Tuesday, November 18, 2014

Retrofitting

  1. What is retrofitting?
civil
Retrofitting
Ans:- Retrofitting is the proper Technic of civil engineering where we make the old buildings protected against earth quake by this procedure.There are three methods of retrofitting.
  • H.D.G.I wire method.
  • Mesh with subsidiary column method.
  • Angle iron method.

Insulation of  buildings

insulation of walls
Insulated Walls
Insulation Of Building Walls:-  This is the best and modern Technique of civil engineering where we insulate the walls internal sites of the building to maintain the temperature of house. This method is applying mostly in cold areas. Some of materials used for insulation are mention under here.
1. P.E. Foam
2. Wooden Strips
3. Reflective Foil
4. Polythene Sheet
5. Expended Metal Mesh
6. Plaster or ply wood
Q. Why insulation is important?

Ans:- Particularly in cold areas, we can't bear the cold temperature. Therefore, we insulate  internal sites of the building against by the cold temperature.

Wednesday, March 26, 2014

STONE MASONRY IN CIVIL ENGINEERING


Introduction: To make bound of stone to use any suitable mortar and have to get constructed structure is called stone masonry. Stone masonry is used to construction for building of pillars, walls, and foundations. Generally, there are some types of stones are used in the stone masonry. Some are under following here.
1. Slate                                              2.Granite
3. Marble                                           4. Sand stone
5. Lime stone                                    6. Laterite
TOOLS USED IN STONE MASONRY
There are some that mostly use during in the stonemasonry work.
1. Trowel                      2.Square
2. Bevel                        3. Spirit Level
4. plumb bob                5. Steel Tape
6. Mallet                       7. Iron Hammer
8. Chisel                       8. Jumpe
TYPES OF STONE MASONRY’
There are two big types of stone masonry.
1. Rubble Masonry
2. Ashlar Masonry
1. Rubble Stone Masonry: In this type of stone masonry is made without to dressing stones. There are types of rubble stone masonry is give under here.
1. Random Rubble Masonry.             2. Coursed Rubble Masonry
3. Square Rubble Masonry                4. Dry Rubble Masonry
2. Ashlar Stone Masonry: In this type of stone masonry is made after its stones dressing. There are some types of ashlar stone masonry.
1. Fine Ashlar Masonry                     2. Rough Faced Ashlar Masonry
3. Chamfered Ashlar Masonry           4. Ashlar Facing

Wednesday, March 5, 2014

Civil engineering study

Civil engineering studyIntroduction: Civil Engineering study is dependent upon measuring, recording and attracting to scale the physical characteristics on the surface of the earth. For distinctive overview destinations, diverse devices and review gear is utilized. The surveyor utilization instruments for measuring, a field book for recording and these days looking over virtual products for plotting and attracting to scale the site characteristics.

Study of Civil Engineering
Study of civil engineering has contained on many different subjects. There are such types of civil engineering subjects are mentioned under here.                                                                                   
1.Surveying
2.Drafting  
3.Quantity survey 
4.Construction 
5.Mechanics of structure
6.Soil mechanics

 

Civil engineering study
Surveying
 
1. Surveying: In civil engineering the field of surveying is the most necessary and popular for the construction of works where we collect the necessary information and that information’s has been appeared on the drawing sheet before the starting of project by the surveying. After surveying of project we come to know about the dimensions and map. After that we start our work the supervision of map and dimensions of project.

Definition of survey: In the civil engineering survey stands to collect necessary information about any area and project. These information's are appeared on drawing sheet. The procedure of survey is called as surveying. There are main two  types of survey. One is plain survey and second is geodetic  survey.






2. Drafting: Drafting field is most popular and necessary field of civil engineering without this field we can not start the work on project and can not find estimate of project. There fore after the surveying of project we draw a map of project according to their dimension and survey details.

