scholarly journals Using of metakaolin to produce colored geopolymer concrete

2021 ◽  
Vol 2114 (1) ◽  
pp. 012018
Author(s):  
M Mohammed Hameed ◽  
A Mohammed Ali

Abstract This study was related to produce colored geopolymer concrete using metakaolin and adding two types of red (iron oxide) and green (chromium oxide) pigments with three additional ratios for each of the listed colors (0, 2, 4, 6 )% wt of metakaolin, and study some mechanical properties of colored geopolymer concrete. The experimental investigation has dealt with the fresh properties(slump) of the colored geopolymer concrete mixes as well as some of the mechanical properties of the hardened concrete by testing specimens in compressive strength, modulus of rupture, Rebound number (RN), and ultrasonic pulse velocity (UPV). Show us that (2% wt) pigment percentage gives the best results.

2021 ◽  
Vol 25 (Special) ◽  
pp. 2-49-2-59
Author(s):  
Mohammed H. Mahmud ◽  
◽  
Mohammed A. Abdulrehman ◽  

This study has been done to study the physical and mechanical characteristics of colored geopolymer concrete by adding two types of pigments yellow (iron oxide hydroxide) and blue (cobalt) with three additional proportions for each of the listed colors (0,2, 4, 6% wt), some materials which are available in the native market and other materials imported from outside of the country. The experimental investigation has dealt with the fresh properties(slump) of the colored geopolymer concrete mixes as well as some of the mechanical and physical characteristics of the hardened concrete by testing specimens in compressive strength, flexural strength, water absorption, Rebound number (RN), and ultrasonic pulse velocity (UPV). In addition to that, Finding a relationship between the destructive (strength of compressive) and (RN and UPV) tests. Show us that (2% wt) pigment percentage gives the best results.


There is a substantial curiosity in academia, the investment community and among manufacturers about the exhilarating opportunities offered by nano materials. Although a lot of applications for nanotechnology remain hypothetical, construction is one area where numerous ‘here and now’ applications have already emerged. While existing use is restricted, the market is likely to approach more than 500 million dollars within ten years. Concrete is most likely exceptional in the construction field, that it is the distinct material exclusive to business and hence, is the recipient of a reasonable quantity of research and development capital from the construction industry. SiO2 (Silica) usually is an integral part of concrete in the normal mix. On the other hand, one of the innovations made by the study of concrete at nano scale level is that particle stuffing in concrete can be enhanced by means of adding nano silica (NS), which results in the densification of the micro and nano structure of cementitious composite resulting in enhanced mechanical properties. In this research paper, the result of a thorough investigational analysis on the utilization of NS in addition to cement so that the strength and quality of concrete can improve has been achieved. The effect of various proportions of NS in concrete has been premeditated to evaluate the properties of NS based hardened concrete according to the standard concrete. The obtained outcomes after testing indicate that the addition of NS together with concrete has improved the mechanical behavior of concrete. The NS blended high strength concrete (HSC) shows a better compressive strength (CS) of 66.00 N/mm2 (MPa) after standard twenty eight days, which is an exceptional development over standard concrete. Each and every mixture containing NS in various proportions gave enhanced outcomes in comparison with the standard predictable concrete. RH (Rebound Hammer), UPV (Ultrasonic Pulse Velocity), SEM (Scanning Electron Microscope) and TEM (Transmission Electron Microscope) examinations further authenticate the above results.


2021 ◽  
Vol 12 (2) ◽  
pp. 39
Author(s):  
Tuba Bahtli ◽  
Nesibe Sevde Ozbay

Studies in the literature show that the physical and mechanical properties of concrete could be improved by the incorporation of different kinds of industrial waste, including waste tire rubber and tire steel. Recycling of waste is important for economic gain and to curb environmental problems. In this study, finely ground CuAl10Ni bronze is used to improve the physical and mechanical properties, and freeze-thaw resistances of C30 concrete. The density, cold crushing strength, 3-point bending strength, elastic modulus, toughness, and freeze-thaw resistances of concrete are determined. In addition, the Schmidt Rebound Hammer (SRH) and the ultrasonic pulse velocity (UPV) tests, which are non-destructive test methods, are applied. SEM/EDX analyses are also carried out. It is noted that a more compacted structure of concrete is achieved with the addition of bronze sawdust. Then higher density and strength values are obtained for concretes that are produced by bronze addition. In addition, concretes including bronze sawdust generally show higher toughness due to high plastic energy capacities than pure concrete.


