Effects of Artificial Silica Fume on Compressive Strength and Workability of Self-Compacting Concrete

2014 ◽  
Vol 887-888 ◽  
pp. 842-849
Author(s):  
Li Zhong Han ◽  
Shuo Qi Zhang
Keyword(s):  
Compressive Strength ◽  
High Activity ◽  
Silica Fume ◽  
Setting Time ◽  
Self Compacting Concrete ◽  
Air Content ◽  
Mineral Mixture ◽  
Early Strength ◽  
Better Than

The C60 self-compacting concrete (SCC) mixed artificial silica fume (ASF) and silica fume (SF) respectively were evaluated systematically through the items, such as compressive strength, slump loss, air content, and setting time, by which effect principles and mechanisms of ASF on compressive strength and workability of self-compacting concrete were obtained. The results indicate that ASF improves performances of fresh SCC better than SF, and it is a kind of high activity mineral mixture with high-early-strength.

Influence of Alkaline Activator on the Strength of Fly Ash-Cement Gel Sand Material

2014 ◽  
Vol 937 ◽  
pp. 472-475 ◽  
Author(s):  
Hai Yan Huang ◽  
Ai Min Gong ◽  
Kun Yuan
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Test Specimen ◽  
Rupture Strength ◽  
Setting Time ◽  
Alkaline Activator ◽  
Early Strength ◽  
Sand Material ◽  
Early Activity ◽  
Better Than

Influence of different kinds and mixing amount of the alkaline activators on the strength of fly ash-cement gel sand materials is discussed through experiment wit 29 group test specimen. The rupture strength and the compressive strength with the age of 3 and 28 days of test blocks mixed with NaOH or CaO are compared each other. The early activity of fly ash can be activated by mixing the alkaline activator. The early activity of fly ash can be activated by mixing with the alkaline activators. The setting time of fly ash-cement binders becomes better. And the early strength can be improved. The activated effect of fly ash-cement binders by different type of the alkaline activators is affected by the age of test blocks. The activated effect mixed with CaO is better than the effect mixed with NaOH.

scholarly journals Effect of Calcium Nitrate on the Properties of Portland–Limestone Cement-Based Concrete Cured at Low Temperature

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1611
Author(s):  
Gintautas Skripkiūnas ◽  
Asta Kičaitė ◽  
Harald Justnes ◽  
Ina Pundienė
Keyword(s):  
Compressive Strength ◽  
Cement Paste ◽  
Setting Time ◽  
Calcium Nitrate ◽  
Curing Temperature ◽  
Hardened Concrete ◽  
Cement Pastes ◽  
Initial Setting Time ◽  
Initial Setting ◽  
Early Strength

The effect of calcium nitrate (CN) dosages from 0 to 3% (of cement mass) on the properties of fresh cement paste rheology and hardening processes and on the strength of hardened concrete with two types of limestone-blended composite cements (CEM II A-LL 42.5 R and 42.5 N) at different initial (two-day) curing temperatures (−10 °C to +20 °C) is presented. The rheology results showed that a CN dosage up to 1.5% works as a plasticizing admixture, while higher amounts demonstrate the effect of increasing viscosity. At higher CN content, the viscosity growth in normal early strength (N type) cement pastes is much slower than in high early strength (R type) cement pastes. For both cement-type pastes, shortening the initial and final setting times is more effective when using 3% at +5 °C and 0 °C. At these temperatures, the use of 3% CN reduces the initial setting time for high early strength paste by 7.4 and 5.4 times and for normal early strength cement paste by 3.5 and 3.4 times when compared to a CN-free cement paste. The most efficient use of CN is achieved at −5 °C for compressive strength enlargement; a 1% CN dosage ensures the compressive strength of samples at a −5 °C initial curing temperature, with high early strength cement exceeding 3.5 MPa but being less than the required 3.5 MPa in samples with normal early strength cement.

Flexural behaviour of hybrid fibre (steel fiber and silica fume) reinforced self compacting composite concrete members

2014 ◽  
Vol 11 (4) ◽  
pp. 323-330 ◽  
Author(s):  
S. Arivalagan
Keyword(s):  
Compressive Strength ◽  
Silica Fume ◽  
Steel Fiber ◽  
Volume Fraction ◽  
Hardened Concrete ◽  
Flexural Behaviour ◽  
Self Compacting Concrete ◽  
Engineering Structures ◽  
Conventional Concrete ◽  
Concrete Members

