scholarly journals Utilization of Industrial Waste in Cement in a Marine Environment with a Tropical Climate

2019 ◽  
Vol 7 (8) ◽  
pp. 245 ◽  
Author(s):  
Thi Chu ◽  
Jinhai Zheng ◽  
Da Chen ◽  
Thi Nguyen ◽  
Elsafi Elbashiry ◽  
...  
Keyword(s):  
Fly Ash ◽  
Silica Fume ◽  
Cement Paste ◽  
Marine Environment ◽  
Industrial Waste ◽  
Building Materials ◽  
Rapid Development ◽  
Chloride Ion ◽  
Tropical Climate ◽  
Test Results

This novel study on cement paste material was conducted with the aim of keeping up with the rapid development of urban construction and contributing to the continuous improvement of building materials to overcome environmental issues. In this study, several kinds of industrial waste were used to enhance the properties of cement paste for application in a marine environment with a tropical climate, such as in Vietnam. This study focuses on evaluating the properties of cement paste containing cement replacement combining 0–30% fly ash, 0–10% silica fume, and plasticizer accounting for 0.3% and 0.4% of the binder by mass. Water demand, chloride ion and sulfate ion permeability, and microstructural properties of the cement paste were determined by thermogravimetric analysis (TGA), X-ray diffraction (XRD), and scanning electron microscope (SEM) and they were investigated after 28 and 56 days. The test results show that an optimum mixture could be obtained with the use of 20% fly ash, 10% silica fume (replacing Portland cement), and 0.4% plasticizer. The application of such materials to sea dikes affected by a tropical climate (characterized by heat, humidity, salty seawater, many big storms, large waves, and strong tides) was investigated for four years on the Vietnamese coast. The test results indicate that fly ash and silica fume can improve the corrosion and abrasion resistance of concrete in coastal areas with a tropical climate, such as in Vietnam.

Effect of Mineral Admixtures on Rheological Properties of Cement Paste

2014 ◽  
Vol 936 ◽  
pp. 1409-1413 ◽  
Author(s):  
Lin Chun Zhang ◽  
Ai Lian Zhang
Keyword(s):  
Fly Ash ◽  
Rheological Properties ◽  
Silica Fume ◽  
Cement Paste ◽  
Reducing Agent ◽  
Mineral Admixtures ◽  
Test Results ◽  
Optimal Ratio ◽  
Mix Proportion

The Marsh cone method and rotary viscosimeter are used to study the effect of mineral admixtures such as ultra-fine fly ash, ultra-fine slag, zeolite powder and silica fume on rheological properties of cement paste. Test results show that the optimal ratio of ultra-fine fly ash, ultra-fine slag, zeolite powder and silica fume are respectively 20%, 20%, 10% and 8%. And the optimized mix proportion is the composition of 8% silica fume and 12% slag. By using water reducing agent and mineral admixtures we could get the cement paste which has good liquidity and no bleeding.

scholarly journals Development of UHPC Mixtures Utilizing Natural and Industrial Waste Materials as Partial Replacements of Silica Fume and Sand

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Shamsad Ahmad ◽  
Ibrahim Hakeem ◽  
Mohammed Maslehuddin
Keyword(s):  
Silica Fume ◽  
Industrial Waste ◽  
Steel Slag ◽  
Limestone Powder ◽  
Waste Materials ◽  
Cement Kiln ◽  
Test Results ◽  
Strength Criteria ◽  
Natural Pozzolana ◽  
Kiln Dust

In the exploratory study presented in this paper, an attempt was made to develop different mixtures of ultrahigh performance concrete (UHPC) using various locally available natural and industrial waste materials as partial replacements of silica fume and sand. Materials such as natural pozzolana (NP), fly ash (FA), limestone powder (LSP), cement kiln dust (CKD), and pulverized steel slag (PSS), all of which are abundantly available in Saudi Arabia at little or no cost, were employed in the development of the UHPC mixtures. A base mixture of UHPC without replacement of silica fume or sand was selected and a total of 24 trial mixtures of UHPC were prepared using different percentages of NP, FA, LSP, CKD, and PSS, partially replacing the silica fume and sand. Flow and 28-d compressive strength of each UHPC mixture were determined to finally select those mixtures, which satisfied the minimum flow and strength criteria of UHPC. The test results showed that the utilization of NP, FA, LSP, CKD, and PSS in production of UHPC is possible with acceptable flow and strength. A total of 10 UHPC mixtures were identified with flow and strength equal to or more than the minimum required.