3.Quantity Survey: In civil engineering the quantity survey is the most necessary survey where we find the cost of project before its staring work on project. We have guessed the cost of project that, how many amounts, would need to complete the project by quantity survey. Quantity survey is the most popular field of civil engineering where we calculate the quantity of every using material on project then we find the rates of material by their quantity and at last we can find the total cost of project. There are three important things need to estimate any project one is drawing of project second thing is specifications of the using material on project and third necessary thing is present  rates of the materials.

4. Construction: Construction is the basic field and subject of civil engineering where we learn  about the procedures of different works  that how we can build any structure. For example the procedure of construction buildings, Roads, Reservoirs, Dams, Channels, and many others etc..

Thursday, February 20, 2014

Road structure

Road Structure
Road Structure
 
Introduction: When we cut the road from vertically side then we can see the different parts of road. This action is called as cross section. We can define easily the different parts of road by cross section. Road structure means the different parts of road which they are made on process just like sub-grate is the first part and step of road that is the natural earth level. Second part of road is sub-base. It is not important part of road. If the sub-grate will be weak then we make sub-base for the strength of road. Third part of road is base that is important part of road and last part of road is surfacing. This is the top part of road. There are some parts of road and its explanation of parts are under here.

1. Sub-grade
2. Sub-base
3. Base
4. Surfacing
1. Sub-grade: Sub-grade is the natural earthen level which on road is made. Generally its surface   is kept 2 feet high from earthen level. So that the water of rain cannot stand on road surface. If the road need to make on cutting part so sub-grade will be made under earth surface. Mostly strength of road depends on sub-grade’s durability.

2. Sub-Base: This part of road is not important but when sub-grade is weak then we make base for the strength of road by lay stone aggregates or use other suitable materials for providing a new layer that is called sub- base.

3. Base: This is the important part of road that bears the load of traffic. All traffics load is converted on this part of road and this part weight mold the on base or on sub-grade. Mostly the strength of road depends on this part of durability. Generally this part of road has been contained on strong aggregate.

4. Surfacing: This is the top part of road which that makes equal level of road surface. Similarly the water of road should not be observed on the surface.  This part of road protects the other parts of road. For example, base, sub-base and sub-grade.

Wednesday, February 19, 2014

Types of road

Types of road
Village road
 
Introduction: Road is the such type of way which on different  types of vehicles can go one place to another place leagly.This type of way is called as road. The width of road and other designs of road depends on the traffic that are using the road. Similarly we think about importance of the road before its structure making and then we choise its material according to specification. As you know that, often we need to design different types of road according to our using objectives.There are many types of roads motioned under here.
1.Village road
2. District road
3. State high way
4. National high way
5. Express high way and Motor way


1. Village Road: This type of road designed on village and it is made by aggregate and clay.First of all its first step make to lay aggregates and compected it then lay the clay on road and mixed for the best bond of clay. This type of roads width is been 3.8 mater and(12 feet).



Types of road
District road
 
2. District roads: These types of roads have linked with the different cities of district. During it’s preparing aggregates and bitumen’s are used. Its width size has contained 3.8 mater (12 feet)



 
3. State high way: This type of roads has linked with different cities to one another and it is also linked with national high way. Generally this type of roads has contained its width nearly 7.50 mater (24 feet).


4. National high way: This type of country roads which they have linked with capital of country to capital of province and join with other cities of country. Similarly this road also touches with our neighbors countries.


5. Express high way and motor way: Express high way and motor way are modern roads. This type of roads is made for most fast traffic. This road has linked with province to province, district to district and city to city. Similarly this road also touches with our neighbors countries.
  

