How to design M25 grade concrete

Mix grade is the method to find out the proportion of cement sand and aggregate for getting the desired strength of concrete. Actually Nominal mix is done on the basis of volumetric batching which is more costly for higher grades.


                      CONCRETE MIX DESIGN M-25 - RCC

A-1):-  Design stipulation :-

(a). Grade of concrete  =   M25

(b).Characteristic compressive strength of concrete at 28 days   =   25 N/mm2

(c). Maximum size of Aggregate  =  20mm anguler

(d). Degree of Workability and Slum  =   75-125mm  ( MORT&H table 1700-4 )

(e). Type of Exposer =  Normal

(f). Degree of Quality Control  =   Good

(g). Concreting Method =   Pump able concrete.

(h). Target Mean strength of concrete =  36 N/mm2


A-2):-  Tested data for materials :-

(1). Type of cement and grade :- Ultratech OPC 43 Grade

(2). Specific Gravity of cement =   3.15

(3). Specific Gravity of 10mm Aggregate =   2.524

(4). Specific Gravity of 20mm aggregate =   2.539

(5). Specific gravity of Fine aggregate(sand)  =    2.512

(6). Water Absorption of  20mm  =    1.24%

(7). Water Absorption of 10mm  =   1.30%

(8). water Absorption of fine aggregate(sand).  =    1.67%

(9). Specific gravity of Admixture  =  1.062  ---( Fosroc Auramix 300 )



A-3) :-  Target Mean Strength  :- 

                       Ftarget = Fck + 1.65xS        -----(from IS 10262-2009 Table -1  Clauses 3.2.1.2)
                              
                                   = 25 + 1..65x4 =  31.6 N/mm2
Target mean strength as per table 1700-5 of  MORT&H

  Hence, Target mean strength is Adopted.


A-4) :- Slection of water cement Ratio :- 

Maximum allowed w/c as per MORT&H is =  0.50
Based on trail Adopted water water cement ratio as =    0.45

0.45 <  0.50  hence,  OK

A-5). :- Selection of water content 

 From IS 10262-2009 Table-2
Maximum water content  for 20mm aggregate  =    186 kg  ( for 25-50mm slum range )

Estimated water content for 50-75mm slum we add the 3% extra   ---( from IS 10262-2009, clause 4.2 )

so, corrected Water content =  186 + (3/100)x186  =   191.58 ltrs

As super plasticizer is used , water content can be reduced up to 20% and Above.

Based on trial with super plasticizer , water content reduction of 18.27% has been achieved.

Hence, the arrived water content = 191.58 - 35.00  =  156.58 ltrs
                                                                      says   =   157 ltrs


A-6).  :- Selection of Cement content :-

             Water cement ratio                                                                                           =    0.45

             Hence, Cement content                                                              =  157/0.45    =    349 kg/cum
          
             Minimum cement content ( from MORT&H 1700-3)                 = 330 Kg

                  Hence, Cement content is O.K.


A-7). Proportion of volume of coarse aggregate and fine aggregate. :-


    Therefore,  volume of coarse aggregate  =          0.60 x 100     =      60.00 %

                    volume of Fine aggregate       =          0.40 x 100     =      40.00 %



A-8). Mix calculation :-


          (a). Volume of Concrete :-      

          (b). Volume of Cement   =  mass of cement/(specific gravity of cement x1000)

                                                = 349/3.15 x 1000

                                                = 0.1108 cum

           (c). Volume of Water   =  mass of water/(specific gravity of water x1000)

                                                 = 157/(1 x 1000)

                                                 = 0.157 cum

           (d). Volume of admixture   =  mass of admixture/(specific gravity of admixture x1000)

                                                   = 3.49/(1.062 x 1000)

                                                   = 0.0033 cum

           (e). Volume of All aggregate   =  a- (b+c+d)

                                                         = 1- (0.1108+0.157+0.0033)  

                                                         =  0.729 cum

           (f). Mass of 20mm coarse aggregate  = 0.729 x 0.60 x 0.60 x specific gravity of 20mm x 1000

                                                         = 0.729 x 0.60 x 0.60 x 2.539 x 1000

                                                         = 666.30 Kg

          (g). Mass of 10mm coarse aggregate  = 0.729 x 0.60 x 0.40 x specific gravity of 10mm x 1000

