Search results for: Libyan cement industry
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 5876

Search results for: Libyan cement industry

5576 Developing Sustainable Rammed Earth Material Using Pulp Mill Fly Ash as Cement Replacement

Authors: Amin Ajabi, Chinchu Cherian, Sumi Siddiqua

Abstract:

Rammed earth (RE) is a traditional soil-based building material made by compressing a mixture of natural earth and binder ingredients such as chalk or lime, in temporary formworks. However, the modern RE uses 5 to 10% cement as a binder in order to meet the strength and durability requirements as per the standard specifications and guidelines. RE construction is considered to be an energy-efficient and environmental-friendly approach when compared to conventional concrete systems, which use 20 to 30% cement. The present study aimed to develop RE mix designs by utilizing non-hazardous wood-based fly ash generated by pulp and paper mills as a partial replacement for cement. The pulp mill fly ash (PPFA)-stabilized RE is considered to be a sustainable approach keeping in view of the massive carbon footprints associated with cement production as well as the adverse environmental impacts due to disposal of PPFA in landfills. For the experimental study, as-received PPFA, as well as PPFA-based geopolymer (synthesized by alkaline activation method), were incorporated as cement substitutes in the RE mixtures. Initially, local soil was collected and characterized by index and engineering properties. The PPFA was procured from a pulp manufacturing mill, and its physicochemical, mineralogical and morphological characterization, as well as environmental impact assessment, was conducted. Further, the various mix designs of RE material incorporating local soil and different proportions of cement, PPFA, and alkaline activator (a mixture of sodium silicate and sodium hydroxide solutions) were developed. The compacted RE specimens were cured and tested for 7-day and 28-day unconfined compressive strength (UCS) variations. Based on UCS results, the optimum mix design was identified corresponding to maximum strength improvement. Further, the cured RE specimens were subjected to freeze-thaw cycle testing for evaluating its performance and durability as a sustainable construction technique under extreme climatic conditions.

Keywords: sustainability, rammed earth, stabilization, pulp mill fly ash, geopolymer, alkaline activation, strength, durability

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5575 Investigation Particle Behavior in Gas-Solid Filtration with Electrostatic Discharge in a Hybrid System

Authors: Flávia M. Oliveira, Marcos V. Rodrigues, Mônica L. Aguiar

Abstract:

Synthetic fibers are widely used in gas filtration. Previous attempts to optimize the filtration process have employed mixed fibers as the filter medium in gas-solid separation. Some of the materials most frequently used this purpose are composed of polyester, polypropylene, and glass fibers. In order to improve the retention of cement particles in bag filters, the present study investigates the use of synthetic glass fiber filters and polypropylene fiber for particle filtration, with electrostatic discharge of 0 to -2 kV in cement particles. The filtration curves obtained showed that charging increased the particle collection efficiency and lowered the pressure drop. Particle diameter had a direct influence on the formation of the dust cake, and the application of electrostatic discharge to the particles resulted in the retention of more particles, hence increasing the lifetime of fabric filters.

Keywords: glass fiber filter, particle, electrostatic discharge, cement

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5574 Studies on the Mechanical Behavior of Bottom Ash for a Sustainable Environment

Authors: B. A. Mir, Asim Malik

Abstract:

Bottom ash is a by-product of the combustion process of coal in furnaces in the production of electricity in thermal power plants. In India, about 75% of total power is produced by using pulverized coal. The coal of India has a high ash content which leads to the generation of a huge quantity of bottom ash per year posing the dual problem of environmental pollution and difficulty in disposal. This calls for establishing strategies to use this industry by-product effectively and efficiently. However, its large-scale utilization is possible only in geotechnical applications, either alone or with soil. In the present investigation, bottom ash was collected from National Capital Power Station Dadri, Uttar Pradesh, India. Test samples of bottom ash admixed with 20% clayey soil were prepared and treated with different cement content by weight and subjected to various laboratory tests for assessing its suitability as an engineered construction material. This study has shown that use of 10% cement content is a viable chemical additive to enhance the mechanical properties of bottom ash, which can be used effectively as an engineered construction material in various geotechnical applications. More importantly, it offers an interesting potential for making use of an industrial waste to overcome challenges posed by bottom ash for a sustainable environment.

Keywords: bottom ash, environmental pollution, solid waste, sustainable environment, waste utilization

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5573 Mineral Slag Used as an Alternative of Cement in Concrete

Authors: Eskinder Desta Shumuye, Jun Zhao, Zike Wang

Abstract:

This paper summarizes the results of experimental studies carried out at Zhengzhou University, School of Mechanics and Engineering Science, research laboratory, on the performance of concrete produced by combining Ordinary Portland Cement (OPC) with Ground-Granulated Blast Furnace Slag (GGBS). Concrete specimens cast with OPC and various percentage of GGBS (0%, 30%, 50%, and 70%) were subjected to high temperature exposure and extensive experimental test reproducing basic freeze-thaw cycle and a chloride-ion attack to determine their combined effects within the concrete samples. From the experimental studies, comparisons were made on the physical, mechanical, and microstructural properties in compassion with ordinary Portland cement concrete (OPC). Further, durability of GGBS cement concrete, such as exposure to accelerated carbonation, chloride ion attack, and freeze-thaw action in compassion with various percentage of GGBS and ordinary Portland cement concrete of similar mixture composition was analyzed. The microstructure, mineralogical composition, and pore size distribution of concrete specimens were determined via Scanning Electron Microscopy (SEM) analysis and X-Ray Diffraction (XRD). The result demonstrated that when the exposure temperature increases from 200 ºC to 400 ºC, the residual compressive strength was fluctuating for all concrete group, and compressive strength and chloride ion exposure of the concrete decreased with the increasing of slag content. The SEM and EDS results showed an increase in carbonation rate with increasing in slag content.

