42908: Engineering - Geo Polymer Concrete - Project Writing Assessment Answer

Engineering Assignment

Assignment Task

Topic for the project proposal is "strength studies on geo polymer concrete and it's application for sustainable construction

1 Executive Summary

Brief overview of project, main aim of project, potential findings and conclusions

2/ Introduction

Presents general project area, relevance of project, specific investigation of project and a brief outline of proposal to follow

3/ Literature Review

Critically reviews existing work, identifies relevant research areas and any opposing views. Links to the gap your project will fill

4/ Research Question/s, Aim & Sub-goals

Provides precise and measurable research question/s that the project aim will answer. States project aim and steps to meet aim. Presents tangible sub-goals

5/ Theoretical Content

Clear theoretical basis for work e.g. hypothesis, theoretical approach/es. Shows impact of theory on project steps

6/ Experimental Set-up

Discussion of lab and/or field set-up and potential limitations

7/ Results, Outcome and Relevance

Explanation of data, variables and parameters and type of results to be investigated. Makes projection of outcome and shows relevance of outcome

8/ Project Planning and Gantt Chart

Transforms sub-goals into a schedule of work using a Gantt Chart showing: the three key review points, milestones and deliverables

9/ Conclusions

Clear precise conclusions on proposed work. Makes supported statement on the longer-term impact of the work on the project area

10/ Referencing

Citations and References list correctly follow Harvard UTS referencing style, with consistent use between text and list

11/ Organisation

Logical organization, reasonable amount of information and flowing paragraphs

Overview

Geo polymer concretes are generally inorganic polymer composites. It is prospective type of concrete with the quality of sustainable construction and are perfect alternatives of the conventional concretes. The term ‘geo polymer’ first introduced in 1978 by Davidovits. In order to describe a family of mineral binders these are chemically same to zeolities and have amorphous structure. Different than ordinary Portland/ pozzolanic material they don’t form calcium silicates hydrates. And for matrix formation and strength, to attain structural strength they use the poly condensation of silica and alumina precursors.In this project we will do the strength studies of geo polymer concretes and its application in sustainable construction.

Aim of the project

Strength studies of Geo polymer concretes are the main aspect of this project, it includes study of its application in sustainable construction. And how use of geo polymer concrete is good for environment?

Results of this project

At the end of the project we will know the advantages of using geo polymer concrete in sustainable construction. Many researchers work is taken in this document to prove strength characteristics of geo polymer concrete. Various applications of GPC has been studied by various authors in order to find areas of application of geo polymer concrete in sustainable construction.

Introduction

Production of one ton OPC, utilizes a huge quantity of energy, with approximately emission of one ton CO2 as a by product, which is a major challenge for sustainable development. It is necessary to find an alternative binder. The output of the industrial waste can be used as replacement of cement materials (Fly ash, slags) and increases annual production too. By producing GPC many problems have been solved. As in GPC there’s no use of any OPC, production of cement will get decreases and atmosphere which gets polluted by the emission of CO2 will get reduced too. In this report, we briefly elaborate the costituents of geo polymer concrete, its strength & applications. Results shows that potential of geo polymer concrete to be a material of choice for the future is excellent.

State of the art/ Literature review

Madheswaran C.K et al.(2013) through the studies of the variation of strength for different grades of GPC by changing molarity of NaOH. Molarities of different type of NaOH (3M,5M,7M) were taken to prepare various mixes & then cured in the ambient temperature. Geo polymer concrete mix formulation with compressive strength in range of 15 to 52 MPa. The compressive strength of GPC specimens tested at age of 7&28 days. Compressive strength of GPC increases with increase in sodium hydroxide concentration.

Ganpathi naidu.p et al (2012) presented out a study on strength of geo polymer concrete after adding GGBS. Efforts are carried out to study the strength properties of GPC by using calcium fly ash of lower quality which is replaced with slag in five different percentages. The obtained compressive strength of GPC increases with increase in percentage of replacement of fly ash is 28.57% by GGBS, the normal setting and fast setting was observed. They observed 25 percent loss in compressive strength when geo polymer exposed to a temperature of 500 degree C for 2 hours.

Mahesh Patel et al. (2013) studied the strength of high performance concrete with GBBS and by replacing fine aggregates using crusher and cement by CGBS. It was concluded that the 20 % replacement of fine aggregates by crusher sand was optimum, based on compressive strength and split tensile strength.

Van jaarsveld et al. (2002) concluded that on reaching elevated temperature curing that for long periods of time weakens structure of hard material.

Mohemed aquib javed et al (2015) carried out studies to find out the optimum level of sustainable geo polymer concrete with combination of manufactured sand and pond ash as a fine aggregate material replacing conventional natural river sand and using ambient curing for its strength development. It was confirmed that 60 percent of mild sand and 40 percent of pond ash as a replacement to natural sand was optimum amount in order to get a favourable strength.

Yogendra O patil et al (2013) carried out an experimental study using GGBS as partial replacement of OPC in cement concrete experiment were made to study the compressive strength of concrete containing various percentage of GGBS at the age of 7,28 & 90 days. They concluded that increase in percentage of GGBS result in decrease in strength of concrete. The optimum replacement of OPC by GGBS was 20 percent.

• Research Question, Aim/ Objectives and Sub goals
• Research Question’s Answer

Application aspects of geo polymer concrete

GPC are made up of alkali activated alumina silicates. It is a new type of concrete which requires on site control effectively for use as an alternative of OPC concrete. There are drawbacks also; loss of workability, rapid setting time and to work with it without implementing safety precautions is dangerous. It can be used in making waste water pipe lines, railway traverse, hydraulic structures and pre tension concrete structures. Geo polymer concrete helps in reduction of energy consumption and helps in making environment fresh and clean.