                                                         = 0.729 x 0.60 x 0.40 x 2.524 x 1000

                                                         = 441.60 Kg

          (h). Mass of Fine aggregate(sand)  = 0.729 x 0.40 x specific gravity of sand x 1000

                                                         = 0.729 x 0.40 x 2.512 x 1000

                                                         = 732.50 Kg

A-9). Mix proportion :-

(a). Cement                                                           =   349 Kgs

(b). Coarse aggregate 20mm                                =  666 Kgs 

(c). Coarse aggregate 10mm                                =  442 Kgs

 (d). Fine aggregate(sand)                                   =  733 Kgs

(e). Water                                                              =  157 ltrs

(f). Admixture ( 1% by weight of cement )          =   3.49 Kgs

A-10). Trial Observations :- 

The slum shall be measured and the water content and dosage of admixture shall be adjusted for achieving the required slum based on trail. If required the mix proportion shall be reworked for the actual water content  and checked for durability requirements. 

        Time                12.15PM                12.45PM             1.15PM                    Remarks

        Duration             1/2 hours                1 hour                   11/2                                  Cohesive mix

       slum (mm)           110mm                    90mm                    65mm

       

                                      



















































































                      

What is Pointing and its types.

POINTING :-

Brick wall  joints are raked for 20mm depth and it is cleaned and kept wet for 2 days.
Mix is generally made in requared proportion like 1:2 , 1:3.  after that we applied the mortar on raked brick wall. Extra mortar comes from joints during pointing is removed smoothly that it shows good appearance. And cured these for 7 days.


Types of Pointings :-


1). Flush Pointing :- This is the simplest pointing in this we press the mortar in the raked joints and level the mortar in the level of bricks edges.

2). Ruled Pointing :- In this pointing mortar is pressed in the clean and dry joint. A tool used to make a groove is made up of steel. Groove size should be 5-6mm deep along a center line joint.
Its mean joint shoud be V shaped. and same processes is applied in the vertical joint.

3). Trunk or Weather pointing :-  The mortar is pressed in the raked joint with with a tool so that the joint is sloping from top to bottom. and the vertical joints are filled like as Ruled Pointing.

4). Raised or Trucked Pointing :- In this pointing mortar pressed in the raked joint are in excess amount to make a Bands. Generally Band are 6mm raised and 10mm wide.

Removal time of Shuttering, props and formwork.

Removal time of Shuttering, Props, and Formwork :-

It is very necessary to remove the shuttering after gaining the strength.
stripping time of shuttering is given below according to IS code 456-2000

Type of Formwork                                                                         Minimum of stripping formwork

(a). Vertical formwork to column,walls,Beams                                                  16-24 hours

(b). Soffit formwork to slab ( Props to be refixed
        immediately after removal of formwork)                                                      3 Days

(c). Soffit formwork to Beams ( Props to be refixed

        immediately after removal of formwork)                                                      7 Days

(d). Props to salb :

      1). Spanning up to 4.5 mtrs                                                                         7 Days

      2). Spanning Over 4.5 mtrs                                                                         14 Days

(e). Props to Beams and Arches :

      1). Spanning up to 6.0 mtrs                                                                         14 Days

      2). Spanning Over 6.0 mtrs                                                                         21 Days

What is water cement ratio ?

Water Cement Ratio (w/c ratio) :-
 water cement ratio is the ratio of the weight of water to weight of cement. it is very neccesary to achive the desired WORKABILITY of concrete.
workability means how ease we use the concrete and it should be easy placed in structure.
Water cement ratio is the impotent factor of durability of concrete. it should be minimum as possible.
Generally Maximum water cement ratio is taken between 0.35 to 0.45 according to IS code 456-2000

 For Nominal Weight aggregate of 20mm, Minimum Cement content, Maximum Water cement ratio and Minimum Grade of concrete for different Exposer are given below :-

According to Environmental conditions water cement ratio is given below :-

Environmental condition                     Max. water cement ratio

(1). Mild                                                        0.45
(2). Moderate                                                0.40
(3). Sever                                                      0.40
(4). Very Sever                                             0.38                    
(5). Extreme                                                  0.35

Concrete covers in slab, Beam, Column and Footing,

What is concrete covers :- It is design depth of steel from the exposed surface of concrete. It is the dimension used in the design and indicated ion the drawing.
It should not be less then the Diameter of Bar.

