FUTURE SCOPE OF GEOPOLYMER CONCRETE

FUTURE SCOPE OF GEOPOLYMER CONCRETE

1.    Geopolymer concrete is an innovative & eco-friendly construction material & is an alternative to Portland cement concrete. By the use of geopolymer concrete we can decrease global warming which is one of the big problem of world.

2.    Use of geopolymer reduces the demand of Portland cement which is responsible for high carbon dioxide  emission .

3.    Geopolymer concrete is made from utilization of waste materials such as fly ash, & GGBS(ground granulated blast furnish slag).

ADVANTAGES AND DISADVANTAGE OF GEOPOLYMER CONCRETE

Advantage of geopolymer concrete

·       It has high compressive strength than that of ordinary concrete

·       Very low shrinkage

·       Resistant to heat & cold

·       It is very strong chemical resistance

 Disadvantage of geopolymer concrete

·       Difficult to create .

·       Geoolymer concrete is sold only as a pre-cast or pre-mix due to its hot(heating) curing process.

GEOPOLYMER CONCRETE

GEOPOLYMERCONCRETE

 Geopolymer is a new development in the world of concrete in which cement is totally replaced by pozzolanic materials like fly ash and activated by highly alkaline solutions to act as a binder in the concrete mix. For the selection of suitable ingredients of geopolymer concrete to achieve desire strength at required workability, an experimental investigation has been carried out for the gradation of geopolymer concrete and a mix design procedure is proposed on the basis of quantity and fineness of fly ash, quantity of water, grading of fine aggregate, fine to total aggregate ratio. Sodium silicate solution with Na2O = 16.37 %, SiO2 = 34.35 % and H2O = 49.28 % and sodium hydroxide solution having 13 M concentration were maintained constant throughout the experiment. Water-to-geopolymer binder ratio of 0.35, alkaline solution-to-fly ash ratio of 0.35 and sodium silicate-to-sodium hydroxide ratio of 1.0 by mass were fixed on the basis of workability and cube compressive strength. Workability of geopolymer concrete was measured by flow table apparatus and cubes of 150 mm side were cast and tested for compressive strength after specified period of oven heating. The temperature of oven heating was maintained at 60 °C for 24 h duration and tested 7 days after heating. It is observed that the results of workability and compressive strength are well match with the required degree of workability and compressive strength. So, proposed method is used to design normal and standard Geopolymer concrete.

Use of concrete is globally accepted due to ease in operation, mechanical properties and low cost of production as compared to other construction materials. An important ingredient in the conventional concrete is the Portland cement. Production of Portland cement is increasing due to the increasing demand of construction industries. Therefore the rate of production of carbon dioxide released to the atmosphere during the production of Portland cement is also increasing. Generally for each ton of Portland cement production, releases a ton of carbon dioxide in the atmosphere . The green house gas emission from the production of Portland cement is about 1.35 billion tons annually, which is about 7 % of the total greenhouse gas emissions . Moreover, cement production also consumes significant amount of natural resources. Therefore to reduce the pollution, it is necessary to reduce or replace the cement from concrete by other cementitious materials like fly ash, blast furnace slag, rice husk ash, etc. Fly ash is a by-product of pulverized coal blown into a fire furnace of an electricity generating thermal power plant. According to the survey, the total fly ash production in the world is about 780 million tons per year but utilization is only about 17–20 % . In India more than 220 million tons of Fly ash is produced annually . Out of this, only 35–50 % fly ash is utilized either in the production of Portland pozzolana cement, workability improving admixture in concrete or in stabilization of soil. Most of the fly ash is disposed off as a waste material that covers several hectares of valuable land. The importance of using fly ash as a cement replacing material is beyond doubt ,replacing cement by fly ash up to 60 % known as high volume fly ash concrete. But it was observed that the pozzolanic action of fly ash with calcium hydroxide formed during the hydration of cement is very slow. The particles of size less than 45 μm are responsible for pozzolanic reaction. Higher size particles present in fly ash acts as filler. Therefore for complete replacement of cement by fly ash and to achieve the higher strength within a short period of curing. Fly ash when comes in contact with highly alkaline solutions forms inorganic alumino–silicate polymer product yielding polymeric Si–O–Al–O bonds known as Geopolymer . To produce concrete of desired strength, various mix proportioning methods are used on the basis of type of work, types, availability and properties of material, field conditions and workability and durability requirements. As geopolymer concrete is a new material in which cement is totally replaced by fly ash and activated by alkaline solutions. Chemical composition, fineness and density of fly ashes are different from cement. Similarly, in cement concrete, water plays main role during hydration process while water come out during polymerisation process as in case of geopolymer concrete. Therefore it is necessary to develop a new mix design procedure for geopolymer concrete to achieve desired strength at required workability. So, in the present investigation, geopolymer concrete mix design procedure is proposed on the basis of quantity and fineness of fly ash to achieve desired strength , quantity of water to achieve required degree of workability , grading of fine aggregate  and fine-to-total aggregate ratio by maintaining solution-to-fly ash ratio by mass of 0.35 , water-to-geopolymer binder ratio of 0.35 , sodium silicate-to-sodium hydroxide ratio by mass of 1  and tested after oven heating at a temperature 60 °C for duration of 24 h and tested after test period of 7 days.

