scholarly journals Impact of Silica Nanoparticles on the Durability of fly Ash Concrete

2021 ◽  
Vol 7 ◽  
Author(s):  
D. Ali ◽  
U. Sharma ◽  
R. Singh ◽  
L. P. Singh
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Silica Nanoparticles ◽  
Silica Fume ◽  
Silica Nanoparticle ◽  
Fly Ash Concrete ◽  
Durability Properties ◽  
Concrete Mix

In the present study, the mechanical and durability properties of silica nanoparticle (SNP)-incorporated fly ash (FA) concrete mix were examined after 365 days of exposure. The dosages of FA replaced by cement in the present study were 30%, 40%, and 50%, while 3% SNPs were added by the weight of cement in the FA incorporated mix. For a comparison of SNPs with silica fume (SF), 6% SF was added (by the weight of cement) and entire casting was performed at a constant water to binder (w/b) ratio of 0.29. The present work is the extension of a previous study wherein durability properties of the same mixes were reported for up to 180 days of exposure. Compressive strength results show that in the presence of SNPs, the enhancement in compressive strength was in the range of 10–14%, while, in presence of SF, 8–10% of the enhancement was observed as compared to control. However, exposed samples in a carbonation environment showed that the compressive strength of the control and SF incorporated mix increased, while SNP-incorporated samples showed negligible enhancement. Further, sulphate exposed mix show that compressive strength decreases, however, the SNP-incorporated mix showed the lowest reduction compared to other mixes. Therefore, the study shows that the SNP-incorporated mix has higher mechanical properties and more durability compared to other mixes in a severe environment.

scholarly journals Strength Characteristics of High Strength Concrete (HSC) with and without Coarse Aggregate

2019 ◽  
Vol 9 (2) ◽  
pp. 4701-4704
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Flexural Strength ◽  
Silica Fume ◽  
High Strength Concrete ◽  
Mechanical Characteristics ◽  
Coarse Aggregate ◽  
High Strength ◽  
Set Up

This paper aimed to investigate the mechanical characteristics of HSC of M60 concrete adding 25% of fly ash to cement and sand and percentage variations of silica fumes 0%,5% and 10% to cement with varying sizes of 10mm,6mm,2mm and powder of granite aggregate with w/c of 0.32. Specimens are tested for compressive strength using 10cm X 10cmX10cm cubes for 7,14,28 days flexural strength was determined by using 10cmX10cmX50cm beam specimens at 28 days and 15cm diameter and 30cm height cylinder specimens at 28 days using super plasticizers of conplast 430 as a water reducing agent. In this paper the experimental set up is made to study the mechanical properties of HSC with and without coarse aggregate with varying sizes as 10mm, 6mm, 2mm and powder. Similarly, the effect of silica fume on HSC by varying its percentages as 0%, 5% and 10% in the mix studied. For all mixes 25% extra fly ash has been added for cement and sand.

MECHANICAL PROPERTIES OF FLY ASH-BASED ALKALI-ACTIVATED CEMENT USING A STATISTICAL ANALYSIS TECHNIQUE

2014 ◽  
Vol 1 (1) ◽  
Author(s):  
Hyuk Lee ◽  
Vanissorn Vimonsatit
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Statistical Analysis ◽  
Fly Ash ◽  
Silica Fume ◽  
Dry Density ◽  
Analysis Method ◽  
Solid Ratio ◽  
Alkali Activated ◽  
Alkali Activated Cement

This paper presents the mechanical properties of fly ash-based alkali-activated cement (AAC). A statistical analysis method was used to determine the effect of mix proportion parameters on the dry density and compressive strength of fly ash-based AAC pastes and mortars. For that purpose, sample mixtures were designed according to Taguchi’s experimental design method, i.e., in a L9 orthogonal array. Four factors were selected: “silica fume content” (SF), “sand to solid ratio” (s/c), “liquid to solid ratio” (l/s), and “superplasticiser content” (SP). The experimental results were analysed by using signal to noise for quality control of each mixture, and analysis of variance (ANOVA) was used to determine the significant effect on the compressive strength of fly ash-based AAC. Furthermore, a regression-analysis method was used to predict the compressive strength according to the variation of the four factors. Results indicated that silica fume is the most influencing parameter on compressive strength, which could be decreased by superplasticiser and l/s ratio. There is no significant effect of sand-to-cementitious ratio on compressive strength of fly ash-based AAC. The dry density decreases as the sand-to-cementitious ratio is decreased. The increasing l/s ratio and superplasticiser dosage could further decrease the dry density of fly ash-based AAC.

