scholarly journals A Preliminary Study on the Physical Properties of an Alternative Coarse Aggregate Made with Red Soil and Fly Ash

2018 ◽  
Vol 12 (1) ◽  
pp. 1-8
Author(s):  
J. Bright Brabin Winsley ◽  
M. Muthukannan
Keyword(s):  
Fly Ash ◽  
Specific Gravity ◽  
Room Temperature ◽  
Coarse Aggregate ◽  
Environmental Issues ◽  
Red Soil ◽  
Test Results ◽  
Ordinary Concrete ◽  
Preliminary Study ◽  
Natural Aggregates

Background and Objective: The demand for course aggregate is increasing every day. Natural aggregate used for ordinary concrete is obtained by quarrying, which cause serious environmental issues. An alternate course aggregate is needed for sustainable development. The objective of this research is to produce an alternative course aggregate in combination with soil available locally near site along with fly ash, to test its properties to make it fit for concrete. Method: An alternative coarse aggregate is produced from red soil and fly ash mixed at various ratios, 100:0, 90:10, 80:20, 70:30, 60:40, 50:50, fresh aggregate granules of different sizes less than 10mm is prepared using hand press, the aggregates were sundried in shade for 24hours, oven dried at 110°C, burned in Muffle furnace at temperature of 950°C and cooled gradually to reach room temperature. After the production, the specific gravity, bulk density, water absorption, Impact and aggregate crushing of the aggregates were tested. Result: Test results showed that aggregates produced are of lesser specific gravity, density with relatively appreciable impact value and crushing value. Conclusion: The test results show that the aggregates produced can be used in construction as replacement for natural aggregates.

Effects of Elevated Temperatures on the Compressive Strength of HFCC

2011 ◽  
Vol 261-263 ◽  
pp. 416-420 ◽  
Author(s):  
Fu Ping Jia ◽  
Heng Lin Lv ◽  
Yi Bing Sun ◽  
Bu Yu Cao ◽  
Shi Ning Ding
Keyword(s):  
Compressive Strength ◽  
Elevated Temperature ◽  
Fly Ash ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Relative Strength ◽  
Ordinary Concrete ◽  
Residual Compressive Strength ◽  
Fly Ash Concrete ◽  
The Relationship

This paper presents the results of elevated temperatures on the compressive of high fly ash content concrete (HFCC). The specimens were prepared with three different replacements of cement by fly ash 30%, 40% and 50% by mass and the residual compressive strength was tested after exposure to elevated temperature 250, 450, 550 and 650°C and room temperature respectively. The results showed that the compressive strength apparently decreased with the elevated temperature increased. The presence of fly ash was effective for improvement of the relative strength, which was the ratio of residual compressive strength after exposure to elevated temperature and ordinary concrete. The relative compressive strength of fly ash concrete was higher than those of ordinary concrete. Based on the experiments results, the alternating simulation formula to determine the relationship among relative strength, elevated temperature and fly ash replacement is developed by using regression of results, which provides the theoretical basis for the evaluation and repair of HFCC after elevated temperature.

The Use of Recycled Aggregate Sludge for the Preparation of GGBFS and Fly Ash Based Geopolymer

Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1486
Author(s):  
Yi-Chen Chen ◽  
Wei-Hao Lee ◽  
Yung-Chin Ding
Keyword(s):  
Fly Ash ◽  
Environmental Concern ◽  
Waste Product ◽  
Recycled Aggregate ◽  
Test Results ◽  
Granulated Blast Furnace Slag ◽  
Mechanical And Physical Properties ◽  
Preliminary Study ◽  
Solid Liquid ◽  
High Treatment

Aggregate sludge is a waste product produced from crushing, screening, and washing processes at aggregate plants. Because of the large quantity and high treatment cost of this sludge, it cannot be disposed of as landfill, and thus, has caused environmental concern over the years in Taiwan. In this preliminary study, the recycled aggregate sludge was reutilized for construction applications through the geopolymerization process. The ground granulated blast furnace slag (GGBFS) and fly ash (FA) were selected as alkaline activated materials for the fabrication of sludge geopolymer. Several process parameters that may affect the mechanical and physical properties of geopolymer were investigated. These parameters are sludge/GGBFS/FA ratios, solid/liquid (alkali solution) ratio, the molarity of NaOH, and curing time. According to the test results, the compressive strength of geopolymer specimens (70/30 sludge/GGBFS ratios) made with 4 M and 6 M NaOH can reach 39.17 MPa and 43.6 MPa after 28 days of curing. The specimen made with 60/40 sludge/GGBFS ratios has a strength of 61.3 MPa. After replacing GGBFS with 10% fly ash (70/20/10 sludge/GGBFS/FA), the strength of the specimen can also reach 43 MPa. According to the test results obtained in this study, it was found that the higher the NaOH concentration, the higher the strength of the geopolymer, and the GGBFS also can contribute more to the mechanical properties of geopolymer than fly ash. This preliminary study suggests that it is possible to reutilize aggregate sludge for construction applications and solve its environmental disposal problem.