2015 ◽  
Vol 75 (5) ◽  
Author(s):  
N. F. Abas ◽  
M. A. Karim

This paper presents the experimental investigation into the properties of mortar blocks containing waste concrete ash (WCA) as a cement replacement. In the experimental investigation, the properties of the mortar blocks were assessed through 3 different type of mixing. The replacement of waste concrete ash (WCA) had been divided into percentage which 0% (control), 5 %, 10 % and 15%. This different type of mixing had been tested with different duration with 7 day, 14 day and 28 day. Three cube specimens and three blocks specimens were prepared for each test. The total specimen that were prepared and tested are 36 cubes and 36 blocks. Workability test (slump test), density test, ultrasonic pulse velocity test, compressive strength test, flexural test and water absorption test were carried out. The experimental results of this study indicate that to observe the inclusion of waste concrete ash (WCA) in mortar blocks enhances the properties of mortar blocks in aspect of replacement of cement. 


Ultrasonics ◽  
2015 ◽  
Vol 60 ◽  
pp. 33-40 ◽  
Author(s):  
Emilia Vasanelli ◽  
Donato Colangiuli ◽  
Angela Calia ◽  
Maria Sileo ◽  
Maria Antonietta Aiello

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
B. Ravali ◽  
K. Bala Gopi Krishna ◽  
D. Ravi Kanth ◽  
K. J. Brahma Chari ◽  
S. Venkatesa Prabhu ◽  
...  

Need of construction is increasing due to increase in population growth rate. The geopolymer concrete is eco-friendly than ordinary concrete. Current experimental investigation was conducted on ordinary and geopolymer concrete using nondestructive testing (NDT) tests like ultrasonic pulse velocity (UPV) test and rebound hammer (RH) test. Cube specimens of dimensions 150 mm × 150 mm × 150 mm are used to conduct these tests at 7, 14, and 28 days. Proportions considered for concrete are cement-fly ash-river sand (100-0-100% and 60-40-100%), cement-fly ash-robo sand (100-0-100% and 60-40-100%) whereas geopolymer concrete fly ash-metakaolin is taken in proportions of 100-0%, 60-40%, and 50-50%. Alkaline activators (sodium hydroxide and sodium silicate with molarity 12M) were used in preparing geopolymer concrete. The major objective of the current study is to obtain relation between compressive strength of concrete and UPV values.


Author(s):  
Christopher Collins ◽  
Saman Hedjazi

In the present study, a non-destructive testing method was utilized to assess the mechanical properties of lightweight and normal-weight concrete specimens. The experiment program consisted of more than a hundred concrete specimens with the unit weight ranging from around 850 to 2250 kg/m3. Compressive strength tests were performed at the age of seven and twenty eight days. Ultrasonic Pulse Velocity (UPV) was the NDT that was implemented in this study to investigate the significance of the correlation between UPV and compressive strength of lightweight concrete specimens. Water to cement ratio (w/c), mix designs, aggregate volume, and the amount of normal weight coarse and fine aggregates replaced with lightweight aggregate, are the variables in this work. The lightweight aggregate used in this study, Poraver®, is a product of recycled glass materials. Furthermore, the validity of the current prediction methods in the literature was investigated including comparison between this study and an available expression in the literature on similar materials, for calculation of mechanical properties of lightweight concrete based on pulse velocity. It was observed that the recently developed empirical equation would better predict the compressive strength of lightweight concrete specimens in terms of the pulse velocity.


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