Use of coal bottom ash and other waste as fine aggregates in lightweight cement-based materials

Author(s):  
B. González-Fonteboa ◽  
F. Martínez-Abella ◽  
R. Rodríguez-Álvaro ◽  
E. Rey-Bouzón ◽  
S. Seara-Paz ◽  
...  
Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5598
Author(s):  
Dongho Jeon ◽  
Woo Sung Yum ◽  
Haemin Song ◽  
Seyoon Yoon ◽  
Younghoon Bae ◽  
...  

This study investigated the use of coal bottom ash (bottom ash) and CaO-CaCl2-activated ground granulated blast furnace slag (GGBFS) binder in the manufacturing of artificial fine aggregates using cold-bonded pelletization. Mixture samples were prepared with varying added contents of bottom ash of varying added contents of bottom ash relative to the weight of the cementless binder (= GGBFS + quicklime (CaO) + calcium chloride (CaCl2)). In the system, the added bottom ash was not simply an inert filler but was dissolved at an early stage. As the ionic concentrations of Ca and Si increased due to dissolved bottom ash, calcium silicate hydrate (C-S-H) formed both earlier and at higher levels, which increased the strength of the earlier stages. However, the added bottom ash did not affect the total quantities of main reaction products, C-S-H and hydrocalumite, in later phases (e.g., 28 days), but simply accelerated the binder reaction until it had occurred for 14 days. After considering both the mechanical strength and the pelletizing formability of all the mixtures, the proportion with 40 relative weight of bottom ash was selected for the manufacturing of pilot samples of aggregates. The produced fine aggregates had a water absorption rate of 9.83% and demonstrated a much smaller amount of heavy metal leaching than the raw bottom ash.


2015 ◽  
Vol 1125 ◽  
pp. 370-376
Author(s):  
Ahmad Farhan Hamzah ◽  
Mohd Haziman Wan Ibrahim ◽  
Norwati Jamaluddin ◽  
Ramadhansyah Putra Jaya ◽  
Norul Ernida Zainal Abidin

The influence of coal bottom ash on fresh properties of self-compacting concrete (SCC) were presented in this paper. Self-compacting concrete mixtures were produced by 0.40 water/powder ratio and coal bottom ash as a replacement of fine aggregates in varying percentages of 0%, 10%, 15%, 20%, 25% and 30%. The fresh concretes were tested for the key workability belongings of self-compacting concrete such as passing and filling abilities and segregation resistance. The fresh properties were investigated by slump flow; T500 spread time, sieve segregation and L-box test. It was found that the slump flow decreased whereas the T500 spread time increased with higher coal bottom ash content. The L-box blocking ratios changed from 0.92 to 0.65 and were mostly showed satisfactory blocking ratio. The presence of coal bottom ash improved the stability of SCC mixture and the segregation index obtained from sieve test reduced with greater bottom ash content. It can be concluding that the filling and passing ability of SCC decreased when the amount of coal bottom ash content increased. In addition, the segregation resistance index decreased with higher coal bottom ash content.


2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
In-Hwan Yang ◽  
Jihun Park ◽  
Nhien Dinh Le ◽  
Sanghwa Jung

Most previous studies on the strength properties of coal bottom ash (CBA) concrete have focused on concrete with a normal compressive strength, and thus, studies on the strength properties of high-strength concrete (HSC) containing CBA are limited. Therefore, the effects of replacing fine aggregates with CBA and variations in the curing age on the strength properties of HSC with a compressive strength of greater than 60 MPa were investigated in this study. The different CBA contents included 25, 50, 75, and 100%, and the different curing ages were 28 and 56 days. The mechanical properties of the HSC with CBA incorporated as fine aggregates were examined. The experimental results revealed that CBA could be partially or totally substituted for fine aggregates during HSC production. The test results also showed that the compressive, splitting tensile, and flexural strengths of the HSC containing CBA fine aggregates slightly decreased as the CBA content increased. Moreover, useful relationships between the compressive strength, splitting tensile strength, and flexural strength were suggested, and the predictions reasonably agreed with the measurements. Compared to those of the control specimen, the pulse velocities of the HSC specimens at various CBA contents decreased by less than 3%. In addition, equations for predicting the strength values of CBA concrete by using the ultrasonic pulse velocity were suggested.


J ◽  
2021 ◽  
Vol 4 (3) ◽  
pp. 223-232
Author(s):  
Esperanza Menéndez ◽  
Cristina Argiz ◽  
Miguel Ángel Sanjuán

Ground coal bottom ash is considered a novel material when used in common cement production as a blended cement. This new application must be evaluated by means of the study of its pozzolanic properties. Coal bottom ash, in some countries, is being used as a replacement for natural sand, but in some others, it is disposed of in a landfill, leading thus to environmental problems. The pozzolanic properties of ground coal bottom ash and coal fly ash cements were investigated in order to assess their pozzolanic performance. Proportions of coal fly ash and ground coal bottom ash in the mixes were 100:0, 90:10, 80:20, 50:50, 0:100. Next, multicomponent cements were formulated using 10%, 25% or 35% of ashes. In general, the pozzolanic performance of the ground coal bottom ash is quite similar to that of the coal fly ash. As expected, the pozzolanic reaction of both of them proceeds slowly at early ages, but the reaction rate increases over time. Ground coal bottom ash is a promising novel material with pozzolanic properties which are comparable to that of coal fly ashes. Then, coal bottom ash subjected to an adequate mechanical grinding is suitable to be used to produce common coal-ash cements.


2021 ◽  
Vol 13 (14) ◽  
pp. 8031
Author(s):  
Syakirah Afiza Mohammed ◽  
Suhana Koting ◽  
Herda Yati Binti Katman ◽  
Ali Mohammed Babalghaith ◽  
Muhamad Fazly Abdul Patah ◽  
...  

One effective method to minimize the increasing cost in the construction industry is by using coal bottom ash waste as a substitute material. The high volume of coal bottom ash waste generated each year and the improper disposal methods have raised a grave pollution concern because of the harmful impact of the waste on the environment and human health. Recycling coal bottom ash is an effective way to reduce the problems associated with its disposal. This paper reviews the current physical and chemical and utilization of coal bottom ash as a substitute material in the construction industry. The main objective of this review is to highlight the potential of recycling bottom ash in the field of civil construction. This review encourages and promotes effective recycling of coal bottom ash and identifies the vast range of coal bottom ash applications in the construction industry.


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