Physio-chemical reactions in recycle aggregate concrete

Construction waste has been increasing due to fast development of construction industries. These wastes usually end up on landfill or to be left nearby construction site. This paper focuses on the potential use of recycled waste aggregate in a development of reinforced concrete rectangular container, RACC, as a solid waste storage. The filled container is intended to be used as a retaining structure at riverbanks to control erosion. The experimental programme include cube and cylindrical specimens tested to determine characteristic properties of recycle aggregate concrete (Pc, Pt, E). The characteristic properties obtained were used in designing the RACC to function as storage container and also as a retaining wall as referred to BS 8110 and BS 8007. Results showed that recycle aggregate concrete has relatively high compressive strength, tensile strength and modulus of elasticity. RACC size of 1.0 m x 1.0 m x 1.0 m with 150 mm thickness is found to be suitable and safe to be used both as container and retaining wall. This is proven by the maximum deflection and crack widths achieved which are lower than the allowable limit values.

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Effects of Steel Fibers (SF) and Ground Granulated Blast Furnace Slag (GBBS) on Recycle Aggregate Concrete

10.21203/rs.3.rs-835983/v1 ◽

2021 ◽

Author(s):

Jawad Ahmad ◽

Fahad Aslam

Keyword(s):

Blast Furnace ◽

Blast Furnace Slag ◽

Mechanical Performance ◽

Reinforce Concrete ◽

Recycle Aggregate ◽

Aggregate Concrete ◽

Recycle Aggregate Concrete ◽

Granulated Blast Furnace Slag ◽

Concrete Production ◽

Furnace Slag

Abstract Recycle aggregate is one of the good options to use in concrete as coarse aggregate which results environmental benefits as well as sustainable development. However, recycle aggregate cause reduction in concrete performance. One the other hand, the removal of industrial waste would be considerably decreased if it could be incorporated in cement concrete production. One of these possibilities is the substitution of the cement by slag, which enhance concrete poor properties of recycle aggregate concrete as well as provides to the decrease of cement consumption, reducing carbon dioxide productions, while resolving a waste management challenge. Furthermore, steel fiber was also added to hance the tensile capacity of recycle aggregate concrete. The main goal of this study is to investigate the characteristics of concrete using Ground granulated blast-furnace slag (GGBS) as binding material on recycle aggregate fibers reinforce concrete (RAFRC). Mechanical performance was assessed through compressive strength and split tensile strength, while durability aspects was study through water absorption, acid resistance and dry shrinkage. The results detected from the different experiments depict that replacement of Ground granulated blast-furnace slag (GGBS) enhance mechanical performance as well as durability aspects of the recycle aggregate fibers reinforce concrete (RAFRC).

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Effect of Silica Fume on Mechanical and Durability Properties of Recycled Coarse Aggregate Concrete

International Journal of Recent Technology and Engineering - 2 ◽

10.35940/ijrte.d1017.1284s291 ◽

2019 ◽

Vol 8 (4S2) ◽

pp. 68-72

Keyword(s):

Silica Fume ◽

Coarse Aggregate ◽

Mineral Admixture ◽

Mix Design ◽

Recycle Aggregate ◽

Aggregate Concrete ◽

Durability Properties ◽

Natural Aggregate ◽

Water Sorptivity ◽

Sorptivity Test

Reusing concrete is the best choice to diminish the eagerness on mind blowing standard assets and to oblige the total of waste which is engineered in landfills. Reused concrete has been regularly used as an unbound material as a touch of dams, bases, and sub-bases. RAC has in like way been utilized as a piece of the improvement of asphalts and wastes yet in less case as the examination in this field is not the most outrageous utmost of RAC has not yet been investigated. In this investigation the reused total was utilized as supplanting with 20%, 40%, 60% and 80% by substitution of typical aggregate. Standard Ordinary Portland cement was supplanted with 10% of mineral admixture silica fume. Tests were coordinated to choose the mechanical properties and durability properties such us rapid chloride penetrability test and water sorptivity test. The results show that increasing the recycle aggregate percentage above 40% with natural aggregate, small modifications to the mix design may be adopted to secure that comparable property to natural aggregate concrete is attained

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A Review of the Durability of Recycle Aggregate Concrete

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.744-746.1357 ◽

2015 ◽

Vol 744-746 ◽

pp. 1357-1360 ◽

Cited By ~ 1

Author(s):

Hong Bo Liu ◽

Jing Sun ◽

Xiao Hong Cong

Keyword(s):

Drying Shrinkage ◽

Present Situation ◽

Recycled Aggregate Concrete ◽

Recycled Aggregate ◽

Recycle Aggregate ◽

Freezing And Thawing ◽

Chloride Permeability ◽

Technical Problems ◽

Aggregate Concrete ◽

Related Literature

Analyzing the related literature at home and abroad, this paper summarized the results and shared them with reasearchers involved in the field on the recycled aggregate concrete (RAC). In this paper, the durability of RAC will be described from the following several aspects: absorption, chloride permeability, freezing and thawing resistance, carbonation, the sulfate corrosion resistance, drying shrinkage, creep and abrasion resistance. This paper expounded the present situation and progress in the study of the durability of recycled aggregate concrete.Then, some key technical problems needed to be studied were pointed out and many suggestions were put forward.