Keywords: accelerated carbonation, chloride-ion, concrete, ground-granulated blast furnace slag, GGBS, high-temperature

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5572 Thermodynamic Cycle Using Cyclopentane for Waste Heat Recovery Power Generation from Clinker Cooler Exhaust Flue Gas

Authors: Vijayakumar Kunche

Abstract:

Waste heat recovery from Pre Heater exhaust gases and Clinker cooler vent gases is now common place in Cement Industry. Most common practice is to use Steam Rankine cycle for heat to power conversion. In this process, waste heat from the flue gas is recovered through a Heat Recovery steam generator where steam is generated and fed to a conventional Steam turbine generator. However steam Rankine cycle tends to have lesser efficiency for smaller power plants with less than 5MW capacity and where the steam temperature at the inlet of the turbine is less than 350 deg C. further a steam Rankine cycle needs treated water and maintenance intensive. These problems can be overcome by using Thermodynamic cycle using Cyclopentane vapour in place of steam. This innovative cycle is best suited for Heat recovery in cement plants and results in best possible heat to power conversion efficiency. This paper discusses about Heat Recovery Power generation using innovative thermal cycle which uses Cyclopentane vapour in place of water- steam. And how this technology has been adopted for a Clinker cooler hot gas from mid-tap.

Keywords: clinker cooler, energy efficiency, organic rankine cycle, waste heat recovery

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5571 Key Parameters for Controlling Swell of Expansive Soil-Hydraulic Cement Admixture

Authors: Aung Phyo Kyaw, Kuo Chieh Chao

Abstract:

Expansive soils are more complicated than normal soils, although the soil itself is not very complicated. When evaluating foundation performance on expansive soil, it is important to consider soil expansion. The primary focus of this study is on hydraulic cement and expansive soil mixtures, and the research aims to identify key parameters for controlling the swell of the expansive soil-hydraulic cement mixture. Treatment depths can be determined using hydraulic cement ratios of 4%, 8%, 12%, and 15% for treating expansive soil. To understand the effect of hydraulic cement percentages on the swelling of expansive soil-hydraulic admixture, performing the consolidation-swell test σ''ᶜˢ is crucial. This investigation primarily focuses on consolidation-swell tests σ''ᶜˢ, although the heave index Cₕ is also needed to determine total heave. The heave index can be measured using the percent swell in the specific inundation stress in both the consolidation-swell test and the constant-volume test swelling pressure. Obtaining the relationship between swelling pressure and σ''ᶜⱽ determined from the "constant volume test" is useful in predicting heave from a single oedometer test. The relationship between σ''ᶜˢ and σ''ᶜⱽ is based on experimental results of expansive soil behavior and facilitates heave prediction for each soil. In this method, the soil property "m" is used as a parameter, and common soil property tests include compaction, particle size distribution, and the Atterberg limit. The Electricity Generating Authority of Thailand (EGAT) provided the soil sample for this study, and all laboratory testing is performed according to American Society for Testing and Materials (ASTM) standards.

Keywords: expansive soil, swelling pressure, total heave, treatment depth

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5570 Phase Behavior Modelling of Libyan Near-Critical Gas-Condensate Field

Authors: M. Khazam, M. Altawil, A. Eljabri

Abstract:

Fluid properties in states near a vapor-liquid critical region are the most difficult to measure and to predict with EoS models. The principal model difficulty is that near-critical property variations do not follow the same mathematics as at conditions far away from the critical region. Libyan NC98 field in Sirte basin is a typical example of near critical fluid characterized by high initial condensate gas ratio (CGR) greater than 160 bbl/MMscf and maximum liquid drop-out of 25%. The objective of this paper is to model NC98 phase behavior with the proper selection of EoS parameters and also to model reservoir depletion versus gas cycling option using measured PVT data and EoS Models. The outcomes of our study revealed that, for accurate gas and condensate recovery forecast during depletion, the most important PVT data to match are the gas phase Z-factor and C7+ fraction as functions of pressure. Reasonable match, within -3% error, was achieved for ultimate condensate recovery at abandonment pressure of 1500 psia. The smooth transition from gas-condensate to volatile oil was fairly simulated by the tuned PR-EoS. The predicted GOC was approximately at 14,380 ftss. The optimum gas cycling scheme, in order to maximize condensate recovery, should not be performed at pressures less than 5700 psia. The contribution of condensate vaporization for such field is marginal, within 8% to 14%, compared to gas-gas miscible displacement. Therefore, it is always recommended, if gas recycle scheme to be considered for this field, to start it at the early stage of field development.

