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.

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.

Influences of Initial Curing Conditions on the Microstructure of Fly Ash Cement System

2010 ◽  
Vol 168-170 ◽  
pp. 532-536 ◽  
Author(s):  
Guo Li ◽  
En Li Lu ◽  
Peng Wang ◽  
Ou Geng ◽  
Yong Sheng Ji
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Cement Mortar ◽  
Early Age ◽  
Concrete Durability ◽  
Cement Concrete ◽  
Hydration Degree ◽  
Curing Conditions ◽  
Cement System ◽  
C 30

In order to study the influences of initial curing conditions on fly ash (FA) cement concrete durability, fly ash cement samples with 30% replacement ratio were fabricated and cured in water at 10°C, 20°C, 30°Cand 40°C for 3d, 7d, 14d and 28d respectively. Hydration degrees of fly ash at early age were measured using the selective dissolve method. Correspondingly the pore structure and morphology of FA-cement mortar and compared cement mortar were studied by using MIP and SEM methods. Then early age compressive strengths of FA-cement concrete and compared normal cement concrete were tested. Experimental results show that initial curing temperatures and ages are important factors to fly ash early age hydration degree, FA-cement system microstructure, morphology and early age compressive strength etc. High curing temperatures and longer curing time can lead higher fly ash hydration degree, and then higher compressive strength of FA-cement concrete, and make the micro-structures of fly ash-cement system denser.

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.

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.

Study of Mechanical Properties and Physical Properties of Rubberized Portland Cement Concrete

2012 ◽  
Vol 512-515 ◽  
pp. 2812-2816
Author(s):  
Wei Li ◽  
Xiao Chu Wang ◽  
Hong Tao Liu
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Portland Cement ◽  
Silica Fume ◽  
Rubber Particle ◽  
Portland Cement Concrete ◽  
Cement Concrete ◽  
Cleavage Strength ◽  
Research Situation

This test summers up the research situation of rubber powder modifier. According to tests of density, flexural strength, compressive strength and cleavage strength, this test analyzes the basic mechanical properties and the variation of rubberized portland cement concrete which is mixing the silica fume modifier. The results show that the flexural strength, compressive strength and cleavage strength of concrete may increase when silica fume concrete admixture modifiers is mixed in cement concrete. The workability, density, flexural strength, compressive strength, ratio of compressive strength and cleavage strength of rubberized portland cement concrete gradually reduced with the increase in dosage of rubber. The rubber particles mixed with concrete which can when the rubber particle size is not more than 30% of the dosage of coarse aggregate, the fine pavement of rubberized portland cement concrete can be got.

scholarly journals Study on Mechanical Properties of Self-Compacting Concrete and Its Filled in-Line Multi-Cavity Steel Tube Bundle Shear Wall

Energies ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3466 ◽  
Author(s):  
Hongbo Li ◽  
Hao Sun ◽  
Wanlong Zhang ◽  
Huiyan Gou ◽  
Qiuning Yang
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Silica Fume ◽  
Tube Bundle ◽  
Shear Wall ◽  
Steel Tube ◽  
Ash Content ◽  
Self Compacting Concrete ◽  
Middle Point

In this paper, five groups of C40 fly ash and silica fume self-compacting concrete (SCC) mix proportion tests and in-line multi-cavity steel tube bundle self-compacting concrete shear wall axial compression performance tests and numerical simulation are completed and presented. The influence of fly ash and silica fume additions on SCC mechanical properties and the filled in-line multi-cavity steel tube bundle shear wall mechanical properties are analyzed and studied. With an increase in the fly ash content from 10% to 40%, the compressive strength of self-compacting concrete increases firstly and then decreases. When the fly ash content is 30% and the silica fume content is 4%, the compressive strength of the 28 d age self-compacting concrete is the highest and the compressive strength formula of the wrapped curing SCC is proposed. The failure of steel tube bundle is multi-wave buckling failure. As the SCC is most obviously affected by the collar at the corner point of the steel tube bundle, its compressive strength is 110 MPa, and is 96 MPa higher than the concrete at the middle point of the web. The deformation resistance of SCC is obviously enhanced by the confinement effect.

Influence of Different Curing Days on Mechanical Properties of Concrete with Admixtures of Fly Ash, Blast Furnace Slag and Silica Fume

2013 ◽  
Vol 405-408 ◽  
pp. 2843-2846
Author(s):  
Jeong Eun Kim ◽  
Wan Shin Park ◽  
Sun Woong Kim ◽  
Do Gyeum Kim ◽  
Myung Sug Cho ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Blast Furnace ◽  
Fly Ash ◽  
Silica Fume ◽  
Blast Furnace Slag ◽  
High Performance ◽  
High Performance Concrete ◽  
Furnace Slag

High performance concrete (HPC) can be made with cement alone or any combination of cement and mineral components, such as, blast furnace slag, fly ash, silica fume, kaolin, rice husk ash, and fillers, such as limestone powder [. In this study, three mixes of high performance concrete (HPC) with same water-binder ratio and different types of mineral admixtures were prepared. he compressive strength, splitting tensile strength and modulus of elasticity values were measured in accordance with the ASTM. The influence of fly ash (FA), blast furnace slag (BS) and silica fume (SF) on mechanical properties of HPC were compared and analyzed. Their mechanical properties are measured at 7 days and 28 days. The results showed that specimen BS45+SF5 performed better than specimens BS30+FA25+SF5 and BS65+SF5 for the compressive strength, splitting tensile strength and modulus of elasticity.

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