Modified water/cement ratio law for compressive strength of fly ash concretes

Compared with natural sand, manufactured-sand is of small porosity, poor grain shape and graded, which impacts mixes workability and the properties after hardening. In Concrete, playing the role of retaining moisture water is mainly powder, including cement, powder in the sand and fly ash etc. The amount of powder has a great influence on the properties of concrete, especially on its workability. This paper mainly discusses the influence of amount of cement, cementitious materials, fly ash, water-cement ratio and other factors on the workability, compressive strength and shrinkage of concrete. The experiments show that, in the case of the low amount of cement, workability of the manufactured-sand concrete mixture, compressive strength and shrinkage deformation of test block all meet the actual requirements.

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Evaluation of Fly Ash on the Basis of Mass Equivalent, Maturity Equivalent and Permeance

MRS Proceedings ◽

10.1557/proc-65-255 ◽

1985 ◽

Vol 65 ◽

Author(s):

R. H. Mills

Keyword(s):

Compressive Strength ◽

Fly Ash ◽

Portland Cement ◽

Gas Flow ◽

Concrete Mixture ◽

Cement Ratio ◽

Water Cement Ratio ◽

Efficiency Factors ◽

Gas Tightness

ABSTRACTCombinations of two types of commercially available Fly Ash (FA) and Portland cement (PC) were tested for compressive strength and permeance to gas flow. The cementitious components were combined in the concrete mixture in proportions PC/FA = 100/0, 75/25, 60/40 and 45/55 for a range of water/cement ratio, and equal workability. Strength and maturity efficiency factors were satisfactory for 75/25 and 60/40 blends. Gas tightness was improved at all levels of Fly Ash substitution.

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Research on Static Compressive Experiment of Concrete Mixed with Limestone Power and Fly Ash

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.405-408.2801 ◽

2013 ◽

Vol 405-408 ◽

pp. 2801-2805

Author(s):

Ji Feng Liang ◽

Lei Lv ◽

Feng Wang

Keyword(s):

Compressive Strength ◽

Fly Ash ◽

Test Method ◽

Limestone Powder ◽

Experimental Result ◽

Enhancement Effect ◽

Cement Ratio ◽

Water Cement Ratio ◽

Orthogonal Test Method ◽

Powder Content

The use of orthogonal test method, the concrete mixed with limestone power and fly ash was carried out static compressive experiment, and contrast with the experiment of single doped with limestone powder and fly ash concrete. The experimental result demonstrated that the compressive strength enhancement effect of the concrete mixed with limestone power and fly ash was obvious. The importance of each factor affecting static compressive strength as follows: water-cement ratio, the amount of fly ash, the amount of limestone powder, sand ratio. The concrete compressive strength reached the maximum when the water-cement ratio reached 0.3, the limestone powder content reached 15%, the fly ash content reached 10%, and sand ratio reached 34%.

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Proportioning of concrete mixes incorporating fly ash

Canadian Journal of Civil Engineering ◽

10.1139/l76-007 ◽

1976 ◽

Vol 3 (1) ◽

pp. 68-82 ◽

Cited By ~ 9

Author(s):

Ram S. Ghosh

Keyword(s):

Compressive Strength ◽

Fly Ash ◽

Portland Cement ◽

Portland Cement Concrete ◽

Cement Concrete ◽

Cement Ratio ◽

Water Cement Ratio

A method is described for proportioning fly ash concretes to produce similar compressive strengths as normal Portland cement concrete at 3, 7, 28, and 90 days. The method is primarily based on the Abrams' law relating compressive strength and water–cement ratio. Curves are also presented, for estimating the most economical fly ash to cement ratio for a particular strength and cost of fly ash.

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Modeling Fly Ash and Water Cement Ratio Influence on High Compressive Strength of Concrete

Advances in Materials Science and Engineering ◽

10.33140/jamser.04.01.02 ◽

2020 ◽

Vol 4 (1) ◽

Keyword(s):