OVEN CURING OF GEOPOLYMER CONCRETE

                             

IMPORTANT POINTS TO REMEMBER FOR SITE ENGINEER

There are many things which should be known by the engineer who are working on site the below mentioned points are the important points which to be remembered by a site engineer to complete the work in systematic way .

1. lapping should be provided in bar diameter upto 36 mm, bar having diameter more than 36 mm should not be allowed for lapping.
2. The minimum spacing between two chair should be 1m.
3. The bar used for preparing chair should have minimum diameter of 12 mm.
4. Dowels bar should have minimum diameter of 12 mm.
5. Minimum bar used for square & rectangle column should be 4 & for circular column should be 6.
6. The distribution bar used in slab should have minimum diameter of 8 mm.
7. The main bar used in slab should have minimum diameter of 8mm if we use HYSD bar & should have minimum diameter of 10 mm if we use mild steel bar.
8. The minimum thickness of should be 125 mm.
9. One metric ton of reinforcement require 8 kg of binding wire (8kg/m t . of  reinforcement)
10. The maximum diameter of bar used in slab should not exceed 1/8 of total thickness of slab.
11. Electric conduits & sanitary pipes shall not run in column .
12. Parapet wall height should not be less than 1.2 m.
13. Mason can cover 25 to 30 m^3 brick work in a day.
14. 1 cubic meter of cement is equal to 28.8 bags of 50kg weight.
15. Thickness of plaster should not be more than 12 mm.

GATE EXAM MAY BECOME COMPULSORY FOR ALL ENGINEERING STUDENT

GATE(Graduate Aptitude Test In  Engineering)

 as per AICTE meeting GATE is going to be

compulsory for all engineering students.The GATE exam will be as a EXIT EXAM for engineering students i.e only after clearing GATE student will get there degree.This decision will be for both private & government college engineering students.This exam will be conducted in the final year of B.Tech and student who will clear the exam will be considered as B.Tech Graduates & the student who will not clear the exam have to re-appear for the exam and have to clear it in order to get his/her degree.

   

 The reason to conduct EXIT EXAM(GATE)

• To change the engineering education system of India.
• This decision will help or make students concern & aware about there study.
• This will increase the Employability of Engineer ,at present only 15% of engineering graduates are able to get job,rest all remains unemployed which creates a big  question marks on engineering education so to fix these problems the AICTE has taken this steps. 
• This decision will definitely increase the employability of engineers and this will also make the students concern about there study .
• this step is taken so that no engineering student have to face problems in the placement.

This decision is taken because of private colleges ,which only takes admission of students and give degrees to them they donot take responsibilities of providing knowledge to student they only take responsibilities of giving degree to student after four year and they need money from student so this all things are responsible for producing less skilled engineer and polluting the engineering education system & this all things decreases the level of engineering.so, to overcome this all bad stuffs in engineering education system AICTE has taken this decision .This will give good qualified Engineers to India which will be very helpful for the development of country.This step will also help engineering education system to maintain  its level and dignity & every engineer will feel proud of being engineer.

