scholarly journals High Strength Geopolymers Produced from Coal Combustion Fly Ash

2013 ◽  
Vol 11 (2) ◽  
pp. 155-161
Keyword(s):  
Particle Size ◽  
Compressive Strength ◽  
Fly Ash ◽  
Coal Combustion ◽  
High Strength ◽  
Coarse Fraction ◽  
Strength Development ◽  
Fly Ashes ◽  
The Relationship ◽  
Geopolymer Material

High strength geopolymers were produced from coal combustion fly ashes. These matrices reached compressive strength values over 100 MPa, much stronger and denser than obtained by using Portland Cement binders. Size fractions were obtained by size separation techniques and the relationship between strength and particle size was investigated. The differences in compressive strength measured in the geopolymers made from fine fractions, the original fly ash and a coarse fraction of the same ash, were not significantly higher than the variation found for a reference geopolymer material. Therefore, a direct size-strength relationship could not be proven. Moreover, the chemistry and the pH of the fractions also varied, and this might as well has played a role in the strength development.

Effects of Fly Ash Particle Sizes on the Compressive Strength and Fracture Toughness of High Performance Concrete

2011 ◽  
Vol 284-286 ◽  
pp. 984-988
Author(s):  
An Shun Cheng ◽  
Yue Lin Huang ◽  
Chung Ho Huang ◽  
Tsong Yen
Keyword(s):  
Fracture Toughness ◽  
Particle Size ◽  
Compressive Strength ◽  
Fly Ash ◽  
High Performance ◽  
High Performance Concrete ◽  
Concrete Strength ◽  
Bending Test ◽  
Strength Development ◽  
Particle Sizes

The study aims to research the effect of the particle size of fly ash on the compressive strength and fracture toughness of high performance concrete (HPC). In all HPC mixtures, the water-to-binder ratio selected is 0.35; the cement replacement ratios includes 0%, 10% and 20%; the particle sizes of fly ash have three types of passing through sieves No. 175, No. 250 and No. 325. Three-point-bending test was adopted to measure the load-deflection relations and the maximum loads to determine the fracture energy (GF) and the critical stress intensity factor (KSIC). Test results show that adding fly ash in HPC apparently enhances the late age strengths of HPC either for replacement ratio of 10% or 20%, in which the concrete with 10% fly ash shows the higher effect. In addition, the smaller the particle size is the better the late age concrete strength will be. The HPC with the finer fly ash can have higher strength development and the values of GF and KSIC due to the facts of better filling effect and pozzolanic reaction. At late age, the GF and KSIC values of concrete with 10% fly ash are all higher than those with 20% fly ash.

scholarly journals Development of quaternary blended high performance concrete made with high reactivity metakaolin

2018 ◽  
Vol 7 (2.1) ◽  
pp. 79 ◽  
Author(s):  
V Srinivasa Reddy ◽  
R Nirmala
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
High Performance ◽  
High Performance Concrete ◽  
Research Work ◽  
High Strength ◽  
Supplementary Cementitious Materials ◽  
Ternary Blend ◽  
Strength Development ◽  
Strength Grade

In the last three decades, supplementary cementitious materials such as fly ash, silica fume and ground granulated blast furnace slag have been judiciously utilized as cement replacement materials as these can significantly enhance the strength and durability characteristics of concrete in comparison with ordinary Portland cement (OPC) alone. Hence, high-performance concretes can be produced at lower water/powder ratios by incorporating these supplementary materials. One of the main objectives of the present research work was to investigate synergistic action of binary, ternary and quaternary blended high strength grade (M80) concretes on its compressive strength. For blended high strength grade (M80) concrete mixes the optimum combinations are: Binary blend (95%OPC +5% FA, 95%OPC +5% MS and 95%OPC +5%MK), ternary blend (65%OPC+20%FA+15%MS) and quaternary blend (50%OPC+28%FA+11%MS+11%MK). Use of metakaolin in fly ash based blended concretes enhances compressive strength significantly and  found to be cost effective in terms of less cement usage, increased usage of fly ash and also plays a major role in early strength development  of fly ash based blended concrete.  