Objectives/Aims

The main objective of this research is to find the suitability and performance of geo polymer concrete. And also to find out that it can be used as an alternative of OPC concrete for sustainable construction.

Sub Goals

Following are the factors which are responsible in affecting compressive strength of the geo polymer concrete-

1. Curing
2. Concentration of hydroxide ratio
3. Temperature
4. Steel fibre

These above parameters are thus directly to be finding out to achieve the criteria for strength of geo polymer concrete of desired strength.

THEORETICAL CONTENT/ METHODOLOGY

Compressive strength and workability of GPC are influenced by the properties of constituent materials and their proportion. High concentration of NaOH solution will results in high strength. And molar ratio of water and sodium hydroxide reduces the strength of GPC.

Split Tensile Test

PROCEDURE

1. After curing for 7 days specimen is taken out from the water
2. Specimen’s surface must be wiped from water.
3. On same axial place, lines are drawn on two ends of the specimen.
4. Specimen’s weight and dimension are noted.
5. Range of compression testing machine is set accurately.
6. Specimen is kept on the plywood strip which is kept at lower strip.
7. Specimen has to be aligned in such a way so that line marked on the end are vertical and centred above the bottom plate.
8. other plywood strip is kept over the specimen.
9. upper plate will be bring down in order to touch it with plywood strip.
10. load must be applied continuously without shock at the rate of 14-21 kg/cm2/minute
11. breaking load (P) must be noted finally.

Experimental Setup

To study the properties of geo polymer concrete using GGBS

In this test GGBS are used as the binder instead of cement in concrete. The GGBS react with the bases and form silicates of calcium which act as the binder to the coarse sand and coarse aggregate. The variation in the amount of NaOH and sodium silicate is done in concrete and their effect on compressive strength and tensile strength is noted down. The process of production of geo polymer concrete is carried out using the usual concrete technology methods in case of Ordinary Portland concrete in concrete laboratory of integral university, Lucknow.

Material used

1. GGBS- By quenching molten iron slag from a blast furnace in water or stea, ground granulated blast furnace slag are obtained which is a by product of iron and steel making. These are generally glassy, granular product which are dried and then grinded for assisting manufacturing of pig iron. Molten slag assist in forming granulated slag. It has pozzolanic property when it is processed properly, and it gets inert hydraulically if slowly air cooled and later can’t be used as pozzolanic material. Calcium silicate and alumina silicate are the main constituent of GGBS. It posses same chemical composition that of OPC but proportion of both is different.
2. Coarse sand- The most common constituent with which sand is made up of silica in the form of quartz, it is chemically inert & hard. Hence used as a coarse sand in concrete.
3. Coarse aggregate- These are used are crushed stone ranging from 10 mm to 20 mm. thus it is necessary to do sieve analysis. NaOH and sodium silicate are commercially available in market in pellets form.

Mixture proportion volume of concrete is given in tabular form for three cubes= .0101 cubic meter.

Casting of concrete- In the laboratory GGBS, coarse sand and coarse aggregates are mixed in a concrete mixer and dry mixing is done for 3 minutes and then NaOH and sodium silicate added to the mixture, the mixing is continued till homogenous slurry is formed. Then mixture is taken to a pan where slump is measured.

Observation and Results

Slump-

The results indicate that the value of slump will remain costant on varying the molarity of geo polymer concrete and hence collapse slump is formed.

Slump = 19.4 cm

Compressive strength-

The test of compressive strength is carried out according to ASTM C 39. Specimen which are cubical in shape are of size 150 * 150 * 150 in mm were prepared for each mix. After 24 hours specimens were taken out of the mould and cured in water is continued for 28 days until testing is carried out. For specimens with uneven surfaces, capping was used to minimize the effects of stress concentration. Value of strength is noted which the average of these three results is obtained from 3 identical cubes.

SPLIT TENSILE STRENGTH -

T = 2P/pi DL

Tensile strength of GPC with G.G.B.S . There is variation in tensile strength of GPC on varying the molarity of NaOH and sodium silicate solution. The variations in tensile strength are give in a tabular form.

SUMMARY

1. Content of bases increases and it also increases both tensile as well as compressive strength.
2. The setting time is very less so it is essential to add super plasticizer to delay the setting time.
3. The bases are very harmful they can cause blindness.

Project planning and Gantt chart

This project helps us to know about the geo polymer concrete characteristics and also its strength studies on various aspects. Project planning has to be done to perform various tests which are helpful in gaining the required aspects of the project.

In above gantt chart it is clearly shown that the project was started on 22 jan and completed on 10 sep. all the aspects from batching of materials to performing compressive and tensile strength etc are carried out in this project.

Conclusions

Based upon above literature review it could be the concluded that all researchers have put their efforts to show the effect of GGBS on geo polymer concrete. However it should be noted that with the variation in the parameters such as sodium silicate/sodium hydroxide Ratio, Molarity of sodium hydroxide, Curing time, curing temperature makes the variation in the strength. Replacing fly ash by GGBS increases the strength and without Oven Curing Provision. Scarcity of information on some aspects of geo polymerization has become apparent and the research community must concentrate on these gaps. Despite the current status and large acceptance of Portland cement, the properties of geo polymers, their environmental advantages and the strong academic and commercial R&D activity suggest that GPC technology is hindered in near future.

It is concluded that geo polymer concrete are the future for sustainable construction as these are responsible for omitting the pollution generated due to manufacturing of Portland cement for current type of construction, thus it is leading to create a green environment with an absolutely excellent alternative with matched strength and higher sustainability. Geo polymer concrete can be the future material for the sustainable construction.