HOW TO CALCULATE MASS OF CONCRETE TO PREPARE ONE CUBE OF 15 CM^3

The cubes are casted to perform different test on concrete.This is widely used in civil engineering & every civil engineer perform different test with concrete cube so the point is that if we have to prepare exact concrete so that we can prepare one cube then how should we do this so here we will know to calculate the exact mass of concrete for preparing one cube of (15 cm × 15 cm × 15 cm ) volume.Usually this calculation is done at the time of study of civil engineering in field it is not so important because the sample is taken from a big amount of prepared concrete as much is requires to cast the desired cube there is no need to calculate the exact volume or mass but this thing will be helpful for calculating quantity of concrete required for big works. so let us start

the first things we have to know is that the density of plane concrete i.e 2400 kg/m^3

now we have to calculate the volume of one cube in cubic meter
=15 cm × 15 cm × 15 cm  =3.375 cm^3 = 3.375 × 10^-6 = 0.00337 m^3
now after converting volume into meter cube we have to apply the formula of density
        DENSITY= MASS/VOLUME
from here
        MASS=DENSITY × VOLUME
as we have to calculate the mass of one cube so we found out the formula of mass now,
        MASS=2400 kg/m^3 × 0.00337 m^3
        MASS= 8.1 kg
In this way we can calculate the mass of one cube

CALCULATION OF QUANTITIES OF CEMENT, FINE AGGREGATE, & COARSE AGGREGATE IN CONCRETE OF GRADE M20 FOR 1 CUBIC METRE VOLUME

CALCULATION OF CEMENT,FINE AGGREGATE,COARSE AGGREGATE QUANTITIES :-

For calculation of  quantities of cement , fine aggregate and coarse aggregate we need to know some data related to ratio of different grades of concrete and density of cement ,fine aggregate, and coarse aggregate.
                GRADES                                                                 RATIO
                 M5                                                                            1:5:10
                M7.5                                                                          1:4:8
                M10                                                                           1:3:6
                M15                                                                           1:2:4
                M20                                                                           1:1.5:3
               M25                                                                           1:1:2


DENSITY OF CEMENT :-1440 Kg/m^3
DENSITY OF FINE AGGREGATE(SAND):-1450 to 1600 Kg/m^3
DENSITY OF COARSE AGGREGATE :-1450 to 1500 kg/m^3

STEP 1:-first of all find the total volume of concrete for which we have to calculate quantities of its ingredients.we are calculating for 1 cubic metre of volume of concrete.So this 1 cubic metre volume of concrete will be the WET VOLUME OF CONCRETE i.e after mixing all ingredients with water we need 1 cubic metre volume of concrete .But we have the ingredients cement ,fine aggregate , coarse aggregate in dry form so we need to calculate the dry volume of  required concrete.
THE DRY VOLUME = WET VOLUME ✖ 1.54
DRY VOLUME OF CONCRETE =1 ✖ 1.54 =1.54 M^3
Now we have to calculate the quantity of different ingredients in total of 1.54 m^3 volume


Now we need the ratio of grade of concrete ,as we have grade of concrete as M20 for this grade the ratio is 1:1.5:3
            ↙   ↓   ↘
cement   fine    coarse
         aggregate  aggregate
     
FORMULA FOR CALCULATING QUANTITIES:-
QUANTITY= ( RATIO OF INGREDIENT WHOSE QUANTITY IS TO BE FOUND) ➗(  SUM OF RATIO OF ALL INGREDIENTS)✖ 1.54

                        
                               ( WHERE 1.54 IS DRY VOLUME)

STEP 2:-CALCULATION OF QUANTITY OF CEMENT:-

CEMENT

          Quantity of cement=(1/5.5) ✖ 1.54  = 0.28 m^3

where 1= ratio of cement 

          5.5 =sum of all ratios (1+1.5+3=5.5)