Keywords: EoS models, gas-condensate, gas cycling, near critical fluid

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5569 The Mechanical Behavior of a Cement-Fiber Composite Material

Authors: K. Harrat, M. Hidjeb, M. T’kint

Abstract:

The aim of the present research work is to characterize a cement palm date fiber composite in order to be used in isolation and in the manufacture of new structural materials. This technique may possibly participate seriously in the preservation of the environment and develop a growing need for plant products. On one hand, It has been shown that the presence of natural fiber in the composite materials manufacture, based on hydraulic binder, has improved the mechanical behaviour of the material. On the Other hand, It has been proven that the durability of composite materials reinforced with untreated fibers was largely affected by the presence of organic matter. In order to extract the organic material, the fibers were treated with boiling water and then coated with different types of products. A considerable improvement in the sensitivity to water of the fibers, as well as in the mechanical strength and in the ductility of the composite material was observed. The fiber being sensitive to water, the study put the emphasis on its dimensional stability.

Keywords: cement composite, durability, heat treatment, mechanical behaviour, vegetal fiber

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5568 Drying Shrinkage of Magnesium Silicate Hydrate Gel Cements

Authors: T. Zhang, X. Liang, M. Lorin, C. Cheeseman, L. J. Vandeperre

Abstract:

Cracks were observed when the magnesium silicate hydrate gel cement (prepared by 40% MgO/ 60% silica fume) was dried. This drying cracking is believed to be caused when unbound water evaporates from the binder. The shrinkage upon forced drying to 200 °C of mortars made up from a reactive magnesium oxide, silica fume and sand was measured using dilatometry. The magnitude of the drying shrinkage was found to decrease when more sand or less water was added to the mortars and can be as low as 0.16% for a mortar containing 60 wt% sand and a water to cement ratio of 0.5, which is of a similar order of magnitude as observed in Portland cement based mortars and concretes. A simple geometrical interpretation based on packing of the particles in the mortar can explain the observed drying shrinkages and based on this analysis the drying shrinkage of the hydration products at zero added solid is estimated to be 7.3% after 7 days of curing.

Keywords: magnesium silicate hydrate, shrinkage, dilatometry, gel cements

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5567 Supply Chain Management Practices in Thailand Palm Oil Industry

Authors: Athirat Intajorn

Abstract:

According to the ASEAN free trade areas (AFTA), Thailand has applied the AFTA agreement for reducing tariffs and reflecting changes in business processes. The reflection of changes in agribusiness processes, in particular, has accumulated as production costs for producers. Palm Oil industry has become an important industry to Thailand economic. Thailand currently ranks the 3rd in the world for Crude Palm Oil CPO. Therefore, the scope of this paper presents a research framework to investigate the supply chain management practices in Thailand palm oil industry. This research is limit to literature review. And the proposed framework identifies the criteria of supply chain management for Thailand palm oil industry in order for linkage among entities within logistics management involving plantation, mill, collection port, refinery and cookie from the data utilization. The Supply Chain Management Practices in Thailand Palm Oil Industry framework has a somewhat different view due to the high complexity of agribusiness logistics management.

Keywords: supply chain management, practice, palm oil industry, Thailand palm oil industry

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5566 Wave Velocity-Rock Property Relationships in Shallow Marine Libyan Carbonate Reservoir

Authors: Tarek S. Duzan, Abdulaziz F. Ettir

Abstract:

Wave velocities, Core and Log petrophysical data were collected from recently drilled four new wells scattered through-out the Dahra/Jofra (PL-5) Reservoir. The collected data were analyzed for the relationships of Wave Velocities with rock property such as Porosity, permeability and Bulk Density. Lots of Literature review reveals a number of differing results and conclusions regarding wave velocities (Compressional Waves (Vp) and Shear Waves (Vs)) versus rock petrophysical property relationships, especially in carbonate reservoirs. In this paper, we focused on the relationships between wave velocities (Vp , Vs) and the ratio Vp/Vs with rock properties for shallow marine libyan carbonate reservoir (Real Case). Upon data analysis, a relationship between petrophysical properties and wave velocities (Vp, Vs) and the ratio Vp/Vs has been found. Porosity and bulk density properties have shown exponential relationship with wave velocities, while permeability has shown a power relationship in the interested zone. It is also clear that wave velocities (Vp , Vs) seems to be a good indicator for the lithology change with true vertical depth. Therefore, it is highly recommended to use the output relationships to predict porosity, bulk density and permeability of the similar reservoir type utilizing the most recent seismic data.

Keywords: conventional core analysis (porosity, permeability bulk density) data, VS wave and P-wave velocities, shallow carbonate reservoir in D/J field

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5565 Marble Powder’s Effect on Permeability and Mechanical Properties of Concrete

Authors: Shams Ul Khaliq, Khan Shahzada, Bashir Alam, Fawad Bilal, Mushtaq Zeb, Faizan Akbar

Abstract:

Marble industry contributes its fair share in environmental deterioration, producing voluminous amounts of mud and other excess residues obtained from marble and granite processing, polluting soil, water and air. Reusing these products in other products will not just prevent our environment from polluting but also help with economy. In this research, an attempt has been made to study the expediency of waste Marble Powder (MP) in concrete production. Various laboratory tests were performed to investigate permeability, physical and mechanical properties, such as slump, compressive strength, split tensile test, etc. Concrete test samples were fabricated with varying MP content (replacing 5-30% cement), furnished from two different sources. 5% replacement of marble dust caused 6% and 12% decrease in compressive and tensile strength respectively. These parameters gradually decreased with increasing MP content up to 30%. Most optimum results were obtained with 10% replacement. Improvement in consistency and permeability were noticed. The permeability was improved with increasing MP proportion up to 10% without substantial decrease in compressive strength. Obtained results revealed that MP as an alternative to cement in concrete production is a viable option considering its economic and environment friendly implications.

