Tính ván khuôn dầm có kích thước tiết diện bxh = 30×60 cm

2.1.2.1 Tính toán ván khuôn đáy dầm

Ván khuôn đáy dầm sử dụng ván khuôn kim loại, dùng các tấm (300×1200) được tựa lên các thanh đà gỗ ngang của hệ chống đáy dầm (đà ngang, đà dọc, giáo PAL). Những chỗ bị thiếu hụt hoặc có kẽ hở thì dùng gỗ đệm vào để đảm bảo hình dạng của dầm đồng thời tránh bị chảy nước xi măng làm ảnh hưởng đến chất lượng bê tông dầm.

Ta có tổ hợp ván khuôn dầm chính

Sơ đồ tính ván khuôn đáy dầm

Tải trọng tác dụng lên ván khuôn đáy dầm gồm có:

Tổng tải trọng tính toán phân bố tác dụng lên ván đáy dầm

q_tt =(q₁+q₂+q₃+q₄)*0,3=2622,9*0,3=786,87 daN/m²

1. Tính toán khoảng cách xà gồ theo điều kiện bền:

+ Điều kiện bền: s =  £ R*g (daN/cm²).

Trong đó: W=6,55 cm³–Mômen kháng uốn của ván khuôn, bề rộng 300mm;

M – Mô men trong ván đáy dầm M =

Vậy chọn khoảng cách giữa các xà gồ ngang là l_xg = 60cm.

1. Tính toán khoảng cách xà gồ theo độ võng

+Tải trọng tiêu chuẩn tác dụng lên ván khuôn trên 1m dài

q_tc  =

+ Độ võng của ván khuôn được tính theo công thức: f =

+ Độ võng cho phép:

Trong đó:  E – Mô đun đàn hồi của thép; E = 2,1.106 kg/cm².

J – Mômen quán tính của bề rộng ván khuôn J = 28,46 cm⁴

Þ Kết hợp 2 điều kiện trên ta chọn l_xg = 60 cm

2.1.2.2 Tính toán ván khuôn thành dầm

– Tính toán ván khuôn thành dầm thực chất là tính khoảng cách cây chống xiên của thành dầm, đảm bảo cho ván thành không bị biến dạng quá lớn dưới tác dụng của áp lực bê tông khi đầm đổ.

– Quan niệm ván khuôn thành dầm làm việc như một dầm liên tục đều nhịp chịu tải trọng phân bố đều q do áp lực của bêtông khi đầm, đổ, áp lực đầm đổ của bêtông có thể coi như áp lực thuỷ tĩnh tác dụng lên ván thành, nó phân bố theo luậtt bậc nhất, có giá trị (n*g*h_d ). Để đơn giản trong tính toán ta cho áp lực phân bố đều trên toàn bộ chiều cao thành dầm.

Chiều cao làm việc của thành dầm.

h = 0,6 – 0,15  = 0,45 cm.

Như vậy sẽ được ghép từ 2 tấm ván b= 25cm và b=20cm.

– Tải trọng tác dụng lên ván thành dầm bao gồm.

+ Áp lực của bêtông:

q₁ =n *g * b_d*h_d

Trong đó: n =1,3 là hệ số độ tin cậy

g = 2500 daN/m3 là dung trọng riêng của bê tông

q₁ = 1,3 * 2500* 0,3* 0,6 = 585 daN/m

+ Áp lực đổ bêtông:

q₂ = n * p_d* h_d

Trong đó: Hệ số độ tin cậy: n =1,3

áp lực đổ bêtông p_d = 400 daN/m2

q₂ = 1,3 * 400* 0,6 =312 daN/m

Tổng tải trọng phân bố tác dụng lên ván thành dầm là:

q_tt = q₁ + q₂ = 585 + 312 = 897 daN/m

Sơ đồ tính ván khuôn thành dầm

1. Tính toán khoảng cách nẹp đứng theo điều kiện bền

– Điều kiện bền: s =  £ R*g  daN/cm²

Trong đó:  W – Mômen kháng uốn của tấm ván thành;

W = 4,57+ 4,3 = 8,87 cm³

M – Mômen trên ván thành dầm; M =

1. Tính toán khoảng cách nẹp đứng theo điều kiện độ võng

+Tải trọng tiêu chuẩn tác dụng lên ván khuôn trên 1m dài:

q_tc  =

+ Độ võng của ván khuôn được tính theo công thức: f =

+ Độ võng cho phép:

Trong đó:  E – Mô đun đàn hồi của thép; E = 2,1.106 kg/cm².

J – Mômen quán tính của bề rộng ván khuôn J = 28,46 cm⁴

Þ Kết hợp 2 điều kiện trên ta chọn l_nd = 120 cm

2.1.2.3 Tính toán đà ngang cho dầm

Tải trọng tác dụng lên đà ngang là toàn bộ tải trọng dầm trong diện truyền tải của nó

(diện truyền tải là một khoảng a_đn). Bao gồm:

+ Tải trọng ván khuôn hai thành dầm:

q₁ = 2*(1,1*39*0,45) = 38,61 (daN/m)

+ Trọng lượng ván khuôn đáy dầm:    q₂ = 1,1*39*0,3 =12,87 daN/m

39 daN/m2 – là tải trọng của 1m2 ván khuôn dầm.

+ Trọng lượng bê tông cốt thép dầm dày h =60 cm

q₃ = n*g*h*b =1,2*2500*0,6*0,3 = 585 daN/m

+ Tải trọng đổ bêtông dầm:                q₄ = n*b*P_d

Trong đó: Hệ số độ tin cậy: n =1,3

Hoạt tải đổ bêtông bằng cần trục: P_d = 400daN/m2

q₄ = 1,3 * 400* 0,3 = 156 daN/m

+ Tải trọng đầm nén: q₅ = n*b*q_tc

Trong đó: Hệ số độ tin cậy: n =1,3

áp lực đầm nén tiêu chuẩn: qtc = 200 daN/m2

q₅ = 1,3 *0,3* 200 = 78 daN/m

+ Tải trọng thi công: q₆ = n*b*P_tc

Trong đó: Hệ số độ tin cậy: n =1,3

hoạt tải thi công tiêu chuẩn: P_tc= 250 daN/m2

q₆ = 1,3 * 0,3*250 = 97,5 daN/m

+ Tải trọng bản thân đà ngang: q_đn = n *b*h* g_g*L

Trong đó: Hệ số độ tin cậy: n =1,1

Dung trọng riêng của gỗ g_g=600 daN/m3

b, h là chiều rộng và chiều cao của đà ngang. Chọn (bh) = (810) cm

q = 1,1*0,08*0,1*600*0,6 = 3,2 daN

Tải trọng tổng cộng tác dụng lên đà ngang

q_tt=(q₁+q₂+q₃+q₄+q₆)a_đn+q_đn=(38,61+12,87+585+156+97,5)*0,6+3,2= 537,19 (daN)

Tải trọng tác dụng lên đà qui về lực tập trung:

P = q* = 537,19* = 322,31 daN

Giá trị momen:  (daN.cm)

Ta có: W =  =  = 133,33 cm³

(bh) =(810) cm là tiết diện ngang của đà ngang.

1. Tính toán theo điều kiện bền

=>daN/cm²

1. Tính toán theo điều kiện độ võng:

+Tải trọng tiêu chuẩn tác dụng lên ván khuôn

P_tc  =

+ Độ võng của ván khuôn được tính theo công thức:

+ Độ võng cho phép:

Þ Kết hợp 2 điều kiện trên ta chọn l = 120 cm

=> Vậy chiều dài đà ngang là 120cm, khoảng cách giữa các thanh đà ngang là 60cm.

2.1.2.4 Tính toán đà dọc cho dầm

Tải trọng tác dụng lên đà dọc (do đà ngang truyền xuống ):

Giá trị momen lớn nhất: M _max = 0,19*P_dd* B = 0,19*161,16*1,2 = 36,74(daN.m)

– Tải trọng bản thân đà dọc: Chọn (bh) = (68)cm

q_bt = 0,06* 0,08* 600* 1,1 = 3,17 (daN/m)

M_bt =

Hình vẽ : Sơ đồ chịu lực của đà dọc dầm 

– Gía trị mômen lớn nhất để tính đà dọc theo bền:  M_max = M_max1+M_bt

Þ M_max = 36,74 + 0,456 = 37,2 (daN.m)

+ Kiểm tra khả năng chịu lực:

=> Thoả mãn.

+ Kiểm tra điều kiện biến dạng:

Vì các tải trọng tập trung gần nhau (cách nhau 0,6m) nên ta có thể xem gần đúng như tải trọng phân bố P=161,16daN/m =1,612daN/cm

áp dụng công thức: f =

Với gỗ ta có: E = 1,1*10⁵ daN/cm²; J = =256 cm⁴

®

Độ võng cho phép:

Ta thấy: f  < [f], do đó tiết diện đà dọc (b*h) = (810) cm là đảm bảo.

Vậy với khoảng cách các xà gồ dọc là 120cm đảm bảo điều kiện chịu lực.

