scholarly journals Old Dumped Fly Ash as a Sand Replacement in Cement Composites

Buildings ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 67 ◽  
Author(s):  
Jolanta Harasymiuk ◽  
Andrzej Rudziński

The use of industrial residues to replace natural resources for the production of building materials is economically and ecologically justified. Fly ash (FA) taken directly from electro-filters is commonly used as a cement replacement material. This is not the case, however, for old dumped fly ash (ODFA) that has been accumulating in on-site waste dumps for decades and currently has no practical use. It causes environmental degradation, which is not fully controlled by the governments of developed countries. The aim of the study was to assess the possibility of using ODFA as a partial replacement for sand in cement composites. ODFA replaced part of the sand mass (20% and 30%) in composites with a limited amount of cement (a cement-saving measure) and sand (saving non-renewable raw material resources). ODFA was activated by the addition of different proportions of hydrated lime, the purposes of which was to trigger a pozzolanic reaction in ODFA. The quantitative composition of the samples was chosen in such a way as to ensure the maximum durability and longevity of composites with a limited amount of cement. The 28-day samples were exposed to seawater attack for 120 days. After this period, the compressive strength of each sample series was determined. The results suggest the possibility of using ODFA with hydrated lime to lay town district road foundations and bike paths of 3.5 to 5 MPA compressive strength. What is more, these composites can be used in very aggressive environments.

2019 ◽  
Vol 25 (3) ◽  
pp. 340-347
Author(s):  
Ting WANG ◽  
Xiaojian GAO ◽  
Jian WANG

As a byproduct of phosphoric acid industry, phosphogypsum has many environmental problems. In order to recycle phosphogypsum to manufacture lightweight building materials, cementitious additives including fly ash, ground granulate blast-furnace slag and Portland cement were added to improve strength and water-resistance and different volume of foam was added to reduce the bulk density. The results show that hydrated lime can improve mechanical strength and water resistance of PG paste and the optimal dosage of hydrated lime is 6 %. Higher addition of fly ash or ground granulated blast-furnace slag improves the fluidity and delays the setting time of PG paste. The addition of 10 ~ 20 % fly ash results in a little reducing influence and 10 % ground granulated blast-furnace slag leads to an increase of 20.7 % for 28 days compressive strength of hardened PG specimen. The higher addition of Portland cement results in the better mechanical strength and water resistance of PG specimens. The 28day compressive and flexural strength reaches 25.9 MPa and 8.9 MPa respectively for the 25 % Portland cement mixture. PG based lightweight building materials can prepared by the addition of 60 % volume of air foam, with compressive strength of 1.7 MPa, bulk density of 521.7 kg/m3 and thermal conductivity of 0.0724 W/(m·K). DOI: http://dx.doi.org/10.5755/j01.ms.25.3.19910


2019 ◽  
Vol 7 (2) ◽  
pp. 102-108
Author(s):  
Yulin Patrisia ◽  
Topan Eka Putra

This study aimed to determine the influence of peat water on the mechanical properties of the paving block (compressive strength and water absorption) using coconut shell waste and fly ash as raw material. The background of the research were the lack utilization of fly ash, preparation for the handling and utilization of fly ash from power station at Pulang Pisau and Tumbang Kajuei (under construction), and the utilization of coconut shell to be more effective and economical. Paving block specimens were immersed in peat water to determine the effect of peat water and the rest were immersed in plain water. This experiment used fly ash as a partial replacement of cement and 2% coconut shell as a partial replacement of fine aggregate. The results of the analysis showed that: (a) Paving block using fly ash and coconut shells which were immersed in plain water experienced the increase in compressive strength and the decrease in water; (b) Paving block using fly ash and coconut shells soaked in peat water showed that by the increase of age, compressive strength was decrease and water absorption was increase; (c) The compressive strength of paving block specimens immersed in plain water and peat water showed relatively similar values at 7 and 28 days age, (d). Water absorption in paving block specimens soaked both in plain water and peat water showed relatively similar values at 7 days age, but at 28 days age the specimens immersed in peat water had greater water absorption.