Keywords: marble powder, strength, permeability, consistency, environment

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5564 Effect of Primer on Bonding between Resin Cement and Zirconia Ceramic

Authors: Deog-Gyu Seo, Jin-Soo Ahn

Abstract:

Objectives: Recently, the development of adhesive primers on stable bonding between zirconia and resin cement has been on the increase. The bond strength of zirconia-resin cement can be effectively increased with the treatment of primer composed of the adhesive monomer that can chemically bond with the oxide layer, which forms on the surface of zirconia. 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP) that contains phosphate ester and acidic monomer 4-methacryloxyethyl trimellitic anhydride(4-META) have been suggested as monomers that can form chemical bond with the surface oxide layer of zirconia. Also, these suggested monomers have proved to be effective zirconia surface treatment for bonding to resin cement. The purpose of this study is to evaluate the effects of primer treatment on the bond strength of Zirconia-resin cement by using three different kinds of primers on the market. Methods: Zirconia blocks were prepared into 60 disk-shaped specimens by using a diamond saw. Specimens were divided into four different groups: first three groups were treated with zirconiaLiner(Sun Medical Co., Ltd., Furutaka-cho, Moriyama, Shiga, Japan), Alloy primer (Kuraray Noritake Dental Inc., Sakaju, Kurashiki, Okayama, Japan), and Universal primer (Tokuyama dental Corp., Taitou, Taitou-ku, Tokyo, Japan) respectively. The last group was the control with no surface treatment. Dual cured resin cement (Biscem, Bisco Inc., Schaumburg, IL, USA) was luted to each group of specimens. And then, shear bond strengths were measured by universal tesing machine. The significance of the result was statistically analyzed by one-way ANOVA and Tukey test. The failure sites in each group were inspected under a magnifier. Results: Mean shear bond strength were 0.60, 1.39, 1.03, 1.38 MPa for control, Zirconia Liner (ZL), Alloy primer (AP), Universal primer (UP), respectively. Groups with application of each of the three primers showed significantly higher shear bond strength compared to the control group (p < 0.05). Among the three groups with the treatment, ZL and UP showed significantly higher shear bond strength than AP (p < 0.05), and there were no significant differences in mean shear bond strength between ZL and UP (p < 0.05). While the most specimens of control groups showed adhesive failure (80%), the most specimens of three primer-treated groups showed cohesive or mixed failure (80%).

Keywords: primer, resin cement, shear bond strength, zirconia

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5563 Evaluation of Eco Cement as a Stabilizer of Clayey Sand

Authors: Jeeja Menon, M. S. Ravikumar

Abstract:

With the advent of green technology and the concept of zero energy buildings, there is an emerging trend in the utilization of indigenous materials like soil as a construction material. However, fine soils like clays and sand have undesirable properties and stabilization of these soils is essential before it is used to develop a building unit. Eco cement or Ground Granulated Blast Furnace Slag (GGBS), a waste byproduct formed during the manufacture of iron has cementitious properties and has the potential of replacing cement which is the most common stabilizer used for improving the geotechnical properties of soil. This paper highlights the salient observations obtained by the investigations into the effect of GGBS as a stabilizer for clayey sand. The index and engineering properties of the soil on the addition of different percentages (0%, 2%, 4%, 5% & 6% of the dry weight of the soil) of GGBS are tested to arrive at the optimum binder content. The criteria chosen for evaluation are the unconfined compressive strength values of different soil- binder composition. The test results indicate that there are significant strength improvements by the addition of GGBS in the soil, and the optimum GGBS content was determined as 5%. Moreover, utilizing waste binders for developing an ecofriendly, less energy induced building units as well as for stabilizing soil will also contribute to the solid waste management, which is the current environmental crisis of the world.

Keywords: eco cement, GGBS, index properties, stabilization, unconfined compressive strength

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5562 Mechanical Properties of Waste Clay Brick Based Geopolymer Cured at Various Temperature

Authors: Shihab Ibrahim

Abstract:

Geopolymer binders as an alternative binder system to ordinary Portland cement are the focus of the past 2 decades of researches. In order to eliminate CO2 emission by cement manufacturing and utilizing construction waste as a source material, clean waste clay bricks which are the waste from Levent Brick factory was activated with a mixture of sodium hydroxide and sodium silicate solution. 12 molarity of sodium hydroxide solution was used and the ratio of sodium silicate to sodium hydroxide was 2.5. Alkaline solution to clay brick powder ratio of 0.35, 0.4, 0.45, and 0.5 was studied. Alkaline solution to powder ratio of 0.4 was found to be optimum ratio to have the same workability as ordinary Portland cement paste. Compressive strength of the clay brick based geopolymer paste samples was evaluated under different curing temperatures and curing durations. One day compressive strength of 57.3 MPa after curing at 85C for 24 hours was obtained which was higher than 7 days compressive strength of ordinary Portland cement paste. The highest compressive strength 71.4 MPa was achieved at seventh day age for the geopolymer paste samples cured at 85C for 24 hours. It was found that 8 hour curing at elevated temperature 85C, is sufficient to get 96% of total strength. 37.4 MPa strength at seventh day of clay brick based geopolymer sample cured at room temperature was achieved. Water absorption around 10% was found for clay brick based geopolymer samples cured at different temperatures with compare to 9.14% water absorption of ordinary Portland cement paste. The clay brick based geopolymer binder can have the potentiality to be used as an alternative binder to Portland cement in a case that the heat treatment provided. Further studies are needed in order to produce the binder in a way that can harden and gain strength without any elevated curing.

Keywords: construction and demolition waste, geopolymer, clay brick, compressive strength.

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5561 Recycling of End of Life Concrete Based on C2CA Method

Authors: Somayeh Lotfi, Manuel Eggimann, Eckhard Wagner, Radosław Mróz, Jan Deja

Abstract:

One of the main environmental challenges in the construction industry is a strong social force to decrease the bulk transport of the building materials in urban environments. Considering this fact, applying more in-situ recycling technologies for Construction and Demolition Waste (CDW) is an urgent need. The European C2CA project develops a novel concrete recycling technology that can be performed purely mechanically and in situ. The technology consists of a combination of smart demolition, gentle grinding of the crushed concrete in an autogenous mill, and a novel dry classification technology called ADR to remove the fines. The feasibility of this recycling process was examined in demonstration projects involving in total 20,000 tons of End of Life (EOL) concrete from two office towers in Groningen, The Netherlands. This paper concentrates on the second demonstration project of C2CA, where EOL concrete was recycled on an industrial site. After recycling, the properties of the produced Recycled Aggregate (RA) were investigated, and results are presented. An experimental study was carried out on mechanical and durability properties of produced Recycled Aggregate Concrete (RAC) compared to those of the Natural Aggregate Concrete (NAC). The aim was to understand the importance of RA substitution, w/c ratio and type of cement to the properties of RAC. In this regard, two series of reference concrete with strength classes of C25/30 and C45/55 were produced using natural coarse aggregates (rounded and crushed) and natural sand. The RAC series were created by replacing parts of the natural aggregate, resulting in series of concrete with 0%, 20%, 50% and 100% of RA. Results show that the concrete mix design and type of cement have a decisive effect on the properties of RAC. On the other hand, the substitution of RA even at a high percentage replacement level has a minor and manageable impact on the performance of RAC. This result is a good indication towards the feasibility of using RA in structural concrete by modifying the mix design and using a proper type of cement.

Keywords: C2CA, ADR, concrete recycling, recycled aggregate, durability

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5560 Polyolefin Fiber Reinforced Self-Compacting Concrete Replacing 20% Cement by Fly Ash

Authors: Suman Kumar Adhikary, Zymantus Rudzionis, Arvind Balakrishnan

Abstract:

This paper deals with the behavior of concrete’s workability in a fresh state and compressive and flexural strength in a hardened state with the addition of polyolefin macro fibers. Four different amounts (3kg/m3, 4.5kg/m3, 6kg/m3 and 9kg/m3) of polyolefin macro fibers mixed in concrete mixture to observe the workability and strength properties difference between the concrete specimens. 20% class C type fly ash added is the concrete as replacement of cement. The water-cement ratio(W/C) of those concrete mix was 0.35. Masterglenium SKY 700 superplasticizer was added to the concrete mixture for better results. Slump test was carried out for determining the flowability. On 7th, 14th and 28th day of curing process compression strength tests were done and on 28th day flexural strength test and CMOD test were carried to differentiate the strength properties and post-cracking behavior of concrete samples.

Keywords: self-compacting concrete, polyolefin fibers, fiber reinforced concrete, CMOD test of concrete

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5559 Durability of a Cementitious Matrix Based on Treated Sediments

Authors: Mahfoud Benzerzour, Mouhamadou Amar, Amine Safhi, Nor-Edine Abriak

Abstract:

Significant volumes of sediment are annually dredged in France and all over the world. These materials may, in fact, be used beneficially as supplementary cementitious material. This paper studies the durability of a new cement matrix based on marine dredged sediment of Dunkirk-Harbor (north of France). Several techniques are used to characterize the raw sediment such as physical properties, chemical analyses, and mineralogy. The XRD analysis revealed quartz, calcite, kaolinite as main mineral phases. In order to eliminate organic matter and activate some of those minerals, the sediment is calcined at a temperature of 850°C for 1h. Moreover, four blended mortars were formulated by mixing a portland cement (CEM I 52,5 N) and the calcined sediment as partial cement substitute (0%, 10%, 20% and 30%). Reference mortars, based on the blended cement, were then prepared. This re-use cannot be substantiating and efficient without a durability study. In this purpose, the following tests, mercury porosity, accessible water porosity, chloride permeability, freezing and thawing, external sulfate attack, alkali aggregates reaction, compressive and bending strength tests were conducted on those mortars. The results of most of those tests evidenced the fact that the mortar that contains 10% of the treated sediment is efficient and durable as the reference mortar itself. That would infer that the presence of these calcined sediment improves mortar general behavior.