Ta có cấu tạo ván khuôn dầm chính như hình vẽ dưới đây:

2.1.3 Thiết kế ván khuôn sàn

2.1.3.1 Tính toán ván khuôn sàn 

Bảng tải trọng tác dụng lên sàn

Sơ đồ tổ hợp ván khuôn sàn tầng điển hình

+ Sàn: Sử dụng các tấm loại: 300´1800mm, 200x1200mm, 300x1200mm

+ Chỗ nào còn hở chèn thêm ván khuôn gỗ dày 20mm.

– Tính khoảng cách giữa các đà ngang, đà dọc đỡ ván khuôn sàn:

Để thuận tiện cho việc thi công, ta chọn khoảng cách giữa thanh đà ngang mang ván sàn l = 60cm, khoảng cách lớn nhất giữa các thanh đà dọc l =120cm (bằng kích thước của giáo PAL).

Từ khoảng cách chọn trước ta sẽ chọn được kích thước phù hợp của các thanh đà.

Tính toán, kiểm tra độ bền , độ võng của ván khuôn sàn và chọn tiết diện các thanh đà.

Kiểm tra độ bền, độ võng cho một tấm ván khuôn sàn:

Hình vẽ: Sơ đồ chịu lực ván khuôn sàn

1. Tính toán theo điều kiện bền:

s =  £ R*g daN/cm².

Trong đó: W = 6,55cm³ – Mômen  kháng uốn của tấm ván khuôn rộng 300

M – Mômen trong ván đáy sàn; M =

1. Tính toán theo điều kiện độ võng

+Tải trọng tiêu chuẩn tác dụng lên ván khuôn trên 1m dài:

q_tc  = 1264daN/cm²

+ Độ võng của ván khuôn được tính theo công thức: f =

+ Độ võng cho phép:

Trong đó:  E – Mô đun đàn hồi của thép; E = 2,1.106 kg/cm².

J – Mômen quán tính của bề rộng ván khuôn J = 28,46 cm⁴

Þ Kết hợp 2 điều kiện trên ta chọn l_d = 60 cm

2.1.3.2  Tính toán kiểm tra thanh đà ngang

– Chọn tiết diện thanh xà gồ ngang: b´h = 8´10cm, gỗ nhóm VI có:

s_gỗ = 150 kG/cm² và E =1,1*10⁵ kG/cm².

• Tải trọng tác dụng:

+ Xà gồ ngang chịu tải trọng phân bố trên 1 dải có bề rộng bằng khoảng cách giữa hai xà gồ ngang l = 60cm.

+ Sơ đồ tính toán xà gồ ngang là dầm liên tục kê lên các gối tựa là các xà gồ dọc

Hình vẽ: Sơ đồ chịu tải của đà ngang đỡ đáy sàn

+ Tải trọng bản thân đà ngang:

q₆ = n *b *h* g_g

Trong đó:

Hệ số độ tin cậy: n =1,1

Dung trọng riêng của gỗ g_g = 600 daN/m3

b, h là chiều rộng và chiều cao của đà ngang. Chọn bxh=8x10cm

q₆ = 1,1*0,08*0,1*600 = 5,28 daN/m

=>Tổng tải trọng phân bố tác dụng lên xà gồ là:

q_tt = (q₁ + q₂ + q₃ +q₄ + q₅)*l_đn+ q₆

q_tt = (42,9+450+520+260+325)*0,6+ 5,28  = 964,02 daN/m

=> Mmax =

Từ công thức : W =  =  = 133,33 cm3

=>  daN/cm2 < [] = 150 daN/cm2

=> Chọn đà ngang (810) là đảm bảo khả năng chịu lực.

–  Kiểm tra độ võng đà ngang:

+ Tải trọng dùng để tính võng của đà ngang (dùng trị số tiêu chuẩn):

q_tc =

+ Độ võng của xà gồ ngang được tính theo công thức:

f =

Trong đó: E – Mô đun đàn hồi của gỗ; E = 1,1*105 kg/cm2.                         MC đà ngang

J – Mômen quán tính của bề rộng ván là:

J =  =  = 666,7cm⁴

+ Độ võng cho phép: [f] = l/400 = 120/400 = 0,3 cm

Ta thấy: f < [f] do đó đà ngang có tiết diện b´h = 8´10 cm là bảo đảm

2.1.3.3 Tính toán kiểm tra thanh đà dọc:

Chọn tiết diện thanh đà dọc: chọn tiết diện b´h = 10´12 cm gỗ nhóm VI có:

s_gỗ = 150 daNcm² và E =1,1*10⁵ daN/cm²

– Tải trọng tác dụng lên thanh xà gồ dọc:

+ Xà gồ dọc chịu tải trọng phân bố trên 1 dải rộng bằng khoảng cách giữa hai đầu giáo Pal là l =120 cm.

+ Sơ đồ tính toán xà gồ dọc là dầm đơn giản kê lên các gối tựa là các cột chống giáo Pal chịu tải trọng tập trung từ xà gồ ngang truyền xuống (xét xà gồ chịu lực nguy hiểm nhất). Có sơ đồ tính:

Hình vẽ: Sơ đồ truyền tải lên xà gồ dọc đỡ ván sàn

– Tải trọng tác dụng lên đà dọc (Tải trọng bản thân đà dọc tính giống như dầm):

Trong đó:       L_đn = 1,2 m,   B_{giáo PAL} = 1,2m.

Có thể gần đúng gía trị mômen M_max, M_min của đà dọc theo sơ đồ:

M_max1 = 0,19*P*B_{giáo PAL} = 0,19*1156,82*1,2 = 263,75 (daN.m)

M_max2 = 0,12*P*B_{giáo PAL} = 0,12*1156,82*1,2 = 166,58 (daN.m)

M_min    = 0,13*P*B_{giáo PAL} = 0,13*1156,82*1,2 = 180,46 (daN.m)

– Tải trọng bản thân đà dọc:

q_bt = 0,1*0,12*600*1,1= 7,92 (daN/m)

M_bt =  = 1,14 (daN.m)

– Gía trị mômen lớn nhất để tính đà dọc theo bền:  M_max = M_max1+M_bt

Þ M_max = 263,75+ 1,14 = 264,89 (daN.m)

– Kiểm tra bền cho đà dọc:

W = b*h²/6 = 10*12²/6 = 240 cm³.

s_tt =  daN/cm² < [s] = 150kG/cm2.

ÞThoả mãn yêu cầu bền

– Kiểm tra võng:

+ Vì các tải trọng tập trung đặt gần nhau cách nhau 0,6m, nên ta có thể tính biến dạng của đà dọc gần đúng theo dầm liên tục đều nhịp với tải trọng phân bố đều P

Trong đó:

p^tc = P/1,2 = 964,02 +7,92/1,2 = 970,62 daN/m

Với gỗ ta có:   E = 1,1*10⁵ daN/cm²; J = b*h³/12 =10*12³/12=1440cm⁴

= 0,099cm

+   Độ võng cho phép:

Ta thấy: f  < [f], do đó đà dọc chọn: b´h = 10´12cm là bảo đảm.

Cấu tạo ván khuôn dầm, sàn 

2.2 Tính toán khối lượng công tác

2.2.1 Khối lượng công tác bê tông (Tính toán cho 1 tầng điển hình)

2.2.2 Khối lượng công tác cốt thép (Tính toán cho 1 tầng điển hình)

 2.2.3 Khối lượng công tác ván khuôn (Tính toán cho 1 tầng điển hình)

 2.2.4 Khối lượng lao động công tác bê tông tầng điển hình

 2.2.5 Khối lượng lao động công tác cốt thép tầng điển hình

 2.2.6 Khối lượng lao động công tác lắp dựng ván khuôn tầng điển hình

2.2.7 Khối lượng lao động công tác tháo dỡ ván khuôn tầng điển hình

The post Calculation of coppha – Formwork appeared first on Công ty TNHH VXD VINA, Thép Hộp Xây Dựng.

1.Processing and installing the reinforcing column:
This work is peeled according to the size of the deployment drawing of each column. Attention should be paid to the steel length for the construction method (eg joints). Peeling is usually based on the reinforcement statistics table needing to check the statistics table against the detailed design drawings.
2.The work of pouring concrete: Divided into 3 cases:
2.1 In case the column has a cross-section greater than the beam (frame columns): column concrete is calculated first, beam concrete is calculated later. Column length is transparent, beam length minus the column edge.
2.2 In case the beam cross-section is equal to the column cross-section, the concrete of the beam or column should be calculated first.
2.3 In case the column has a cross-section less than the beam (the columns for stiffening the wall), we calculate the concrete of the beam first, the concrete of the column is calculated later. The beam length is calculated, the column length minus the beam height.
3. Processing and installation of formwork.
Regarding the construction sequence, this work is done before pouring concrete, but the peeling should be done later to take advantage of the peeling data of the concrete. The weight of formwork is calculated by the surface of the concrete column, Multiply the column circumference by the column height.

