FACULTY OF CIVIL ENGINEERING UNIVERSITI TEKNOLOGI MARA MALAYSIA
RESEARCH METHODOLOGY (ECW 501)
TITLE PROPOSAL:
Advancement of Concrete Durability and Strength by Added Super-Fine Mineral Dust GROUP ECB6L
Prepared by:
AHMAD NASRI BIN ABDUL RAHIM
Prepared for:
DR HARYATI AWANG
Date of Submission:
16
TH
DECEMBER 2011
2010641226
Advancement of Concrete Durability and Strength by Added Super-Fine Mineral Dust
1.0 Abstract
Concrete is a wide use material in construction, most of buildings in the world choose concrete as the main material in construction. It is because concrete has high compression strength and it easy to mould. Furthermore, concrete also easy to bond with steel, those have high tension strength. strength. In contrast, many of people did not know know that concrete also is the main production of carbon dioxide in the world, so to overcome this problem, The green concrete is used in construction, which is produce less carbon dioxide. Green concrete is a concrete which is concrete mix that added which some fine mineral dust in mixing process. Because this powder is small compare cement molecule it will make concrete more durable indirectly reduce the problem of bleeding and segregation. Other than that this powder also can produce extra hydrated S-C-H gel that can improve the bonding in concrete. Beside of that, the green concrete capable for sustainable development is characterized by application of industrial wastes to reduce consumption of natural resources and energy and pollution of the environment. Complex mineral superfine dust made by grinding the mix of calcined coal gangue and slag in certain proportion. Through reaction with the concrete admixture, this material improved pozzolanic reaction, micro-aggregate filling, and concrete durability. The concrete cement content was reduced by 40%-60%. The concrete resistance to sulphate attack and acid rain was enhanced greatly. Application of complex mineral superfine dust is an effective way to reduce environment pollution and improve durability of concrete under severe conditions.
1
2.0 Introduction
Ordinary
concrete is
a composite construction
material,
composed
of cement of cement
(Commonly Portland Cement), Cement), aggregate (generally a coarse aggregate made of gravel or crushed
rocks
such
as limestone,
or granite,
plus
a
fine
aggregate
such
as sand), sand), water and chemical admixtures. These types of concrete usually have a problem because it is lack of strength and durable. Other than that it also produces a lot of carbon dioxide to the atmosphere. So, to reduce this problem, cementitious material such as fly ash and slag cement is added into cement mix. This material is called Supplementary cementing materials (SCM). SCM can improve the durability of concrete because its size, which is small compare cement molecule, and its shape that is very sphere. In this proposal, I want propose the usage of the super-fine mineral dust in concrete mix. This material is a mix by grinding the calcined coal gangue with slag, fly ash and silica fume .Coal gangue is a rock included in the coal bed and a waste discharged during coal mining and transportation as well as the most industrial waste discharged. It is estimated that the amount of gangue calculated as 15% of the coal output, there would be 100 million ton increment annually. Most of the coal gangue is a clay rock, it is main mineral composition consists of clay mineral, followed by primary mineral quartz, feldspar, mica and pyrite, carbonate. After calcination under high temperature of 700-900°, the clay mineral is dewatered and disintegrated, the carbon 278 International Workshop on Sustainable Development and Concrete Technology component is removed with the deteriorative impurity burned out. The crystal cr ystal is disintegrated and transformed into amorphous non-crystal; this makes the coal gangue active. The activity depends on the phase composition of coal gangue and temperature of calcination as well. The calcined coal gangue is ground to a specific surface of more than 2
4500 cm /g and content of SiO2 and Al2O3 more than 80%. The active SiO 2 and Al2O3 in it can react with Ca(OH) 2 and produce C-S-H gel, calcium aluminate and calcium sulfoaluminate hydrates.
2
3.0 Objective
The objective of this research is to determine the increasing of workability and strength of concrete by adding mineral super fine dust. Other than that this research this research will determine determine the durability durability of concrete that added mineral mineral super fine dust. dust. The concrete must be tested in term of the impact, strength, and durable to ensure it meets the requirement of standard concrete.
4.0 Scope of work
This research will be limit to the determination of durability, workability and strength of concrete. This test will take Ordinary Portland Cement as the material for cement. Other than that the fine aggregate that is use is sand and the other material is course aggregate and water. These improve concrete will compared with ordinary concrete. This test also will cover most of environments in Malaysia.
5.0 Literature Review
Malhotra and Link (1999) examine the use of Ordinary Portland cement (OPC) in concrete has significant greenhouse gas implications, where the manufacture of each tonne of “ greenhouse gas OPC generates ap proximately 0.9 tonnes of carbon dioxide emissions. The “greenhouse signature” of concrete can be reduced by partial replacement of OPC with supplementary cementing materials (SCM). Typical supplementary cementing materials include fly ash, ground granulated blast furnace slag, and silica fume, ground limestone, natural pozzolans and metakaolin (A.M Neville, et al., 2006). Zhang and Malhotra, (1995) has been discovered that the by-product of oil sands operations, namely the clay from tailings ponds, can be processed into a material with similar properties to metakaolin for use in paper making, ceramics, concrete, and other industrial 3
applications. The oil sands operations will produce a quantities of tailings, which are stored in gigantic tailings ponds. Fine clay, which represents a significant part of these tailings, takes a long time to settle, and therefore makes it very difficult to recycle the process water. Extraction and processing of this clay is a promising means of turning the by product into a value-added product product and clarifying the process water for reuse r euse in the operations. According to Chen Gui-zhi Gui- zhi “Distribution of Acid: Chemical, Admixtire and Retarder and Pollutant.” (1993). Starting from existing scientific and technical information produced by the oil sands industry and the research community, this study investigates the validity and feasibility of the concept of reclaiming and processing the tailings into a product that can be used as an an SCM in concrete. In the study, study, the Concrete Project has has reviewed the existing research and technical studies, has commissioned an independent pre-feasibility study, and engaged the various stakeholders in the process and decision-making.