Requirement of concrete cover :- It is provided to protect the steel bars from corrosion depends upon the quality of concrete.

Nominal cover in the COLUMN should not less then 40mm

Nominal cover in the FOOTING should not less then 50mm

Nominal cover in the SLAB should not less then 15mm

Cover in the BEAM is  should not less then the 25mm

The minimum Cover is depends upon the exposer condition of concrete.


  Exposure                    -        Nominal concrete cover in mm not less then

(1).  Mind                     -                                   20
(2).  Moderate              -                                   30
(3).  Sever                    -                                   45
(4).  Very sever            -                                   50    
(5).  Extreme                -                                   75

Note:-
(1). In Mild exposer rainforcement up to 12mm bars normal cover may e reduced by 5mm.
(2). Foe sever and very sever expose reduction of 5mm is made where grade of concrete is M35 and above.
  

What is shear force and bending moment diagrams ?

Shear force diagrames :- Theses are the diagrams those shows the value of shear force at various sections of the members.

Bending moment diagrams :- These are the diagrams those shows the value of the bending moment at various sections of the members.

(A). CANTILEVER BEAMS :- These beams are fixed from one Ends.

(1). Cantilever beams carry W concentrated load of length l.

Considering any section X from distance x from end B.
So     S.F.  at X=S=+W
        B.M. at X=M= -Wx

at x=0 then M=0 

if x=l then M= -Wl


(2). Cantilever beam of length l having uniformaly distributed load w

S.F and B.M at any section X will be

S= wx and M= -(wx^2)/2

if x=l Then
   M= -(wl^2)/2






(3). cantilever beam of length l carry uniformly distributed load w per unit length runs in whole length and have concentrated load W at free end.




S= wx+W
M= -{(wx^2)/2 +Wx}

if x= l then

S= (wl+W)
M= -{(wl^2)/2 +Wl}



(4). Cantilever beam of length l ccarry UDL w per unit length for a distance 'a' from the free end

Here, At x=0 S= 0   and   M= 0

Now section between A and D distance x from end B

S = +wa
M= -wa{x-(a/2)}

At x=a
M= -wa{l -(a/2)}





(B). SIMPLY SUPPORTED BEAMS :-


(1). SSB have concentrated load W at mid having span length l

S.F. at C point

S = -W/2
BM = M= Wl/4

hence BM increase uniformaly

from zero at A to  Wl/4 at C then decrease to zero at B.

(2). SSB have eccentric concentrated load on the span.

assume AD=a  and DB=b
Va and Vb are vertical reaction at the ends.

Vb = Wa/l    and Va = Wb/l

So, shear force between A and D  S = Va = +Wb/l  
      shear force between D nad B  S = Vb = -Wa/l

Bending moment at section between A and D at distance x from A.

M= + (Wb/l)x  at x=0 M= 0

if x= a  M= Wab/l




(3). SSB carry UDL w per unit length over whole span.




At x=0      S = wl/2    and M=0

At  x =l    S=  -(wl/2)    and    M = 0

At l/2        S = 0   and M =  + (wl^2)/8

Minimum area required for Rooms, W/C, Bathroom,

                                     Minimum Area For Rooms, W/C,  and Bathroom,


Before designing of any building we should know the minimum area required for the bathroom rooms and water closet, and the combined bathroom and water closet.

(1). Haritable Rooms :- Rooms may be bedroom, living room, or study rooms. The minimum Hight not be less then 2.74 meters. for row houses hight should be minimum 2.6 meters, and for air conditioner rooms 2.4 meters.
Area of single room should not be less then be 9.5 sqr mtr. with minimum width of 2.4 mtr.
In case of two rooms area of one room should be minimum 9.5 sqr mtr and other should be minimum qr 7.5 sqr mtr with minimum width 2.4 mtr.

(2). Water closet :- It does not includes the bathroom. minimum heigth should be 2,2 mtr and 1.1 sqr mtr minimum area.

(3). Bathrooms :- This place used for bathing whose area should not e less then 1.8 sqr mtr or 1.5x1.2 mtrs
and the hight should not be less then 2.2mtrs.