2. PRESSURE MEASURING THE ROOFING CONCRETE WORKING

Roofing concrete work in the norm and the average unit price for the height <= 16m (equivalent to a 5-storey building, there are 3 component works:

1.The roof floor concrete pouring work:

We peel each floor, roof. In each floor we divide into simple shapes with the same calculation, the floor area should include the area of ​​the beam minus the area of ​​the column and then subtract the area of ​​the voids like a normal staircase, The elevator, ventilation holes … This area we use to calculate other volume.

2.The production, erection and removal of roof formwork:

We subtract the area of ​​the above concrete pouring from the base of the beam, pay attention to the area of ​​formwork into the floor and the roof of the floors.

3.The production and erection of rebar roof floor:

Calculated from the statistics table of reinforcement floor. Attention should be paid to check through the drawings.

3. MEASURING THE QUANTITY OF CONCRETE WORKING – UNDERWEAR – BAND

In the unit price calculated for the average height <= 16m, in particular, the production and erection of reinforcement must be divided into 2 groups: <= 4m and> 4m.

1.The work of pouring concrete:

Simply peel each one.

2.The production, erection and removal of formwork:

Based on the above poured area, try to read back and forth of the roof deck formwork to avoid duplication or omission.

3.The production and erection of rebar:

Based on statistics table. It is necessary to compare with the drawings to check.

4. QUANTITY MEASURE OF BRIDGE BRIDGE – DOOR WORK

Bridge work

– Construction of solid brick stairs.

-Slave the stairs.

Staircase tube.

-Two beams for stairs.

– Paint beam for stairs.

-Stair handles.

-Handrail.

DOOR WORK

– Manufacture of doors, door molds of all kinds.

-Constructing doors, door molds of all kinds.

-The door accessories: ke locks hinges, latches …

5. WORKING PRESSURE MEASUREMENT: CONCRETE STEEL CONCRETE PILE

1. Pre-cast concrete piles:

Unit of measure m3.

Specification:

-Check the detailed design drawing of the pile and the statistics of the pile reinforcement statistics, the size of the pile head plate number of the piles, the grid top layer …

-The concrete marks read in the notes.

-Calculate the concrete mass by dividing the pile according to the basic geometry to calculate.

2.The machining and installation of pile formwork:

Calculate the area around the pile.

3. Processing and installation of rebar:

There are 3 common steel types are f <= 10; f <= 18; f> 18.
6. WORKING PRESSURE MEASUREMENT: CLOSING – PRESSING STEEL CONCRETE PILE

APPLICABLE REGULATIONS:

– The norm of computerized piling for 100m of the piles is submerged in the non-submerged section, calculating machine waste, labor waste with a coefficient of 0.75 compared to the respective pile driving norm, Material consumption is calculated by design.

– When driving slant piles, the norm of labor and constructional machines is multiplied by a factor of 1.22 compared to the corresponding pile driving norm.

– In case of using the lead pile to drive the negative piles, the norm of labor and the construction machine for driving the piles is multiplied by the coefficient 1.05 compared to the level of corresponding pile driving. machining and fabrication of piles.

– The norm of piling by pile driving machine on the water does not include the work of making the platform to clamp the floating float

– In other material wastes, the waste of the pile top cushion material is included.

– Regulations on land allocation are as follows:

+ If the total depth of soil layer I> = 60% of the length of the pile, the soil level I shall apply.

+ If total depth of soil layer I is <40% of designed pile length, then the soil level of grade II applies.

In the case where a guide pile must be used, the section of the pile driven through the conductive drilling depth is equal to the norm of driving the pile to the ground level I. (Conductive drilling is not included in the norm).

– Pile driving of various types has not taken into account the costs of erosion and sediment extraction in the pile.

The work of piling steel sheet piles (larsen piles) of steel pipe piles and shaped steel piles is rated for 100m of piles that are located in the project.

In case the pile is reused many times, the material waste is determined as follows:
– Waste calculated by time and environment:

If the pile material is wasted for one time of piling, corresponding to the time the pile is in the work <= 1 month, equal to 1.17%, if it stays in the work for 2 months or more, then every month, the waste of piles is added. as follows:

+ If the piles are placed on land or in fresh water, it is 1.17% / month.

+ If the pile is placed in brackish water, it is 1.22% / month.

+ If the pile is piled in salt water, it will be 1.29% / month.

– Loss due to chip head chipping:

+ Close to soil level I and II, loss is equal to 3.5% / 1 time of payment.

+ Close to rocky soil with stress> = 5Kg / cm2, take 4.5% / 1 time.

In case the pile cannot be extracted, the part of the pile lying in the work is calculated 100% according to the weight of the pile located in the work.
CALCULATION METHOD:

Based on the design drawings clearly stated the size of the area to be reinforced, the pile size, the pile density, and the pile type we will determine the number of piles.

TOTAL LENGTH = INCREASED AREA x PILE LENGTH x PILE Density

– The work of pressing (driving) piles:

+ The weight of the long meter pressed pile depends on the design elevation of the pile top compared to the natural one.

+ Pay attention to the land allocation and calculation unit in accordance with the unit price.

+ Note that if there is negative pressure, it must be separately compensated (for external negative presses, the labor and machine costs such as mass presses, and extra work of negative presses materials are allocated).

– Pile head dam work:

+ Beat by hand or hammer.

+ What is the length of the pile to be smashed

7. WORKING PRESSURE MEASUREMENT: PILE DRILL

Underwater bored piles are rated for vertical drilling without auxiliary wall pipes, drilling depth <= 30m (from the ground for terrestrial drilling, from water surface for underwater drilling for with water depth <4m, flow rate <2m / s) the difference between rising and falling tidal water level <= 1.5m, the drilling depth of the rock is equal to 1 times the diameter. If bored pile drilling is different from the above conditions, it is calculated as follows:

-In case of depth> 30m, from the 31st meter onwards, the norm is multiplied by a factor of 1,015 compared to the corresponding norm.

– The drought in the place where the flow> 2m / s is multiplied by the factor 1.1, the drilling at the ports in operation, the estuary, the estuary, the islands is multiplied by the factor 1.2 compared to the equivalent norm. application.

– In case of technical requirements to drill diagonally into the ground, it is multiplied by the coefficient 1.2 of drilling diagonally into the rock multiplied by the coefficient 1.3 compared with the corresponding norm.

– For an underwater drilling field where the water depth is> 4m deep, for every 1m deep water level is multiplied by the coefficient 1.05 compared with the corresponding norm, drilling in strong tidal areas. The difference in tidal water level from the time of rise compared to the time when the water level falls is> 1.5m, for every 1m difference of the tidal water level up and down is multiplied by a factor of 1.05 with the corresponding drilling norm.

-In case of drilling with auxiliary wall pipes, the length of the auxiliary wall pipe> 30% of the length of the pile is multiplied by the factor 1.1 compared to the corresponding norm.

-In case the depth of drilling in rock is> 1 time the diameter of the pile, for every 1m deep into the rock, it is multiplied by a factor of 1.2 compared to the quota of drilling in the corresponding rock.

– The drilling of piles stuffed into flexible clay, hard clay to very hard, medium to very tight sand, mixed with pebbles with a size of <= 10cm, the drilling norm in this soil is multiplied by a factor of 1.2 compared with the rate of drilling into the respective soil.

8. WORKING QUANTITY MEASUREMENT: TRAINING – LANDING THE LAND

Including works such as: digging foundation works, digging pipes, ditching drainage ditches, covering the road foundation, filling foundation foot …

– Unit of measure: m3 for manual digging and 100m3 for excavator digging.

– Land group: There are 4 groups of land, the work of land depends on the soil group, so it is necessary to specify the soil group.

– Size: there are two types of peaches:

+ Type 1: digging ice foundation, wall foundation, ditch digging: the width must be divided: <= 3m and> 3m. Depth has 4 levels: <= 1m; <= 2m; <= 3m;> 3m. This means that when you peel the prognosis you have to figure out what kind of nail this nail has and what level of depth.

+ Type 2: Independent holes: Width is divided into: <= 1m and> 1m; Depth is divided: <= 1m and> 1m.

So, just like the one above, you have to show what kind of deep, wide independent foundation or pit is.

Placing soil, we are interested in the soil group.

– Suggestions about calculation method:

– The size is calculated based on the plan and section of the foundation, we often divide it into simple small shapes to calculate, of course, depending on the habits and ability of each person, we will get the results. exactly to what extent.

– In some cases, for example, when we calculate the bid volume or estimate the estimate without the construction drawing, we make an approximate calculation at some stages.

For example: Vapour = 1/3 Vao (to be exact, Vap = Vao – V burial works)

* SOME PROVISIONS APPLY TO THE TRAINING OF SAND CAT LAND:

-The digging quota is calculated for 1m3 of digging native soil at the excavation site.

– The earth embankment norm is calculated for 1m3 of embankment soil according to design tightness at the embankment site.

