scholarly journals PROPERTIES OF CEMENT-FLY ASH MIXTURES WITH SUBSTANDARD FLY ASH AS A PARTIAL CEMENT AND FINE AGGREGATE REPLACEMENT

2021 ◽  
Vol 11 (3) ◽  
pp. 71-88
Author(s):  
Piseth Pok ◽  
Parnthep Julnipitawong ◽  
Somnuk Tangtermsirikul

This research investigated the effects of using a substandard fly ash as a partial cement and/or fine aggregate replacement on the basic and durability properties of cement-fly mixtures. Experimental results showed that utilizing the substandard fly ash led to increase in water requirement and autoclave expansion of pastes. The strength activity indexes of the substandard fly ash passed the requirements of TIS 2135 and ASTM C618. Utilization of the substandard fly ash as cement replacement led to higher expansion of mortar bars stored in water and sodium sulfate expansion as compared to that of the OPC mixture. However, sodium sulfate resistance of mortar mixtures improved when utilizing the substandard fly ash as sand replacement material. The compressive strength of concrete at all ages was higher with the increase of the content of the substandard fly ash as sand replacement material. When the substandard fly ash was used as cement replacement material in concrete, the carbonation depth increased. On the other hand, the use of the substandard fly ash as sand replacement material decreased the carbonation depth of the concrete. Utilization of the substandard fly ash, both to replace cement and/or fine aggregate, reduced the rapid chloride penetration of the concrete.

2020 ◽  
Vol 10 (1) ◽  
pp. 9-24 ◽  
Author(s):  
Nilankham Banchong ◽  
Warangkana Saengsoy ◽  
Somnuk Tangtermsirikul

The use of fly ash in concrete improves several characteristics of conventional cement-based pastes, mortars, and concrete such as reduces heat of hydration, increases strength in long-term and enhances durability. However, types and volume of fly ash affect behavior of resulting pastes, mortars and concrete. In this study, the characteristics of pastes, mortars, and concrete with 20% and 30% binder replacement with a Hongsa fly ash from Laos (FAH3) and two fly ashes from Thailand (FAM and FAB) were studied. Further, mechanical and durability properties of Hongsa fly ash mortars and concrete are investigated through specific gravity, Blaine fineness, normal consistency, setting times, water requirement, strength index, slump and slump retention, compressive strength of concrete with a fixed slump, compressive strength of concrete with a fixed w/b of 0.5, semi-adiabatic temperature, total shrinkage, carbonation depth, H2SO4 acid resistance, rapid chloride penetration (RCP) and chloride distribution. The experimental results show that the Hongsa fly ash contains large amount of non-spherical particles with coarse cavities, leading to high surface area and high Blaine fineness value. Accordingly, Hongsa fly ash was found to have high water requirement. In comparison to the ordinary Portland cement type I (OPC) and Mae Moh fly ash (FAM), the Hongsa fly ash was found to generate lower heat. As a result, the Hongsa fly ash shows its potential in the application of mass concrete. Similarly, the Hongsa fly ash mortar exhibited the lowest carbonation depth when compared to the FAM and FAB mortars. In term of RCPT and chloride distribution test, the Hongsa fly ash concrete shows the lowest Cl⁻ penetrability when compared with Portland cement type I (OPC) concrete, FAM and FAB concretes. Based on the experimental results, the Hongsa fly ash was found to be applicable in concrete works.


2016 ◽  
Vol 857 ◽  
pp. 36-40 ◽  
Author(s):  
Kumar S. Rajesh ◽  
Amiya K. Samanta ◽  
Dilip K. Singha Roy

This investigation is focused on the physical and mechanical properties of Alccofine (AF) incorporating silica fume (SF) on M20 grade concrete. Normally, these industrial wastes (SF) are disposed off in landfill. The use of these industrial waste in concrete could reduce waste in the environment as well helps the environment against pollution as it is known that one ton of cement manufacture released one ton of carbon dioxide to the environment .Alccofine is a new replacement material on which very limited research has been done, its effect with flyash has been studied. The current study is a new experimental research undertaken to study the effect of alccofine on SF based concrete. Alccofine was varied in percentages of 0, 5, 10 and 15%, Silica fume was varied in percentages of 0, 5, 10, 15 % The aim of the investigation was to see the effect of alccofine on compressive strength of concrete and do a comparison on 7, and 28 days strength.The results showed that the cement replacement by 10% of alccofine gives higher values when compared with all other mix. The cement replacement by 10% alccofine gave a good improvement in compressive strength. Alccofine has the better performance when compare to the other slag material. It is helpful to make concrete workable