Monday, February 17, 2014

Civil Technalogist-Roles and Responsiblities

Civil Technalogist-Roles and Responsiblities
Civil work
 
Introduction: Civil technology is the famous and vast side  of  technology. This is the type of technology which contains with the construction and building, bridges, reservoirs, design of highways, tunnels and other several facilities. Civil technologists have a great deal of responsility in their side. The are directly responsible for the management and planning of construction to take place. Not  only do they aid in designing but also take an effective part in estimating, scheduling, obtaining materials, planning, costs, controlling costs and selecting equipment that is be used. In the field of a construction civil technologists, construction design of the process analysis, mathematics and science all are very important and necessary. Civil technologists are directly responsible for the construction of many proper buildings that you come across on a daily basis.
There are two crucial aspects within this field. You may difficulty in consulting both a civil technology and constructing a civil technologist. They key responsibility of a consulting civil technologist is regarding designing of the project while contracting civil technologists deal with the actual construction where they play a significant roll in transforming a planed designed layout into real architecture. Moreover, being a civil engineer, there are many further specialization that are an essential part of the sector.
A civil technologist job is engaged in different activities starting from the selection of land to the final construction. Some of the responsibilities and key roles of a civil technologist are as follows.


1. A civil technologist start from analyzing many areas and factors that are link to designing and construction.
2. Search, enquire and check the location of field and conform whether it is appropriate for construction purposes.
3.This is the job of civil technologist to work according to a plan with regards what are the key essential and what necessities to be modified before the construction start.
4. Check and approve project reports and designs.
5. A civil technologist should develop detailed design layout that covers the requirement the client.
6. Asses both challenges and potential risks of the planed project.
7. A civil technologist's job includes putting across construction proposal and site to the specified and supervising the tendering process.
8. The civil technologist most also check if all tools and methods like procedures of chemical testing, land surveying, drafting software .
9. Set a complete schedule for purchase of tools and raw material.
10. The civil technologist should ensure the project is completing on time within the planned project.

Tuesday, February 11, 2014

RATE ANALYSIS OF CONCRETE WORK

RATE ANALYSIS OF CONCRETE WORK
Calculator

Introduction: There is need unit rate to analyze the rate of concrete work. This unit of rate is supposed 10 cubic meter or 100 cubic feet. To do find  the materials quantity So, we have need to analyzed  the unit rate. As you know that concrete is prepared in the wet form. This quantity we change into dry quantity do multiply by 1.54. After the find of concrete work's rate that time we also include cost of labor and cost of materials. There is found the concrete's components like fine aggregates, course aggregate and cement from the dry materials volume. Before the start our work we must have calculator for calculation .  First of all we find the sum  . For example, we have the ratio of concrete is 1:2:4. Then we find its sum by this formula.

Cement +Fine aggregate+ Course aggregate=Sum of components
              1 : 2 : 4 = 7



Second we find the quantity of material by this formula.

Quantity of material = Ratio of material  ÷  Sum of ratio × dry material of concrete
Now,  we try  to analyze the 100  Cft cement  concrete  quantity according to  the ratio of  (1:2:4)  in F.P.S . System.
Solution:
                Quantity of wet material =   100  Cft
                Quantity of dry material =   100  ×  1.54 = 154 Cft
                Ratio of concrete =   1  :  2  :  4
Now  we  find sum of this ratio (1  :  2  :  4)
                  =   1  +  2 +  4   =   7
1. First of all we find the quantity of cement  by this formula.
Cement quantity = Cement ratio/Sum of ratio × Dry material
                = 1 / 7 ×   154   =   22 Cft
The volume of one bag cement is equal to 1.25
Then we find the bags to divide the volume of bag (1.25)   from the found out the cement quantity (22).
                = 22  ÷   1.25  = 17.6 Say 18 bags.
2.In second step we will find the quantity of sand.
Sand quantity = Sand ratio / Sum of ratio × Dry material.
                Sand quantity  =  2 / 7 ×  154  =  Say 44 Cft sand.
3. In third step we will find the quantity of aggregates by this formula.
Quantity of aggregates =  Ratio  of  aggregates / Sum of ratio × Dry materials.
                Quantity of aggregates  = 4  /  7 × 154  =  Say 88 Cft aggregates quantity.
Cost of material:
                                     18 bags cement @Rs.690/bag = 18 × 690 = 12420.
                                     44 Cft sand @Rs.200/50 =  44 × 200/50 = 176
                                     88 Cft bajri @ Rs.300/50 = 88 × 300/50 = 52
Total cost of material = 12420 + 176 + 528 = 13124 amount
Note:
          These are not exact rates of materials just for understanding.
Cost o f carriage :
                                18 bags cement @Rs.500/50 means (1 load =50 Cft ) = 18 × 500 / 50 = 180 say 200
                                44Cft sand @Rs.500/50 =  44 × 500 / 50  = 440 say 500

