scholarly journals INFLUENCE OF MINERAL AGGREGATE CONCENTRATION ON THE TECHNOLOGICAL PROPERTIES OF FRESH CONCRETE MIXTURE / MINERALINIŲ UŽPILDŲ KONCENTRACIJOS ĮTAKA ŠVIEŽIO BETONO MIŠINIO TECHNOLOGINĖMS SAVYBĖMS

2013 ◽  
Vol 5 (2) ◽  
pp. 54-60 ◽  
Author(s):  
Albertas Klovas ◽  
Mindaugas Daukšys ◽  
Gintas Brazas
Keyword(s):  
Fine Particles ◽  
Fresh Concrete ◽  
Flow Characteristics ◽  
Concrete Mixture ◽  
Fine Aggregate ◽  
Technological Properties ◽  
Sand Fraction ◽  
Mineral Aggregate ◽  
Air Content ◽  
Slump Flow

The main aim of this research was to investigate how the concentration of mineral aggregate influences the technological properties of concrete mixture such as: slump, flow characteristics and air content, as well as the density of concrete mixture. To sum up, 18 concrete mixture compositions were casted. First six compositions were casted in order to establish the dependence between the ratio of fine aggregate (sand fraction: 0/1 and 0/4) and the technological properties of fresh concrete mixture. Another six compositions were casted in order to investigate the link between course aggregate (gravel, fraction 4/16) concentration and the concrete mixture's technological properties. The last six mixtures were casted in order to test how the amount of fine particles (not exceeding 0.25 mm in diameter) influences the concrete mixture's technological properties. Santrauka Pagrindinis šio tyrimo tikslas – nustatyti, kaip mineralinių užpildų koncentracija veikia technologines betono mišinio savybes: slankumą, sklidumą, oro kiekį ir mišinio tankį. Iš viso buvo tirta 18 skirtingų betono mišinio sud≑čių. Pirmosios šešios sudėtys buvo analizuojamos siekiant nustatyti priklausomybę tarp smulkaus užpildo koncentracijos (smėlio frakcijos: 0/1 bei 0/4) ir technologinių betono mišinio savybių. Kitos šešios sudėtys buvo analizuojamos siekiant rasti priklausomybę tarp stambaus užpildo koncentracijos (žvirgždo frakcija 4/16) ir technologinių betono mišinio savybių. Paskutinės šešios betono mišinio sudėtys buvo analizuojamos siekiant nustatyti smulkiųjų dalelių, kurių skersmuo neviršija 0,25 mm, kiekio įtaką technologinėms betono mišinio savybėms.

scholarly journals THE INFLUENCE OF GRANITE SIFTINGS ON THE PROPERTIES OF CLEAVED SURFACE EXTERIOR CONCRETE BRICKS

2010 ◽  
Vol 2 (6) ◽  
pp. 43-49 ◽  
Author(s):  
Mindaugas Tumosa ◽  
Mindaugas Daukšys ◽  
Ernestas Ivanauskas
Keyword(s):  
Mechanical Properties ◽  
Concrete Mixture ◽  
Fine Aggregate ◽  
Technological Properties ◽  
Product Durability

Research deals with granite siftings as fine aggregate possibilities to be used for manufacturing cleaved surface exterior concrete bricks. The article describes the influence of granite siftings on the technological properties of concrete mixture and on the physical mechanical properties of cleaved surface exterior concrete bricks formed using these mixtures and forecasts product durability. The following several compositions of concrete mixture for producing exterior concrete bricks are composed: using only 0/4 fraction sand (B1) as a fine aggregate, using only 0/2 fraction granite siftings (B2), and 50% of 0/4 fraction sand replacing with 0/2 fraction granite siftings (B3) depending on the volume. The products were formed in metal moulds; at a later stage, they were cleaved in half. The technological properties of concrete mixture and the physical mechanical properties of cleaved surface exterior concrete bricks formed using the above introduced mixtures were tested forecasting product durability. The results of the conducted research reveal that due to the properly selected ratio between sand and granite siftings in the fine aggregate, granite siftings may be used for manufacturing cleaved surface exterior concrete bricks.

