scholarly journals Influence of treated mud on free shrinkage and cracking tendency of self-compacting concrete equivalent mortars

2019 ◽  
Vol 69 (334) ◽  
pp. 186
Author(s):  
F. Taieb ◽  
N. Belas ◽  
H. A. Mesbah
Keyword(s):  
Fly Ash ◽  
Autogenous Shrinkage ◽  
Mortar Sample ◽  
Self Compacting Concrete ◽  
Free Shrinkage ◽  
Total Shrinkage ◽  
Mineral Additions ◽  
Western Algeria ◽  
Cracking Tendency

The present work aims at studying the formulation and characterization of self-compacting concrete equivalent mortars, using calcined mud from the dredged sediments brought from the dam (Western Algeria) and fly ash from the Central Thermal EDF (France). Three SCCEM samples were prepared; a control mortar sample and two mortar samples containing 22% of mineral additions, with a ratio W/B = 0.47. The analysis of the experimental results obtained indicates that mortars comprising calcined mud develop greater compressive strengths than those containing fly ash. Regarding free shrinkage, mortar with calcined mud is characterized by an autogenous shrinkage similar to those of control and fly ash mortars. However, it is more sensitive to total shrinkage and drying as compared to the other mortars. Under the conditions of restrained shrinkage, control and calcined mud mortars are more sensitive to early cracking than mortar based on fly ash.

Eco-Efficient Self-Compacting Concrete with Reduced Portland Cement Content and High Volume of Fly Ash and Metakaolin

2014 ◽  
Vol 634 ◽  
pp. 172-181 ◽  
Author(s):  
Marcos A.S. Anjos ◽  
Aires Camões ◽  
Carlos Jesus
Keyword(s):  
Fly Ash ◽  
Portland Cement ◽  
Cement Content ◽  
High Volume ◽  
Hydrated Lime ◽  
Self Compacting Concrete ◽  
Flow Test ◽  
Mineral Additions ◽  
Hardened State ◽  
Low Levels

The eco-efficient, self-compacting concrete (SCC) production, containing low levels of cement in its formulation, shall contribute for the constructions' sustainability due to the decrease in Portland cement use, to the use of industrial residue, for beyond the minimization of the energy needed for its placement and compaction. In this context, the present paper intends to assess the viability of SCC production with low cement levels by determining the fresh and hardened properties of concrete containing high levels of fly ash (FA) and also metakaolin (MK). Hence, 6 different concrete formulations were produced and tested: two reference concretes made with 300 and 500 kg/m3of cement; the others were produced in order to evaluate the effects of high replacement levels of cement. Cement replacement by FA of 60% and by 50% of FA plus 20% of MK were tested and the addition of hydrated lime in these two types of concrete were also studied. To evaluate the self-compacting ability slump flow test, T500, J-ring, V-funnel and L-box were performed. In the hardened state the compressive strength at 3, 7, 14, 21, 28 and 90 days of age was determined. The results showed that it is possible to produce low cement content SCC by replacing high levels of cement by mineral additions, meeting the rheological requirements for self-compacting, with moderate resistances from 25 to 30 MPa after 28 days.

scholarly journals Setting, Strength, and Autogenous Shrinkage of Alkali-Activated Fly Ash and Slag Pastes: Effect of Slag Content

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2121 ◽  
Author(s):  
Marija Nedeljković ◽  
Zhenming Li ◽  
Guang Ye
Keyword(s):  
Fly Ash ◽  
Setting Time ◽  
Experimental Studies ◽  
Autogenous Shrinkage ◽  
Engineering Properties ◽  
Engineering Practice ◽  
Granulated Blast Furnace Slag ◽  
Alkali Activated

The engineering properties of alkali activated materials (AAMs) mainly depend on the constituent materials and their mixture proportions. Despite many studies on the characterization of AAMs, guidelines for mixture design of AAMs and their applications in engineering practice are not available. Extensive experimental studies are still necessary for the investigation of the role of different constituents on the properties of AAMs. This paper focuses on the development of alkali-activated fly ash (FA) and ground granulated blast furnace slag (GBFS) paste mixtures in order to determine their suitability for making concretes. In particular, the influence of the GBFS/FA ratio and liquid-to-binder (l/b) ratio on the slump, setting, strength, and autogenous shrinkage of the alkali activated pastes is studied.It is shown that fresh properties largely depend on the type of precursor (GBFS or FA). The slump and setting time of GBFS-rich pastes was significantly reduced. These pastes also have higher compressive strength than FA-rich pastes. The study identifies important practical challenges for application of the studied mixtures, such as the behavior of their flexural strength and high amplitudes of autogenous shrinkage of GBFS-rich mixtures. Finally, the optimum GBFS/FA ratio for their future use in concretes is recommended.

Characterization of lead-bearing phases in municipal waste combustor fly ash

1996 ◽  
Vol 54 ◽  
pp. 516-517
Author(s):  
L. L. Sutter ◽  
G. R. Dewey ◽  
J. F. Sandell
Keyword(s):  
Fly Ash ◽  
Bottom Ash ◽  
Municipal Waste ◽  
Primary Concern ◽  
Leaching Behavior ◽  
Waste Combustion ◽  
Lead And Cadmium ◽  
Lead Speciation ◽  
Accepted Practice

Municipal waste combustion typically involves both energy recovery as well as volume reduction of municipal solid waste prior to landfilling. However, due to environmental concerns, municipal waste combustion (MWC) has not been a widely accepted practice. A primary concern is the leaching behavior of MWC ash when it is stored in a landfill. The ash consists of a finely divided fly ash fraction (10% by volume) and a coarser bottom ash (90% by volume). Typically, MWC fly ash fails tests used to evaluate leaching behavior due to high amounts of soluble lead and cadmium species. The focus of this study was to identify specific lead bearing phases in MWC fly ash. Detailed information regarding lead speciation is necessary to completely understand the leaching behavior of MWC ash.

Effect of Local Mineral Additions on the Shrinkage of Self-Compacting-Concrete

2017 ◽  
Vol 8 (2) ◽  
pp. 47
Author(s):  
F. Benmerioul ◽  
Abdelkadir Makani ◽  
Ahmed Tafraoui ◽  
Said Zaouai
Keyword(s):  
Self Compacting Concrete ◽  
Mineral Additions

Synthesis and characterization of coal fly ash supported zinc oxide catalyst for biodiesel production using used cooking oil as feed

2021 ◽  
Vol 170 ◽  
pp. 302-314
Author(s):  
Adeyinka S. Yusuff ◽  
Aman K. Bhonsle ◽  
Jayati Trivedi ◽  
Dinesh P. Bangwal ◽  
Lok P. Singh ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Fly Ash ◽  
Oxide Catalyst ◽  
Coal Fly Ash ◽  
Biodiesel Production ◽  
Synthesis And Characterization ◽  
Cooking Oil ◽  
Used Cooking Oil

Fresh and mechanical characteristics of roselle fibre reinforced self-compacting concrete incorporating fly ash and metakaolin

2021 ◽  
Vol 290 ◽  
pp. 123209
Author(s):  
R. Prakash ◽  
Sudharshan N. Raman ◽  
N. Divyah ◽  
C. Subramanian ◽  
C. Vijayaprabha ◽  
...  
Keyword(s):  
Fly Ash ◽  
Mechanical Characteristics ◽  
Self Compacting Concrete

Characterization of Fly Ash Sources in the Synthesis of Geopolymer

Silicon ◽  
2021 ◽  
Author(s):  
Thulasirajan Krishnan ◽  
Revathi Purushothaman
Keyword(s):  
Fly Ash
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