scholarly journals Effect of Fly Ash as Cement Replacement on Chloride Diffusion, Chloride Binding Capacity, and Micro-Properties of Concrete in a Water Soaking Environment

2020 ◽  
Vol 10 (18) ◽  
pp. 6271 ◽  
Author(s):  
Jun Liu ◽  
Jiaying Liu ◽  
Zhenyu Huang ◽  
Jihua Zhu ◽  
Wei Liu ◽  
...  
Keyword(s):  
Diffusion Coefficient ◽  
Fly Ash ◽  
Binding Capacity ◽  
Chloride Ion ◽  
Chloride Content ◽  
Chloride Ions ◽  
Chloride Diffusion ◽  
Chloride Binding ◽  
Test Results ◽  
New Equation

This paper experimentally studies the effects of fly ash on the diffusion, bonding, and micro-properties of chloride penetration in concrete in a water soaking environment based on the natural diffusion law. Different fly ash replacement ratio of cement in normal concrete was investigated. The effect of fly ash on chloride transportation, diffusion, coefficient, free chloride content, and binding chloride content were quantified, and the concrete porosity and microstructure were also reported through mercury intrusion perimetry and scanning electron microscopy, respectively. It was concluded from the test results that fly ash particles and hydration products (filling and pozzolanic effects) led to the densification of microstructures in concrete. The addition of fly ash greatly reduced the deposition of chloride ions. The chloride ion diffusion coefficient considerably decreased with increasing fly ash replacement, and fly ash benefits the binding of chloride in concrete. Additionally, a new equation is proposed to predict chloride binding capacity based on the test results.

Study on the Corrosion Performance of Reinforced Concrete by Using the Seawater Hot Rain Testing Equipment

2013 ◽  
Vol 699 ◽  
pp. 173-178
Author(s):  
Yue Li ◽  
Zhong Wei Gu ◽  
Xian Ming Qin
Keyword(s):  
Reinforced Concrete ◽  
Marine Environment ◽  
Rust Resistance ◽  
Chloride Ion ◽  
Crystalline Material ◽  
Test Results ◽  
Ion Permeability ◽  
Corrosion Performance ◽  
Different Types ◽  
Rust Inhibitor

In order to investigate the corrosion performance of reinforced concrete in the marine environment, the seawater hot rain testing (SHRT) equipment was used to imitate the marine environment and accelerate corrosion rate by circularly spraying seawater to the samples under high temperatures which can attain 70°C. The test results show that SHRT can accelerate the chloride ion permeability which can quickly investigate the corrosion performance of reinforced concrete. Different types of material admixtures have different influences on the corrosion performance of reinforcement concrete, and rust inhibitor and cementitious capillary crystalline material can improve the anti-rust resistance of reinforced concrete effectively.

Shrinkage of Blended Cement Pastes with Mineral Additions

2013 ◽  
Vol 539 ◽  
pp. 55-59
Author(s):  
Yi Chen ◽  
Wu Yao ◽  
Dan Jin
Keyword(s):  
Fly Ash ◽  
Silica Fume ◽  
Cement Paste ◽  
Mercury Intrusion Porosimetry ◽  
Construction Materials ◽  
Blended Cement ◽  
Cement Pastes ◽  
Mercury Intrusion ◽  
Mineral Additions ◽  
By Products

Mineral additions such as fly ash and silica fume are industrial by products, and play an important role in properties improvement for construction materials. In this work, the shrinkage of cement paste blended with fly ash and silica fume by different substitute ratio was studied. Pore structures of specimens at different ages were determined by mercury intrusion porosimetry (MIP) and shrinkage deformation was measured by standard shrinkage tests. The effects of mineral addtions on shrinkage were discussed. The results show that the fly ash was significantly effective on shrinkage at early ages. Based on the research, several suitable advices were offered to optimize the performances of materials and reduce the shrinkage.