Effect of steel slag powder, fly ash, and silica fume on the mechanical properties and durability of cement mortar

2019 ◽  
Vol 9 (9) ◽  
pp. 1049-1054
Author(s):  
Yunxia Lun ◽  
Fangfang Zheng
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Silica Fume ◽  
Cement Mortar ◽  
Steel Slag ◽  
Mineral Admixtures ◽  
Partial Replacement ◽  
Slag Powder ◽  
Steel Slag Powder

This study is aimed at exploring the effect of steel slag powder (SSP), fly ash (FA), and silica fume (SF) on the mechanical properties and durability of cement mortar. SSP, SF, and FA were used as partial replacement of the Ordinary Portland cement (OPC). It was showed that the compressive and bending strength of steel slag powder were slightly lower than that of OPC. An increase in the SSP content caused a decrease in strength. However, the growth rate of compressive strength of SSP2 (20% replacement by the weight of OPC) at the curing ages of 90 days was about 8% higher than that of OPC, and the durability of SSP2 was better than that of OPC. The combination of mineral admixtures improved the later strength, water impermeability, and sulfate resistance compared with OPC and SSP2. The compressive strength of SSPFA (SSP and SF) at 90 days reached 70.3 MPa. The results of X-ray diffraction patterns and scanning electron microscopy indicated that SSP played a synergistic role with FA or SF to improve the performance of cement mortar.

Physical and mechanical characteristics of cement mortars and concretes with addition of clinoptilolite from Beli Plast deposit (Bulgaria), silica fume and fly ash

Clay Minerals ◽  
2011 ◽  
Vol 46 (2) ◽  
pp. 213-223 ◽  
Author(s):  
V. Lilkov ◽  
I. Rostovsky ◽  
O. Petrov
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Silica Fume ◽  
Mechanical Characteristics ◽  
Physical And Mechanical Properties ◽  
Specific Pore Volume ◽  
Cement Mortars ◽  
Physical And Mechanical Characteristics

AbstractCement mortars and concretes incorporating clinoptilolite, silica fume and fly ash were investigated for changes in their physical and mechanical properties. It was found that additions of 10% clinoptilolite and 10% Pozzolite (1:1 mixture of silica fume and fly ash) were optimal for improvement of the quality of the hardened products, giving 8% and 13% increases in flexural and compressive strength respectively. The specific pore volume of the mortars incorporating zeolite decreased between the 28th and 180th day to levels below the values for the control composition due to the fact that clinoptilolite exhibits its pozzolanic activity later in the hydration. In these later stages, pores with radii below 500 nm increased at the expense of larger pores. The change in the pore-size distribution between the first and sixth months of hydration occurs mostly in the mortars with added zeolite.

Comparative Investigations of some Properties Related to Durability of Cement Concretes Containing Different Fly Ashes

2014 ◽  
Vol 1054 ◽  
pp. 154-161 ◽  
Author(s):  
Wojciech Kubissa ◽  
Barbara Pacewska ◽  
Iwona Wilińska
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Silica Fume ◽  
Low Permeability ◽  
Concrete Durability ◽  
Cement Concrete ◽  
Fly Ashes ◽  
Chloride Migration ◽  
Good Workability