(4). Combined Lat-Bath :- Area should not be less then 2.8 sqr mtr with minimum width 1.2mtrs.

What is covered Area and plinth Area in building ?

                                       Difference between covered area and plinth area

when we go to purchase the flat we should know the covered area and plinth area. because price of building  is depended upon the plinth area of building. actually party toled us that the covered area of building area is this and the plinth area is this.

Covered Area :- It is the area covered by the building above the plinth area. wall structures staircase gate and swimming pools are not comes in this area.

Plinth Area :- It is the built up covered area measures at floor level of the basement.

Types of Bonds in brick masonry.

                                                          
                                                            Types of Bonding

Bonding - It is the process arrangement of the bricks with mortar to tie them together. Bonding is neccesary to avoid the continuous vertical joints. There are 14 types of bonds in brick masonry.

(1). Stretcher Bond :- In this type bricks are laid with their length in the direction of wall. This pattern is used only for the walls having thickness 90mm only.

(2). Header Bond :- In this bricks are laid with their Ends towards the face of wall. used for one brick thick walls, also used in curved walls.

(3). English bonds :- In this alternate course of strecher and header are laid.queen closer is placed after the first header in the heading course to avoid vertical joints.

(4). Double flemish bond :- In this bond alternete header and strecher are laid to each course. these bonds are good in appearance. Queen closer is placed next to the quoin header alternate course to avoid vertical joints.

(5). Single flemish bonds :- these bonds have double felmish in facing and english bond in backing in each course. Minimum thickness requred for these bonds is 1 1/2 brick. construction of these bonds requred skilled labour.

(6). Garden wall bonds :- these bonds are used in construction of garden compound walls.
 is placed next to the 3/4 bat in every alternative strecher courses.

(7). Facing bonds :- In this different thickness bricks are used in facing and backing of wall. in this header course is placed after several stretcher courses.

(8). Dutch bonds :- This is the modify form of english bond In strecher bond 3/4 bat is used as quoin. A header

(9). :- Raking Bonds :- In this alternet courses are placed in different directions.the raking courses are laid at certain intervell along the hight of the wall in very thick walls having no. of headers more then the no. of stretchers in between the facing and backing.

(10). Zigzag Bonds :- This is used in the paving the brick floors. bricks are arranged in zigzag.

(11). English cross bonds :- They have more strength then english bond. In this every alternate strecher course has a header placed next to the quoins strecher.

(12). Brick on edge bond or soldier bond :- In this types of bponds bricks are laid on edges these bonds are economical bbur week in strength. bbricks are placed as header and stretcher in alternate courses in such a manner that header are placed on bed and strecher are placed on edges forming continuous cavity.

(13). Bound in column :- column shape may be rectangulaer square circuler, english and flemish bbonds are used in the column.

(14). Bond at junction :- A point where two walls meet each other called junction. there are two junctions Tee junction and Cross junction.

Types of Rubble masonry

                                          
                                                  Types of Rubble masonry

Stone masonry is divided in in two :-
(a). Rubble masonry
(b). Ashlar masonry

Rubble masonry :- In this category the stone used have either undressed or roughly dressed have wider joints, they are again subdivided as:-

(1). Uncoursed rubble masonry:- this is the cheapest, roughest and poorest form of stone masonry. Stones used in this masonry h
ave uneven shape and size and thickness of joints kept not more then 13mm.

(2). Uncoursed random Rubble :- The week corners and edges are removed with hammer, The vertical joints are not constructed in plumb. Generally bigger stones are employed as Quoins and Jambs to increase strength of masonry.

(3). Uncoursed Squared Rubble :- In this stones are make roughly squared. they can be of varrying size and are placed in irregular pattern. joints are made uniforms.

(4). Coursed Random Rubble :- these masonry are used in low hight walls or public buildings. The stones employed are 50mm to 200mm size.The joints are abbout 15mm thick. hight of each course in same.

(5). Coursed Square Rubble :- This type of masonry is made up of hammer squared stone facing with bonded backing of uncoursed random rubble masonry.These stones employed in each course are of equal hight. The hight of courses may be reduced in upper portion of wall.