Compressive Strength ◽

Fly Ash ◽

Modeling And Simulation ◽

High Strength ◽

Partial Replacement ◽

Strength Development ◽

Rate Variation ◽

Cement Ratio ◽

Water Cement Ratio ◽

Mix Proportion

This paper monitors the behaviour of compressive strength influenced by variation of water cement ratios and fly ash as partial replacement for cement. The study has express the pressure from this material from water cement ratios and fly ash on the designed mixed for high strength concrete, the study generated various compressive strength base on mixed proportions, this were applied to determine strength development at different mix proportion, such application generated compressive strength values numerically and analytically, this application was applied to compare the strength rate at every twenty four hours and that of seven days interval, the growth rate variation from the water cement ratios was applied to determine the mixed proportion to be applied that will always generate better strength, pending on the level of applied impose loads, furthermore, the study monitor increase rate of fly ash as partial replacement against the percentage dosage of fly ash content, these observed strength at optimum growth were recorded at 25%, variation increase on compressive strength from water cement ratios were between [0.23,0.40 and 0.50] it was observed that water cement ratio of [0.23] obtained the maximum strength compare to [0.40,and 0.50], the study applying modeling and simulation were subjected to model validation, and both parameters developed best fits correlations, the study has express various rate these material can develop strength applying modeling and simulation.

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Implementing The Multi Expression Programming, Nonlinear Regression, Artificial Neural Network, and M5P-Tree Models to Predict The Long-Term of Compressive Strength of Cement- Mortar Modified With Fly Ash

10.21203/rs.3.rs-1123704/v1 ◽

2022 ◽

Author(s):

Aso Abdalla ◽

Ahmed Mohammed

Keyword(s):

Neural Network ◽

Artificial Neural Network ◽

Compressive Strength ◽

Fly Ash ◽

Nonlinear Regression ◽

Cement Mortar ◽

Cement Ratio ◽

Water Cement Ratio ◽

Tree Models ◽

Multi Expression Programming

Abstract In the recent decade, supplementary cementing ingredients have become an essential part of various strength ranges of concrete and cement-mortar mix design. Examples are natural materials, by-products, industrial wastes, and materials that require less energy and time to generate. Fly ash is one of the most widely utilized additional cementing ingredients. Fly ash is a by-product substance produced by coal combustion. It's being used in cement mortar and concrete as a pozzolanic substance. It has demonstrated significant influence in improving liquid and solid properties of cement mortar, such as compressive strength. Multi Expression Programming (MEP) is employed in this study to estimate the compressive strength (CS) of cement mortar modified with fly ash. The outcomes of this model were compared and evaluated with several other models such as the Nonlinear Regression model (NLR), Artificial Neural Network (ANN), and M5P-tree models that have been used in the construction fields. The input parameters included water/cement ratio (w/c), curing time (t days), and fly ash content (FA %), while the target property was compressive strength up to 360 days of curing. Four hundred fifty (450) data are collected from previous literature on modifying cement mortar with fly ash for that purpose. The water/cement ratio ranged from 0.24 to 1.2, and the fly ash was used to replace cement up to 55% (%wt. of dry cement). Based on the Coefficient of Determination (R2), Root Mean Squared Error (RMSE), Scatter Index (SI), Objective (OBJ), Mean Absolute Error (MAE), t-test value, the uncertainty of 95%, Performance Index (ρ), and boxplot for actual and predicted compressive strength. The MEP model performed better than other developed models according to evaluation tools. The compressive strength was also correlated with flexural and splitting tensile strengths using different nonlinear models.

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Use of Nondestructive Testing of Ultrasound and Artificial Neural Networks to Estimate Compressive Strength of Concrete

Buildings ◽

10.3390/buildings11020044 ◽

2021 ◽

Vol 11 (2) ◽

pp. 44

Author(s):

Fernando A. N. Silva ◽

João M. P. Q. Delgado ◽

Rosely S. Cavalcanti ◽

António C. Azevedo ◽

Ana S. Guimarães ◽

...

Keyword(s):

Neural Networks ◽

Compressive Strength ◽

Artificial Neural Networks ◽

Cross Sections ◽

Influential Factors ◽

Average Error ◽

Ann Model ◽

Cement Ratio ◽

Water Cement Ratio ◽

Artificial Neural

The work presents the results of an experimental campaign carried out on concrete elements in order to investigate the potential of using artificial neural networks (ANNs) to estimate the compressive strength based on relevant parameters, such as the water–cement ratio, aggregate–cement ratio, age of testing, and percentage cement/metakaolin ratios (5% and 10%). We prepared 162 cylindrical concrete specimens with dimensions of 10 cm in diameter and 20 cm in height and 27 prismatic specimens with cross sections measuring 25 and 50 cm in length, with 9 different concrete mixture proportions. A longitudinal transducer with a frequency of 54 kHz was used to measure the ultrasonic velocities. An ANN model was developed, different ANN configurations were tested and compared to identify the best ANN model. Using this model, it was possible to assess the contribution of each input variable to the compressive strength of the tested concretes. The results indicate an excellent performance of the ANN model developed to predict compressive strength from the input parameters studied, with an average error less than 5%. Together, the water–cement ratio and the percentage of metakaolin were shown to be the most influential factors for the compressive strength value predicted by the developed ANN model.