The results of research of mechanical properties and selected other characteristics influencing durability of cement concretes containing cement substitutes were presented. Cement concretes performed with conventional fly ash, fluidised fly ash and their mixture were investigated. The obtained results were compared with findings registered for two types of concrete performed without cement replacements and with cement concrete containing silica fume. The results have shown that cement concrete with predetermined 28-day compressive strength of about 50 MPa and good workability may be obtained using different cement replacements. Generally, these cement concretes exhibited also favorable properties related to concrete durability, i.e. low permeability and sorptivity, and significant reduction of chloride migration coefficient. Favourable results were obtained for cement concrete containing mix of conventional and fluidised fly ashes: good workability, compressive strength after 28th day exceeding 50 MPa, low permeability of water, and low sorptivity, as well as low coefficient of chloride migration. These features were similar as for cement concrete containing silica fume.

Influence of Variable Temperature Curing on Mechanical Properties of Fly Ash Concrete

2011 ◽  
Vol 250-253 ◽  
pp. 178-181
Author(s):  
Ya Ding Zhao ◽  
Xue Ying Li ◽  
Ling Chao Kong ◽  
Wei Du
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Elastic Modulus ◽  
Fly Ash ◽  
Flexural Strength ◽  
Variable Temperature ◽  
Improve Performance ◽  
Curing Conditions ◽  
Fly Ash Concrete ◽  
Better Than

Under variable temperature curing conditions(30 oC ~70 oC), concrete with fly ash whose compressive strength, flexural strength, and dynamic elastic modulus are better than ones without fly ash.Compared with constant temperature 20oC, 50 oC and 70 oC, variable temperature curing(VTC) is benefit for the improvement of mechanical properties of 30% fly ash concrete, but which is no advantage to improve performance of 50% fly ash concrete.

Predictive compressive strength models for green concrete

2019 ◽  
Vol 11 (2) ◽  
pp. 169-184 ◽  
Author(s):  
Yasmin Murad ◽  
Rana Imam ◽  
Husam Abu Hajar ◽  
Dua’a Habeh ◽  
Abdullah Hammad ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Silica Fume ◽  
Gene Expression Programming ◽  
Plain Concrete ◽  
Content Type ◽  
Experimental Database ◽  
Green Concrete ◽  
Fly Ash Concrete ◽  
Strength Models

Purpose The purpose of this paper is to develop new predictive models using gene expression programming in order to estimate the compressive strength of green concrete, as accurate models that can predict the compressive strength of green concrete are still lacking. Design/methodology/approach To estimate the compressive strength of plain concrete, fly ash concrete, silica fume concrete and concrete with silica fume and fly ash, four predictive GEP models are developed. The GEP models are developed using a large and reliable database that is collected from the literature. The GEP models are validated using the collected experimental database. Findings The R2 is used to statistically evaluate the performance of the GEP models wherein the R2 values for the GEP models including all data are 85, 95, 80 and 95.3 percent for the models that predict the compressive strength of plain concrete, fly ash concrete, silica fume concrete and concrete with silica fume and fly ash, respectively. Originality/value The GEP models have high R2 values and low RMSE and MAE, which indicates that they are capable of predicting the compressive strength of green concrete with a reasonable accuracy.

Evaluation of Relations among Basic Mechanical Properties of Fly-Ash Concrete with Machine-Made Sand

2013 ◽  
Vol 438-439 ◽  
pp. 15-19
Author(s):  
Chun Jie Liu ◽  
Chun Yan Jia ◽  
Chang Yong Li
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Elastic Modulus ◽  
Fly Ash ◽  
Concrete Structures ◽  
Ordinary Concrete ◽  
Strength Grade ◽  
Fly Ash Concrete ◽  
Axial Compressive Strength

Although the machine-made sand was widely used for concrete in recent years in China, it was short of studies on the relations among the basic mechanical properties of fly-ash concrete with machine-made sand (MSFAC). However, these relations such as the compressive strength, the tensile strength and the elastic modulus with the cubic compressive strength (i.e. strength grade) are the basis of design for concrete structures. This paper summarizes the test data from the published references, and discusses the relations among these properties by statistical analyses compared with those of ordinary concrete. The results show that only the tensile strength of MSFAC can be safely forecasted by the same formula of ordinary concrete specified in current Chinese design code. When the strength grade is higher than C45, the axial compressive strength of MSFAC is largely forecasted by the formula of ordinary concrete. The elastic modulus of MSFAC is larger than that of ordinary concrete, which should be prospect by the formula in this paper. This work gives out some cautions for the proper use of the MSFAC in concrete structures.