Rice Husk Ash as Fine Aggregate Sustainable Material for Strength Enhancement of Conventional and Self Compacting Concrete

2016 ◽  
Vol 692 ◽  
pp. 94-103
Author(s):  
S.S. Samantaray ◽  
K.C. Panda ◽  
M. Mishra
Keyword(s):  
Rice Husk ◽  
Rice Husk Ash ◽  
Fresh Concrete ◽  
Partial Replacement ◽  
Hardened Concrete ◽  
Fine Aggregate ◽  
Self Compacting Concrete ◽  
Strength Enhancement ◽  
Slump Flow ◽  
Concrete Property

Rice husk ash (RHA) is a by-product of the rice milling industry. Near about 20 million tonnes of RHA is produced annually which creates environmental pollution. Utilization of RHA as a supplementary cementitious material adds sustainability to concrete by reducing CO2 emission of cement production. But, the percentage of utilization of RHA is very less. This paper presents the results of an experimental investigation to study the effects of partial replacement of fine aggregate with RHA on mechanical properties of conventional and self-compacting concrete (SCC). The fine aggregate is replaced by RHA in conventional concrete (CC) with six different percentage by weight such as 0%, 10%, 20%, 30%, 40% and 50% having w/c ratio 0.375 with variation of super plasticiser dose, whereas in SCC the replacement of fine aggregate by RHA is 0%, 10%, 20%, 30%, 40%. The design mix for CC is targeted for M30 grade concrete. The fresh concrete test of SCC is conducted by using slump flow, T500, J-ring, L-box, U-box and V-funnel to know the filling ability, flow ability and passing ability of SCC. As fresh concrete property concerned, the result indicates that the slump flow value satisfied the EFNARC 2005 guidelines upto 30% replacement of fine aggregate with RHA whereas 40% replacement did not satisfy the guideline. As hardened concrete property concerned, the compressive strength, split-tensile strength and flexural strength of CC and SCC are determined at 7, 28 and 90 days. The test result indicates that upto 30% replacement of fine aggregate with RHA enhances the strength in CC whereas the strength enhancement in SCC upto 20% replacement.

Performance and Uniformity of Self-Compacting Concrete

2005 ◽  
Vol 1914 (1) ◽  
pp. 71-80
Author(s):  
Mohamed Nagib Abou-Zeid ◽  
Mohamed Samir Roushdy
Keyword(s):  
Coarse Aggregate ◽  
Fresh Concrete ◽  
Mechanical Vibration ◽  
Hardened Concrete ◽  
Fine Aggregate ◽  
Self Compacting Concrete ◽  
Rebound Hammer ◽  
Slump Flow ◽  
Hardened Properties ◽  
The Impact

Self-compacting concrete (SCC) can be achieved by adjusting mix proportions and incorporating adequate admixtures, such as viscosity-modifying (VM) admixtures, with no vibration. Yet, the impact of the mix proportions and the role played by the VM admixtures as opposed to those played by superplasticizer admixtures are not fully understood. There also seems to be no unique means for assessment of such concrete, and the correlation between various tests needs further work. This study aims to achieve a better understanding of the influence of mix proportions on the properties of SCC. Twenty-six mixtures were prepared with various water-to-cementitious material ratios, fine aggregate-to-coarse aggregate ratios, and admixture dosages. Fresh concrete tests, including slump flow, L-box, U-box, and hardened concrete tests, including hardened density, compressive and flexural strength, as well as the rebound hammer tests, were performed. The uniformity of SCC properties among the column specimens was examined. The results revealed that adjustment of the mix proportions has a major impact on the fresh and hardened properties of SCC. The fresh concrete tests were found to correlate well with one another, and the SCC strength was comparable to that of reference concrete made with mechanical vibration. Yet, the components of the SCC examined exhibited a remarkable uniformity of properties. Further work that should involve large specimens in which concrete properties are evaluated in various locations is needed.

scholarly journals Investigating the Effects of Using Plastic Waste as Fine Aggregate in Self Compacting Concrete

