Prediction Model for Cementing Efficiency of Fly Ash Concrete by Statistical Analyses

2011 ◽  
Vol 250-253 ◽  
pp. 1293-1296 ◽  
Author(s):  
Hong Bum Cho ◽  
Nam Yong Jee
Keyword(s):  
Fly Ash ◽  
Prediction Model ◽  
Statistical Analyses ◽  
Test Results ◽  
Construction Sites ◽  
K Value ◽  
Fly Ash Concrete ◽  
Mix Proportion ◽  
Wide Range ◽  
Binder Ratio

This paper offers the model that can estimate the cementing efficiency of fly ash (k value) based on a mix proportion of concrete containing fly ash (FA). The prediction model was derived using various statistical analyses, based on a wide range of mix proportions and a number of strength test results of ready mixed concretes used in eight construction sites. The k value increases with increasing water-binder ratio. As the FA replacement ratios increase, the k value increases at FA replacement ratios of less than 15%, but decreases at ratios of 15% or more. The k values obtained from the cementing efficiency estimate model range from 0.1 to 2.1.

Strength Prediction of Fly Ash Concrete Using Cementing Efficiency by Statistical Analysis

2011 ◽  
Vol 374-377 ◽  
pp. 1774-1777
Author(s):  
Hong Bum Cho ◽  
Nam Yong Jee ◽  
Jun Ho Shin
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Prediction Model ◽  
Mean Squared Error ◽  
Strength Prediction ◽  
Test Results ◽  
Construction Sites ◽  
Fly Ash Concrete ◽  
Squared Error ◽  
Wide Range

This paper offers a model that can estimate the 28-day compressive strength of concrete containing fly ash (FA) using the concept of cementing efficiency. Using various statistical analyses, the prediction model was derived from a wide range of mix proportions and a number of strength test results of concretes used in eight construction sites. A strength prediction model was proposed in terms of a function of the modified cement-water ratio reflecting the equations for cementing efficiency. This prediction model that has R2 of 0.88 and root mean squared error (RMSE) of 1.6MPa is capable of properly predicting the 28-day compressive strength within strength variation of FA concrete.

scholarly journals Hardened Behavior of Fly Ash Incorporated Concrete with Bottom Ash (FACB) as Partial Replacement of Fine Aggregate

2020 ◽  
Vol 9 (4) ◽  
pp. 2898-2907 ◽  
Keyword(s):  
Fly Ash ◽  
Thermal Power ◽  
Bottom Ash ◽  
Partial Replacement ◽  
Fine Aggregate ◽  
Experimental Scheme ◽  
Fly Ash Concrete ◽  
Wide Range ◽  
Binder Ratio ◽  
User Friendly

The utilization of thermal power plant waste ashes (fly ash and bottom ash) in concrete as partial replacement of cement and sand could be an important step toward development of sustainable, user-friendly and economical infrastructure. For this purpose, different concrete mixes were considered at constant binder content of 300kg/m3 and differ water-to-binder ratio (w / (c + f) mainly as 0.5 , 0.55 and 0.6. Also six wide range of fly ash replacement levels (f/c ratio) namely 0, 0.11, 0.25, 0.43, 0.67 and 1.0 were introduced in the experimental scheme. The 3-days to 180 days compressive strengths of FACB was measured at interval of 3, 7, 28, 56 and 90 days. This study also presents a relationship between the ratios of split tensile (ft) strength to compressive strength (fc). It is applicable to lean concrete having consideration of curing period at early age (3day) to long term (180days). The results of this investigation are principally important, because the comprehensive information on the dependability of the relationships has not been available for (w/c+f) and bottom ash combination. The investigational results of this work are indicated that waste-Bottom ash with the regular sizes can be used successfully as a fine aggregate in fly ash concrete (FAC). The Study also reflected in finding constant “k” by ACI code equation for fly ash and bottom ash mix concrete. It has obtained between 0.337 - 0.504. This could be useful in finding splitting tensile strength when concrete carrying fly ash and bottom ash.

scholarly journals Effect of Nano-CaCO3 on the Mechanical Properties and Durability of Concrete Incorporating Fly Ash

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Yanqun Sun ◽  
Peng Zhang ◽  
Weina Guo ◽  
Jiuwen Bao ◽  
Chengping Qu
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Second Phase ◽  
Fly Ash Concrete ◽  
Concrete Mixtures ◽  
Orthogonal Experiments ◽  
Mix Proportion ◽  
Electron Microscopy Analysis ◽  
Binder Ratio ◽  
Durability Of Concrete

Concrete mixtures consisting of nanomaterials and fly ash have been shown to be effective for improving the performance of concrete. This study investigates the combined effects of nano-CaCO3 and fly ash on the mechanical properties and durability of concrete; the mix proportion is optimized through orthogonal experiments. In the first phase, nine concrete mixtures were prepared with three water-to-binder ratios (0.4, 0.5, and 0.6), three fly ash contents (15%, 20%, and 25% replacement of the cement weight), and three nano-CaCO3 contents (1%, 2%, and 3% replacement of the cement weight). Based on the orthogonal analysis, the optimal concrete mix proportion was determined as a water-to-binder ratio of 0.4, 20% fly ash, and 1% nano-CaCO3. In the second phase, further investigations were carried out to examine the superiority of the optimal concrete and evaluate the synergistic effect of nano-CaCO3 and fly ash. The results showed that nano-CaCO3 contributed to increasing the compressive strength of fly ash concrete at the early ages, but its effect was quite limited at later ages. Furthermore, the scanning electron microscopy analysis revealed that the seeding effect, filling effect, and pozzolanic effect were the primary mechanisms for the improvement of concrete performance.