-When digging for earth filling, the volume of excavated soil is equal to the volume of embankment multiplied by the conversion coefficient N:

+ N = 1.07 when the compaction coefficient is 0.85, soil weight is gama = 1.85T / m3-1.60T / m3

+ N = 1.1 when the compaction coefficient is 0.9, soil density is gama = 1.75T / m3

+ N = 1.13 When the compaction coefficient is 0.95, soil density is gama = 1.8T / m3.

+ N = 1.16 when the compaction coefficient is 0.98, soil density is gama = 1.8 T / m3.

Particularly for the volume of mixed rock to be excavated for embankment, the conversion coefficient N = 1.13.

9. WORKING QUANTITY MEASUREMENT: CONCRETE

– Unit: m3.

– Principle of peeling measurement: Usually you separate the volume of concrete, you have to find where there is concrete (of course in a certain order) then divide it into the following categories:

– Type of concrete: crushed stone 4 × 6, 2 × 4, 1 × 2, broken brick concrete, reinforced concrete or non-reinforced concrete.

– Grade concrete: concrete grade 100 broken bricks, grade 200 …

– Type of structure: beam concrete, knitting plate concrete, panel, automobile linen …

– Location of concrete structures: Divide into <= 4m and> 4m.

– Method of construction: pour on the spot, pour by hand, pour with concrete pump, pour with crane,

* Note when calculating:

Of course we have to use our intellect to calculate the total amount of concrete in the building. Pay attention to study the drawing carefully. When calculating the volume of concrete, it should be divided into the volume of concrete in the wall (such as wall braces, beams in the wall ..) and outside walls (beams, columns, ..). All the bt in the wall then subtract the amount of bt in the wall just calculated. Study the following lines for ease of calculation:

+ Foundation excavation area = lined concrete area

+ Area of ​​embankment = area of ​​concrete lining

+ Wall bracing area = foundation length.

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– The weight of formwork is measured and classified separately according to design requirements, materials used to make formwork (steel, wood, filtered plywood …)

– The weight of formwork is measured according to the contact surface between formwork and concrete (including protruding parts according to technical standards or instructions) and must subtract expansion joints, voids in tanks. structure surface has an area of> lm2, the intersection between foundation and beam, column with wall, beam with beam, beam with column, beam and column with floor, wall clapboard head … is counted once.

– For large volume of sheet formwork (size 1.5mx2m), when constructing according to technical requirements, it is not required to subtract formwork area of ​​voids on the surface of concrete structure.

Note:

– Formwork production, erection and dismantlement (including wood formwork and metal formwork) is calculated for 1m2 of concrete surface area of ​​each type of structure where formwork needs to be used. Formwork for some silo-slide, lift cage, tunnel formwork, cantilever-cantilever formwork is rated for the first production, erection and subsequent travel.

– If on a concrete structure surface tank with a void area <1m2, formwork area will not be deducted and additional formwork is not included for wall tanks, edges around the void.

– For formwork of some types of structures (beam, beam, floor, roof …) when calculating for civil and industrial constructions, if the anti-formwork height exceeds the aperture (throughput), the basis is into the design requirements and specific construction conditions to calculate the amount of material (supports, bracing, nails) and labor accordingly.

Reinforcement work

– The weight of the reinforcement must be measured and classified according to the type of steel (normal and prestressed steel, plain steel, strip steel), steel grade, steel group, reinforcement diameter according to structural parts (foundation , columns, walls …) and construction conditions. Some special reinforcement work must also be measured, peeled and classified according to the height of the structure.

– The weight of reinforcement measured for peeling includes the weight of reinforcement, splice, threaded connections, pipe connections, spacer, gaskets, bolts, and the weight of construction method reinforcing steel (such as steel between 2 reinforcement …), if any.

– Information on standard strength, surface shape and other identifiable features should be specified in the calculation table, measuring and stripping the volume of works, work items.

Note:

The production and erection of rebar is rated for 1 ton of rebar, including steel loss during construction, not including steel overlap, reinforcement between layers of reinforcement, steel waiting and steel structures. Non-standard buried in concrete.

Pile work

– Pile weight must be measured, classified according to pile fabrication material (bamboo, wood, reinforced concrete, steel), pile size (length of each pile, diameter, cross section), method connection of piles, piling depth, rock grade, construction conditions (terrestrial, underwater, freshwater, brackish water, plum juice) and construction methods (manual, mechanical construction).

– The weight of the pile, after measuring the peel off, is also supplemented with the weight of cutting, breaking the head of the pile, loading and transporting the waste after cutting, demolishing, if any.

– Information related to the lowering of piles such as the necessary requirements when driving the piles should be specified in the calculation table, measuring the volume of works, work items.

For bored piles, Barrete pile structures or field prefabricated reinforced concrete piles, the measurement of the workload of concrete, the reinforcement of the pile is as instructed on the workload of concrete (section 3) and reinforcement (item 5) above.

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Formwork and scaffolding have material and labor costs that account for about 40-60% of the cost of concrete.
1. Concepts

1.1. The effects of formwork, momentum
Formwork is used as a mold to shape and size the structure, to protect the concrete mixture when pouring and compacted against cement splatter or water loss and to protect the concrete structure during freezing.
The scaffolding is a formwork support system, ensuring the formwork is in position, stable and stable throughout the process of pouring, compacting, curing concrete and slipping when the formwork is removed.
Classification of formwork
Formwork can be classified in the following ways:
According to the subdivision material
Bamboo formwork
Bamboo ratters or bamboo sticks are used to make formwork for vortex staircases, small rolls, round columns, floor boards where there is a lot of bamboo. Bamboo is cheap and is available in all rural areas. However, the processing and erection of bamboo formwork is costly, with low circulation, and poor concrete surface quality. Plywood bamboo is a new material used for flooring and formwork.
Wood formwork
Wood formwork has many types: formwork made by sawn wood, plywood formwork, plywood.
Formwork of sawn wood (raw wood)
Usually made from wood of group VII (oval, pink color), group VIII (bamboo shoots), pillars use group VI wood (oval, oak, crocodile, …). The width of the plank for formwork should not be more than 20cm, the thickness must be at least 2cm.
Lumber formwork is often used for small constructions. ! Low quality wood, irregular size, unable to create large standard boards; concrete is often pockmarked with high moisture absorption of wood, less smooth and smooth concrete surface; ability to use from 3 to 5 times; After a period of use, the wood is susceptible to warping and cracking.
b) Plywood formwork:
Plywood is produced into 1.22 × 2.44cm centers. thickness of 5 to 25mm. To make the plywood sheet hard, people use wooden ribs or metal ribs. For quick and convenient disassembly work, some metal binding details are also made.
Laminate is now used more because it creates high quality concrete surface tank, does not warp, is light, is easier to install and dismantle than metal formwork, lower cost. the rotation rate from 5 to 40 times; It is also used as a portable formwork.
In the US, plywood formwork is manufactured as coated panels. The main phenolic coating is the kraft paper impregnated with phenolic resin to saturation level. Coatings increase the surface properties of plywood. Coating panels come in a variety of types, the choice of which depends on: the quality of the concrete finish and the return on the investment.
Different brands of panel coatings of each style will provide a wide range of concrete trim styles and different gloss grades. For example, concrete poured with an M-coated formwork will have a surface finish, adhere to paint, and is susceptible to adhesives and coatings.
In order to increase investment efficiency in formwork, attention should be paid to:
Choose the type of coated mold panel that is appropriate for the type of base mix used, the high test container mix is ​​more destructive and requires better control of the coating panels.
Requirements for concrete surface tanks when using.
Structural and strength requirements.
How many times is the formwork required to do this (or that thing).
Costs for potential use.
Advantages of the coated mold panel: Reducing finishing costs (finishing costs range from 25% to 55% of total labor costs).
High quality concrete.
Metal formwork
Made from iron, alloy, heavy iron formwork so transport, erection and dismantling is difficult; light alloys but higher cost. The advantage of the metal formwork is easy to disassemble and less laborious, long side. for smooth and flat concrete surface tanks.
Metal formwork is typical panels with ribs made of flat steel, 2.5mm cross-section welded to a black steel face plate 1 to 2mm thick: each plate size: 20x120cm, 30x150cm, 30xl80cm … Along the ribs In addition to the sheet metal large holes were created. small for bonding the formwork together with pins and nails. Weight of each plate is from 20-40kg.
Metal formwork used as formwork for all types of structures: foundations, square columns, round columns, floors, … for smooth and flat concrete surfaces, standard structure sizes.
Wood and steel formwork combined:
Usually with steel ribs, plywood panels. The advantage of this type of formwork is easy to replace face plate, many times of reuse, low cost.

