nho.

San o co kieu ban ke bon canh: La loai san suon trong do dam chinh, dam phu

lay bang nhau va cho gap nhau cua dam ngang doc la cac cot do . Luoi cot thuong

dung tao nen mot mang luoi o vuong hay o chu nhat gan vuong voi dien tich o khong

qua 36m2 .Ban co chieu day 8-15cm, Loai sann nay co uu diem tao nen mat tran co he

dam deu dep de trang tri hay ap dung trong nhung khong gian lon co the bo tri cot nhu

tien sanh, khach san, benh vien, truong hoc..v.v.

San kieu luoi o nho: La mot loai san suon trong do cac suon ngang doc lay cao

bang nhau , tao thanh mot luoi o vuong tu 80cm -2m. Chieu cao cac suon lay bang

1/30-1/35l ( buoc cot, khau do lon cua phong). Ban san chi day 5cm va ca tam san tua

truc tiep len bon tuong hay cac goi tua xung quanh. San co the phu tren mot phong co

dien tich 60-70m2 ma khong can cot do giua , no chi dung khi phong co hinh thuc

vuong hay gan vuong co yeu cau my quan cao ( vi loai san nay kem kinh te hon cac

san toan khoi ke tren) san thi cong phuc tap, ton cop pha.

Cac suon co the dat song song voi cac canh phong hay dat chech 450 so voi canh

phong

Cung co the ket hop kieu san ke bon canh va o co de phu lop cac phong co dien

tich lon bang cach tao nen mot luoi o vuong voi khoang cach cac cot 6-9m va tu cot

nay sang cot kia co dam noi lien. Loai san nay cung chi ap dung trong cac phong nhu

tien sanh, gian trien lam.v.v.

3. San nam : gom mot ban day co mat bang vuong hoac tron duoc dat o tren

mot dau cot chiu luc o trung tam ban, cho san tua vao dau cot, ung suat cuc bo se rat

lon co the dam thung san, de khac phuc cau tao mu cot loe ra theo goc 450, rong 0.2-

0.3 buoc cot, Chieu day ban san thuong lay bang 1/35- 1/40 khoang cach cot, thuong

bang 150-200mm, voi mot so truong hop ban san co the day hon, ban san tua len mot

luoi cot 6000x6000mm, 8000x8000mm. Loai san nay thich hop cho cong trinh kien

truc co mat bang tuong doi lon nhu sieu thi, cho hoac xuong che tao.

Loai san nay co uu diem mat tran phang, my quan va co kha nang chiu luc chan

dong cung nhu tai trong lon. Nhung co nhuoc diem khong tinh te vi ton vat lieu . San

nap ap dung trong truong hop khi san phai chiu tai trong lon hayco yeu cau dac biet.