                                88 Cft bajri @Rs.500/50 = 88 × 500 / 50 = 880 say 90
Total cost of carriage: 200 + 500 + 900 = 1600



Sunday, February 2, 2014

SIMPLE HOME DESIGN

Introduction: House is basic need of our life. As you know that, without house we are not secured, comfortable, safe and confident in our life. So, It is necessary to build a home for every person who wants to spend good life. Mostly people think that, they have not large plot and have not  lot of money. But,  should not have to fear. Now, we can build a simple home on short plot and on minimum value. We have tried to draw a simple home design for the people they have found to build a home in minimum cost on a short plot. There is a sample of a simple home design map to give some ideas about home for the people. This map of simple house is made on imaginary basis to give concept of people. As you know there is no mentioned any dimension.



Simple home design
Description about this simple home: This simple house is contained on seven different portions. This simple home has three rooms attached with two toilets and one is open toilet that is separate from the rooms. The dining room and kitchen is attach with to gather and it is attached with store.

Thursday, January 30, 2014

AFFECTING THE FACTORS ON CONCRETE'S PROPERTIES

Environment.Introduction: The fresh concrete is week but the concrete placing after some days It will be strong able  to take load and slowly its strength will be high. During the preparation of concrete we should have to properly take care of the selection ratio and need to look after the placing concrete still to two weeks. That's why, This is the time where some reactions have been affected on concrete's strength and on its property. Some factors they affected on  concrete are given here.
 
1. Quality of  ingredients.
2. Ratio of concrete.
3. Mixing technique.
4. Transportation.
5. Placing.
6. Curing.
7. Environment.


AFFECTING THE FACTORS ON CONCRETE'S  PROPERTIES
Concrete
 
1.Quality of ingredients: During the preparation of concrete their are used different components. They are affected on concrete's quality. We use the cement in concrete that is affected on concrete's properties and on other qualities of concrete. If we use quick setting time of cement in concrete so concrete will get good strength in minimum time and If we use expanding cement in concrete so concrete without freezing it will be expend. The using of other components are also affected on concrete's strength like that aggregates and water quality. If the course aggregate prepared by hard stone.That type of aggregate is better for the quality of concrete. If the unnecessary and harmful minerals or other impurities are include in water so, concrete quality can not be good for the concrete. We want to get proper properties from concrete then the preparation of concrete we should also include compulsory components and admixtures to get good strength of concrete.

2. Ratio of concrete: We prepare concrete according to ratio of different components. They are affected on concrete's strength and on its property. If we use more cement in concrete. So  as well the strength of concrete will be high. Rich concrete has unobserved soft surface.  The size of aggregates also affected on concrete's properties. The size of aggregate should use some big but in possible limit. The voids of components ratio should be minimum in fresh concrete. So concrete's strength will be increase and also be increase porosity of concrete.

3. Mixing method of concrete: If the technique of mixing concrete will be better as result concrete can get good strength. The concrete's mixing method should be good so that after the concrete ratio mixing, the concrete should appear equal all the parts of  concrete ratio.

4. Transportation and placing: If we have to transfer the fresh concrete one place to another place in minimum time.  That time, we should care and use proper technique. During the placing of concrete its components should not be separate to one another and should not mix other to create bad affected components for example clay and  organic things.

5. Curing: To do curing of concrete as result the concrete's strength will be high day by day. That's why, the need of water quantity for the setting concrete. During  preparation of concrete the fresh concrete has loosed its water quantity and need more water in setting time. So, we do curing of concrete to get good strength and impervious.