Reinforced concrete formwork
Both function as formwork and part of the structure, it can bear the loads that must be born in construction and compressive and flexural loads of the structure. The outer surface is finished to make the surface of the concrete, the inside has steel beard and roughness for bonding.
Plastic formwork
Using synthetic resin formwork for a flat concrete surface with small edges increases the adhesion of the plastering, lightweight, compact transport, erection, dismantling and storage; Resistant to rain, sun and impact is quite high, tightly sealed, difficult to lose cement water, the number of uses is over 50 times. However, the formwork has less stiffness, so it costs a lot of momentum (1.2 to 1.3 times compared to the metal formwork).
According to the structure and construction method divided
Clustering phase
Specially engineered for the special structural types of the program. After disassembling, if you want to use it for other projects, you must reprocess. Therefore, this type of formwork is usually made of wood such as formwork of vortex staircases, rolling arches; sometimes with large construction parts such as ring-shaped overpass, it is machined with metal: shaped hard ribs, faceted steel plate. In these cases, there is no economic effect.
Forming formwork (penalty shootout)
Manufactured available in the factory or the machining workshop according to a number of standard sizes suitable for the majority of the size of structural components, when going to the gate, it is usually only necessary to arrange and assemble at the location of the culverts. . When removed, it remains in shape.
Shootout formwork has two types, small plate formwork and large plate formwork. The small formwork is presented in section 1.2. Classification of formwork. The flying formwork is a large sheet formwork that is designed, fabricated and organized at a high level. Formwork used for construction of high-rise floor panels.
Structure of flying formwork includes: flooring can be made of metal or plywood which is firmly fixed to the rafting system, the unloading system is a fixed space frame; The horizontal movement and adjustment system is mounted under the pillars. After the reinforced concrete slab has strengthened to dismantle the formwork, the entire formwork system will be lowered by the lifting mechanism; The wheel system or the sliding device will help the crane pull the formwork system out of the cell and room easily and bring them upstairs for installation. is a schematic diagram of the flight formwork horizontal movement and adjustment system.
c) Mobile formwork
A set of fixed formwork that is moved gradually during pouring by a jacking system (usually head size). The working cycle time of the formwork is calculated by calculation. According to the direction of movement, people divide; The formwork moves vertically, the formwork moves horizontally.
The formwork moves in the correct direction:
According to the displacement, it is divided into: Sliding formwork: is a type of formwork that moves continuously up during the pouring process thanks to special structures and jacking systems.
Sliding formwork is used for construction of works such as silos, chimneys, water towers, … In the construction of today’s high-rise buildings-, people started to apply the method of sliding formwork and pre-engineered pre-stressed floors to speed up construction progress, improve work quality and save formwork.
The height of the formwork is sliding from 1 to
5m, it surrounds the entire wall to be poured with concrete (high-rise buildings) or the entire cross-section of the structure (chimney …). The structure of the sliding formwork is shown in figure II.6.
The hydraulic jack is responsible for the sun for the entire household of the formwork to slide continuously up. Lifting capacity of a hydraulic jack is 3-5 tons.
Climbing formwork:
Cling to the structure to climb from site to site using the crane.
The structure of climbing formwork is very special, can be 1 row (Fig. II.7 a,
or 2 to 3 rows (Figure II.7 c), each row from 0.6 to l, 2m in height, the rows linked together and linked to the bearing structure.
Climbing formwork is used when need to pour concrete walls, walls. After the section has been poured to the required strength, the formwork is removed and moved to another piece.

The climbing formwork is used to pour structures with variable cross-sections such as chimneys. Hanging formwork:
Slab steel slabs, welded with angular steel ribs, with upper working platforms (for moving and storing materials), and lower (for finishing and inspection) suspended to the central pillar. (3) by wiring and increasing dirt (4). The wiring household is equipped with a check chain to move the formwork system up.
Formwork moves horizontally:
The entire formwork can be moved on rails or wheels through a jacking or winch system.
This type of formwork is used for the construction of reinforced concrete structures with constant cross-section and large length such as: tunneling underground tunnels (e.g. tunnels at Ngang Pass), or slopes, simple book, … Construction of tunnels is often done first, while ceilings and walls are constructed together by the method of formwork moving horizontally.
Special formwork
rubber formwork. formwork to draw water in concrete, …
Sequence of construction of formwork and momentum
Including the following parts: Fabrication and erection of formwork and momentum; inspect and accept the formwork gate and the spearhead before placing the reinforcement; monitoring, checking, adjusting (if necessary) formwork and momentum during concrete pouring; disassembly and repair work.
The processing of formwork and momentum is carried out in the production workshop or the processing workshop by line construction method, utilizing modern machinery and equipment to improve labor productivity.
The erection of formwork and scaffolding must comply with the order of magic and construction drawings to ensure safety during erection and dismantling.
Check and accept the formwork and scaffolding according to the requirements of TCVN 4453: 1995.
The monitoring and inspection of formwork and scaffolding must be strictly implemented to promptly repair and correct construction problems with formwork and scaffolding during the pouring of concrete.
Formwork removal and scaffolding: Allowable time and sequence to remove formwork and scaffolding must comply with the design requirements and TCVN 4453: 1995.
2. Technical requirements for formwork and scaffolding (TCVN 4453: 1995) 2.1. General requirements
Formwork and scaffolding should be designed and constructed to ensure rigidity, stability, ease of assembly, and no difficulty in the installation of reinforcement, pouring and compacting of concrete.
Formwork must be sealed and tight so as not to lose the water of the cement when pouring and concrete beams, and at the same time protect the new concrete poured from the impact of the weather.
Formwork and momentum should be machined and erect to ensure the correct shape and size of the structure according to the design regulations.
Materials for formwork and spear
Formwork, beam can be made of wood, diaphragm, steel, precast concrete or plastic. Da spears can use bamboo, luong and luong.
Choosing materials for formwork, spear beam must be based on specific conditions and economic efficiency.
Wood for formwork, momentum wood is used in accordance with the Vietnamese standard of building wood TCVN l075: 1971 and current standards, and can also use indifferent types of wood.
Metal formwork, spear should be used so that it is suitable for the ability to rotate many times for different types of structures.
Erection of formwork and momentum
Installation of formwork and scaffolding must meet the following requirements:
Formwork tanks in contact with concrete should be non-sticking; the door-side formwork of walls, floors, beams and columns should be installed in such a way that it is suitable for early dismantling without affecting the remaining formwork and scaffolding that remains to support (such as bottom formwork beams, floors and pillars); erection of scaffolding formwork of floor panels and other parts of multi-storey buildings should ensure that each part can be dismantled and moved gradually according to the pouring and solidifying process of concrete; support pillar of the scaffolding must be firmly placed on a hard foundation, not slipping and deformed under load and impact during construction.
When erecting the formwork, it is necessary to have calibration markers or appropriate measures to facilitate checking of the axial center and elevation of structures.
During the installation of the formwork, it is necessary to construct some suitable holes at the bottom so that when cleaning the surface of the water, there is room to escape. Before pouring concrete, these holes are sealed.
3. Formwork anti-unloading system
Formwork anti-unloading system has many types from single scaffold to combinational scaffolding depending on the type of construction and the nature of the work that are used accordingly.
3.l. Single spear
Single spear can be made of bamboo, wood or metal. Wooden trusses used as pillars for construction of low-rise buildings. With high-rise buildings, people often use metal single-metal spears, which are stronger and safer.
Wood pillars:
Made of log or sawn timber.
Scaffolding pillars can only use wood from group VI and below and use non-bent wood, which is heavily bent (with scarring, lumpy eyes, rotting), which may affect construction safety and quality. the building is not used. The cross-section of the pillar is calculated by calculation, usually using sawn timber with minimum cross-section 8.locm, log timber with a diameter of 80 – 120, length of 3 to 4m. The beam formwork supports are usually machined into a T-shape.
The support post is stored flat to place it firmly on the wedge. Wood pillar wedge is usually made of wood, or sand box.
The wedge has the effect of making height adjustment and column removal easy. The pillars are spaced 700 – 800mm apart and are tied diagonally in both vertical and horizontal directions. Cross bracing is arranged according to the project’s perimeter, inside there is a bracing system for every two rows of columns. Wooden bracing bar with section 25.lo0mm.
Single mast with adjustable height:
Made of tube steel, available in the following forms:
Single mast adjusts the height by connecting segments. This type has many different size segments, depending on the working height that choose them accordingly. Bolted between pipe sections to connect flanges
Stacked column, adjustable in screw thread height:
Consists of 2 interlocking pipes, linked by horizontal and tough latches; used to fight against formwork of beams, floors with small size under 5m; Simple structure, easy to transport and store. Simple disassembly, height adjustment mechanism (adjustable rotation), rotates many times. The screw-threaded height-adjusting guard can, when used, be fitted with a combination column, or an additional column with a fixed length.
To ensure stability for column-support, cross bracing is required. The brace can be a steel tube (spear tube) when it is linked to the support by a spear; when the bracing is made of wood it is linked to the column
anti with arc lock.
The pipe ends of the screw thread assembly, and the screw thread, must be carefully painted against impact, and regularly covered with rust.
Anti-oblique:
Work to keep the formwork stable, vertical or oblique at a certain angle a during concrete pouring and compacting until the total concrete strength reaches the required strength and can remove the wall. The lower end of the anti-slant rests against the foundation or the work floor, the other end is connected to the edge of the wall.
For ease of filling and adjustment, it is recommended to use adjustable slant struts or a combination of adjustable length bevel supports with wooden skewers.
Anti-combinatorial spear
Pa1 is used in wide form of interest in many countries, with the advantage of being a universal support, safe and economical, used for all projects with large structures, high floor height. Made of mild steel, simple structure, convenient transportation, erection and dismantling.
Pal spear is designed based on the principle of triangular frame system, forming solid pieces of continuous triangles, highly flexible and solid. You can create a square stand with side 120.120cm, or a foot for a triangle with side 120cm.
Spear Pal consists of parts:
Click on the column blanket and the jack at the top of the top column. The cross and cross ties (SN-12 and SD-12).
Standard triangular frame (S-1215).
Coupling (SA-01).
Fasteners for coupling (SA-02).
Attention when erection:
horizontal in 2 directions
perpendicular and cross braces against horizontal displacement. Do not replace the stand parts and accessories with other objects during erection.
The entire stand system must be firmly linked together and controlled high and low by the nuts of the jacks.
The coupling must be adjusted to the correct position in order to install the coupling pin. In case the triangular frame is under compressive load, the coupling pin is not required.
3.3. The price of the charge
Used to support formwork in small outward concrete structures such as: eaves, support wall formwork and working floor (Figure II.17) titer bracket is linked to brick wall, concrete wall by anchors . With brick wall using flat steel anchors, it is more convenient to penetrate the mortar circuit than using round steel anchors.
Note: The heart of the column in two directions must be perpendicular, fix the column leg firmly in the positioning frame (the column footer), then place the slant and adjust the straightness of the column formwork.
The erection order is as follows:
Check all of the columns on a section of the house, conduct the heart line (in both directions) with red paint on the foundation or floor.
Fix the spherical bracket in the correct position and the center of the two directions (Figure 11.23).
Erection of column formwork. Column steel reinforcement is usually installed before pouring, if you install the column form by hand, you should assemble the 3 outside boards, then build up and place, fix the remaining board, then insert the column and use adjustable wedge; pay attention to the electric column must be square. It is possible to combine the column formwork into a mold box and then use the crane to install.
Place the skewer, drop the beam in two directions (or use a water bottle) and adjust the skewer to bring the column back to a firm vertical position.
Round column formwork
Made of wood or steel. Wooden formwork is made of thahh lati and rings, linked between them by palace. Depending on the diameter of the column to be molded, one can process 2 or 4 separate sheets. then put together into a round mold. The link between the loose formwork panels is made by wood panels or bolts. Wood formwork is used when the mass of the column needs to be cast is low or when the column is of special size.
Steel formwork is made of steel plates and steel ribs, welded together to form (Figure 11.25). The steel formwork for the round column is usually made up of 2 separate plates, fixed together by pins.
Steel formwork for the concrete tank is smooth and round. Steel formwork is used when the column mass is high and the column size is common.
Round column formwork is similar to that of square columns or rectangular columns.
When adjusting the verticality of the traverse column, three plumb strings are often used.
Polygonal column formwork
Polygonal columns often have hexagonal or hexagonal cross-sections.
The polygonal column formwork is usually made of wood. Formwork panels should be machined in an edge-to-edge manner so that the contact line between the formwork is on the road
radius through the polygon center, the column angles will be beautiful.
Beam formwork (Figure 11.27)
The beams have small electrical properties, large radios, and are placed on high so the formwork structure is relatively complicated. The main parts of the outside formwork
wall boards, anti-skewers also have planks, braces to keep the legs of the boards and T-pillars.
The bottom board and the pillar, in addition to the self-load, also withstand the re-weight of the concrete, reinforcement, load of people and means of transport, the thickness of the board and the cross-section of the support column are calculated according to the calculation. ensure the permissible strength and deflection of the stone board and the allowed thinness of the pillar. For beams with a height greater than 60cm, there must be internal bracing bolts to prevent bulging for the wall.
Plank into girder outside the bottom board so that the bottom of the box is sealed, the positioning of the footboard is sure and also makes it easy to remove the wall in the future. Veneer and beam wall boards are shaped panels made of lumber or plywood with 25-30mm thickness.
The order of erection of compact formwork is as follows:
Check, the main regulator then line the core of the beam on all the girder locations in the part of the house.
Based on the position of the marked foot of the column on the plywood, erect the T-pillars, adjust the vertical supports, then brace the pillars against, insert the column wedge.
Place the girder bottom board, and attach the girder bedboard to the top, bottom and middle 3 column support. Adjust the wedge under the foot of the pillar for the two ends of the board to use the column, stretch the rope over the two ends of the board, follow the wedge-shaped main line under the pillar to make the stone plank level. If the span is larger than 4m, the construction rainbow must be created.
Put 2 planks into beams, beam 2 braces to hold the foot of the wall to position.
Place the stick temporarily, place the anti-skewers, the main pipe for the board upright.
Floor beam formwork
The floor formwork uses eight plywood profiles or pre-machined lumber chutes, each piece should not weigh more than 50kg for easy transport. These planks are placed on wooden purlin system. Under wooden beams are a system of wooden or metal supports.
After installing the beam formwork, erect the floor board in the following order:

Place purlins and fillers.
Set the purlin system and support column for the floor after pouring using the adjustment wedge to make the board vertical.
Place frill planks, use water pipes to adjust the level of the fringes.
Place each piece of floor board to fasten the floor board with purlins.
Stretch through the fringed boards and adjust to level and level flooring.
Figure 11.29 shows L-shaped compacted formwork.
The form of the stairs has a cone
It is a form of continuous-slab formwork, but stage-1 floor and second-stage slab are tilted at a certain angle compared to the horizontal. Projection, the next beam should also be carefully paid attention otherwise the construction of the stairs will be difficult.

Stair formwork is usually wood plank, plywood; Stump supports using wood, sawn timber or single metal pillars to change the height.
Installation of stair formwork is similar to that of floor beam formwork, firstly the installation of formwork and scaffolding for forward beams, landing beams and stair beams; adjust them to the correct heart, core, design size and then install formwork and floor scaffolding and phase 2 staircase, phase 1 floor and staircase. figure 11.30.
Checking and accepting the erection of formwork and scaffolding (TCVN 4453: 1995-3.5)
Formwork and spears, once applied, are checked according to the requirements in Table II. 1, Deviations shall not exceed the values ​​shown in Table II.2.
Board: The requirements to check formwork, spear
The requirements should be checked
Test method
Search results
()
(2)
(3)
The formwork has been installed
Shape and size
Visually, measure with a ruler of the appropriate length
In accordance with the structure of the design
Formwork structure
By eyes
Comply with the provisions of TCVN4453: 1995-3.3.3
Spread between coupling plates
By eyes
The degree of lumber between panels is 3mm
Tightness, tightness between the formwork, between the film and the background
By eyes
The formwork is sealed and tight, ensuring no loss of cement water when pouring and compacting the concrete
Details buried and placed papules
Determine the size, location and quantity by suitable means
Make sure the size, position and quantity as prescribed
Anti-stick formwork
By eyes
The anti-adhesive layer covered all the exposed face of the concrete
Clean inside the formwork
By cool
No trash, mud and other contaminants left inside the formwork

()
(2)
(3)
The inclination, height and size of the formwork
Visually, surveyors and suitable equipment
Do not exceed the values ​​shown in Table 2
Moisture of wood formwork
By eyes
Wood formwork was watered before inspection
Daism has been installed
Muscles texture
Visually, contrasting with the lance design
The scaffolding is installed to ensure the size, number and location according to the design
Post-beams
By losing, use your hand to shake vigorously the pillars, the wedges in each pillar
Pillars are supported, cushioned and placed on a hard foundation, ensuring stability
Hardness and stability
Visually, contrasting with the lance design
The mast is cross-braced and horizontal with sufficient quantity, size and position according to the design

The pre-acceptance test of the construction of formwork, momentum and scaffolding was carried out in the field, combined with the evaluation and consideration of the test results as prescribed in Table II. 1 and deviations shall not exceed the values ​​shown in the table

Name is wrong
Acceptable level (mm)
1. The distance between the pillars to support the formwork and the supporting structure

bending and the distance between the unloading posts is stable. nco and

pillar against design distance:

a) Per meter length
ten
± 25
b) On the entire stage
± 75
2. Formwork plane deviation and junction of

them relative to the design vertical or inclination:

a) Per meter length
5
b) On the entire shaving direction of the structure:

– Foundation
20
– Wall and column unloading the whole block with a height of 5m
ten
– Walls and columns for unloading floor panels of the whole block are over 5m high
15
– Column column is linked by beam
worry
– Beams and arches
5
3. Deviation of formwork shaft compared to design:

a) Foundation
15
b) Walls and columns
8
c) Beams and arches
ten
d) Foundations of steel structures
According to the law

of the design
4. Deviation of sliding formwork, climbing formwork and di-formwork
worry
work compared to the construction axis
1 w

Formwork release agent
The formwork release agent enables quick formwork removal, keeping the concrete surface and formwork from damage during removal. People often use the marks of the waste machine to lubricate the inside of the formwork, after removing the gray concrete surface. dirty. Nowadays, open-pit constructions such as bridges, silos, water towers and works with high artistic requirements all need clean and beautiful surfaces for easy decoration. Some formwork release agents are used in Vietnam (such as separol) for a clean concrete surface. pretty.
Quality separol is 0.83kg / liter. The consumption on a wooden formwork is 1 liter for 2lm2. on plastic and steel formwork is 42m. The coating surface before spraying, rolling or applying the degreaser must be clean and free from grease. Before the release is dry, cover the formwork surface to insulate the water.