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Study on Preparation of Solid Concrete Brick with Recycled Aggregate

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.648.108 ◽

2013 ◽

Vol 648 ◽

pp. 108-111

Author(s):

Qi Jin Li ◽

Guo Zhong Li

Keyword(s):

Compressive Strength ◽

Mass Fraction ◽

Recycled Aggregate ◽

Preparation Process ◽

Mass Ratio ◽

Construction Waste ◽

Cement Ratio ◽

Water Cement Ratio ◽

Optimal Value

The construction waste was processed into recycled aggregate to produce solid construction waste brick with grade of MU20. The preparation process of recycled aggregate and the optimal value of mass ratio of water to cement (water cement ratio) and mass ratio of recycled aggregate to cement was studied. The results shows that when the water cement ratio is 0.86 and the mass ratio of recycled aggregate to cement is 5.5 and the dosage of activator is 0.25% (mass fraction with recycled aggregate), the compressive strength of sample is 22.5MPa and can be satisfied with the requirement of MU20 solid concrete brick.

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Assessment of Hydration Degree of Cement in the Fly Ash-Cement Pastes Based on the Calcium Hydroxide Content

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.875-877.177 ◽

2014 ◽

Vol 875-877 ◽

pp. 177-182 ◽

Cited By ~ 2

Author(s):

Xiang Li ◽

Hua Quan Yang ◽

Ming Xia Li

Keyword(s):

Fly Ash ◽

Calcium Hydroxide ◽

Cement Hydration ◽

Ash Content ◽

Content Increase ◽

Hydration Degree ◽

Equilibrium Calculation ◽

Cement Pastes ◽

Cement Ratio ◽

Water Cement Ratio

The hydration degree of fly ash and the calcium hydroxide (CH) content were measured. Combined with the equilibrium calculation of cement hydration, a new method for assessment of the hydration degree of cement in the fly ash-cement (FC) pastes based on the CH content was developed. The results reveal that as the fly ash content increase, the hydration degree of fly ash and the CH content decrease gradually; at the same time, the hydration degree of cement increase. The hydration degree of cement in the FC pastes containing a high content of fly ash (more than 35%) at 360 days is as high as 80%, even some of which hydrates nearly completely. The effect of water-cement ratio to the hydration degree of cement in the FC pastes is far less distinct than that of the content of fly ash.

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Influence of Aggregate Gradation on the Engineering Properties of Lightweight Aggregate Concrete

Applied Sciences ◽

10.3390/app8081324 ◽

2018 ◽

Vol 8 (8) ◽

pp. 1324 ◽

Cited By ~ 3

Author(s):

How-Ji Chen ◽

Chung-Hao Wu

Keyword(s):

Compressive Strength ◽

Lightweight Aggregate ◽

Normal Weight ◽

Engineering Properties ◽

Lightweight Aggregate Concrete ◽

Aggregate Gradation ◽

Aggregate Concrete ◽

Cement Ratio ◽

Water Cement Ratio ◽

Expanded Shale

Expanded shale lightweight aggregates, as the coarse aggregates, were used to produce lightweight aggregate concrete (LWAC) in this research. At the fixed water-cement ratio, paste quantity, and aggregate volume, the effects of various aggregate gradations on the engineering properties of LWAC were investigated. Comparisons to normal-weight concrete (NWC) made under the same conditions were carried out. From the experimental results, using normal weight aggregates that follow the specification requirements (standard gradation) obtained similar NWC compressive strength to that using uniform-sized aggregates. However, the compressive strength of LWAC made using small uniform-sized aggregates was superior to that made from standard-grade aggregates. This is especially conspicuous under the low water-cement ratio. Even though the workability was affected, this problem could be overcome with developed chemical additive technology. The durability properties of concrete were approximately equal. Therefore, it is suggested that the aggregate gradation requirement of LWAC should be distinct from that of NWC. In high strength LWAC proportioning, following the standard gradation suggested by American Society for Testing and Materials (ASTM) is optional.

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