Tuesday, January 28, 2014

HOUSE DESIGNS



House design
House
Introduction: House is our basic need to pass good safe ,comfortable   and protected life. So we think house is important for the best life. House should have some  properties. The house should be complete air full and open. the house should be  near the school, hospital, road, shops, office, bank, parks and their is also available electricity net facility and TV facility. Before  we think about our house to design that we need money and plot for the starting design, estimating, drafting of house map and need to collect  different materials. First we have ideas and information's in mind according to our desires, then we have to collect the money, everybody know that without money we can't do any thing. Before the design of  our house we come to know so many information like that some questions raise. How many members will be live in this house. So according to this condition. We need a proper place and plot size then we will design different  portions according to our need of family members. The house has different necessary portions and  their name are bed room, dining room, kitchen, toilet, dressing room, bath
House
room porch and with store. The set of home will be  design to see the plot and family members and then try to adjust a home on plot supervision of map this is called also alignments. After that, we give layout for the construction create easy during to do work and materials bring one place to another place.  This was the simple description about our home design. But we have to pass a long process of engineering system to design a house. As you know, First of all surveyors survey the plot of our home then we draw a rough sketch of plot according to our survey and the design of our house to see the survey sketch of plot we include also our desires by the best
designer of house .After that, we have to need some staff to built our house according to be on specifications. A house constructed by two methods. One by contractor and second by owner. If we want to build a house by contractor then we have to publish tender and to give a contract on basis of our specification and agreement to contractor. So we can take supervisor for the supervision to do work according to our specification. After a agreement signed the contractor  will start work by his staff and machinery under owner's supervision.


HOUSE DESIGNS

Saturday, January 25, 2014

Some Tests Of Cement

Different Tests Of Cement To Check Its Quality
tests of cement
test of cement
Introduction: These are need to be adopted for testing two ways and methods. One is field based testing and second is laboratories testing. There are some tests to check the quality of cement. These are nearly 6 tests of cement under here with detail about their objective that, why we do practical of these tests and what we can gain to do these type of practical's.

 




1.  Fineness test of cement.
2.  Setting time test of cement.
3.  Soundness test of cement.                      
4.  Compression test cement.                                                  
5.  Tensile test of cement.
6.  Consistency test of cement.

1.  Fineness test:- Fineness test  is analyzed to find the strength of cement. If the cement is more crushed then its early strength will be increase. Its heat will be release and cracks appears on cement due to shrinkage. Standard  sieve is used for this purpose. There are used sieve no170 of  British standard type for this purpose.

tests cement
cement test
 
2.  Setting time test of cement:-This is analyzed to check the cement that is fresh or can be old as result the cement is weak.Its second purpose is that to find difference b/w ordinary Portland cement and quick setting cement as result we find initial setting time of cement and final setting time of cement by this test.

3.  Soundness test of cement:-Soundness test is analyzed after setting of cement that to find changing its volume. There are many reasons to create changing in volume of cement. Actually, due to late setting of cement past, free limes and other components.

4.  Compression test of cement:-This is the best test to find compressive strength of cement that how much load takes the cement.

5.  Tensile test of cement:-With the help of this test to find tensile strength of cement and It is called also briquette test..

6.  Consistency test of cement:-Consistency test of cement is need to prepare the best past of cement and give the best quality for cement. So, we use this type of test is called consistency test.

 


Thursday, January 23, 2014

CONCRETE MIX DESIGN

Introduction: There are used different techniques and to make concrete mix designing. These techniques are most benefits for the concrete mix design. Usually, some methods are using under here.

concrete mix design1. Arbitrary Method.

2. Minimum Voids Method.

3. Maximum Density Method.

4. Fineness Modulus Method.

5. Water Cement Ratio Method.

1.Arbitrary Method of concrete Mix Design: In the arbitrary method of concrete mix design is supposed to do quantity voids in fresh concrete that the voids of course aggregate will full fill by the fine aggregate. So as the fine aggregate will be equal to the voids quantity of course aggregate. The cement quantity is used according to given strength of concrete. It is maintained a ratio between cement and quantity. Just like that,(1:1),(1:1.5),(1:2),(1:3)and (1:4) etc.

concrete mix design2. Minimum void method of concrete mix design: In this method this is supposed that some fine aggregates to use more than the voids quantity of course  aggregate as result voids quantity will be minimum. If the cement quantity  more use than the voids quantity of fine aggregate  the voids quantity will be minimum.