Keywords: sediment, characterization, calcination, substitution, durability

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5558 A Review on New Additives in Deep Soil Mixing Method

Authors: Meysam Mousakhani, Reza Ziaie Moayed

Abstract:

Considering the population growth and the needs of society, the improvement of problematic soils and the study of the application of different improvement methods have been considered. One of these methods is deep soil mixing, which has been developed in the past decade, especially in soft soils due to economic efficiency, simple implementation, and other benefits. The use of cement is criticized for its cost and the damaging environmental effects, so these factors lead us to use other additives along with cement in the deep soil mixing. Additives that are used today include fly ash, blast-furnace slag, glass powder, and potassium hydroxide. The present study provides a literature review on the application of different additives in deep soil mixing so that the best additives can be introduced from strength, economic, environmental and other perspectives. The results show that by replacing fly ash and slag with about 40 to 50% of cement, not only economic and environmental benefits but also a long-term strength comparable to cement would be achieved. The use of glass powder, especially in 3% mixing, results in desirable strength. In addition to the other benefits of these additives, potassium hydroxide can also be transported over longer distances, leading to wider soil improvement. Finally, this paper suggests further studies in terms of using other additives such as nanomaterials and zeolite, with different ratios, in different conditions and soils (silty sand, clayey sand, carbonate sand, sandy clay and etc.) in the deep mixing method.

Keywords: deep soil mix, soil stabilization, fly ash, ground improvement

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5557 Proposal for a Model of Economic Integration for the Development of Industry in Cabinda, Angola

Authors: T. H. Bitebe, T. M. Lima, F. Charrua-Santos, C. J. Matias Oliveira

Abstract:

This study aims to present a proposal for an economic integration model for the development of the manufacturing industry in Cabinda, Angola. It seeks to analyze the degree of economic integration of Cabinda and the dynamics of the manufacturing industry. Therefore, in the same way, to gather information to support the decision-making for public financing programs that will aim at the disengagement of the manufacturing industry in Angola and Cabinda in particular. The Cabinda Province is the 18th of Angola, the enclave is located in a privileged area of the African and arable land.

Keywords: economic integration, industrial development, Cabinda industry, Angola

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5556 Tourism Industry in Pakistan: Challenges Faced and Future Prospects

Authors: Misbah Shaheen, Anam Qureshi

Abstract:

In this work we will discuss the challenges faced by tourism industry in Pakistan. Tourism plays vital role in the socio-economic growth of a country. The countries of world, with less tourism opportunities are lagging behind from other nations of the world. Pakistan is one of those countries which rich in historical places, natural beauty, and uniqueness in handmade items and also of green forests. Present study will discuss the challenges being faced by tourism industry with special focus on hotel industry and law and order situation.

Keywords: Pakistan, tourism, handmade items, hotel industry

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5555 Usage of Palm Oil Industrial Wastes as Construction Materials

Authors: Mohammad Momeenul Islam, U. Johnson Alengaram, Mohd Zamin Jumaat, Iftekhair Ibnul Bashar

Abstract:

Palm oil industry produces millions of tonnes of industrial wastes and these wastes create huge storage and environmental problems. In order to solve these problems various research works have been performed for past decades. The commonly available wastes are Oil palm shells (OPS) and Palm oil fuel ash (POFA). These materials have already acquired well recognition as alternate of conventional construction materials. OPS has been used as coarse aggregate and compressive strength was found up to 56 MPa for 56-day. It is said that 30 grade Oil Palm shell concrete (OPSC) is possible without adding any cementitious materials. The maximum modulus of elasticity for OPSC was found 18.6 GPa. The Oil palm shell concrete (OPSC) are used in country areas and nearby areas where the palm oil factories are located for houses, road-kerbs, drain blocks, etc. In case of superstructure like beams and slab are also produced by utilizing OPS. Many experimental works have been performed to establish POFA as a substituting binding material in replace of Ordinary Portland cement (OPC). Throughout the research it has been showed that up to 20% of cement by mass can be replaced by POFA. POFA is one of the most enriched pozzolanic materials. The main purpose of this review is to discuss the usage and opportunity of the palm oil industrial wastes as construction materials following the previous experimental research work.

Keywords: construction materials, oil palm shells (OPS), palm oil fuel ash (POFA), aggregates

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5554 Prospective Use of Rice Husk Ash to Produce Concrete in India

Authors: Kalyan Kumar Moulick

Abstract:

In this paper the author studied the possibilities of using Rice Husk Ash (RHA) available in India; to produce concrete. The effect of RHA on concrete discussed. Traditional uses of Rice Husk in India pointed out and the advantages of using RHA in making concrete highlighted. Suggestion provided regarding prospective application of RHA concrete in India which in turn will definitely reduce the cost of concrete and environmental friendly due to utilization of waste and replacement of Cement.