2020 ◽  
Vol 5 (1) ◽  
pp. 85-92
Author(s):  
Ankur Singh ◽  
◽  
Ankita Singh ◽  
Disha Agrawal
Keyword(s):  
Fresh Concrete ◽  
Plastic Waste ◽  
Fine Aggregate ◽  
Height Ratio ◽  
Self Compacting Concrete ◽  
Curing Period ◽  
Slump Flow ◽  
Experimental Parameters ◽  
Funnel Flow ◽  
High Deformability

Self-Compacting Concrete (SCC) has properties of low yield stress, high deformability, and good segregation resistance. It is defined as fresh concrete that flows under its own weight and does not require external vibration to undergo compaction. The aim of this was to study and find the viability of replacing sand (fine aggregate) partially with recycled plastic waste (PET). Different SCC mixes were prepared with a consistent water/cementitious ratio of 0.368 with 550 kg/m3 of paste volume. The plastic waste content was varied with 0, 2.5, 5, 7.5, 10, 12.5% by weight of sand and was designated as Fine plastic waste (FPW) and was considered as the experimental parameters. The mixes were tested against their workability properties as SCC mixes, regarding tests namely L-Box test height ratio, V-funnel flow time, and slump flow diameter. Cubic compressive strength was also measured against a 28-days curing period. The experimental results indicated that plastic in small percentages could be incorporated and can successfully partially replace fine aggregate in self-compacting concrete.

scholarly journals INFLUENCE OF THE GRANITE SCREENINGS TO THE PROPERTIES OF THE CONCRETE PAVING BLOCKS

2012 ◽  
Vol 4 (3) ◽  
pp. 89-95
Author(s):  
Mindaugas Laurinavičius ◽  
Mindaugas Daukšys ◽  
Albertas Klovas
Keyword(s):  
Mechanical Properties ◽  
Frost Resistance ◽  
Physical And Mechanical Properties ◽  
Concrete Mixture ◽  
Fine Aggregate ◽  
Technological Properties ◽  
Research Results ◽  
Concrete Mixtures ◽  
Better Than ◽  
Durability Of Concrete

The research deals with the granite screenings as fine aggregate influence on the technological properties of concrete mixtures and on the physical and mechanical properties and durability of concrete paving. The following several compositions of concrete mixture for the production of environment arrangements are researched: fine aggregate using only 0/2 fraction sand (B1), 10% of 0/2 fraction sand replacing with 0/2 fraction granite screenings (B2) and using only granite screenings (B3). Concrete mixtures were prepared in the laboratory, and concrete paving blocks – in the factory. The technological properties of concrete mixtures and physical and mechanical properties of concrete paving blocks (made from the mentioned concrete mixtures) were determined; the durability of the products in the cycles of frost resistance was forecasted. The research results reveal that due to the properly selected ratio between sand and granite screenings in the fine aggregate, the characteristics of concrete paving blocks are better than using only sand as fine aggregate.

scholarly journals Flow Characteristics and Grain Size Distribution of Granular Gangue Mineral by Compaction Treatment

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Ran Yuan ◽  
Dan Ma ◽  
Hongwei Zhang
Keyword(s):  
Weight Loss ◽  
Grain Size ◽  
Size Distribution ◽  
Grain Size Distribution ◽  
Water Flow ◽  
Fine Particles ◽  
Flow Characteristics ◽  
Test System ◽  
Chemical Components ◽  
Gangue Mineral

A test system for water flow in granular gangue mineral was designed to study the flow characteristics by compaction treatment. With the increase of the compaction displacement, the porosity decreases and void in granular gangue becomes less. The main reason causing initial porosity decrease is that the void of larger size is filled with small particles. Permeability tends to decrease and non-Darcy flow factor increases under the compaction treatment. The change trend of flow characteristics shows twists and turns, which indicate that flow characteristics of granular gangue mineral are related to compaction level, grain size distribution, crushing, and fracture structure. During compaction, larger particles are crushed, which in turn causes the weight of smaller particles to increase, and water flow induces fine particles to migrate (weight loss); meanwhile, a sample with more weight of size (0–2.5 mm) has a higher amount of weight loss. Water seepage will cause the decrease of some chemical components, where SiO2 decreased the highest in these components; the components decreased are more likely locked at fragments rather than the defect of the minerals. The variation of the chemical components has an opposite trend when compared with permeability.