Design Method of Fly Ash Concrete Mix Proportion Based on Stable Paste-Aggregate Ratio

2012 ◽  
Vol 490-495 ◽  
pp. 2110-2114
Author(s):  
Qing Wei Sun ◽  
Han Zhu
Keyword(s):  
Fly Ash ◽  
Design Method ◽  
Concrete Strength ◽  
Cementitious Materials ◽  
Fly Ash Concrete ◽  
Mix Proportion ◽  
Absolute Volume ◽  
Concrete Mix ◽  
Binder Ratio ◽  
Current Design

According to problems with the paste to aggregate ratio increases significantly and lack of recognition to cementitious materials effect of fly ash in current design method of fly ash concrete mix proportion, the paper introduces a new design method of fly ash concrete mix proportion that completely bases on the stable paste to aggregate ratio. The thoughts of parts of cement replaced by equal fly ash or by excessive fly ash in traditional method are not used in this method that starting from the stable paste to aggregate ratio directly, and using the connections of water-binder ratio and concrete strength to deduce the calculation formula of fly ash concrete mix proportion with method of absolute volume. The paper sums up the calculation steps of this new method, and combines with an example to verify the feasibility and effectiveness of this method.

scholarly journals Experimental Study on Durability Improvement of Fly Ash Concrete with Durability Improving Admixture

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Hong-zhu Quan ◽  
Hideo Kasami
Keyword(s):  
Fly Ash ◽  
Experimental Studies ◽  
Drying Shrinkage ◽  
Replacement Ratio ◽  
Fly Ash Concrete ◽  
Air Content ◽  
Carbonation Resistance ◽  
Binder Ratio ◽  
Water Binder Ratio

In order to improve the durability of fly ash concrete, a series of experimental studies are carried out, where durability improving admixture is used to reduce drying shrinkage and improve freezing-thawing resistance. The effects of durability improving admixture, air content, water-binder ratio, and fly ash replacement ratio on the performance of fly ash concrete are discussed in this paper. The results show that by using durability improving admixture in nonair-entraining fly ash concrete, the compressive strength of fly ash concrete can be improved by 10%–20%, and the drying shrinkage is reduced by 60%. Carbonation resistance of concrete is roughly proportional to water-cement ratio regardless of water-binder ratio and fly ash replacement ratio. For the specimens cured in air for 2 weeks, the freezing-thawing resistance is improved. In addition, by making use of durability improving admixture, it is easier to control the air content and make fly ash concrete into nonair-entraining one. The quality of fly ash concrete is thereby optimized.

scholarly journals Prediction Model of Asphalt Content of Asphalt Mixture Based on Dielectric Properties

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Yanhui Zhong ◽  
Yilong Wang ◽  
Bei Zhang ◽  
Xiaolong Li ◽  
Songtao Li ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Prediction Model ◽  
Room Temperature ◽  
Asphalt Mixture ◽  
Aggregate Size ◽  
Asphalt Pavements ◽  
Test Results ◽  
Wide Range ◽  
Asphalt Content ◽  
Ground Penetrating

The rapid detection of asphalt content in asphalt mixture is of great significance to the quality evaluation of asphalt pavement. Based on the dielectric properties of an asphalt mixture, the prediction model of asphalt content is deduced theoretically using three types of dielectric models: Lichtenecker-Rother (L-R) model, Rayleigh model, and Bottcher equation. Under the condition of laboratory mixing at room temperature (about 20–25°C), a dielectric test of asphalt mixture is conducted to verify the applicability of the model. The test results indicate that the dielectric constant of the asphalt mixture is inversely proportional to the asphalt content and directly proportional to the aggregate size of the mixture. Among the models, the Rayleigh model has a wide range of applications and exhibits a high accuracy, with an average relative error of only 1.86%. The results provide a theoretical basis for the nondestructive testing of asphalt pavements using ground-penetrating radar.