Effect of Metakaolin-Based Modifier on the Permeability of Concrete Structure in the Marine Environment

2013 ◽  
Vol 438-439 ◽  
pp. 117-120
Author(s):  
Jun Tao Ma ◽  
Liang Yan ◽  
Yu Ping Tong ◽  
Hui Xian Wang
Keyword(s):  
Fly Ash ◽  
Marine Environment ◽  
Concrete Structure ◽  
Chloride Ion ◽  
Penetration Resistance ◽  
Chloride Ion Penetration ◽  
Working Performance ◽  
Electric Flux ◽  
Penetration Behavior ◽  
Strength And Durability

Corrosion of the steel reinforcement in the concrete structure caused by chloride ion penetration becomes more serious in the marine environment. Metakaolin has been widely used in the concrete structure to improve the strength and durability. The combination of metakaolin (MK) and fine fly ash (FA) was studied in the article and the penetration behavior of concrete with various contents of metakaolin-based modifier is investigated. The penetration resistance of concrete was tested in combination of electric flux test. The improving mechanism was studied with mercury intrusion porosimetry analysis (MIP). The experiment results indicate that metakaolin-based modifier improved the penetration resistance of concrete obviously. The combination of fine fly ash weakened the water sucking action of metakaolin and preserved the working performance of concrete. The pore size distribution of concrete containing metakaolin-based modifier has been optimized to improve the microstructure and enhance the penetration resistance of concrete.

Research on Some Properties of Fly Ash Concrete with Nano-CaCO3 Middle Slurry

2009 ◽  
Vol 405-406 ◽  
pp. 186-190 ◽  
Author(s):  
Kuang Liang Qian ◽  
Tao Meng ◽  
Xiao Qian Qian ◽  
Shu Lin Zhan
Keyword(s):  
Fly Ash ◽  
Chloride Ion ◽  
Test Results ◽  
Hydration Degree ◽  
Fly Ash Concrete

Some long-term properties such as anti-carbonation properties, shrinkage, penetrability of chloride ion of fly ash concrete with nano-CaCO3 middle slurry were studied. Test results showed that the properties of anti-carbonation and impenetrability for chloride of fly ash concrete increased by adding nano-CaCO3 middle slurry because the tiny hole was filled by nano-CaCO3 and the density of concrete increased. But at the same time, the shrinkage of fly ash concrete with and without nano-CaCO3 was the same. Results of SEM also implied the hydration degree of fly ash could be increased by nano-CaCO3.

Effect of Mineral Admixtures and Water/Binder Ratios on the Resistance to the Chloride Ions Penetration into Concrete

2011 ◽  
Vol 99-100 ◽  
pp. 758-761
Author(s):  
Yan Jun Hu ◽  
Yan Liang Du
Keyword(s):  
Blast Furnace ◽  
Fly Ash ◽  
Silica Fume ◽  
Blast Furnace Slag ◽  
Chloride Ion ◽  
Test Methods ◽  
Chloride Ions ◽  
Mineral Admixtures ◽  
Chloride Permeability ◽  
Furnace Slag

In this study, concrete prisms were made with three mineral admixtures: fly ash, blast furnace slag or silica fume and with three water-to-binder ratios(w/b). Chloride penetration was measured by the rapid chloride permeability test (RCPT)-ASTM C1202, 150-days ponding test and alternate wetting and drying test by cyclic loading with salt solution and oven drying, and the results by the three test methods were compared. This paper discussed the effects of mineral admixtures and w/b on the concrete chloride permeability. Blending concrete with blast furnace slag, fly ash or silica fume was beneficial with regard to the resistance against chloride ion penetration. Concrete specimens with lower w/b showed lower chloride permeability.

scholarly journals Determination of Mechanical Properties of Rubberized Concrete in Marine Environment

2019 ◽  
Vol 8 (2) ◽  
pp. 5761-5765
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Marine Environment ◽  
Concrete Specimen ◽  
Crumb Rubber ◽  
Fine Aggregate ◽  
Test Results ◽  
Rubberized Concrete ◽  
Split Tensile Strength

With an objective of saving the environment by providing crumb rubber as an alternative to natural fine aggregate this paper presents a study carried out to find the mechanical properties of rubberized concrete. Rubberized concrete is made up of waste rubber from vehicle tyres and other rubber waste which otherwise is left out polluting the environment. In this paper, 7.5% of crumb rubber (obtained by shredding the vehicle tyres) as an alternative to fine aggregate and 7.5% of fly-ash as an alternative to cement is added with other ingredients of concrete to produce an eco-friendly concrete which can be used economically and effectively for construction along the coastal areas. Various properties like workability, compressive strength, split tensile strength, and flexural strength was carried out on concrete specimens exposed to the natural marine environment along the coast of Visakhapatnam, Andhra Pradesh. The total exposure of concrete specimen was about 150 days, and various specimens were tested at 7, 28, 90, 120 and 150 days, respectively. The test results showed that with a slight compromise in strength, the workability of concrete and resistance to the effect of seawater on the strength of concrete significantly improved with the addition of crumb rubber and fly-ash.

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