2021 ◽  
Vol 5 (2) ◽  
pp. 72-80
Author(s):  
Heba Adnan

Cement is one of the most widely used building materials on the planet. Cement manufacturing has also increased carbon emissions to their greatest level in recent years. Alternative or low-emissions binders have become more popular as a partial cement substitute in recent years. Because of its huge yearly output as waste material and low cost, fly ash is now regarded as one of the most accessible choices. Fly ash-based construction materials have a lot of promise as cement substitutes because of their high performance and inexpensive cost. The purpose of this article is to look at how fly ash affects the workability, setting time, compressive strength, and tensile strength of concrete. The kinds and characteristics of fly ash were also investigated.


Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3079
Author(s):  
Beata Jaworska ◽  
Dominika Stańczak ◽  
Joanna Tarańska ◽  
Jerzy Jaworski

The generation of energy for the needs of the population is currently a problem. In consideration of that, the biomass combustion process has started to be implemented as a new source of energy. The dynamic increase in the use of biomass for energy generation also resulted in the formation of waste in the form of fly ash. This paper presents an efficient way to manage this troublesome material in the polymer–cement composites (PCC), which have investigated to a lesser extent. The research outlined in this article consists of the characterization of biomass fly ash (BFA) as well as PCC containing this waste. The characteristics of PCC with BFA after 3, 7, 14, and 28 days of curing were analyzed. Our main findings are that biomass fly ash is suitable as a mineral additive in polymer–cement composites. The most interesting result is that the addition of biomass fly ash did not affect the rheological properties of the polymer–cement mortars, but it especially influenced its compressive strength. Most importantly, our findings can help prevent this byproduct from being placed in landfills, prevent the mining of new raw materials, and promote the manufacture of durable building materials.


2013 ◽  
Vol 438-439 ◽  
pp. 30-35 ◽  
Author(s):  
Nirdosha Gamage ◽  
Sujeeva Setunge ◽  
Kasuni Liyanage

The Victoria State of Australia has the second largest reserves of brown coal on earth, representing approximately 20% of the worlds reserves, and at current use, could supply Victoria with its energy for over 500 years. Its combustion, annually, yields up to 1.3 million tonnes of fly ash, which is largely use for land-fills. Disposal of fly ash in open dumps cause massive environmental problems such as ground water contamination that may create various health problems. This study focuses on the usability of brown coal fly ash to develop a sustainable building material. A series of laboratory investigations was conducted using brown coal fly ash combined with cement and aggregate to prepare cold pressed samples aiming to test their properties. Initial results indicate that compressive strength satisfies minimum standard compressive strength required for bricks or mortar.


2013 ◽  
Vol 594-595 ◽  
pp. 527-531
Author(s):  
Mohamad Ezad Hafez Mohd Pahroraji ◽  
Hamidah Mohd Saman ◽  
Mohamad Nidzam Rahmat ◽  
Kartini Kamaruddin ◽  
Ahmad Faiz Abdul Rashid

Millions tons of coal ash which constitute of fly ash and bottom ash were produced annually throughout the world. They were significant to be developed as masonry brick to substitute the existing widely used traditional material such as clay and sand brick which were produced from depleting and dwindling natural resources. In the present study, the coal ash from coal-fired thermal power plant was used as the main raw material for the fabrication of cementless unfired lightweight brick. The binder comprising of Hydrated Lime (HL)-activated Ground Granulated Blastfurnace Slag (GGBS) system at binding ratio 30:70, 50:50 and 70:30 were used to stabilize the coal ash in the fabrication process of the brick. Foam was used to lightweight the brick. The compressive strength and ambient density were evaluated on the brick. The results indicated that the brick incorporating HL-GGBS system achieved higher strength of 20.84N/mm2 at 28 days compare to the HL system with strength of 13.98N/mm2 at 28 days. However, as the quantity of foam increase at 0%, 25%, 50%, 75% and 100%, the strength and density for the brick decreased.


