scholarly journals Characteristics of Metakaolin-Based Geopolymer with Cathode Ray Tube Glass

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1149
Author(s):  
Marcin Górski ◽  
Natalia Wielgus ◽  
Krzysztof Loska ◽  
Michał Kozioł ◽  
Marcin Landrat ◽  
...  
Keyword(s):  
Compressive Strength ◽  
High Strength ◽  
Optimal Composition ◽  
Curing Conditions ◽  
Temperature Changes ◽  
Strength Tests ◽  
Cathode Ray Tube ◽  
New Material ◽  
Curing Regime ◽  
Mass Loss Temperature

Geopolymers can be treated as an environmentally friendly alternative for concrete and enables utilization of various wastes. This paper focuses on the possibility of application of discarded cathode ray tube (CRT) glass inside a metakaolin-based geopolymer in the form of an aggregate, providing an ecological method of recycling of this hazardous material. The main goal of this paper was to develop an optimal composition of a new geopolymer and to describe its behavior under varying curing conditions. A geopolymer made of different mixtures was subjected to flexural and compressive strength tests. The density, mass loss, temperature changes, and metals leaching were determined as well. The results demonstrated that neither the content of CRT glass nor the curing regime has a significant influence on the mechanical behavior. However, the strength of the geopolymer containing 50% CRT glass by mass increased with time in contrast to a geopolymer with a higher CRT glass content. The development of temperature inside the mixture was dependent on the amount of metakaolin. The concentration of toxic metals in an aqueous extract decreased considerably after the encapsulation of CRT glass inside the geopolymer. The presented results indicate that discarded CRT glass can be considered an aggregate for a metakaolin-based geopolymer. The new material shows high strength and makes the CRT glass safe for the environment.

The Effect of Dry Mix Sodium Hydroxide onto Workability and Compressive Strength of Geopolymer Paste

2020 ◽  
Vol 12 (9) ◽  
Author(s):  
A. Z. Mohd Ali ◽  
◽  
N. A. Jalaluddin ◽  
N. Zulkiflee ◽  
◽  
...  
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Sodium Hydroxide ◽  
Sodium Silicate ◽  
Alkaline Solution ◽  
High Emission ◽  
New Material ◽  
Curing Regime ◽  
Solid Form ◽  
Geopolymer Paste

The production of ordinary Portland cement (OPC) consumes considerable amount of natural resources, energy and at the same time contribute in high emission of CO2 to the atmosphere. A new material replacing cement as binder called geopolymer is alkali-activated concrete which are made from fly ash, sodium silicate and sodium hydroxide (NaOH). The alkaline solution mixed with fly ash producing alternative binder to OPC binder in concrete named geopolymer paste. In the process, NaOH was fully dissolved in water and cooled to room temperature. This study aims to eliminate this process by using NaOH in solid form together with fly ash before sodium silicate liquid and water poured into the mixture. The amount of NaOH solids were based on 10M concentration. The workability test is in accordance to ASTM C230. Fifty cubic mm of the geopolymer paste were prepared which consists of fly ash to alkaline solution ratio of 1: 0.5 and the curing regime of 80℃ for 24 hours with 100% humidity were implemented. From laboratory test, the workability of dry method geopolymer paste were decreased. The compressive strength of the dry mix of NaOH showed 55% and the workability has dropped to 58.4%, it showed strength reduction compared to the wet mix method.

scholarly journals Effect of Curing Temperature Histories on the Compressive Strength Development of High-Strength Concrete

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Keun-Hyeok Yang ◽  
Jae-Sung Mun ◽  
Myung-Sug Cho
Keyword(s):  
Compressive Strength ◽  
High Strength Concrete ◽  
High Strength ◽  
Relative Strength ◽  
Curing Temperature ◽  
Strength Development ◽  
Curing Conditions ◽  
Strength Concrete ◽  
Equivalent Age ◽  
Compressive Strength Development