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1. What is a construction estimate
A table that summarizes all the data such as a summary of prices, detailed price tables, unit price analysis, analysis of mortar, labor, machine … based on technical designs, or construction designs. .

– The construction estimate is made and used as a basis for the technical department, the accounting department to split related costs.

2.1 Rationale for estimation
When the bid has been won for participating in the bid, the volume and value of the project’s bid are already available. The winning estimate must be based on the bid-winning estimate to separate and base the accounting.

What is the breakdown of construction cost estimates: Based on the cost estimates to take raw material costs, labor costs, general costs, machine costs, camp costs, income before tax, then Compare the total value of each item, from the total value of the items plus compare the value of the whole project.

Step 1: Need to separate materials – labor – machine
– Column “TT”: is the order of work items.

– Column “Name of work”: is the name of the items according to the approved general cost estimate.

– Column “Unit”: is the unit of calculation of that item usually m3.

– Cot “volume”: is the volume of the item according to the estimate, the volume corresponding to the name of the work item.

– The part “Unit Price” is divided into 4 columns, including: “material – NCTT – machine research – machine”. In this part, we take the unit price in the project estimate corresponding to the item and workload.

Note: There is a different unit price depending on each item, there is an item with only the unit price of “material – NCTT” or there is an item with only “machine-machine NC”, depending on each work item.

– The part “into money” is divided into 9 columns, including “Materials – Training – NC machine – machine – cost # – general cost – Personal income tax – 10% tax – camp” as follows:

+ Column “Material” = column “volume” x column “unit price of material”

+ Column “Research research” = column “Volume” x column “unit price of current research”

+ Column “machine research” = column “volume” x column “unit price of machine research”

+ Column “machine” = column “volume” x column “unit price of machine”

+ Column “charge #” = total column (material + case study + machine study + machine) x 1.5 – 2% depending on the project, we have to see the general estimation page to know when building the estimate so that the cost # covers many%.

+ Column “general cost” = total column (material + case study + machine study + machine) x 4.5 – 6%, depending on the project, we have to look on the general estimate page to know when building the estimate for the general cost. how much %.

+ Column “self-created experiments” = total column (material + experiment + machine study + machine) x 5.5% depending on each project, we have to see the general estimation page to know how much% when building the estimate for self-created experiments.

+ Column “Tax 10%” = total column (material + case study + machine research + machine + cost # + general cost + personal income) x 10%

+ Column “camp cost” = total column (material + case study + machine study + machine + cost # + general cost + personal income + 10% tax) x 1-2% depending on the project, we must see the project page. aggregate math to know when building an estimate how much to spend camps.

Conclusion: After the accounting cost table has been extracted, based on the total data of the table above, we will know how to account (the sum of columns in the sum of money must be equal to the total cost estimate)

Construction warranty accounting procedures

Step 2: Next, extracting the detailed costs of raw materials
Breaking up this table, the accountant will know how much materials of the project are in detail to keep track of whether the materials put into the building are redundant or insufficient compared to the project estimate. The table is divided into 2 parts: the above part is the details of materials of the items, the following part is a summary of how much the works and materials occupy.

– Column “TT”: is the order of items

– Column “Name of material”: we look on the sheet “tong CF” to see which items have the value of the material, we will copy that line to the sheet “VT-VL”. If the cost estimates do not detail the types of materials, they must use the book “construction norms of the construction set” to look up what types of materials are included in this item. annual financial reporting service

– Column “Unit”: is the unit of calculation of those materials

– Column “weight” has the same value as the sheet “tong CF”

– Column “norm” look up this value in the book “construction norms of the construction set”

– Column “coefficient” takes the value of the total of the item (the coefficient is 1 +% of other materials)

– Column “Total VL” = column “volume” x column “norm” x column “coefficient”

– Column “Unit price”: we look up the unit price of the above materials in the unit price book issued by the Ministry of Construction in detail for each district of a certain province.

– Column “amount to money” = column “Total VL” x column “unit price”. The sum of the sum of the money column must be equal to the “material” column on the “tong CF” sheet.

After peeling the details of items with material, we make a summary table below to summarize the items to see how much each material is.

Step 3: Next, separating the cost of diesel oil, electricity and gasoline used in the project

Like on the sheet “VT-VL”, the valuable parts in the column “machine” on the sheet “tong CF” we copy the items and the weight to sheet “Dau”. use the book “construction norms” and “price of machine shift and construction equipment” to look up fuel usage norms of machines. Depending on each item, look up what kind of machinery that item uses in the book “construction norms” and look up the fuel use norm of each type of machine in the book “price of machine shift and construction equipment”.

– Column “TT”: order of items

– Column “work items”: names of items with “machine” part value

– Column “Unit” is the unit of calculation of the item

– Column “weight”: the value of the mass is taken according to the sheet “tong CF”

– Column “shift”: take the value in the book “construction norms” to see how many machine shifts are used

– Column “Tca” = column “volume” x “column” shift ”

– Column “electricity or oil”: look up data in the book “price of machine shift and construction equipment” to see how the norm of using the machine you have.

– Column “Total oil”: equal to the total of “Ta” columns.

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1, Peel off the concrete part without the exception of steel or rope taking place
This many people know, but there are also people who do not know where the convention is. Please refer to the provisions in section 3.3, part II of the Decision 788/2010 / BXD on the publication of guidelines for measuring and stripping the work volume.
However, when preparing the settlement dossier, people also need to pay attention: Because there is no space for steel, there are times when the actual amount of concrete is much less, for example: 1000m3 of concrete should be used. all 1015m3 of mortar block (poured by pump), but in fact buying mortar only buys 990m3 for example. This is not okay if you present invoices and documents when making the final settlement, the invoice principle still has to write 1015m3.

2, Peeling concrete must subtract expansion joints, voids on the surface of concrete structures with volume> 0.1m3.
This is also specified in Section 3.3, part II – QD788 – BXD
People reading this sentence will probably think right away: with the volume of slits, holes in the surface with volume <= 0.1m3, it is not subtracted. However, not really, this means that if you do not subtract, it is not wrong, but if the Investor requires to subtract, it is still normal. Because we only say unless the volume> 0.1m3, not say <0.1m3, “no subtraction” as in the case of steel as above.

3, Peeling the formwork must subtract the minus the expansion joints, the voids on the surface of concrete structures with an area of> 1m2.
This is specified in Section 3.4, Part II – QD788 – BXD
Many of you may think that less than 1m2 is not deductible, but as in the case of removing concrete, it is normal for the investor to subtract less than 1m2. But please note: if you do not subtract, you must not calculate formwork.
Similarly in Section 3.10- Part II also stipulates for finishing, if expansion joints or voids have surface area> 0.5m2, it must be subtracted. If <= 0.5m2, you can subtract or not subtract it from the calculation

4, Peel off the formwork of columns, prefabricated square reinforced concrete piles with 2 or 3 sides?
There are a number of auditors who check the dissection of the work of prefabricated column formwork or concrete piles, often calculating only two sides, they reasoned, by definition, the formwork area is the area of ​​the sheet with contact. with concrete (regulated in Decision 788-BXD). However, this is not correct, if only two sides are included, the contractor needs to calculate the cost to build the casting site, that is, to cast the piles, it is necessary to have a casting site and that is part of the cost to get the pile. cardboard. Thus, the calculation of column formwork and 3-sided reinforced concrete piles is appropriate.
5, Separation does not divide the building height
Previously, when dissecting, the building height was divided into levels <4m, from 4-16m, from 16-50m and> 50m to remove works. Actually this is not true. The heights specified in the Norms are confirmed by the Economic Institute of the Ministry of Construction as the height of the building, and when dissecting, if the building height is at any level, strip the code effects with that height. Example: For a 20-storey building with a height of 70m, all job codes will be> 50m. Recently in the Norm 1091, the Ministry of Construction has once again reiterated “the specified height in the DMT is the building height”.

6, What components does the intersection count in? For example: To which part are beams and columns, concrete or formwork included?
In fact, there is no rule on which structure intersections count. So where to peel it depends on the decision of the person performing the measurement. However, usually, the psychology of the estimate maker will be counted in the fastest and most favorable places, and the constructor’s mentality will be more beneficial when in fact, this volume is not too much. I would like to give a comparison example for everyone to refer to:
Column concrete will be higher than beam concrete (up to tens of thousands of 1m3)
However, girder formwork is higher than column formwork (several thousand 1m2)

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Most of the housing construction works are using tiles. This type of construction material not only helps protect but also decorate the building more beautiful.