Influence of Artificial Aggregates on the ITZ's Microstructure of Recycling Concrete

2013 ◽  
Vol 743-744 ◽  
pp. 180-185
Author(s):  
Jun Hua Zhang ◽  
Zong Hui Zhou ◽  
De Cheng Zhang ◽  
Xin Cheng
Keyword(s):  
Fly Ash ◽  
Mineral Composition ◽  
High Performance ◽  
Raw Materials ◽  
Steel Slag ◽  
Interfacial Transition Zone ◽  
Hydration Products ◽  
Ordinary Concrete ◽  
Natural Aggregates ◽  
Furnace Slag

Artificial aggregates with high-performance were prepared by the methods including steel slag, furnace slag, fly ash and coal gangue, and the recycling concrete was prepared by artificial aggregates instead of natural aggregates. This kind of concrete abandoned was able to completely regenerate cement, which will make the reuse of concrete possible. The composition and characteristics of the artificial aggregates will produce a significant effect on the interfacial transition zone (ITZ) in recycling concrete. The morphological features and mineral composition of three artificial aggregates were analyzed by SEM and XRD, and the ITZ of three recycling concrete and one ordinary concrete was investigated by SEM and EDS. The results showed that compared with ordinary concrete, although the recycling concretes ITZ had a small amount of CH crystal, most of the space was filled with dense hydration products. The interface width was 40μm, which less than 50μm of ordinary concrete. Artificial aggregates with different ratio of raw materials had a great effect on recycling concretes ITZ. The ITZ of recycling concrete prepared with 30% steel slag, 50% furnace slag, 20% fly ash had the smallest Ca/Si and much more C-S-H. the structure of ITZ was much denser and the microstructure was relatively better.

Study on the Influence of Mix Design Parameters on the Properties of Self-Compacting Concrete

2013 ◽  
Vol 857 ◽  
pp. 10-19
Author(s):  
Ji Liang Wang ◽  
Xiang Qian Wen ◽  
Jun Hong Shan ◽  
Ying Liu
Keyword(s):  
Fly Ash ◽  
Volume Content ◽  
Coarse Aggregate ◽  
Mineral Admixture ◽  
Design Parameters ◽  
Fine Aggregate ◽  
Test Results ◽  
Self Compacting Concrete ◽  
Volume Stability ◽  
Dry Shrinkage

the influence of mixing amount of mineral admixture, volume content of fine and coarse aggregate have been systematical studied on the workability, mechanical properties and volume stability of self-compacting concrete. Test results showed that with the fly ash content increased, the workability of self-compacting concrete improved significantly, early compressive strength decreased, but increase rate of later strength improved remarkably, and the mixing amount of fly ash inhibited significantly the dry shrinkage of self-compacting concrete; with the volume content of coarse aggregate increased, the workability of self-compacting concrete decreased significantly, but the volume stability of self-compacting concrete improved obviously, thus the optimum volume content of coarse aggregate of self-compacting concrete was range from 0.30 to 0.34; when the volume content of fine aggregate varied at the range of 0.40~0.50, there may be little effects on the workability of self-compacting concrete, but the increase self-compacting concretes volume content could reduce obviously the dry shrinkage of self-compacting concrete. Moreover, the variation in the volume content of coarse and fine aggregate should have slight influence on the early strength of self-compacting concrete, and the influence of the volume content variety on the later strength of self-compacting concrete could be neglected eventually.

scholarly journals EFFICACY OF BASALT AND GRANITE AS COARSE AGGREGATE IN CONCRETE MIXTURE

2020 ◽  
Vol 7 (9) ◽  
pp. 1-9
Author(s):  
S.E Ubi ◽  
P.O Nkra ◽  
R.B Agbor ◽  
D.E Ewa ◽  
M. Nuchal
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Specific Gravity ◽  
Coarse Aggregate ◽  
Strength Properties ◽  
Test Results ◽  
Physical Test ◽  
Coarse Aggregates ◽  
Structural Tests ◽  
Comparative Results