Effect of Treated Polyethylene Waste on some Mechanical Properties of Cement Mortar

2020 ◽  
Vol 870 ◽  
pp. 3-9
Author(s):  
Nahla N. Hilal ◽  
Mohammed T. Nawar ◽  
Abdulkader I. Al-Hadithi
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Silica Fume ◽  
Cement Mortar ◽  
Volume Density ◽  
Modulus Of Rupture ◽  
Reactive Material ◽  
All Treatment

In the present work, the properties of Polyethylene Waste cement mortar containing Polyethylene Waste treated by a reactive material are tested and compared with normal Polyethylene Waste and normal cement mortar. The Polyethylene, which is cured by a different reactive material such as: (cement, a fly ash and silica fume) is used as fine as aggregate a volumetric fractional replacing of the sand in a cement mortar. The percent of replacement was 10% by volume, density, compressive strength, modulus of rupture, and absorption are tested for all mixes at variable ages. The current results display that the cure of Polyethylene by cement were significantly improves the characteristics of Polyethylene cement mortar. Moreover, the results show that all treatment improved properties of cement mortar as a compared with Polyethylene without treatment.

scholarly journals Studi Mengenai Perancangan Campuran Beton Abu Terbang dengan Pendekatan Blended Sand (Hal. 88-97)

2018 ◽  
Vol 4 (4) ◽  
pp. 88
Author(s):  
Reza Fauzi Nirwan ◽  
Priyanto Saelan
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Aggregate Size ◽  
Maximum Aggregate Size ◽  
Fine Aggregate ◽  
Concrete Compressive Strength ◽  
Fly Ash Concrete ◽  
Is Research ◽  
Strength Tests ◽  
Concrete Mix

ABSTRAKPenelitian ini dilakukan untuk mengetahui hasil perancangan campuran beton abu terbang yang mensubtitusi semen dengan cara pendekatan sand blended, yaitu abu terbang yang mensubtitusi semen diperlakukan sebagai agregat halus, sehingga agregat halus merupakan campuran dari pasir dan abu terbang. Penelitian dilakukan dengan kuat tekan rencana 20 MPa dan 30 MPa. Substitusi semen oleh abu terbang sebesar  10 %, 20 %, dan 30 % dari berat semen. Ukuran maksimum agregat kasar yang digunakan adalah 20 mm, dan pasir dengan modulus kehalusan 2,768, slump rencana 6 cm dan 10 cm. Hasil pengujian tekan silinder beton berdiameter 10 cm dan tinggi 20 cm menunjukkan bahwa kuat tekan beton abu terbang yang dihasilkan berdekatan dengan beton acuan yaitu beton tanpa abu terbang, untuk semua kadar abu terbang yaitu sampai dengan kadar subtitusi semen oleh abu terbang sebesar 30 %. Pendekatan sand blended dapat dilakukan dalam perancangan campuran beton abu terbang.Kata Kunci : beton abu terbang, kuat tekan, pasir blendedABSTRACTThis is research was performed to know the result of the test of fly ash concrete mix designed by sand blended method. Fly ash will be treated as fine aggregate so that the total fine aggregate is the consist of fly ash and sand. 20 MPa and 30 MPa concrete mix are designed for 10 %, 20 % and 30 % by weight of cement subtitution by fly ash. Concrete mix use 20 mm maximum aggregate size, finess modulus of sand 2.768, and 6 cm and  10 cm slump. Compressive strength tests of 10 cm diameter and 20 cm height cylinder showed that the stength of fly ash concrete is the same as the strength of initial concrete. Fly ash concrete mix can be designed by sand blended approximation.Keywords : fly ash concrete, compressive strength, blended sand

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