(6). Built to regular Courses :- In this masonry uniform hight of stones are used in horizontal layers not less then 150mm in hight. The stones are arranged in suh a manner so that vertical joint not conside with continues courses.

(7). Polygonal Rubble masonry :- In this stones are roughly dressed to irregular polygonal shape. chips should not be used to support stones on facing.

(8). Flint Rubble masonry :- This type of masonry is used in the areas where flint is available in plentry. their thickness varies from 80mm to 150mm and in length from 150mm to 300mm.

(9). Dry rubble masonry :- This type of masonry is used in the constructiopn of retaining walls, pitching earthen dams and canal slops in the form of random rubble masonry without any mortar.





 

Types of Foundation ?

                                                    
                                                          TYPES OF Foundations

Foundtion is the part of the building which comes directly contac to groung, it transfeer the load of struccture  to the soil. It provides the level surface for the structure. It prevent the diffential settlement of structure.

Types of foundation depends upon the type of structure and type of soil under the structure.

foundation is devided in two parts:-

(A). SHALLOW OR OPEN FOUNDATION :- A foundation is said to be shallow if Depth of foundatyion is equale to or less then width of foundation. there are Seven types of shallow foundation.

(1). Wall footing:- These are used for light structures. the width of base of concrete is at least equal to Twice of width of wall. The depth of concreat bed is atlest kept equal to projection and projection is generally kept 15cm.

(2). Isolated or Column foundation:- They are used to support individual column Generally 15cm offset is provided on all sides of concreat.They may be either stepped type or have projection in concreat.

(3). Combined footing:- These type of footing supports two or more column. Generally they are constucted by concrete. if column carry equale loads footing may be rectanguler in shape Or can be trapezoidal if footing carry unequal loads

(4). Inverted Arch foundation :- This types of structures are used on soft soil to reduce the depth of foundation. Loads above an opening are transmitted from supporting walls through inverted arches to the soil.

(5). Continuous Footings :- A single RCC slab is provided as foundation for two or three or more columns.

(6). Strap or cantilever footings :- these footing are combination of two or more individual footings. these are used at a place where distance between columns is so more.

(7). Grillarge footings:- These footings are used to transmit the heavy loads from steel column to saoil having low bearing capacity. It is made up of rolled steel joists known as grillage beams provided in single or double tiers.

(B). RAFT FOUNDATION :- A or Mat is combined footing that covers the entire area of structure. when structural loads are heavy use of these footings covers more then half of the building area. These rafts may go large settlement without cause harmful differential settlement. When Hard soil is not available to 1.5 to 2.5 mtr these footing are used..

(C). DEEP FOUNDATIONS :- These are used for soils have low bearing capacity. These foundations are in general used as basement, cylinders, shafts and piles.

(1). PILE FOUNDATION :- Pile foundation is a construction supported on piles. Piles may be composed of Timber, concreat or steel, or combination of them.They may be INSITU or PRECAST.

Types of piles :-
1. Bearing piles
2. Frictional piles
3. Screw Piles
4. compaction piles.
  

Minimum estimated quantity of steel in Slab, Coloum, Beam?

Mininum percentage of steel taken in slab,Beams, and Columns.


Steel reinforcement is calculated as per detailed drawing.
The percentage of steel rainforcement is depends on the design of structure.In absence of detailed drawings of design the percentage of steel concrete may be taken approximate:-

The Density of steel is taken as 7.85 T/cum
Or 7850kg/cum


(1). Lintels or Slab :- 0.7 to 1.0%

(2). Beams    :-  1.0 to 2.0%

(3). Columns :- 1.0 to 5.0%

(4). Foundation Raft, Footings  :- 0.5 to 0.8%

For small Span and light loads less steel is required and for bigger span and heavier loads Greater amount of Steel required.

Eg:-
For lintels or slab:-

        7850×0.7/100  TO  7850×1/100

So,   54.95 kg/cum To 78.50 kg/cum

For Beams:-
         7850×1/100 To 7850×2/100

  So, 78.5kg/cum To 196.25kg/cum

For Columns:- 
         7850×1/100 To 7850×5/100

So,    78.5kg/cum To 392.5kg/cum

Types of Bricks in civil construction work ?