2021 ◽  
Vol 10 (2) ◽  
Author(s):  
Maliduwa Liyanage Chamini Surangi ◽  
Parnthep Julnipitawong ◽  
Somnuk Tangtermsirikul ◽  
Yoshifumi Ohgi ◽  
Yusuke Ishii

A shortage of natural fine aggregates has occurred worldwide, especially due to excessive consumption of them in construction activities. For this, the availability of sustainable alternative materials for natural fine aggregate is researched. Fly ash is identified as one such material that can partially replace fine aggregate in concrete. The current study demonstrates the feasibility of using fly ash as a partial fine aggregate replacing material in concrete and its effects on the compressive strength and some significant durability properties when cured under different curing temperatures. Fine aggregate and cement were partially replaced with Class F fly ash in different percentages. The curing methods (used in this study) were isothermal heat curing at 30ºC, 50ºC, and 70ºC, and one-day accelerated heat curing. The compressive strength test, carbonation depth test, rapid chloride penetration test, and surface resistivity test were performed for concrete mixtures with different fly ash replacement levels and curing temperatures. Test results reveal that the use of fly ash as a partial fine aggregate replacing material in concrete gives higher compressive strength than that of concrete with fly ash as a partial cement replacing material at both an early age and a later age. One-day accelerated curing is the most beneficial curing method, regarding the compressive strength at all the tested ages. Moreover, concrete with fine aggregate replacement gives better results for carbonation resistance, chloride penetration resistance, and surface resistivity when compared with the control mixture and mixtures with fly ash as a partial cement replacing material.


2021 ◽  
Vol 328 ◽  
pp. 10017
Author(s):  
Nu’ Man ◽  
Abdul Gaus ◽  
Mufti Amir Sultan

In this study, the method according to the Indonesian National Standard (SNI) was applied. The objects test in the form of cylindrical concrete in which the fine aggregate was pumice sand and ordinary sand. The test objects made were tested for compressive strength. There were 6 test objects made in this study with a size of 15 cm x 30 cm. In detail, 3 test objects were made of pumice sand, while the other 3 test objects were made of ordinary sand. The coarse aggregate for all test objects was crushed stone. The result shown the use of pumice sand as a substitute for fine aggregate can reduce the compressive strength of concrete by 23.53%. However, it can reduce the weight of concrete by 7.03%. Therefore, for construction that prioritizes weight, concrete with pumice sand as fine aggregate is better compared to concreate with ordinary sand as fine aggregate.


Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7164
Author(s):  
Ivan Gabrijel ◽  
Marija Jelčić Rukavina ◽  
Nina Štirmer

This paper presents the results of an experimental study aimed at determining the influence of wood fly ash (WFA) from three Croatian power plants on the properties of concrete. First, the chemical and physical properties of WFA’s were determined. It was found that these properties are highly influenced by combustion technology, the type and parts of wood used as fuel, and the local operating conditions. Subsequently, workability, heat of hydration, stiffness development, 28-day compressive strength, apparent porosity, and capillary absorption were determined on concrete mixes prepared with WFA as cement replacement from 5–45% by weight. Cement replacement up to 15% with the finest WFA accelerated hydration, stiffness development, and increased compressive strength of concrete up to 18%, while replacement with coarser WFA’s led to a decrease in compressive strength of up to 5% and had more gradual heat liberation. The dominant effect that could explain these findings is attributed to the filler and filling effect mechanisms. At the same time replacement content of up to 45% had very little effect on capillary absorption and could give concrete with sufficiently high compressive strength to be suitable for construction purposes.


Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 488
Author(s):  
Sylvia Kelechi ◽  
Musa Adamu ◽  
Abubakar Mohammed ◽  
Yasser Ibrahim ◽  
Ifeyinwa Obianyo

Waste tire disposal continues to pose a threat to the environment due to its non-biodegradable nature. Therefore, some means of managing waste tires include grinding them to crumb rubber (CR) sizes and using them as a partial replacement to fine aggregate in concrete. However, the use of CR has a series of advantages, but its major disadvantage is strength reduction. This leads to the utilization of calcium carbide waste (CCW) to mitigate the negative effect of CR in self-compacting concrete (SCC). This study investigates the durability properties of SCC containing CR modified using fly ash and CCW. The durability properties considered are water absorption, acid attack, salt resistance, and elevated temperature of the mixes. The experiment was conducted for mixes with no-fly ash content and their replica mixes containing fly ash to replace 40% of the cement. In the mixes, CR was used to partially replace fine aggregate in proportions of 0%, 10%, and 20% by volume, and CCW was used as a partial replacement to cement at 0%, 5%, and 10% by volume. The results indicate that the mixes containing fly ash had higher resistance to acid (H2SO4) and salt (MgSO4), with up to 23% resistance observed when compared to the mix containing no fly ash. In addition, resistance to acid attack decreased with the increase in the replacement of fine aggregate with CR. The same principle applied to the salt attack scenario, although the rate was more rapid with the acid than the salt. The results obtained from heating indicate that the weight loss was reduced slightly with the increase in CCW, and was increased with the increase in CR and temperature. Similarly, the compressive strength was observed to slightly increase at room temperature (27 °C) and the greatest loss in compressive strength was observed between the temperature of 300 and 400 °C. However, highest water absorption, of 2.83%, was observed in the mix containing 20% CR, and 0% CCW, while the lowest water absorption, of 1.68%, was found in the mix with 0% CR, 40% fly ash, and 10% CCW. In conclusion, fly ash is recommended for concrete structures immersed in water, acid, or salt in sulphate- and magnesium-prone areas; conversely, fly ash and CR reduce the resistance of SCC to heat beyond 200 °C.


2020 ◽  
Vol 9 (3) ◽  
pp. 150-156
Author(s):  
Bunyamin Bunyamin ◽  
Amir Mukhlis

The compressive strength of concrete depends on the physical characteristics of the concrete forming materials. Oyster shells originating from Krueng Neng, Aceh Besar are very abundant, left unattended by fishermen, causing pollution of the surrounding environment. Oyster shell dust contains CaO, which can be used as a partial substitution of cement. Therefore, it is necessary to study oyster shell ash as cement replacement and fine aggregate in concrete production. This research aims to determine the compressive strength of concrete using shell ash as cement replacement and fine aggregate. The oyster shells were obtained from Krueng Neng, Lamjamee Village, Jaya Baru, Aceh Besar District. The oyster shells were crushed with a Los Angeles Test machine and sieved with sieve size 2.36 mm for fine aggregate and sieve #200 for cement replacement. The water-cement ratios (w/c) were 0.4, 0.5 and 0.6. The results showed that concrete's compressive strength with 5% cement replacement level was higher than the concrete with cement only. Meanwhile, for other replacement levels, the compressive strengths of concrete specimens were lower than control specimens.  


2021 ◽  
Vol 11 (3) ◽  
pp. 1037
Author(s):  
Se-Jin Choi ◽  
Ji-Hwan Kim ◽  
Sung-Ho Bae ◽  
Tae-Gue Oh

In recent years, efforts to reduce greenhouse gas emissions have continued worldwide. In the construction industry, a large amount of CO2 is generated during the production of Portland cement, and various studies are being conducted to reduce the amount of cement and enable the use of cement substitutes. Ferronickel slag is a by-product generated by melting materials such as nickel ore and bituminous coal, which are used as raw materials to produce ferronickel at high temperatures. In this study, we investigated the fluidity, microhydration heat, compressive strength, drying shrinkage, and carbonation characteristics of a ternary cement mortar including ferronickel-slag powder and fly ash. According to the test results, the microhydration heat of the FA20FN00 sample was slightly higher than that of the FA00FN20 sample. The 28-day compressive strength of the FA20FN00 mix was approximately 39.6 MPa, which was higher than that of the other samples, whereas the compressive strength of the FA05FN15 mix including 15% of ferronickel-slag powder was approximately 11.6% lower than that of the FA20FN00 mix. The drying shrinkage of the FA20FN00 sample without ferronickel-slag powder was the highest after 56 days, whereas the FA00FN20 sample without fly ash showed the lowest shrinkage compared to the other mixes.


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