          1.54=dry volume 

so quantity of cement we found out as 0.28 m^3 if we want this volume in cubic feet we can get by multiplying meter cube with 35.315 then we can get result in cubic feet i.e 0.28 ✕ 35.315 =9.88 cft.
now we have to calculate mass of cement ,the formula for calculating mass is
 MASS = VOLUME ✕ DENSITY
             =0.28 ✕ 1440 kg/m^3
            =403.2 kg
Now we have to calculate number of bags of cement and 1 bag of cement contain mass of 50 kg so we will now divide total mass by 50 to get number of bags of cement.
No. of bags of cement =403.2 /50
                                   = 8.06 bags
STEP 3:-CALCULATION OF QUANTITY OF FINE AGGREGATE:-

FINE AGGREGATE

    quantity of fine aggregate=(1.5 /5.5)✕1.54  = 0.42 m^3

where 1.5= ratio of fine aggregate

          5.5 =sum of all ratios (1+1.5+3=5.5)

          1.54=dry volume 

so quantity of fine aggregate we found out as 0.42 m^3 if we want this volume in cubic feet we can get by multiplying meter cube with 35.315 then we can get result in cubic feet i.e 0.42✕ 35.315 =14.83 cft.

now we have to calculate mass of fine aggregate,the formula for calculating mass is
 MASS = VOLUME ✕ DENSITY
             =0.42 ✕ 1500 kg/m^3
            =630 kg
STEP 4:-CALCULATION OF QUANTITY OF COARSE AGGREGATE:-

         quantity of coarse aggregate=(3 /5.5)✕1.54  = 0.84 m^3
where 3= ratio of coarse aggregate

          5.5 =sum of all ratios (1+1.5+3=5.5)

          1.54=dry volume 

so quantity of coarse aggregate we found out as 0.84 m^3 if we want this volume in cubic feet we can get by multiplying meter cube with 35.315 then we can get result in cubic feet i.e 0.84✕ 35.315 =29.66 cft.

now we have to calculate mass of fine aggregate,the formula for calculating mass is
 MASS = VOLUME ✕ DENSITY
             =0.84 ✕ 1500 kg/m^3
            =1260 kg
In this way we can calculate mass/volume of different ingredients of concrete.
  we found the quantities as :-
               INGREDIENTS                         VOLUME                    MASS
                 CEMENT                                     0.28 M^3                      403.2 kg
            FINE AGGREGATE                        0.42 M^3                      630 kg
           COARSE AGGREGATE                 0.84 M^3                      1260 kg
 AND TO CHECK THE CALCULATION WE HAVE TO ADD ALL THE INGREDIENTS VOLUME AND THE SUM MUST BE EQUAL TO THE DRY VOLUME OF CONCRETE.
     0.28 +0.42 + 0.84  =1.54 WHICH IS EQUAL TO DRY VOLUME OF CONCRETE SO CALCULATIONS ARE CORRECT.

PLINTH BEAM

WHY PLINTH BEAM ARE PROVIDED IN BUILDING ??

•THE REASON TO PROVIDE IS TO AVOID DIFFERENTIAL SETTLEMENT IN BUILDING.

•TO MAINTAIN THE PLINTH PLANE PROPER.

•TO AVOID DIFFICULTIES IN CONSTRUCTION OF WALLS.

•TO CONNECT THE ALL COLUMNS.

•THIS WILL PREVENTING ENTRY OF ANY RAIN WATER,DUST TO ENTER THE BUILDING.

•IT ACTS AS ELEMENT WHERE THE WALL CAN REST WHICH HELP THE WALL FROM NOT

DIRECT LAYING IT ON THE GROUND.

AAC BLOCKS-NEW AGE GREEN BUILDING MATERIAL

AAC BLOCKS

AAC stand for Autoclaved Aerated concrete Blocks.IT is also know by different names such as Autoclaved cellular concrete block, Autoclaved light weight concrete block.It was invented in 1924 in Sweden.It has become one of the most used building material in Europe countries ,and is rapidly
growing in many other countries including India around the world.It is considered as a new age green building material because it don't produces carbon dioxide gas during its production or manufacture. AAC block consist of

1. Silica rich material(fly ash)  - 65 to 70%
2. Lime                                     - 08 to 12%
3. Cement                                 - 10 to 15%
4. Gypsum                                - 04 to 05%

AAC blocks helps cut (decrease) construction cost upto 30%.Construction  work with AAC block required less labor as compared to red bricks and help to complete work fast.