Influence of Mixture Proportion and Curing Condition on Contribution of Fly Ash to Strength of Concrete

2006 ◽  
Vol 302-303 ◽  
pp. 235-241 ◽  
Author(s):  
F.-R. Wu ◽  
Yoshihiro Masuda ◽  
S. Nakamura ◽  
S. Sato
Keyword(s):  
Fly Ash ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Cement Content ◽  
Ash Content ◽  
K Value ◽  
Fly Ash Concrete ◽  
Curing Condition ◽  
Strength Difference

To investigate the strength efficiency of fly ash in concrete, the contribution of fly ash to strength, k value was calculated with the equation: the strength difference between fly ash concrete and control concrete with no fly ash due to the different fly ash content divides by the strength difference between both control concrete with no fly ash due to the different cement content which equals to the former different fly ash content. The k values were organized with fly ash specific surface area, concrete curing condition and age of specimens. Based on a large number of data collected from several proceedings and journals published in Japan during 1981 to 2003, the influences of fly ash property, mixture proportion and curing condition on k value were investigated. Within the range of study the following observations were made: (1) When fly ash concrete kept in moist curing, the k value of fly ash with specific surface area from 250 to 500 m2/kg is averagely 0.5 to 0.6 or higher at an age of 91 days and later, whereas that of fly ash with specific surface area from 150 to 250 m2/kg is around 0.4 to 0.5, and with some cases contributing little to the strength. (2) In the range of a portland cement content of 250 to 450 kg/m3, the strength contribution tends to increase as the cement content increases. (3) The contributions of fly ash to strength at 91 and 364 days are 1.44 to 1.97 times as large as those at 28 days, respectively, by standard curing, but conversely decrease to 0.75 to 0.79 times those at 28 days by air curing.

Research on Some Properties of Fly Ash Concrete with Nano-CaCO3 Middle Slurry

2009 ◽  
Vol 405-406 ◽  
pp. 186-190 ◽  
Author(s):  
Kuang Liang Qian ◽  
Tao Meng ◽  
Xiao Qian Qian ◽  
Shu Lin Zhan
Keyword(s):  
Fly Ash ◽  
Chloride Ion ◽  
Test Results ◽  
Hydration Degree ◽  
Fly Ash Concrete

Some long-term properties such as anti-carbonation properties, shrinkage, penetrability of chloride ion of fly ash concrete with nano-CaCO3 middle slurry were studied. Test results showed that the properties of anti-carbonation and impenetrability for chloride of fly ash concrete increased by adding nano-CaCO3 middle slurry because the tiny hole was filled by nano-CaCO3 and the density of concrete increased. But at the same time, the shrinkage of fly ash concrete with and without nano-CaCO3 was the same. Results of SEM also implied the hydration degree of fly ash could be increased by nano-CaCO3.

Proposal of a Simplified Prediction Formula for Compressive Strength of Fly Ash Concrete

2011 ◽  
Vol 287-290 ◽  
pp. 1201-1208 ◽  
Author(s):  
Wen Bo Zhang ◽  
Isamu Yoshitake ◽  
Tadashi Saitoh
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Early Age ◽  
Strength Ratio ◽  
Prediction Formula ◽  
Replacement Ratio ◽  
Fly Ash Concrete ◽  
Wide Range ◽  
Water Ratio ◽  
Simplified Formula

To propose a prediction formula of compressive strength of concretes containing fly ash (FA concrete), over 1600 strength data are collected from previous studies and discussed in this study. In particular, the study focuses on developing strengths of FA concrete. The study deals with test data of concrete with wide range of FA replacement, namely 0-50% by mass of cement. Compressive strength at age of 7 days has strongly relation to the cement-water ratio, so the strength can be predicted by using only water and cement contents. In addition, early age strengths within 7 days can be estimated by using the Goral curve based on strength ratio. Strength after the age of 7 days can be predicted by using replacement ratio of fly ash because the strength ratios are proportional to the replacement ratio. Based on the findings, a simplified formula for predicting compressive strength at various ages is proposed in the paper.

scholarly journals EFFECTS OF MIX PROPORTION ON ELECTRICAL RESISTIVITY OF CONCRETE WITH FLY ASH

2017 ◽  
Vol 7 (2) ◽  
pp. 53-65
Author(s):  
Su Wai Hnin ◽  
Pakawat Sancharoen ◽  
Somnuk Tangtermsirikul
Keyword(s):  
Compressive Strength ◽  
Electrical Resistivity ◽  
Fly Ash ◽  
Chloride Penetration ◽  
Mix Proportion ◽  
Binder Ratio ◽  
Saturated Concrete ◽  
Paste Content ◽  
Water Saturated ◽  
Water Binder Ratio

The aim of this paper is to investigate the effects of mix proportion on electrical resistivity of concrete with fly ash. The electrical resistivity of concrete is measured by using four Wenner probes. The varied parameters in this study were water/binder ratio, fly ash content, and paste content. Electrical resistivity of water-saturated concrete at several different ages was studied and compared with compressive strength and rapid chloride penetration. Based on experimental results, a good relationship was obtained between results of compressive strength and rapid chloride penetration with electrical resistivity of concrete. The results of this study can be applied further to predict electrical resistivity of concrete when mix proportions are provided. According to the results, lower water/binder ratio concrete had higher resistivity than those with higher water/binder ratios. When cement was replaced at 40% by fly ash, electrical resistivity increased four times when compared to that of OPC concrete.

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