Keywords: cement replacement, concrete, environmental friendly, rice husk ash

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5553 Stabilization of Expansive Soils by Additions Binders Hydraulic Lime and Cement

Authors: Kherafa Abdennasser

Abstract:

A literature review was conducted to gather as much information. Concerns the phenomenon of swelling clays, as well as a presentation of some bibliographic findings on factors affecting the swelling potential. Citing the various techniques of stabilization of clays as well as a presentation of some literature results on the stabilization of swelling. Then a characterization of the materials was carried out at basic bibliographic study. These are standard mechanical geotechnical testing. Simple practical, economical and efficient to minimize the phenomenon swelling.

Keywords: stabilization, expansive soils, cement, lime, oedometer

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5552 A New Binder Mineral for Cement Stabilized Road Pavements Soils

Authors: Aydın Kavak, Özkan Coruk, Adnan Aydıner

Abstract:

Long-term performance of pavement structures is significantly impacted by the stability of the underlying soils. In situ subgrades often do not provide enough support required to achieve acceptable performance under traffic loading and environmental demands. NovoCrete® is a powder binder-mineral for cement stabilized road pavements soils. NovoCrete® combined with Portland cement at optimum water content increases the crystallize formations during the hydration process, resulting in higher strengths, neutralizes pH levels, and provides water impermeability. These changes in soil properties may lead to transforming existing unsuitable in-situ materials into suitable fill materials. The main features of NovoCrete® are: They are applicable to all types of soil, reduce premature cracking and improve soil properties, creating base and subbase course layers with high bearing capacity by reducing hazardous materials. It can be used also for stabilization of recyclable aggregates and old asphalt pavement aggregate, etc. There are many applications in Germany, Turkey, India etc. In this paper, a few field application in Turkey will be discussed. In the road construction works, this binder material is used for cement stabilization works. In the applications 120-180 kg cement is used for 1 m3 of soil with a 2 % of binder NovoCrete® material for the stabilization. The results of a plate loading test in a road construction site show 1 mm deformation which is very small under 7 kg/cm2 loading. The modulus of subgrade reaction increase from 611 MN/m3 to 3673 MN/m3.The soaked CBR values for stabilized soils increase from 10-20 % to 150-200 %. According to these data weak subgrade soil can be used as a base or sub base after the modification. The potential reduction in the need for quarried materials will help conserve natural resources. The use of on-site or nearby materials in fills, will significantly reduce transportation costs and provide both economic and environmental benefits.

Keywords: soil, stabilization, cement, binder, Novocrete, additive

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5551 The Influence of Microsilica on the Cluster Cracks' Geometry of Cement Paste

Authors: Maciej Szeląg

Abstract:

The changing nature of environmental impacts, in which cement composites are operating, are causing in the structure of the material a number of phenomena, which result in volume deformation of the composite. These strains can cause composite cracking. Cracks are merging by propagation or intersect to form a characteristic structure of cracks known as the cluster cracks. This characteristic mesh of cracks is crucial to almost all building materials, which are working in service loads conditions. Particularly dangerous for a cement matrix is a sudden load of elevated temperature – the thermal shock. Resulting in a relatively short period of time a large value of a temperature gradient between the outer surface and the material’s interior can result in cracks formation on the surface and in the volume of the material. In the paper, in order to analyze the geometry of the cluster cracks of the cement pastes, the image analysis tools were used. Tested were 4 series of specimens made of two different Portland cement. In addition, two series include microsilica as a substitute for the 10% of the cement. Within each series, specimens were performed in three w/b indicators (water/binder): 0.4; 0.5; 0.6. The cluster cracks were created by sudden loading the samples by elevated temperature of 250°C. Images of the cracked surfaces were obtained via scanning at 2400 DPI. Digital processing and measurements were performed using ImageJ v. 1.46r software. To describe the structure of the cluster cracks three stereological parameters were proposed: the average cluster area - A ̅, the average length of cluster perimeter - L ̅, and the average opening width of a crack between clusters - I ̅. The aim of the study was to identify and evaluate the relationships between measured stereological parameters, and the compressive strength and the bulk density of the modified cement pastes. The tests of the mechanical and physical feature have been carried out in accordance with EN standards. The curves describing the relationships have been developed using the least squares method, and the quality of the curve fitting to the empirical data was evaluated using three diagnostic statistics: the coefficient of determination – R2, the standard error of estimation - Se, and the coefficient of random variation – W. The use of image analysis allowed for a quantitative description of the cluster cracks’ geometry. Based on the obtained results, it was found a strong correlation between the A ̅ and L ̅ – reflecting the fractal nature of the cluster cracks formation process. It was noted that the compressive strength and the bulk density of cement pastes decrease with an increase in the values of the stereological parameters. It was also found that the main factors, which impact on the cluster cracks’ geometry are the cement particles’ size and the general content of the binder in a volume of the material. The microsilica caused the reduction in the A ̅, L ̅ and I ̅ values compared to the values obtained by the classical cement paste’s samples, which is caused by the pozzolanic properties of the microsilica.