Civil Engineering: REBARIN TECHNIQUES/ PROCESS USED IN CONSTRUCTION O...

Civil Engineering: REBARIN TECHNIQUES/ PROCESS USED IN CONSTRUCTION O...: REBARING Rebaring is a process of connecting old RCC structure with new RCC structure with the help of rebaring chemicals(Epoxy).It is a...

REBARIN TECHNIQUES/ PROCESS USED IN CONSTRUCTION OF NEW STRUCTURE WITH AN OLD STRUCTURE

REBARING
Rebaring is a process of connecting old RCC structure with new RCC structure with the help of rebaring chemicals(Epoxy).It is a new techniques used in construction industry to connect two structure or to elongate or extend structure with strong connection with old structure .You can see in image the steel bars are connected with the structure with the help of rebaring chemicals by doing this the steel bars create a strong connection or bonds with the structure and this steel bar can be now elongated or extend as required by the help of lapping and then we can construct new RCC structure which will be connected with old one.To be more clear we can take a example suppose we are constructing a framed structure building in which we use beams and columns and we started construction and we constructed foundation after that plinth beam after that column after that beam and slab after construction of these all things we also require RCC LINTEL BEAM in certain place now how can we place this RCC lintel beam between two prepared column for this construction of RCC LINTEL BEAM we can use rebaring process to construct RCC LINTEL BEAM.

LINTEL BEAM CASTING WITH THE HELP OF REBARING PROCESS

LINTEL BEAM  CONSTRUCTION BETWEEN TWO PREPARED COLUMN

The images of rebaring will make you clear about what actually is rebaring process and how it will be usefull in construction industries.If we talk about connection of old rcc structure with new one in traditional way we simply broke some part of structure to make connection of structure with other structure but this decreases the strength of structure so now we do rebaring for joining or extending the rcc structure.For this we only need one additional material i.e REBARING CHEMICAL or EPOXY.The process of doing rebaring are listed below step by step.

1. Drilling of holes:-The holes diameter should be 2mm greater then the dia of steel bar which will be used for rebaring.
2. Cleaning of drilled hole:-The drilled hole should be cleaned properly by blowing air in the drilled hole and also with the help of water jet to ensure no dust particles in hole.
3. Placing of rebaring chemical or epoxy (eg-HILTI HIT RE 500):-The hole should be filled 2/3 parts by rebaring chemical .
4. Placing of steel bar into hole:-The steel bar should be placed into hole the steel bar while placing into hole should be gently  rotated throughout  placing of steel bar.

EPOXY

SIGNATURE BRIDGE

SIGNATURE BRIDGE

   SIGNATURE BRIDGE

Signature bridge is located in the capital of India New Delhi which is now open for public from 5th November 2018. The Signature bridge is a cantilever spar(longitudinal beam) cable stayed bridge on Yamuna river at Wazirabad section,connecting Wazirabad to East Delhi.It is a India's first cable stayed bridge.The column(pylon) of Signature bridge is tallest structure in Delhi and is double the height of Qutub Minar.It will help in reducing the travel time between north and northeast Delhi.The total length of Signature bridge is 675 metres (2,215 ft.) .The width of Signature bridge is 35.2 metres (115 ft.).The height of signature bridge is 165 metres (541 ft.) .The longest span of bridge is 251 metres (823 ft.).The construction of the bridge was started on 2004 and is now open from 4 November, 2018 .Signature bridge also have the facilities to transport tourists on top of the main pillar (column), which is 154 m high, from where distance view of north Delhi can be seen.The contract was given to joint venture Gammon India and Tensa India for the construction of signature bridge .Signature bridge consist of 3 driving lane and one shoulder lane on each side.Signature bridge is considered as a good tourist place.Four lift is provided in the bridge which will carry the visitor to the top of the main pillar of the bridge from where visitor can see the distance view of north Delhi.Bridge will also have selfie spot from where visitors can captures the different memories, views etc.The signature bridge is inaugurated by Delhi chief minister Arvind kejriwal on 4th November.

SWAY ANALYSIS OF PORTAL FRAME BY MOMENT DISTRIBUTION METHOD||TOS||STRUCT...