This study examined the relative strength-maturity relationship of high-strength concrete (HSC) specifically developed for nuclear facility structures while considering the economic efficiency and durability of the concrete. Two types of mixture proportions with water-to-binder ratios of 0.4 and 0.28 were tested under different temperature histories including (1) isothermal curing conditions of 5°C, 20°C, and 40°C and (2) terraced temperature histories of 20°C for an initial age of individual 1, 3, or 7 days and a constant temperature of 5°C for the subsequent ages. On the basis of the test results, the traditional maturity function of an equivalent age was modified to consider the offset maturity and the insignificance of subsequent curing temperature after an age of 3 days on later strength of concrete. To determine the key parameters in the maturity function, the setting behavior, apparent activation energy, and rate constant of the prepared mixtures were also measured. This study reveals that the compressive strength development of HSC cured at the reference temperature for an early age of 3 days is insignificantly affected by the subsequent curing temperature histories. The proposed maturity approach with the modified equivalent age accurately predicts the strength development of HSC.

scholarly journals Recycling Glass Cullet from Waste CRTs for the Production of High Strength Mortars

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Stefano Maschio ◽  
Gabriele Tonello ◽  
Erika Furlani
Keyword(s):  
Compressive Strength ◽  
Fine Fraction ◽  
High Strength ◽  
Leaching Tests ◽  
Glass Cullet ◽  
Glass Waste ◽  
Small Glass ◽  
Cathode Ray Tube ◽  
Overall Performance ◽  
Icp Analysis

The present paper reports on the results of some experiments dealing with the recycling of mixed cathode ray tube (CRT) glass waste in the production of high-strength mortars. Waste CRT glass cullet was previously milled, and sieved, and the only fine fraction was added to the fresh mortar in order to replace part of the natural aggregate. The addition of superplasticizer was also investigated. All hydrated materials displayed high compressive strength after curing. Samples containing CRT mixed glass showed a more rapid increase of strength with respect to the reference compositions, and materials with a superplasticizer content of 1% showed the best overall performance due to the favourable influence of the small glass particles which increase the amount of silicate hydrated produced. The induced coupled plasma (ICP) analysis made on the solutions, obtained from the leaching tests, confirmed the low elution of hazardous elements from the monolithic materials produced and consequently their possible environmental compatibility.

scholarly journals Alkali-Activated Fly Ashes: Influence of Curing Conditions on Mechanical Strength

2018 ◽  
Vol 3 (2) ◽  
pp. 57-67
Author(s):  
Filipe Almeida ◽  
Nuno Cristelo ◽  
Tiago Miranda ◽  
Castorina S. Vieira ◽  
Maria De Lurdes Lopes ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Relative Humidity ◽  
Mechanical Strength ◽  
Research Groups ◽  
Fly Ashes ◽  
Curing Conditions ◽  
Alkaline Activation ◽  
Strength Tests ◽  
Higher Temperature ◽  
Alkali Activated

Alkaline activation of fly ashes is a procedure that enables an alternative binder which has been receiving much interest by several research groups particularly on the manufacturing of mortars and concretes. The properties of the materials that are developed during the alkaline activation are influenced by the curing conditions (temperature and relative humidity). Another relevant facet related to the curing procedures is the possibility of carbonation occur, which may have an impact on the mechanical strength of the alkaline cements. In this research, several sets of curing conditions were tested to understand which one results in a higher strength and reveals carbonation. Uniaxial compressive strength tests were conducted to assess mechanical behavior. The outcome suggests that higher temperature and low relative humidity yields higher mechanical strength.

scholarly journals Tests on workability and strength of high strength-flowable concrete containing PET waste fiber

2020 ◽  
Vol 7 (3) ◽  
pp. 115-139
Author(s):  
Sarkawt Karim ◽  
◽  
Azad Mohammed ◽  
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Fiber Length ◽  
High Strength ◽  
Fiber Reinforced Concrete ◽  
Time Increase ◽  
Fiber Volume ◽  
Split Tensile Strength ◽  
Pet Waste ◽  
Strength Tests