6.0 Research method
In this research, mix concrete will add with super fine mineral dust. Beside that ordinary concrete that is mix between ordinary Portland cement, water, sand and coarse aggregate is used to compare with improved concrete (concrete that added with super fine mineral dust). Concrete will be tested on strength, durability and workability. 6.1 Workability Test
6.1.1
Slump Test
This tested is conducted to calculate the slump value, and to know more about the workability, and fresh concrete. The slump test cone is placed on a smooth, level surface with the smaller opening at the top. It is filled in three layers of equal volume, each of, which is compacted 25 times with a standard rod having a hemispherical tip. The rod is then struck off, and the cone is slowly lifted and set beside the unsupported concrete.
4
The rod is laid across the cone and a measure of the distance from the bottom of the rod to the average top of the concrete is taken. A vary stiff mix will have near zero slump. Lean mixes tend to be harsh and slumps can vary from true to shear in different sample of the same mixes. The same slump can be recorded for concrete of different workability, depending on the aggregate used. The slump test is not a true determination of workability, but it is a useful for on-site checks of variations in material or mixing condition.
There will be three possibility results that is collapse, shear type of slump or true slump. According to European Standard EN 206-1:2000 five classes of slump is designated.
5
6.1.2
Compaction Test
This test is conducted to measure the compaction index of concrete. The compaction factor apparatus shall consist of two conical hoppers mounted above a cylinder. The sample of concrete is placed in the upper hopper up to the brim. Then the trap-door is opened so that the concrete falls into the lower hopper. After that the trap-door of the lower hopper is opened and the concrete is allowed to fall into the cylinder. The excess concrete remaining above the top level of the cylinder is then cut off with the help of plane blades. blades. The concrete in the cylinder is weighed. weighed. This is known as weight of partially compacted concrete. Finally, the cylinder is filled with a fresh sample of concrete and vibrated to obtain f ull compaction. The concrete in the cylinder is weighed again. This weight is known as the weight of fully compacted concrete.
6.2 Concrete Strength Test
6.2.1
Compressive Test
The compressive strength of concrete is the ability to resist a crushing force is, as previously explained, controlled by the water-cement ratio.
6
However, the theoretical compressive strength related to a particular watercement ratio will be attained only if the actual amount of water added is carefully regulated according to the considerations previously mentioned. Samples cast from the mix being used must be cured and tested to determine what compressive strength was actually attained.
Idelised Normal Distribution of Concrete Strength (Reference: Pillai, S.U., and a nd Menon, Reinforcement Concrete Design)
7.0 Expected result / outcome and analysis
The workability and strength of this improved concrete will increase due to the micro filling and dissolving effects of the super fine mineral dust other than that because the additional S-C-H bond by extended reaction of water, cement and super fine mineral dust the bond inside concrete will increase thus make the concrete more durable. The slump losses for the concrete mix with super fine mineral dust is less than that the other mix without addition. For the strength of concrete, it will show a slightly less strength of concrete at early age, in some degree but it will show the highest strength at 28 days strength, it also beneficial to the durability of the concrete.
7
8.0 Discussion
Super fine mineral dust or other name mineral material that a mix by grinding the calcined coal gangue with slag can improve the durability and strength of concrete because their particle of size is very small, by this wall its particle can fill the air and water void inside concrete. Beside of that, it also can reduce the problem of segregation and bleeding of concrete by reduces the usage of water. In the same time the hydration process also will decrease indirectly reduce the problem like latain in upper layer of concrete. Other than that this type of concrete also good for environment, for example concrete is the fully calcined coal gangue ground in mix with slag and fly ash can serve as additives for high performance concrete. Meanwhile, Piling up of coal gangue in large amount seriously will cause the pollution of environment and there is latent danger of self-combustion. However, the utilization of coal gangue fell behind that of other industrial wastes such as fly ash, and slag. Beside of that, the coal gangue can be used for concrete provided that the proper mix proportion is chosen and high quality admixture is used t o improve the properties of concrete, even the high performance concrete can be prepared with the characteristics of green concrete.
8
9.0 Reference
Chen Jian-xiong “Investigation on Durability of Buildings under Severe Acid Rain.” Concrete, 2001 (11).
State Bureau of Environment Protection. Building Materials on Industrial Wastes. Environmental Science Press, 1992.
Gollapudi, U.K., Knutson, C.L., Bang, S.S., and Islam, M.R., “A New method for Controlling Leaching through Permeable Channels”, Chemosphere, v. 30, No. 4, 1995.
A.M. Neville, “Properties of Concrete”, Pearson Education Limited (2006)
Mehta, P.K. and Gjorv O. E., 1982, ‘ Properties of Portland Cement Concrete Co ncrete containing Fly ash and Condensed Silica Fume’, Cement and concrete Re Research search Journal.
Fournier, B. Program Manager, Concrete Technology Program, “Presentation of Zhang and Malhotra, 1995 Results”, October 16, 2001.
9