The present day world is witnessing the construction of very challenging and difficult civil engineering structures. Self-compacting concrete (SCC) offers several economic and technical benefits; the use of steel fiber extends its possibilities. Steel fiber acts as a bridge to retard their cracks propagation, and improve several characteristics and properties of the concrete. Therefore, an attempt has been made in this investigation to study the Flexural Behaviour of Steel Fiber Reinforced self compacting concrete incorporating silica fume in the structural elements. The self compacting concrete mixtures have a coarse aggregate replacement of 25% and 35% by weight of silica fume. Totally eight mixers are investigated in which cement content, water content, dosage of superplasticers were all constant. Slump flow time and diameter, J-Ring, V-funnel, and L-Box were performed to assess the fresh properties of the concrete. The variable in this study was percentage of volume fraction (1.0, 1.5) of steel fiber. Finally, five beams were to be casted for study, out of which one was made with conventional concrete, one with SCC (25% silica fume) and other were with SCC (25% silica fume + 1% of steel fiber, 25% silica fume + 1.5% of steel fiber) one with SCC (35% silica fume), and other were SCC (35% Silica fume + 1% of steel fiber, 35% Silica fume + 1.5% of steel fiber). Compressive strength, flexural strength of the concrete was determined for hardened concrete for 7 and 28 days. This investigation is also done to determine the increase the compressive strength by addition of silica fume by varying the percentage.

scholarly journals The Compressive Strength of High-Performance Concrete and Ultrahigh-Performance

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
E. H. Kadri ◽  
S. Aggoun ◽  
S. Kenai ◽  
A. Kaci
Keyword(s):  
Experimental Data ◽  
Compressive Strength ◽  
Silica Fume ◽  
High Performance ◽  
High Performance Concrete ◽  
Cementitious Materials ◽  
Strength Gain ◽  
Proposed Model ◽  
Partial Cement Replacement ◽  
Better Than

The compressive strength of silica fume concretes was investigated at low water-cementitious materials ratios with a naphthalene sulphonate superplasticizer. The results show that partial cement replacement up to 20% produce, higher compressive strengths than control concretes, nevertheless the strength gain is less than 15%. In this paper we propose a model to evaluate the compressive strength of silica fume concrete at any time. The model is related to the water-cementitious materials and silica-cement ratios. Taking into account the author's and other researchers’ experimental data, the accuracy of the proposed model is better than 5%.

scholarly journals Prediction Models for the Mechanical Properties of Self-Compacting Concrete with Recycled Rubber and Silica Fume

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1821 ◽  
Author(s):  
Robert Bušić ◽  
Mirta Benšić ◽  
Ivana Miličević ◽  
Kristina Strukar
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Silica Fume ◽  
Prediction Models ◽  
Crumb Rubber ◽  
Fine Aggregate ◽  
Rubberized Concrete ◽  
Self Compacting Concrete ◽  
Recycled Rubber ◽  
European Standards

The paper aims to investigate the influence of waste tire rubber and silica fume on the fresh and hardened properties of self-compacting concrete (SCC) and to design multivariate regression models for the prediction of the mechanical properties of self-compacting rubberized concrete (SCRC). For this purpose, 21 concrete mixtures were designed. Crumb rubber derived from end-of-life tires (grain size 0.5–3.5 mm) was replaced fine aggregate by 0%, 5%, 10%, 15%, 20%, 25%, and 30% of total aggregate volume. Silica fume was replaced cement by 0%, 5%, and 10% of the total cement mass. The optimal replacement level of both materials was investigated in relation to the values of the fresh properties and mechanical properties of self-compacting concrete. Tests on fresh and hardened self-compacting concrete were performed according to the relevant European standards. Furthermore, models for predicting the values of the compressive strength, modulus of elasticity, and flexural strength of SCRC were designed and verified with the experimental results of 12 other studies. According to the obtained results, mixtures with up to 15% of recycled rubber and 5% of silica fume, with 28 days compressive strength above 30 MPa, were found to be optimal mixtures for the potential future investigation of reinforced self-compacting rubberized concrete structural elements.

scholarly journals INVESTIGATIONS ON THE RELATIONSHIP BETWEEN POROSITY AND STRENGTH OF ADMIXTURES MODIFIED HIGH PERFORMANCE SELF-COMPACTING CONCRETE

2016 ◽  
Vol 22 (4) ◽  
pp. 520-528 ◽  
Author(s):  
Beata ŁAŹNIEWSKA-PIEKARCZYK
Keyword(s):  
Compressive Strength ◽  
High Performance ◽  
Total Porosity ◽  
Self Compacting Concrete ◽  
Research Results ◽  
Air Content ◽  
New Generation ◽  
The Relationship ◽  
Viscosity Modifying Admixture

The influence of a type of new generation: superplasticizer (SP), anti-foaming admixture (AFA) and viscosity modifying admixture (VMA) on the air-content, workability of high performance self-compacting concrete (HPSCC) is analyzed in the paper. The purpose of this study was to examine the influence of type of the admixtures on porosity of HPSCC in the aspect of the compressive strength. The research results indicated that type of admixtures and its combina­tions result in different strengths of HPSCC, regardless of the total porosity characteristics of HPSCC.

Compressive strength and chloride resistance of self-compacting concrete containing high level fly ash and silica fume

2014 ◽  
Vol 64 ◽  
pp. 261-269 ◽  
Author(s):  
Watcharapong Wongkeo ◽  
Pailyn Thongsanitgarn ◽  
Athipong Ngamjarurojana ◽  
Arnon Chaipanich
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Silica Fume ◽  
Self Compacting Concrete ◽  
Chloride Resistance ◽  
High Level
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