Study on Techniques for Rapidly Testing the Composition of Concrete Mixture

2013 ◽  
Vol 838-841 ◽  
pp. 30-35
Author(s):  
Xiao Bin Sun ◽  
Tian Ling Du ◽  
Bo Tian
Keyword(s):  
Quality Control ◽  
Laboratory Test ◽  
Rapid Detection ◽  
Measurement Accuracy ◽  
Fresh Concrete ◽  
Concrete Mixture ◽  
Quality Problem ◽  
Detection Techniques ◽  
Concrete Quality ◽  
Practical Engineering

With regards to the quality problem of concrete that cant be found out earlier in the quality control, this paper discussed the principle to rapidly detect composition of concrete mixture and analyzed the measurement accuracy of water checker for fresh concrete through laboratory test. Experiments showed that the error in unit cement and unit water measured by instruments is relatively small and able to meet the accuracy requirements. And, the application of rapid detection techniques to the concrete quality control in practical engineering has achieved good results.

scholarly journals The Effect of the Morphology of Coarse Aggregate on the Properties of Self-Compacting High-Performance Fibre-Reinforced Concrete

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1372 ◽  
Author(s):  
Krzysztof Ostrowski ◽  
Łukasz Sadowski ◽  
Damian Stefaniuk ◽  
Daniel Wałach ◽  
Tomasz Gawenda ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
High Performance ◽  
Coarse Aggregate ◽  
Fresh Concrete ◽  
Physical And Mechanical Properties ◽  
Concrete Mixture ◽  
Rheological Parameters ◽  
Transverse Strain ◽  
Fibre Reinforced Concrete ◽  
High Performance Fibre

When understanding the effect of the morphology of coarse aggregate on the properties of a fresh concrete mixture, the strength and deformability of self-compacting high-performance fibre-reinforced concrete (SCHPFRC) can be seen to be critical for its performance. In this research, regular and irregular grains were separated from granite coarse aggregate. The morphology of these grains was described while using digital image analysis. As a result, the aspect ratio, roundness and area ratio were determined in order to better understand this phenomenon. Then, the principal rheological, physical, and mechanical properties of SCHPFRC were determined. The obtained results indicated that the morphology of the grains of coarse aggregate has an impact on the strength and stiffness properties of SCHPFRC. Moreover, significant differences in the transverse strain of concretes were observed. The morphology of the coarse aggregate also has an impact on the rheological parameters of a fresh concrete mixture. To better understand this phenomenon, the hypothesized mechanism of the formation of SCHPFRC caused by different morphology of coarse aggregate was proposed at the end of the article.

scholarly journals Rheology, Strength and Durability Characteristics of Alccofine Blended Fibre Reinforced Self Consolidating Concrete

2018 ◽  
Vol 7 (3.12) ◽  
pp. 209
Author(s):  
Bletty Baby ◽  
Jerry Anto ◽  
Basil Johny ◽  
Sreenath S
Keyword(s):  
Steel Fibre ◽  
Flow Characteristics ◽  
Strength Degradation ◽  
Fibre Content ◽  
Split Tensile Strength ◽  
Self Consolidating Concrete ◽  
Slump Flow ◽  
Strength Tests ◽  
Hardened Properties ◽  
Strength And Durability

In this study, observations were made on the effect of blending cement with fly ash and Alccofine on the fresh and hardened properties of micro steel fibre reinforced self-consolidating concrete (SCC). SCC mixes were prepared based on EFNARC guidelines. Blending has been done by replacing 5%, 10% and 15% of cement with Alccofine. Slump flow, L-box and V-funnel tests were conducted to study the flow characteristics of SCC. Compressive strength, split tensile strength, and flexural strength tests were performed to assess the strength characteristics. It was observed that the SCC with 10% replacement of cement with Alccofine showed better results than the other mixes. Further, the modification of the optimum blend with 10% Alccofine was made by adding variable percentages (0.5%, 1% and 1.5% by volume) of micro steel fibres and strength tests were conducted to optimise the fibre content. The strength degradation of the SCC with optimum Alccofine and fibre content exposed to alkaline, chloride and sulphate solutions was also studied.

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