This present research was on the comparison of the efficacious use of basalt and granite as coarse aggregates in concrete work. In order to obtain the basis for comparison, physical and structural tests were conducted on the different materials of the concrete and the concrete samples respectively. Physical test results revealed that basalt have a specific gravity of 2.8 and 2.5, while granite have a specific gravity of 2.9 and 2.6. In density, basalt have a density of 1554.55kg/m3 while granite had a density of 1463.64kg/m3. Aggregate impact test conducted on both aggregates revealed a percentage of 11.05% for basalt and 12.63% for granite. The following structural tests were carried out: compressive strength tests, flexural and tensile strength test and the comparative results are as follows. Compressive strength for basalt 36.39N/mm2 while 37.16N/mm2 for granite. 24.81N/mm2 tensile strength for basalt while 12.57N/mm2 for granite, 31.83N/mm2 flexural strength for basalt while 27.97N/mm2 for granite. From the above results, it can be deduced that basalt has higher strength properties than granite. Therefore, more suitable for coarse aggregate in achieving higher strength with some quantity of other composition of the concrete mix when compared to granite.

The Effects of Na2SiO3/NaOH Ratios on the Volumetric Properties of Fly Ash Geopolymer Artificial Aggregates

2019 ◽  
Vol 967 ◽  
pp. 228-235
Author(s):  
I Dewa Made Alit Karyawan ◽  
Januarti Jaya Ekaputri ◽  
Iswandaru Widyatmoko ◽  
Ervina Ariatedja
Keyword(s):  
Electron Microscope ◽  
Fly Ash ◽  
Scanning Electron Microscope ◽  
Specific Gravity ◽  
Water Absorption ◽  
Asphalt Mixture ◽  
Interfacial Transition Zone ◽  
Volumetric Properties ◽  
Test Results ◽  
Scanning Electron

This study was conducted as a part of a research to assess the influence of the volumetric properties of geopolymer artificial aggregates made of fly ash to the performance of asphalt mixture to be used in pavement layers. This paper presents the parameters adopted during the production of geopolymer artificial aggregates which may affect the volumetric properties and the structure of the aggregates. The investigated volumetric properties included specific gravity and water absorption. In the experiment laboratory, two variables were utilized for producing the artificial aggregates, which might affect the considered volumetric properties. Those variables are pan-granulator slopes and alkaline ratios (the ratios of Sodium Silicate to Sodium Hydroxide). The pan-granulator slopes were set at 3 different angles, i.e. 45o, 50o, and 55o. The selected alkaline ratios were 1.5, 2.0, 2.5, and 3.0. The test results indicated that the best volumetric properties were obtained at a slope of 50o and alkaline ratio of 2.5. The bulk specific gravity values at the best volumetric properties were found to be: 1) oven dry at 1.9 grams/cm3; 2) saturated surface dry (SSD) at 2.0 grams/cm3, and 3) apparent at 2.1 grams/cm3 with 6% water absorption. In addition, the interfacial transition zone and microstructure aggregates were examined by using Scanning Electron Microscope (SEM). In this study, it was found that there were effects of Na2SiO3/ NaOH ratios and the granulation method on the volumetric properties.

Impacts of Gradation on the Property of Lime-Fly Ash Bound Macadam

2012 ◽  
Vol 178-181 ◽  
pp. 1321-1324 ◽  
Author(s):  
Wen Xue ◽  
Xiang Ping Han ◽  
Zhi Guo Xia ◽  
Qi Zheng
Keyword(s):  
Fly Ash ◽  
Construction Projects ◽  
Coarse Aggregate ◽  
High Strength ◽  
Pavement Performance ◽  
Good Effect ◽  
Test Results ◽  
Aggregate Content ◽  
Fine Aggregates ◽  
Skeleton Structure

This paper studied the lime-fly ash bound macadam mixed with different proportions of lime fly-ash and aggregates which is often used in construction projects, analyzed the impacts of the aggregate content to the unconfined compressive strength, modulus of compressive resilience property with various lime content and is showed that dense skeleton lime-fly ash bound macadam reached the desirable strength property and had good effect on pavement performance Therefore, it is concluded that lime-fly ash bound macadam with desirable property, replacing fine aggregates is achievable, Test results show that coarse aggregate of lime fly-ash stabilized aggregate can form skeleton structure and has the advantage of high strength and other better material properties which can meet the requirements pavement.