We all know that Bricks play a vital role in the building construction work,
Generally, There are Three Types of bricks in construction :-
(A). First Class Bricks
(B). Second Class Bricks
(C). Third Class Bricks

(A). First Class Bricks :- These Bricks have following features
                          (1). They have uniform colour.
                          (2). They have uniform size.
                          (3). Water absorption is less then 20% if immersed in water foor 24 hours.
                          (4). Crushing strength of bricks is 105 kg/cm2.
                          (5). They are uniformly burnt..
                          (6). These bricks have high quality.
                        
(B). Second Class Bricks :- These bricks have following features
                          (1). Quality of these bricks is little bit less then first class bricks.
                          (2). Size may be slightly differ .

                          (3). Water absorption is less then 22% if immersed in water foor 24 hours.

                          (4). Crushing strength of bricks is 70 kg/cm2.

                          (5). These bricks may be slightly over or less burnt.

 (B). Second Class Bricks :- These bricks have following features

                          (1). Quality of these bricks is not so good.

                          (2). Size may be differ .

                          (3). Water absorption is less then 25% if immersed in water foor 24 hours.

                          (4). Crushing strength of bricks is 30 kg/cm2.

                          (5). These bricks may be over burnt or less burnt

Note:- bricks are also classified by material.

              

How many sqr feet in 1sqr meter ?

Now we convert the 1sqr meter in square feet ?

we know,

              25.4mm = 1 inch

             25.4*12mm = 1inch*12  (multiply both sides by 12)

      So,  25.4*12mm = 1 feet    ( becouse 12inch=1feet)

Then,     1mm = 1/25.4*12 feet

             1000mm = 1*1000/(25.4*12) feet

   OR,   1mtr = 3.280 feet 

Then,  1meter sqr = 3.280^2 = 3.280*3.280

                            = 10.758 sqr feet

How many cubic feets in one cubic meter ?

Now we convert the 1cum in cubic feet ?

we know,
              25.4mm = 1 inch
             25.4*12mm = 1inch*12  (multiply both sides by 12)
      So,  25.4*12mm = 1 feet    ( becouse 12inch=1feet)

Then,     1mm = 1/25.4*12 feet
             1000mm = 1*1000/(25.4*12) feet
   OR,   1mtr = 3.280 feet

Then, 1cubic mtr = 3.280^3 = 3.280*3.280*3.280
                          = 35.287 cubic feet

Heat of hydration

What is heat of hydration in concrete?

The term hydration is involved water.When water is added in dry cement a chemical reaction occurs, in which heat comes out. Actually the reaction is exothermic. This heat is called the Heat of hydration.

To manage the heat of hydration CURING is requared. We need to add some extra water in concreat or dry cement. Becouse some water evoporate in atmosphere so reation elements used water present in concrete that why cracks develop on surface. These cracks are called shrinkage cracks.

Heat of hydration is responsible for development of shrinkage cracks on surface of concrete.

How much cement sand required in 100sqm area plaster of thickness 12mm single coat

How to calculate cement sand in 100 sqm area plaster of thickness 12mm single coat ? 

 Let's take propotion is 1:6

Now,

  Total area = 100sqm

Thickness = 12mm

So,

     Total qnty of cement sand                                                                        = 100×.012 = 1.2cum

So 

cement = 1.2/(1+6) = 0.1714cum

Extra cement for voids of sand is taken 20%

So,

0.1714×20/100 = 0.03428

Now Total cement = (0.1714+0.03428)

                                  = 0.2056cum

Now take 20% extra for uneven surface of brick wall

So, 

0.2056×20/100 = 0.0411

Now,

        Total Cement = (0.2056+0.0411)

                                 = 0.2468 cum

                            OR

 0.2468/0.0345 = 7.15 ~ 7.2 Bags

(Here vol. Of 50kg cement bag is 0.0345)

Now sand = 0.2468×6 = 1.48 cum

 FOR DOUBLE COAT

CEMENT = 13.113 bags

How much cement sand required in 10cum brick work.

Cement sand quantity in 10cum brick work

Here size of brick is 230×110×76mm

Dry mortar = 30% of brick work = 3cum

So,

One part of cement = 3cum/sum of perportion.

