scholarly journals DURABILITY OF CONCRETE CONTAINING RECYCLED ASPHALTIC CONCRETE AGGREGATE AND HIGH CALCIUM FLY ASH

2020 ◽  
Vol 19 (74) ◽  
pp. 8-14 ◽  
Author(s):  
Prinya Chindaprasirt
Keyword(s):  
Fly Ash ◽  
Concrete Aggregate ◽  
Asphaltic Concrete ◽  
High Calcium ◽  
High Calcium Fly Ash ◽  
Durability Of Concrete

scholarly journals Beneficial utilization of recycled asphaltic concrete aggregate in high calcium fly ash geopolymer concrete

2021 ◽  
pp. e00615
Author(s):  
Athika Wongkvanklom ◽  
Patcharapol Posi ◽  
Apichit Kampala ◽  
Traitot Kaewngao ◽  
Prinya Chindaprasirt
Keyword(s):  
Fly Ash ◽  
Concrete Aggregate ◽  
Geopolymer Concrete ◽  
Asphaltic Concrete ◽  
High Calcium ◽  
High Calcium Fly Ash

Performance of a Fly Ash Stabilized Pavement

1989 ◽  
Vol 178 ◽  
Author(s):  
Joakim G. Laguros ◽  
Curt Hayes
Keyword(s):  
Fly Ash ◽  
Concrete Surface ◽  
Asphaltic Concrete ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Calcium ◽  
Field Samples ◽  
High Calcium Fly Ash ◽  
Term Basis

AbstractAn expansive shale roadbase, stabilized with a Class C (high-calcium) fly ash received an 11–inch full–depth asphaltic concrete surface layer and the highway was opened to traffic six years ago. Periodic sampling and visual observations indicate that the performance of the pavement test sections are above average.Analyses of field samples showed that fly ash was effective in ameliorating the texture and plasticity of the shale and imparting strength to it on a long term basis. Pavement deflections and the extent of cracking have not increased beyond acceptable levels during the six year period.X-ray diffraction studies show a reduction of the areas under the peaks and the SEM observations reveal a dense degree of packing and reduction of the void areas. These modifications occur during the first two years of service and any changes beyond that period appear to be minor.

Use of Recycled Concrete Aggregate in High-Calcium Fly Ash Geopolymer Concrete

2016 ◽  
Vol 718 ◽  
pp. 163-168 ◽  
Author(s):  
Tawatchai Tho-In ◽  
Vanchai Sata ◽  
Trinh Cao ◽  
Prinya Chindaprasirt
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Fly Ash ◽  
Pulse Velocity ◽  
Recycled Concrete ◽  
Concrete Aggregate ◽  
Geopolymer Concrete ◽  
Comparison Results ◽  
High Calcium ◽  
High Calcium Fly Ash

The comparison results of using crushed limestone (NA) and recycled concrete aggregates (RCA) as coarse aggregates in high-calcium fly ash geopolymer concrete with and without temperature curing are presented. Local river sand with a fineness modulus of 2.1, sodium hydroxide solution concentrations of 8, 12, and 16 Molar, and sodium silicate were used to produce geopolymer concrete (GC). The curing was separated in two conditions: the first was cured at ambient temperature (AT) and another was cured at temperature of 60°C for 48 hrs. (CT). The compressive strength, thermal conductivity, and ultra pulse velocity of GC were investigated at age 7 days. The results found that RCA could be use as coarse aggregate in GC. The thermal conductivity increased with the increasing of compressive strength. Curing at 60°C yielded compressive strength about 3 times higher than that of AT. However, both AT and CT curing, GC containing RCA had thermal conductivity and ultra pulse velocity lower than those of containing NA.

Natural fiber reinforced high calcium fly ash geopolymer mortar

2020 ◽  
Vol 241 ◽  
pp. 118143 ◽  
Author(s):  
Ampol Wongsa ◽  
Ronnakrit Kunthawatwong ◽  
Sakchai Naenudon ◽  
Vanchai Sata ◽  
Prinya Chindaprasirt
Keyword(s):  
Fly Ash ◽  
Natural Fiber ◽  
Fiber Reinforced ◽  
High Calcium ◽  
High Calcium Fly Ash

scholarly journals Novel Analytical Method for Mix Design and Performance Prediction of High Calcium Fly Ash Geopolymer Concrete

Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 900
Author(s):  
Chamila Gunasekara ◽  
Peter Atzarakis ◽  
Weena Lokuge ◽  
David W. Law ◽  
Sujeeva Setunge
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Gradient Algorithm ◽  
Geopolymer Concrete ◽  
Statistical Regression ◽  
Solid Ratio ◽  
Marquardt Algorithm ◽  
High Calcium ◽  
High Calcium Fly Ash ◽  
Matlab Programming

Despite extensive in-depth research into high calcium fly ash geopolymer concretes and a number of proposed methods to calculate the mix proportions, no universally applicable method to determine the mix proportions has been developed. This paper uses an artificial neural network (ANN) machine learning toolbox in a MATLAB programming environment together with a Bayesian regularization algorithm, the Levenberg-Marquardt algorithm and a scaled conjugate gradient algorithm to attain a specified target compressive strength at 28 days. The relationship between the four key parameters, namely water/solid ratio, alkaline activator/binder ratio, Na2SiO3/NaOH ratio and NaOH molarity, and the compressive strength of geopolymer concrete is determined. The geopolymer concrete mix proportions based on the ANN algorithm model and contour plots developed were experimentally validated. Thus, the proposed method can be used to determine mix designs for high calcium fly ash geopolymer concrete in the range 25–45 MPa at 28 days. In addition, the design equations developed using the statistical regression model provide an insight to predict tensile strength and elastic modulus for a given compressive strength.

scholarly journals Influence of Particle Size Distribution of High Calcium Fly Ash on HVFA Mortar Properties

2018 ◽  
Vol 20 (2) ◽  
pp. 51
Author(s):  
Antoni . ◽  
Hendra Surya Wibawa ◽  
Djwantoro Hardjito
Keyword(s):  
Particle Size ◽  
Compressive Strength ◽  
Fly Ash ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Setting Time ◽  
High Volume ◽  
High Volume Fly Ash ◽  
High Calcium ◽  
High Calcium Fly Ash

This study evaluates the effect of particle size distribution (PSD) of high calcium fly ash on high volume fly ash (HVFA) mortar characteristics. Four PSD variations of high calcium fly ash used were: unclassified fly ash and fly ash passing sieve No. 200, No. 325 and No. 400, respectively. The fly ash replacement ratio of the cementitious material ranged between 50-70%. The results show that with smaller fly ash particles size and higher levels of fly ash replacement, the workability of the mixture was increased with longer setting time. There was an increase in mortar compressive strength with finer fly ash particle size, compared to those with unclassified ones, with the highest strength was found at those with fly ash passing mesh No. 325. The increase was found due to better compactability of the mixture. Higher fly ash replacement reduced the mortar’s compressive strength, however, the rate was reduced when finer fly ash particles was used.

scholarly journals Durability of blended cement against sodium sulphate attack and alkali-silica reaction

2021 ◽  
Author(s):  
Giri Raj Adhikari
Keyword(s):  
Fly Ash ◽  
Silica Fume ◽  
Alkali Silica Reaction ◽  
Sulphate Attack ◽  
Ternary Blends ◽  
Replacement Level ◽  
Fly Ashes ◽  
Study Results ◽  
High Calcium ◽  
High Calcium Fly Ash

Blended cements were studied for their efficacy against sulphate attack and alkali-silica reaction using six different types of fly ashes, a slag, a silica fume and four types of General Use Portland cement of different alkalinity. The study results showed that low calcium fly ash, silica fume and ground granulated blast furnace slag enhanced the sulphate resistance of cement with increased efficacy with the increase in the replacement level. However, slag and silica fume, especially at low replacement levels, exhibited increased rate of expansion beyond the age of 78 weeks. On the contrary, high calcium fly ashes showed reduced resistance to sulphate attack with no clear trend between the replacement level and expansion. Ternary blends consisting of silica fume, particulary in the amount of 5%, high calcium fly ashes and General Use (GU) cement provided high sulphate resistance, which was attributable to reduced permeability. In the same way, some of ternary blends consisting of slag, high calcium fly ash and GU cement improved sulphate resistance. Pre-blending optimum amount of gypsum with high calcium fly ash enhanced the latter's resistance to sulphate attack by producing more ettringite at the early stage of hydration. In the context of alkali-silica reaction permeability was found to be a contributing factor to the results of the accelerated mortar bar test. High-alkali, high-calcium fly ash was found to worsen the alkali silica reaction when used in concrete containing some reactive aggregates. Ternary blend of slag with high calcium fly ash was found to produce promising results in terms of counteracting alkali-silica reaction.

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