Keywords: cement paste, cluster cracks, elevated temperature, image analysis, microsilica, stereological parameters

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5550 Effect of Plasticizer Additives on the Mechanical Properties of Cement Composite: A Molecular Dynamics Analysis

Authors: R. Mohan, V. Jadhav, A. Ahmed, J. Rivas, A. Kelkar

Abstract:

Cementitious materials are an excellent example of a composite material with complex hierarchical features and random features that range from nanometer (nm) to millimeter (mm) scale. Multi-scale modeling of complex material systems requires starting from fundamental building blocks to capture the scale relevant features through associated computational models. In this paper, molecular dynamics (MD) modeling is employed to predict the effect of plasticizer additive on the mechanical properties of key hydrated cement constituent calcium-silicate-hydrate (CSH) at the molecular, nanometer scale level. Due to complexity, still unknown molecular configuration of CSH, a representative configuration widely accepted in the field of mineral Jennite is employed. The effectiveness of the Molecular Dynamics modeling to understand the predictive influence of material chemistry changes based on molecular/nanoscale models is demonstrated.

Keywords: cement composite, mechanical properties, molecular dynamics, plasticizer additives

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5549 Software Obsolescence Drivers in Aerospace: An Industry Analysis

Authors: Raúl González Muñoz, Essam Shehab, Martin Weinitzke, Chris Fowler, Paul Baguley

Abstract:

Software applications have become crucial for the aerospace industry, providing a wide range of functionalities and capabilities. However, due to the considerable time difference between aircraft and software life cycles, obsolescence has turned into a major challenge for industry in last decades. This paper aims to provide a view on the different causes of software obsolescence within aerospace industry, as well as a perception on the importance of each of them. The key research question addressed is what drives software obsolescence in the aerospace industry, managing large software application portfolios. This question has been addressed by conducting firstly an in depth review of current literature and secondly by arranging an industry workshop with professionals from aerospace and consulting companies. The result is a set of drivers of software obsolescence, distributed among three different environments and several domains. By incorporating monitoring methodologies to assess those software obsolescence drivers, benefits in maintenance efforts and operations disruption avoidance are expected.

Keywords: aerospace industry, obsolescence drivers, software lifecycle, software obsolescence

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5548 A Study of Industry 4.0 and Digital Transformation

Authors: Ibrahim Bashir, Yahaya Y. Yusuf

Abstract:

The ongoing shift towards Industry 4.0 represents a critical growth factor in the industrial enterprise, where the digital transformation of industries is increasingly seen as a crucial element for competitiveness. This transformation holds substantial potential, yet its full benefits have yet to be realized due to the fragmented approach to introducing Industry 4.0 technologies. Therefore, this pilot study aims to explore the individual and collective impact of Industry 4.0 technologies and digital transformation on organizational performance. Data were collected through a questionnaire-based survey across 51 companies in the manufacturing industry in the United Kingdom. The correlations and multiple linear regression analyses were conducted to assess the relationship and impact between the variables in the study. The results show that Industry 4.0 and digital transformation positively influence organizational performance and that Industry 4.0 technologies positively influence digital transformation. The results of this pilot study indicate that the implementation of Industry 4.0 technology is vital for increasing organizational performance; however, their roles differ largely. The differences are manifest in how the types of Industry 4.0 technologies correlate with how organizations integrate digital technologies into their operations. Hence, there is a clear indication of a strong correlation between Industry 4.0 technology, digital transformation, and organizational performance. Consequently, our study presents numerous pertinent implications that propel the theory of I4.0, digital business transformation (DBT), and organizational performance forward, as well as guide managers in the manufacturing sector.

Keywords: industry 4.0 technologies, digital transformation, digital integration, organizational performance

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5547 Properties of Concrete with Wood Ashes in Construction Engineering

Authors: Piotr-Robert Lazik, Lena Teichmann, Harald Garrecht

Abstract:

Many concrete technologists are looking for a solution to replace fly ashes as a component that occurs as a major component of many types of concrete. The importance of such a component is clear -it saves cement and reduces the amount of CO₂ in the atmosphere that occurs during cement production. For example, the amount of cement in ultrahigh strength concrete (UHPC) is approximately 700-800 kg/m³ in normal concrete up to 350 kg/m³. For this reason, it is easy to follow that the use of components like fly ashes or wood ashes protect the environment. The newest investigations carried out at the University of Stuttgart have clearly shown that the use of wood ashes with appropriate pre-treatment in concrete has a positive effect. German-wide, there are hundreds of tons of wood ashes, which can be used in a wide range of construction materials. The strengths of the concrete with different types of cement and with wood ashes have given the same or, in some cases, better results than those with the use of fly ashes. There are many areas in building construction, where the clays of wood ashes can be used as a by-product. This does not only require a strength test but also, for example, an examination of structural-physical parameters. Especially the heat and moisture characteristics have an important role in times of energy-efficient construction. These are therefore determined and then compared with the characteristics of the concretes with fly ashes. The University of Stuttgart has decided to investigate the buildings' physical properties of different types of concrete with wood ashes to find their application in construction. After the examination of the buildings' physical properties in combination with strength tests, it is possible to determine in which field of civil engineering, this type of concrete can be used.

Keywords: fly ashes, wood ashes, structural-physical parameters, UHPC

Procedia PDF Downloads 122