On the market, there are many types of paving bricks with their own characteristics, suitable for the use of different spaces. However, there are four types that are commonly used today: cool bricks, ceramic tiles, ceramic tiles, glass polished tiles and natural stone. Along refer to the following article to grasp the market trend for your home.

Glass ball bricks

Glass ball bricks also have other names as quartz bricks, homogeneous bricks, … are types of unglazed tiles, the main structural component is stone powder. Tiles are more limited in color compared to other types of bricks.

This type of tile should not be used for lining near or in contact with water such as forecasts, bathrooms because it is very slippery. If you want to use it, you should choose a rock with a rough surface. The size of glass ball bricks used by many people today is 30 × 60 cm, 60 × 60 cm. The popular selling price is from 170 to 180 thousand VND / m2.

Ant tiles should not be lined near or in contact with water such as the front yard, the bathroom because it is very slippery

The outstanding advantage of this tile is that it has a high surface hardness so it has better bearing capacity than other types of tiles. This tile is also resistant to scratches, anti-fouling, easy to clean, reduces openings and brings high aesthetics.

Glass tile is often used in crowded places, luxury or easy to clean places such as hall, living room, staircase, cabinet or kitchen shelf, creating elegance and cleanliness for the interior of the room.

Ceramic tiles

Ceramic tiles are chosen by many people today because of some good properties and reasonable prices. It has a relatively cheap price compared to glass tile, only 120 – 160 thousand VND / m2 of brick.

Solid ceramic tiles stand out with their good properties and affordable prices

This is a very popular product, consisting of an enamel coating on the bone surface of the brick. Floor tiles have properties such as low water absorption, anti-slip resistance. Brick has a high gloss so it is easy to clean, creating a cool feeling for the room.

Ceramic tiles

Ceramic brick or many people still call “ba Tau” brick, because it is made from terracotta. The main composition of this brick includes 70% clay, 30% stone powder and penphate. Ceramic tiles are suitable for tiling for outdoor living areas such as front yard, backyard or terrace. The type with a pattern of fake grass, square is used a lot.

Ceramic tiles have a high price of 300,000 VND / m2

Ceramic has a high selling price of about 300,000 VND / m2 of brick, depending on the specific model and size. Ceramic tiles have a color that is always durable in extreme weather conditions, does not fade with time, does not crack, or mold. The color is bright and eye-catching so it is highly aesthetic. However, due to its high water absorption, the tiles are often stained and have poor scratch resistance.

Natural stone

Currently on the market there are a number of natural stones commonly used in construction, interior design such as Granite, Marble, Onix … Natural stone also has many applications such as can be used for flooring, wall cladding, cladding. Stairs, kitchen tables, auxiliary structures, hallways, swimming pools, or used for decoration.

Granite has the advantage of hardness, which is very suitable for exterior cladding of buildings, corridors, walkways, but lags behind other stones in color. Marble has beautiful colors, rich patterns, but the hardness is not high, often used to paving the living room, dining table, kitchen counter, auxiliary works … Onix stone with beautiful lines, eye-catching colors and luster light can penetrate, often used to decorate and create highlights of buildings. The selling price of this type of paving stone is also very high, ranging from 300,000 to several million VND / m2.

Cool bricks

Cool brick is an ultra-light material with high thermal and sound insulation properties. The product is composed of PU (Polyurethane) in the middle and a special texture of cement on the two surfaces of the product.

Cool brick – super light material for heat insulation, high sound insulation

Cool bricks are used for walls, ceilings, roofs, floors, and walls. For floors, products used for floor cladding, molded fake floors, attic or used for lining / lifting the floor … and construction items as required by customers.

In addition to the function of high sound insulation, the Cool Gach also helps to reduce the load, reduce labor costs, minimize damage to areas with earthquakes, and increase to> 3% of useful usable area. , bring great benefits to both Investor and users.

Contract

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Specifications 18mm film-coated formwork

Dimensions (length × width): 1220mm × 2440mm

– Thickness: 18mm ± 0.5

– Wood gut: Poplar, glue, rubber, eucalyptus

– Type of wood: AA

– Pressure: 155 tons / m3

– Number of hot pressing times: 02

Glue: WBP (Water Boiled Proof) Melamin and Phenol waterproof adhesive

– Processing 4 edges: Paint waterproof glue

Film type: Black Dynea imported from Singapore and Malaysia.

– Humidity: <12%

– Density: 709kg / m3

– Weight: 38.54 (± 1) kg / sheet

– Modulus of elastic bending according to:

+ Vertical: 6100Mpa

+ Horizontal: 5310Mpa

– Number of times of reuse: From 8 – 15 times
More about this source textSource text required for additional translation information

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• Concrete casting stage: At this stage, the concrete material is still in the form of a mixture of liquid (also called mortar) and fresh (that is not setting), calculated from the time it leaves the mixing plant (the concrete mortar is formed). until the concrete begins to set (starting to form chemical bonds between the mineral components in the concrete mortar, also known as pre-setting). At this stage, the concrete is in liquid form (fresh concrete), so it is easy to form when stored in the mold. (The characteristic for the ease of casting of concrete mortar is the fluidity ie slump of the concrete mixture). The concrete mortar at this time has no bearing strength and has a small consistency that requires compacting. But if we exceed this stage, but we immediately touch the concrete mortar, it will break the bonds that have just formed in the concrete but cannot be permanently restored. Therefore, this phase is the stage where concrete can be constructed and requires a mold to accommodate and withstand the change of concrete. This stage usually lasts about 1.5 – 3.0 hours, depending on the ambient temperature and the type of cement that makes the concrete mortar (for concrete usually without additives) and about 3.0 – 4, 0 hours (for concrete with slow setting additive).
• Curing and curing concrete stage: the concrete mortar is now stable in the mold and gradually forms a system of bonding components in the concrete. As mentioned above, this phase is no longer allowed to construct. This is the stage to control the deformation of the mold so as not to break the setting. At the end of this period the concrete solidifies (the formed concrete structure) and permanently retains the shape that the mold gives it. Temporary loads to be applied to the mold have most effect. At the same time the concrete has started to have a certain strength, so some forms of molded molds are only subjected to temporary loads, after this stage, all the roles can be dismantled. This stage usually lasts about 18 – 24 hours after the concrete has started setting.
• Stage of strength development of the concrete structure: the concrete structure has hardened and increased gradually in a gradual manner, the speed of increase is slower. The mold is still subjected to frequent loads in place of the concrete structure, but the degree decreases with time, due to the gradual takeover of the concrete structure. If the concrete quality is good and fully cured according to the construction standards, the concrete structure can reach its design mark, on day 28. When the concrete reaches a certain strength, enough to bear the loads. With regular weight, depending on the specific conditions specified in the construction standards, it is possible to dismantle the bearing molds (the type of molds subject to both permanent and temporary loads), at the end of this period.

With the above characteristics, when constructing concrete structures, it is necessary to have a concrete casting system with two main tasks: both as a mold or formwork containing mortar to create the design shape. and at the same time bear the force instead of mortar and concrete structures later formed from that mortar, when they do not have or have not met the required bearing capacity as required. Therefore, the structure of all molds usually consists of two main parts:

• Formwork system: the main task is to contain and shape the concrete structure, in addition, to transfer the load to the remaining components. (To be exact, formwork or plate form is just one part of the molding system. All the phrases New scaffold or bracing formwork is equivalent to the mold system. But in construction in Vietnam slowly formwork is often used to refer to the entire formwork system.)
• Bearing system is located outside or below the mold plate: it is responsible for the main load bearing for the entire die structure system. These include: gong, bracing, splashing, support, momentum (horizontal momentum), spear (spear), check chain, …

Requirements for concrete formwork formwork

• The mold must be tight: in order to accommodate the fresh and liquid concrete mortar within it,
• The shape and size of the molds and their installation positions at the building must be in accordance with the mold design, in order to fabricate a concrete structure in accordance with the shape, size and position according to that structural design.
• Mold must maintain its shape to fabricate the structure of concrete and reinforced concrete during the formation of that concrete structure (especially in the second stage of concrete: setting stage and curing). To ensure this requirement, the mold structure needs to be designed with the second limit state: strain limit state.
• The mold must be capable of bearing capacity, as it must bear the load instead of concrete when in mortar concrete and possibly even when the concrete has been cured and the concrete structure is formed, until the concrete reach the strength values ​​that can permit dismantling (especially at the construction stage of concrete, where the concrete is completely unbearable but has the greatest variety of loads at the same time). on the mold). To ensure this requirement, the die structure needs to be designed with the limit state I: strength limit state.
• Molds are construction equipment, so their use is only temporary during the construction of concrete structures. Until the concrete structure has formed and has reached certain strength values ​​that are sufficient for the structure to withstand at least its own weight, the mold ceases to function and needs to be removed and can be reused. Therefore, the mold needs to be designed and fabricated so that it is easy to disassemble.

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Film-coated formwork products:

Film-coated formwork is a specialized material designed for use in construction projects; Constructed by gluing thin boards together with a water-resistant adhesive, and covered with film on one or two sides

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