Effect of Gypsum on Strength Development of Steam-Cured Concrete

2011 ◽  
Vol 194-196 ◽  
pp. 1085-1088
Author(s):  
Zhi Min He ◽  
Xiao Ju Shen ◽  
Jun Zhe Liu
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Strength Development ◽  
Early Age ◽  
Strength Gain ◽  
Fly Ashes ◽  
Steam Curing ◽  
Gain Rate ◽  
Early Strength ◽  
Chemical Activator

The use of fly ashes for cement-replacement purposes, especially in high volumes, decreases rate of early strength development of the steam curing concrete. To resolve it, this paper developed a new steam-cured concrete incorporating fly ash and a chemical activator (gypsum). Experiments were conducted to investigate the mechanical properties at early and later ages of steam and standard curing concretes. The corresponding mechanism was also discussed by testing the microstructure of concretes. Results indicate that the demoulding compressive strength of steam curing concrete with 4% gypsum dosage can meet production requirements, and compressive strength of this concrete at later ages increase well. Compared with that of ordinary pure cement steam-cured concrete, concrete with 4% gypsum has a higher compressive strength gain rate. At an early age, addition of the gypsum can distinctly accelerate the extent of hydration of the steam curing fly ash cement systems, and thus the microstructure of concrete becomes denser. However, in standard curing condtion, the effect of gypsum is not distinct.

scholarly journals The Relationship of Compressive Strength and Chemically Bound Water Content of High-Volume Fly Ash-Cement Mortar

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6273
Author(s):  
Chunping Gu ◽  
Jikai Yao ◽  
Yang Yang ◽  
Jie Huang ◽  
Linhao Ma ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Water Content ◽  
Cement Mortar ◽  
Bound Water ◽  
High Volume ◽  
Strength Development ◽  
Cement Based Materials ◽  
The Relationship ◽  
Bound Water Content

Fly ash (FA) has been widely used in cement-based materials, but limited work has been conducted to establish the relationship between the compressive strength and hydration process of high-volume FA (HVFA)-cement-based material. In this study, the compressive strength and chemically bound water contents of FA-cement-based materials with different water-to-binder ratios (0.4, 0.5, and 0.6) and FA contents (0%, 30%, 40%, 50%, 60%, and 70%) were tested. Replacing more cement with FA reduced the compressive strength and of HVFA-cement-based materials. The compressive strength and chemically bound water content reduced by about 60–70% when 70% cement was replaced by FA. Water-to-binder ratio showed more significant influence on the chemically bonded water at later ages than that at early ages. Based on test results, the prediction equation of chemically bound water content was established, and its accuracy was verified. The error was less than 10%. The relationship between the compressive strength and chemically bound water content was also fitted. The compressive strength and chemically bound water content showed linear relationships for different water-to-binder ratios, hence the compressive strength of HVFA-cement mortar could be predicted with the chemically bound water content and water-to-binder ratios. The results of this study could be used for the prediction of the compressive strength development of HVFA-cement mortars, and is helpful to develop the mix design method of HVFA-cement-based materials.

Experimental Study on Particle Size Distribution of Admixtures on the Strength Influence of Low Clinker Cement

2012 ◽  
Vol 557-559 ◽  
pp. 1415-1419
Author(s):  
Bao Ying Yu ◽  
Fen Lian Xu ◽  
Yu Xin Gao
Keyword(s):  
Experimental Study ◽  
Particle Size ◽  
Compressive Strength ◽  
Fly Ash ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Strength Development ◽  
Particle Size Analyzer ◽  
Packing Effects ◽  
Scanning Electron

By testing flexural and compressive strength at different ages, the influence of particle size distribution of slag and fly ash on the strength of LCC (low clinker cement) were systematically studied. The SEM (scanning electron microscope) and laser particle size analyzer were used to study the multi-component cementitious and dense-packing effects of LCC. The results show that the strength development of LCC4 with 30% clinker could completely meet the requirements of P.O 42.5R by varying the type, content or fineness of admixtures; based on a higher fly ash and lower clinker dosage, the strength development of LCC9 is also relatively good.