3. Maximum density method of mix design: Maximum density method is called also trial mixture method. It is tried to get minimum volume from different concrete components to mix in various ratios according to this technique.

4. Fineness modulus method of mix design: To do fine the components of this technique is called also sieve analysis method. According to this technique there is analyzed to prepare different ratio samples of fine aggregate and course aggregates by sieve and find their fineness modulus.

5. Water cement ratio method of mix design: To do find the concrete design and for the given concrete strength is find by water ratio graph. According to using of concrete to choose fineness modulus and then concrete is prepare  according to this ratio. After that, to find its strength.




 
 
 

Saturday, January 18, 2014

TYPES OF STEEL

TYPES OF REINFORCEMENT


types of reinforcementIntroduction: Different types of steel has been using in concrete. From that we get proper benefits. Steel has been divided from different methods. Some important methods are here.

1.TYPES OF STEEL ACCORDING TO SHAPE: Steel bars are prepare in different shapes. Mostly use round  shape steel bars in RCC work. Without that square steel bars, pentagon shaped steel bars, hexagon shaped steel bars and octagon shaped steel bars are prepared also.

             
2.TYPES OF STEEL ACCORDING TO SURFACE: Mostly use round shaped steel bars  in RCC works. Its surface has been prepared by two methods.
a. Plain steel bar.
b. deformed steel bar.
(a) Plain steel bar: In old times, its using was a lot. But nowadays ,its using is very few in concrete works.so that, its surface is smooth as result, bond can not be strong.
(b) Deformed steel bar: This type of steels has harshness on its surface. In present, its using is every where.Its best property is that, the steel make strong bonding with concrete.

3.TYPES OF STEEL ACCORDING TO STRENTH: This steel is divided according to strength. Its strength is appear  yield strength. This strength is called grate of steel. Mostly use 40 grade and 60 grade in present. Without that,75 grade and 90 grade of steel use on places. Forty grade of steel has 40 thousands fee square inch strength. So as 60 grade of steel has 60 thousands pound fee square inch strength.
4.TYPES OF STEEL ACCORDING TO USE: There are 6 types of steel according to use.
types of reinforcementa. Tensile steel.
b. Compression steel.
c. Shear reinforcement.
d. Bond reinforcement.
e. Torsional reinforcement.
f. Temperature steel.
 

5. TYPES OF STEEL ACCORDING TO MATERIAL: There are three types of steel according to material.
a. Mild Steel.
b. Medium Carbon Steel.
c. High Carbon Steel.
  (a) Mild Steel: In ordinary RCC works use mild steel. This type steel is easy to bending, cutting and binding. In this steel the quantity of carbon is 0.05 to 0.3 person.
(b) Medium Carbon Steel: Medium carbon steel has so many strength. But it is very difficult to bending, cutting and binding. This steel is used in prestressed concrete. The quantity of carbon is include 0.3 to 0.6 person in this steel.
(c) High Carbon Steel: The carbon of steel is include 0.6 to 1.5 person in high carbon steel. If we use much the quantity of carbon in steel as result, the steel will be strong and hard. But, It is very difficult to work on this steel.

6.TYPES OF STEEL ACCORDING TO STRESS: There are two types of steel according to stress.
a. Ordinary Reinforcement.
b. Prestressed Reinforcement.


                     

Thursday, January 16, 2014

RCC WORK


RCC work
RCC WORK
 

Introduction: In the RCC work the steel has used with concrete. The steel and concrete both should be monolithic each other. Some necessary properties of both materials are given under here.
 
 




1. Both materials should make strong bond between them.
2. Both materials co-efficient of thermal expansion nearly should be equal.
3. They should be strong with each other.
4. They should not be reacted any bad  chemical   between them.
5. These materials should avail easily and in low price.
6. During the steel cutting, binding and welding should be easy.