This study describes two workability tests, compressive strength and tensile strength tests of high strength flowable concrete containing plastic fiber prepared from polyethylene terephthalate (PET) waste bottles. For the high fluidity mix Vebe time and V-funnel time tests were carried out. Results show that there is a Vebe time increase with PET fiber addition to concrete being increased with increasing fiber volume and fiber length. V-funnel time was found to reduce when up to 0.75% fiber volume is added to concrete, followed by an increase for larger fiber volumes. When fiber length is increase, there is more time increase, but in general, V-funnel time increase was lower than that of Vebe time, indicating a different influence of PET fiber on the compatibility and flowability. The measured V-funnel time for all mixes was found to conform to the limits of European specifications on the flowability of self compacting concrete. Small descending in compressive strength was recorded for RPET fiber reinforced concrete that reached 15.74 % for 1.5 percent fiber content with 10 mm fiber length. Attractive results was recorded in split tensile strength of RPET fibrous samples which resulted in improvement up to 63.3 % for 1.5 percent of 40 mm fiber length content.

scholarly journals RESISTÊNCIA A COMPRESSÃO EM TESTEMUNHO DE CONCRETO: INFLUÊNCIA DO FATOR DE ESBELTEZ, DIÂMETRO DA AMOSTRA E MÉTODO DE EXTRAÇÃO

2017 ◽  
Vol 13 (1) ◽  
Author(s):  
Marcelo Henrique Farias de Medeiros ◽  
Ana Paula Brandão Capraro ◽  
Giovana Costa Réus ◽  
Marcel Luiz Escobedo
Keyword(s):  
Compressive Strength ◽  
Slenderness Ratio ◽  
Extraction Procedure ◽  
Resistance Level ◽  
Curing Conditions ◽  
Standard Specimens ◽  
Strength Tests ◽  
Axial Compressive Strength ◽  
The Difference ◽  
Shape Ratio

RESUMO: Este trabalho tem como objetivo avaliar a influência dos fatores de forma nos ensaios de resistência à compressão em testemunhos de concreto. Para isso foram moldadas e extraídas amostras de concreto de 20 e 30 MPa. Variou-se o diâmetro da base das amostras (50 e 100mm) e sua esbeltez (de 1 a 3). Para verificar a diferença entre amostras moldadas e extraídas, no momento da fabricação do concreto foram moldados corpos de prova de 100 x 200 mm e dois blocos de 500 x 630 x 270 mm de onde os testemunhos foram extraídos. Os dados indicam que os valores de resistência à compressão obtidos em testemunhos de 50 mm de diâmetro tenderam a ser mais baixos do que os obtidos com 100 mm. A magnitude desta diferença é afetada pelo nível de resistência do concreto avaliado. Além disso, a resistência dos testemunhos extraídos foi menor ou igual à obtida em corpos de prova moldados, mesmo mantendo as condições de cura constantes entre o bloco e os corpos de prova normalizados. Dessa forma, o que pode ser concluído neste estudo é que, a resistência real da estrutura é minorada pelo procedimento da extração, sendo este influenciado por diversos fatores. Dentre as possíveis variáveis da extração, o diâmetro foi um fator que demonstrou influência significativa na propriedade do material ensaiado
 
 ABSTRACT: This study aims to evaluate the influence of shape ratio in compressive strength tests. Concrete specimens with 20 and 30 MPa was made and extracted. The diameter of the specimen’s base was 50 and 100mm and its slenderness ratio vary 1 to 3. To verify the difference between molded and samples taken at the time of manufacture of concrete molded bodies were evidence of 100 x 200 mm and two blocks of 500 x 630 x 270 mm where witnesses were extracted. The results indicated that the axial compressive strength values obtained with concrete cores extracted of 50 mm diameter tended to be lower than those obtained with 100 mm, and the magnitude of this difference is affected by the resistance level of the evaluated concrete. Furthermore, the resistance of concrete cores extracted was less than or equal to the obtained in the molded test specimens, while maintaining constant the curing conditions between the block and standard specimens. Thus, it can be concluded in this study is that the real strength of the structure is alleviated by the extraction procedure, which is influenced by several factors. Among the possible variables of extraction, the diameter was a factor that showed a significant influence on the property of the material tested.

scholarly journals Experimental Research on Compressive and Shrinkage Properties of ECC Containing Ceramic Wastes Under Different Curing Conditions