                    OR

Cement quantity = 3/(a+b)

(A). If ratio is 1:6 then,

Cement = 3/(1+6) = 0.428cum OR 12.77bags~ 13bags

Sand = 0.428×6 = 2.56cum

(B). If ratio is 1:4 then,

Cement = 3/(1+4) = 0.60cum OR 17.71bags~ 18bags

Sand = 0.60×4 = 2.40cum

Sizes of bricks

                           SIZE OF BRICKS


Bricks play the main role to build the building and in building materials of any civil  structure.
Size of Mould used for moulding the bricks is greater than the size of bricks.

Standard size of brick is 90×90×9 cm and they are provided by a oval shapped  grove between the brick called frog.
Size of frog is 6×4×1cm.
Nominal size of brick is 200×100×100mm it incuded the thickness of mortar.
Mould size to mould the standerd bricks is 21×10×10cm.

There is one more type of brick called the traditional Bricks.
Size of TRADITIONAL bricks is 230×115×76mm OR (9"*4"*3")
 .

How to find weight of 8mm,10mm,12mm, 16mm, 20mm, 25mm, 32mm steel bars?

How to find weight per unit length of different dia HYSD bars:- 

Formula :- (d×d)/162.2 OR d^2/162.2

Generally length of steel bar is 12mtr

We are calculate weight for 1mtr length of bar :-

(1):- 8mm dia :- 8×8/162.2 = 0.314 kg/mtr
(2):- 10mm dia :- 10×10/162.2 = 0.616 kg/mtr
(3):- 12mm dia :- 12×12/162.2 = .887 kg/mtr


Like that 16mm = 1.578 kg/mtr
                 20mm = 2.466 kg/mtr
                 25mm = 3.853kg/mtr
                 32mm = 6.313 kg/mtr

Difference between Lap length, development length and anchorage length.

There are 3 types of extra steel length is provided in concrete:-
(1):- lap length
(2):- Development length
(3):- Anchorage length

Lap length:- It is extra length of steel bar provide to safely transfer stress from one bar of steel to other.

Development length:- It is extrs length of steel bar provide to safely transfer stress from steel to concreat.

Anchorage length:- This is provided for safely transfer strees from steel to concreat where Development length can not be provided. Eg:- we provide bend at the end of concreat.

Cement,sand and aggregate Quantity in M20 Grade concreat

Cement qnty in 1cum M20 grade concreat

Ratio of M20 grade
Ratio of M20:- 1:1.5:3

Formula :- cement qnty=1.52/(a+b+c)
Here a=1, b=1.5, c=3
So
     1.52/(1+1.5+3) = 0.276 cum cement
Vol. Of 1 cement bag.= .0334
So cement in bags= 0.276/.0334= 8.2 bags

Now sand :- 0.276×1.5= 0.42cum
Now aggregate:- 0.276×3= 0.828cum

Note:- This qunty of cement is exceeding                   from design qnty of cement. It will                 come to 350 kg in weight batching.

Cement,sand and aggregate Quantity in M15 grade concreat

Cement qnty in 1cum in M15 grade concreat:--

Ratio of M15 grade
Ratio of M15:- 1:2:4

Formula :- cement qnty=1.52/(a+b+c)
Here a=1, b=2, c=4
So
     1.52/(1+2+4) = 0.217cum cement
Vol. Of 1 cement bag.= .0334
So cement in bags= 0.217/.0334= 6.4 bags

Now sand :- 0.217×2= 0.43 cum
Now aggregate:- 0.217×4= 0.87 cum

Cement, sand, aggregate in M10 grade

Cement qnty in 1cum concreat

Ratio of M10 grade
Ratio of M10:- 1:3:6

Formula :- cement qnty=1.52/(a+b+c)
Here a=1, b=3, c=6
So
     1.52/(1+3+6) = 0.152cum cement
Vol. Of 1 cement bag.= .0334
So cement in bags= 0.152/.0334= 4.5 bags

Now sand :- 0.152×3=0.45cum
Now aggregate:- 0.152×6=0.912 cum

What is civil engineering ?

WHAT IS CIVIL ENGINEERING ?

Civil engineering Is the brach of engineering which deals with construction, designing, and maintenance of structures.

According to me it is art which make life easy and comfortable.

Example:- house, Dam, bridges highways, trains, etc. All makes our life easy to live and make us comfortable. By protecting us from sunlight, cooled. And make us easy to go any where easily by highways.