Experimental Study on the Influence of Ceramist Properties Compressive Strength of Shale Ceramist Concrete

2012 ◽  
Vol 204-208 ◽  
pp. 4093-4096
Author(s):  
Wei Jun Yang ◽  
Zhi Gang He ◽  
Yi Yong
Keyword(s):  
Experimental Study ◽  
Particle Size ◽  
Compressive Strength ◽  
Concrete Strength ◽  
Aggregate Size ◽  
Strength Development ◽  
Concrete Compressive Strength ◽  
Absorption Time ◽  
The Relationship ◽  
Ceramic Cylinder

There are 6 group of experimental research to explore the relationship between shale ceramist concrete compressive strength and ceramic cylinder compressive strength, particle size, absorption time. The result shows that the strength of shale ceramist concrete is not only relevant with the ceramic cylinder compressive strength, but also relevant with the aggregate size, absorption time. For single graded particle size concrete, the strength of concrete decreased with grain size increasing. The longer time of ceramic absorption, the more sufficient the ceramist concrete strength development.

Effect of Modified Phosphogypsum on the Mechanical Properties of Super Sulphate Cement

2012 ◽  
Vol 161 ◽  
pp. 264-268 ◽  
Author(s):  
Yu Xin Gao ◽  
Bao Ying Yu ◽  
Fen Lian Xu
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Compressive Strength ◽  
Chemical Composition ◽  
High Performance ◽  
High Strength ◽  
Strengthening Mechanisms ◽  
Particle Size Analyzer ◽  
Composition Analyzer ◽  
The Relationship

The effect of phosphogypsum (PG) modified on mechanical properties of super sulphate cement (SSC) was systematically studied in this paper. Then attentions and researches were focused on the relationship between specific surface (SSA) and the mechanical properties of SSC containing PG modified by calcining, floating, neutralizing with alkali. Strengthening mechanisms of SSC were further investigated and analyzed by laser particle size analyzer and chemical composition analyzer at last. Results showed that the high strength SSC with the compressive strength 35MPa at 7 days, over 60MPa at 28 days, and some even more than 70MPa at 56 days, could be successfully developed. This research can provide a key reference for the utilization of PG and development of high performance eco-SSC.

Compressive Strength Development of High Strength High Volume Fly Ash Concrete by Using Local Material

2016 ◽  
Vol 872 ◽  
pp. 271-275 ◽  
Author(s):  
Mochamad Solikin
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
High Strength ◽  
High Volume ◽  
Strength Development ◽  
Fly Ash Concrete ◽  
Concrete Mixtures ◽  
Local Material ◽  
High Volume Fly Ash ◽  
Compressive Strength Development

This paper presents a research to produce high strength concrete incorporated with fly ash as cement replacement up to 50% (high volume fly ash concrete) by using local material. The research is conducted by testing the strength development of high volume fly ash concrete at the age of 14 days, 28 days and 56 days. As a control mix, the compressive strength of Ordinary Portland Cement (OPC) concrete without fly ash is used. Both concrete mixtures use low w/c. consequently, they lead to the use of 1 % superplasticizer to reach sufficient workability in the process of casting. The specimens are concrete cubes with the dimension of 15 cm x15 cm x 15 cm. The totals of 24 cubes of HVFA concrete and OPC concrete are used as specimens of testing. The compressive strength design of concrete is 45 MPa and the slump design is ± 10 cm. The result shows that the compressive strengths of OPC concrete at the age of 14 days, 28 days, and 56 days are 38 MPa, 40 MPa, and 42 MPa. Whereas the compressive strength of HVFA concrete in the same age of immersing sequence are 29 MPa, 39 MPa, and 42 MPa. The result indicates that HVFA concrete can reach the similar compressive strength as that of normal concrete especially at the age of 56 days by deploying low water cement ratio.

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

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.

Study on Strength Development of High Strength Concrete Containing Alccofine and Fly-Ash

2012 ◽  
Vol 2 (3) ◽  
pp. 102-104 ◽  
Author(s):  
Suthar Sunil B ◽  
◽  
Dr. (Smt.) B. K. Shah Dr. (Smt.) B. K. Shah
Keyword(s):  
Fly Ash ◽  
High Strength Concrete ◽  
High Strength ◽  
Strength Development ◽  
Strength Concrete
Sign in / Sign up

Export Citation Format

Share Document