scholarly journals A Study of the Replacement of Natural Coarse Aggregate by Spherically-Shaped and Crushed Waste Cathode Ray Tube Glass in Concrete

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
N. N. M. Pauzi ◽  
◽  
M. R. Karim ◽  
M. Jamil ◽  
R. Hamid ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Smooth Surface ◽  
Coarse Aggregate ◽  
Control Specimen ◽  
Test Results ◽  
Complete Replacement ◽  
Ordinary Concrete ◽  
Coarse Aggregates ◽  
Optimum Proportion ◽  
Cathode Ray Tube

The aim of this study is to conduct an experimental investigation on the influence of complete replacement of natural coarse aggregate with spherically-shape and crushed waste cathode ray tube (CRT) glass to the aspect of workability, density, and compressive strength of the concrete. After characterizing the glass, a group of concrete mixes was prepared to contain a 40% spherical CRT glass and 60% crushed CRT glass as a complete (100%) replacement of natural coarse aggregates. From a total of 16 types of concrete mixes, the optimum proportion was selected based on its best performance. The test results showed that the use of spherical and crushed glass that possesses a smooth surface, rounded, irregular and elongated shape, and low water absorption affects the workability of concrete. Due to a higher specific gravity of crushed glass, concrete mixes containing CRT glass had a higher density compared to ordinary concrete. Despite the spherical and crushed CRT glass being stronger than gravel, the results revealed a reduction in compressive strength of the concrete. However, using a lower water to binder (w/b) ratio and a higher superplasticizer (SP) dosage, it is found to enhance the compressive strength of 60.97 MPa at 28 days that is lower by 13% than the control specimen. These findings indicate that waste CRT glass in the form of spherical and crushed could be used as an alternative of coarse aggregate that may pave the way for the disposal of hazardous e-waste.

Research on Pavement Performance of Dense Skeleton Lime Fly-Ash Stabilized Aggregate in Gravelly Conditions

2011 ◽  
Vol 287-290 ◽  
pp. 1033-1036
Author(s):  
Jian Ning Guo ◽  
Shi Bin Ma ◽  
Lei Wang
Keyword(s):  
Fly Ash ◽  
Service Life ◽  
Material Properties ◽  
Coarse Aggregate ◽  
High Strength ◽  
Pavement Performance ◽  
Rigid Base ◽  
Test Results ◽  
Base Course ◽  
Skeleton Structure

Lime fly-ash stabilized aggregate is the commonly material used as semi-rigid base course of pavement and the performance of pavement directly affects its service life. This paper focuses on pavement performance of dense skeleton lime fly-ash stabilized aggregate in gravelly conditions. Test results show that coarse aggregate of lime fly-ash stabilized aggregate can form skeleton structure and has the advantage of high strength and other better material properties which can meet the requirements pavement.

scholarly journals The Beneficial Effect of the Addition of Fly Ash on Reduction of the Size of Microcracks in the ITZ of Concrete Composites under Dynamic Loading

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 668
Author(s):  
Grzegorz Ludwik Golewski
Keyword(s):  
Fly Ash ◽  
Beneficial Effect ◽  
Dynamic Loading ◽  
Coarse Aggregate ◽  
Interfacial Transition Zone ◽  
Dynamic Loads ◽  
Cement Matrix ◽  
Test Results ◽  
Average Width ◽  
Average Value

The paper presents results of tests on the effect of the addition of fly ash (FA) in the amounts of 0%, 20%, and 30% by weight of cement on the interfacial microcracks in concrete composites subjected to dynamic loads. The analyses were carried out based on the results of the microstructural tests using a scanning electron microscope (SEM). The average width of the microcracks (Wc) in the interfacial transition zone (ITZ) of coarse aggregate with cement matrix was evaluated. During the studies beneficial effect of the addition of FA on reduction of the size of Wc in the ITZ of concrete composites under dynamic loading were observed. Based on obtained test results, it was found that using the 20% FA additive causes favorable changes in the microstructure of mature concrete. In this composite, the average value of Wc was lower by more than 40% compared to the result obtained for the reference concrete. In contrast, concrete containing 30% FA additive had greater microcracks in the ITZ area by over 60% compared to the material without additive. In all analyzed composites, an increase in the Wc value by almost 70% to over 110% in the case of occurrence of dynamic loads was also observed. This was the most evident in the case of concrete with a higher content of FA.

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