2021 ◽  
Vol 8 ◽  
Author(s):  
Yan Xiong ◽  
Yi Yang ◽  
Shuai Fang ◽  
Di Wu ◽  
Yingfeng Tang
Keyword(s):  
Compressive Strength ◽  
Opposite Effect ◽  
Engineering Application ◽  
Drying Shrinkage ◽  
Cementitious Materials ◽  
Compressive Properties ◽  
Curing Conditions ◽  
Hydrothermal Curing ◽  
Large Dosage ◽  
Curing Regime

Engineered cementitious composites (ECCs) suffer from high shrinkage and low early strength due to large dosage of cementitious materials and slow hydration of fly ash. This study aims to improve compressive properties and reduce drying shrinkage of ECC using ceramic wastes and hydrothermal curing. Experimental results have indicated that ceramic polishing powder (CPP) and recycled ceramic sand (RCS) exert opposite effect on the compressive strength of ECC. Hydrothermal-cured ECC enhances elasticity modulus and compressive strength and reduces later drying shrinkage as compared with that under standard curing. A CPP dosage of 35% and a hydrothermal curing regime with a temperature of 70°C and age of 7 days are recommended for the engineering application of ECC.

Flood Mud as Geopolymer Precursor Materials: Effect of Curing Regime on Compressive Strength

2015 ◽  
Vol 815 ◽  
pp. 177-181 ◽  
Author(s):  
Mohd Mustafa Al Bakri Abdullah ◽  
Mukridz Md Mohtar ◽  
Liew Yun Ming ◽  
Muhammad Faheem Mohd Tahir ◽  
Kamarudin Husin ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Sodium Hydroxide ◽  
Sodium Silicate ◽  
Strength Properties ◽  
Sem Analysis ◽  
Raw Material ◽  
Curing Temperature ◽  
Strength Tests ◽  
Maximum Compressive Strength ◽  
Curing Regime

This paper studies the effect of curing temperature and curing duration to the flood mud based geopolymer on compressive strength properties. Flood mud was used as a raw material for geopolymer and geopolymer samples were synthesized by using sodium silicate and sodium hydroxide 14M solution. These samples were cured at different temperature (100°C, 150°C, 200°C and 250°) for different curing duration (6h, 12h and 24h) respectively. Compressive strength tests were carried out at after 28 days. The compressive strength and SEM analysis of geopolymer products were evaluated. Result showed that the maximum compressive strength was 24 MPa at temperature of 150°C for 24 hours. With increasing ageing day, densification of geopolymer gel was observed.

scholarly journals Discarded Cathode Ray Tube Glass as an Alternative for Aggregate in a Metakaolin-Based Geopolymer

2021 ◽  
Vol 13 (2) ◽  
pp. 479
Author(s):  
Natalia Wielgus ◽  
Marcin Górski ◽  
Jan Kubica
Keyword(s):  
Compressive Strength ◽  
Room Temperature ◽  
Sodium Hydroxide Concentration ◽  
Factors Influencing ◽  
Cathode Ray Tube ◽  
Different Types ◽  
New Material ◽  
New Type ◽  
Preliminary Research ◽  
Points Of View

Cathode Ray Tube (CRT) glass belongs to the group of wastes which are hard to be recycled due to their toxic metals content. Geopolymers are relatively new environmentally friendly materials which allow for the use of different types of wastes within their matrix. The following paper combines both issues and presents a new geopolymer mixture containing discarded CRT glass as a replacement for an aggregate. The main goal of the paper is to describe the basic mechanical behavior of the new type of metakaolin-based geopolymer and to discuss different factors influencing it. After the preliminary research, the mixture containing 50% of CRT glass was chosen for further tests. However, according to results, CRT glass content has no evident influence on flexural or compressive strength. Summarizing the second part of the research, it was decided that the following parameters are optimal from the mechanical, economic and environmental points of view: metakaolin to CRT glass ratio 1:1 (by mass), CRT glass of size up to 4 mm, curing at the room temperature, sodium hydroxide concentration 10 mol/L. According to the authors, the presented geopolymer is a promising building material. Further tests shall be done to describe new material more precisely.

Sign in / Sign up

Export Citation Format

Share Document