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Leaching Behaviour of Organic Materials in Reinforced Concrete Artificial Reef with RAC

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.708.76 ◽

2016 ◽

Vol 708 ◽

pp. 76-82

Author(s):

Noridah Mohamad ◽

Abdul Aziz Abdul Samad ◽

Afif Iman ◽

Hazel Monica ◽

Josef Hadipramana ◽

...

Keyword(s):

Compressive Strength ◽

Reinforced Concrete ◽

Water Sample ◽

Total Phosphorus ◽

Compression Strength ◽

Fish Habitat ◽

Artificial Reef ◽

Recycle Aggregate ◽

Aggregate Concrete ◽

Leaching Behaviour

This paper reports the leaching behaviour of pineapple skins incorporated in the artificial reef fabricated from recycle aggregate concrete. Pineapple skin was mixed with the concrete as added material which produce nutrients to attract fish habitat. Material test was conducted on the concrete reef specimens to determine its compressive strength. The nutrients dispersed were measured by using total phosphorus and nitrate test of the water sample collected from each of the artificial reef within the six days duration. Results showed the compression strength of the reef decreased with the increase of percentage pineapple skin used. However, it was found that the total phosphorus and nitrate leached from the reef increased gradually with time as the percentage of pineapple skin used increased.

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Surface reactions observed by photoemission electron microscopy (PEEM)

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100121831 ◽

1992 ◽

Vol 50 (1) ◽

pp. 286-287

Author(s):

H.H. Rotermund

Keyword(s):

Electron Microscopy ◽

Electron Microscope ◽

Work Function ◽

Chemical Reactions ◽

Reaction Diffusion ◽

Dynamic Processes ◽

Clean Surface ◽

Crystal Surfaces ◽

Single Crystal Surfaces ◽

Photoemission Electron

Chemical reactions at a surface will in most cases show a measurable influence on the work function of the clean surface. This change of the work function δφ can be used to image the local distributions of the investigated reaction,.if one of the reacting partners is adsorbed at the surface in form of islands of sufficient size (Δ>0.2μm). These can than be visualized via a photoemission electron microscope (PEEM). Changes of φ as low as 2 meV give already a change in the total intensity of a PEEM picture. To achieve reasonable contrast for an image several 10 meV of δφ are needed. Dynamic processes as surface diffusion of CO or O on single crystal surfaces as well as reaction / diffusion fronts have been observed in real time and space.

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Microwaves: Application in Electron Microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100158248 ◽

1990 ◽

Vol 48 (3) ◽

pp. 140-141

Author(s):

Anthony S-Y Leong ◽

David W Gove

Keyword(s):

Electron Microscopy ◽

Light Microscopy ◽

Chemical Reactions ◽

Electromagnetic Waves ◽

Tissue Fixation ◽

Primary Method ◽

Dipolar Molecules ◽

Wide Range ◽

Time Required ◽

Cryostat Sections

Microwaves (MW) are electromagnetic waves which are commonly generated at a frequency of 2.45 GHz. When dipolar molecules such as water, the polar side chains of proteins and other molecules with an uneven distribution of electrical charge are exposed to such non-ionizing radiation, they oscillate through 180° at a rate of 2,450 million cycles/s. This rapid kinetic movement results in accelerated chemical reactions and produces instantaneous heat. MWs have recently been applied to a wide range of procedures for light microscopy. MWs generated by domestic ovens have been used as a primary method of tissue fixation, it has been applied to the various stages of tissue processing as well as to a wide variety of staining procedures. This use of MWs has not only resulted in drastic reductions in the time required for tissue fixation, processing and staining, but have also produced better cytologic images in cryostat sections, and more importantly, have resulted in better preservation of cellular antigens.

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Fine structure and properties of defects in naturally occurring silicates and oxides

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100175430 ◽

1990 ◽

Vol 48 (4) ◽

pp. 460-461

Author(s):

David R. Veblen

Keyword(s):

Chemical Reactions ◽

High Resolution Electron Microscopy ◽

Extended Defects ◽

Single Chain ◽

Naturally Occurring ◽

Resolution Electron ◽

Fine Structures ◽

Image Simulations ◽

Similar Crystal Structure

Extended defects and interfaces control many processes in rock-forming minerals, from chemical reactions to rock deformation. In many cases, it is not the average structure of a defect or interface that is most important, but rather the structure of defect terminations or offsets in an interface. One of the major thrusts of high-resolution electron microscopy in the earth sciences has been to identify the role of defect fine structures in reactions and to determine the structures of such features. This paper will review studies using HREM and image simulations to determine the structures of defects in silicate and oxide minerals and present several examples of the role of defects in mineral chemical reactions. In some cases, the geological occurrence can be used to constrain the diffusional properties of defects.The simplest reactions in minerals involve exsolution (precipitation) of one mineral from another with a similar crystal structure, and pyroxenes (single-chain silicates) provide a good example. Although conventional TEM studies have led to a basic understanding of this sort of phase separation in pyroxenes via spinodal decomposition or nucleation and growth, HREM has provided a much more detailed appreciation of the processes involved.

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