Note: The concrete and steel have above all  properties.

Wednesday, January 15, 2014

SPECIAL ADMIXTURES

 
special admixtures
Sugar
 
Introduction: During the preparation of concrete work we add some components to create good quality in concrete. These components as known special admixtures. There are some types of  special admixtures.

 1. Water Proofing Admixtures
 2. Air Entraining Admixtures.
 3. Bonding Admixtures.
 4. Expansion Admixtures.
 5. Pazzolanic Admixtures.
 6. Bacterial Admixtures.

ADMIXTURES

admitures
ADMIXTURE
 
 Definition Of Admixtures: During the preparation of concrete without its compulsory components to create expecting of quality in concrete the extra components  mixing as known called admixture. We can say them also additives. Really during the preparation of cement we mix some components in cement is called Additives. When, the preparation of  concrete add some components in concrete is called admixtures. Some admixtures are here. Aluminum, Strict Acid and Polymer Emulsion.



                                                   
Question. Why we use admixtures in concrete?
Answer: We can get many benefits to use admixtures during the preparation of concrete. Some benefits
of admixture are under here.
1. we create extra qualities to use admixtures in concrete. Like that ,these admixtures also use to
reduce the resistance and defects on create high  temperature and low temperature in concrete work.
2. During the design work we enhance the setting time of concrete to use admixtures.
3. Some time we use admixtures in cement to reduce the setting time of cement for the repairing structures.
4. Some area they have water crises .There, we use admixtures to get good structure in minimum water. So,  for this purpose we mix in concrete  Lignosulfonic Acid and Alumina cement.

Retarders and Acceleraters


acceleraters and retarders
Accelerators
 

Accelerators:During the concrete work If the temperature
fall into freezing point in cold days. That time the concrete can not set in time and can't get complete strength .So we use accelerators 
to enhance heat in concrete for good setting. Often, this type of situations create on very cold areas. For this purpose we can use  Calcium chloride, Calcium Chloride, Calcium nitrate and Sodium chloride.

Retarders:When we have to do concrete work If the temperature of environment is very hot. So before concrete setting the water of concrete be decrease as result concrete lose his strength and durability. Therefore, we use many type of retarders to maintain the setting time of concrete water and we get good strength. This type of situations  create on hot areas. Some retarders are given under. Sugar and Carbohydrate.

retarders
Sugar
 
                                                               

                                                                          

PCC AND RCC WORK

(1)  RCC:Reinforced cement concrete. (2) PCC:Plain cement concrete

rcc and concrete
RCC WORK
Introduction: Reinforced cement concrete consist on five type of materials such as cement ,aggregates, steel, sand and water. During preparation of concrete should need suitable tempreture.This suitable temperature is 18 degree centigrade to 21 degree centigrade. First of all we prepare the frame of structure according to given design. Second we lay the steel of frame and third we preparation of concrete.

 
 


Q1.What is the procedure of preparation concrete?
rcc and pcc
CONCRETE
 
Answer: First of all we check the specification of materials. Are they  materials according to specification. Then we pile material on clean place. First we aggregates lay on place according to volume then add sand, cement and after that mix with water  according to given ratio. We can also mixing by machine or hands. If we have a large work then concrete mix by machine otherwise we can mix by hand. At last passing after that process we require the concrete. Now concrete is ready to lay on the frame work. After a day we should do curing of concrete.


 
 Q2. How we can achieve good strength of concrete?
Answer: We has achieve nearly 50  person strength concrete placing after 3 days from total days of 28.7 days after It has achieve 70 person strength. It has understood that 28 days after strength has been completed.
 

Q3.Why  we use retarders and accelerators and give their names?
When the temperature fall into freezing point that time we use accelerators for  quick setting of concrete. So concrete set on time and durable so as when the temperature will be very hot in summer season that time, the water of concrete hydrate before the setting of concrete. Such as it's strength will be reduce. Therefore, we use many type of retarders to achieve quality of strength. Some of retarders and accelerators are given under.

Retarders                                              Accelerators