2020 ◽  
Vol 4 (2) ◽  
Author(s):  
Dwi Septiyana Sari ◽  
◽  
Susanti Sundari

Abstract This study discusses the use of fly ash waste from coal burning on the manufacture of PCC (Portland composite cement) at PT. XYZ Lampung. The purpose of this research is to look at the technical studies and the efficiency of raw materials in the use of fly ash in cement making, in this case PCC cement (Portland Composite Cement). The steps taken in analyzing the data in this study were viewed from a technical aspect by means of a physical test, namely the cement compressive strength test at the age of 3 days, 7 days, and 28 days using the Compression Testing Machine. This test was conducted to see the comparison of the compressive strength of PCC cement using limestone and fly ash as raw materials, then calculate the difference in raw material costs in the year before and after the replacement of limestone with fly ash. The results showed that cement with the addition of fly ash after 3 days, 7 days and 28 days had an increased compressive strength value, which increased 21.69%, 16.07% and 8.05% respectively of the compressive strength of cement using limestone. The use of fly ash as a substitute for limestone has an effect on the cost of raw materials, where the difference between the cost of raw materials in 2019 and the cost of raw materials in 2018 is Rp. 39,440,952,074.


2020 ◽  
Vol 10 (3) ◽  
pp. 5728-5731 ◽  
Author(s):  
S. A. Chandio ◽  
B. A. Memon ◽  
M. Oad ◽  
F. A. Chandio ◽  
M. U. Memon

This research paper aims at investigating the effects of fly ash as cement replacement in green concrete made with partial replacement of conventional coarse aggregates with coarse aggregates from demolishing waste. Green concrete developed with waste materials is an active area of research as it helps in reducing the waste management issues and protecting the environment. Six concrete mixes were prepared using 1:2:4 ratio and demolishing waste was used in equal proportion with conventional aggregates, whereas fly ash was used from 0%-10% with an increment of 2.5%. The water-cement ratio used was equal to 0.5. Out of these mixes, one mix was prepared with all conventional aggregates and was used as the control, and one mix with 0% fly ash had only conventional and recycled aggregates. The slump test of all mixes was determined. A total of 18 cylinders of standard size were prepared and cured for 28 days. After curing the compressive strength of the specimens was evaluated under gradually increasing load until failure. It is observed that 5% replacement of cement with fly ash and 50% recycled aggregates gives better results. With this level of dosage of two waste materials, the reduction in compressive strength is about 11%.


2018 ◽  
Vol 1 (1) ◽  
Author(s):  
Ahmad Nurfiki Alwi ◽  
Arif Rahman Setiaji ◽  
Abdurrohim Kurnia Agung ◽  
Abdul Halim

The number of economic needs is one of the fundamental aspects to support the survival of every individual in an area.  If seen in general, the cost of building the building and residential community still use building materials and installation costs are relatively higher.  With the advancement of technology has found a lightweight brick that has better strength, lighter, faster installation and environmentally friendly, so many people began to switch to using lightweight bricks.  For now the price of lightweight brick is still expensive, but this deficiency is covered with the speed of mounting and light weight so overall lightweight brick usage on certain patterns is very profitable.  The use of cement on lightweight bricks leads to high production costs.  With the above problems we have a breakthrough to replace the cement by using zeozolites containing silica compounds that resemble one of the cement compounds.  In this research, cement replacement with Zeolite is 20%, 40% and 60%.  Before use Zeolite was first activated using Fly Ash ratio of 65% Zeolite: 35% Fly Ash and 50% Zeolite: 50% Fly Ash, also activated using Ca (OH) 2 ratio 65% Zeolite: 35% Ca (OH) 2  And 50% Zeolite: 50% Ca (OH) 2.  Thus, there are 15 compositions including the control composition, each composition will be made up of 10 specimens.  Hypothesis testing using two way anova, tested is the effect of cement change treatment with Zeolite and comparison of Zeolite composition with Fly Ash and Ca (OH) 2 to compressive strength, absorption and cost. Keywords: Zeolite, Cement, compressive strength, Cost


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