Wet packing of crushed rock fine aggregate

2008 ◽  
Vol 42 (5) ◽  
pp. 631-643 ◽  
Author(s):  
W. W. S. Fung ◽  
A. K. H. Kwan ◽  
H. H. C. Wong
Keyword(s):  
Crushed Rock ◽  
Fine Aggregate

scholarly journals SHAPE ANALYSIS OF FINE AGGREGATES USED FOR CONCRETE

2016 ◽  
Vol 35 (3) ◽  
pp. 159 ◽  
Author(s):  
Huan He ◽  
Luc Courard ◽  
Eric Pirard ◽  
Frederic Michel
Keyword(s):  
Image Analysis ◽  
Coarse Aggregate ◽  
Diffraction Method ◽  
Crushed Rock ◽  
Fine Aggregate ◽  
River Sand ◽  
Fine Aggregates ◽  
Essential Components ◽  
Different Origins ◽  
Shape Characterization

Fine aggregate is one of the essential components in concrete and significantly influences the material properties. As parts of natures, physical characteristics of fine aggregate are highly relevant to its behaviors in concrete. The most of previous studies are mainly focused on the physical properties of coarse aggregate due to the equipment limitations. In this paper, two typical fine aggregates, i.e. river sand and crushed rock, are selected for shape characterization. The new developed digital image analysis systems are employed as the main approaches for the purpose. Some other technical methods, e.g. sieve test, laser diffraction method are also used for the comparable references. Shape characteristics of fine aggregates with different origins but in similar size ranges are revealed by this study. Compared with coarse aggregate, fine grains of different origins generally have similar shape differences. These differences are more significant in surface texture properties, which can be easily identified by an advanced shape parameter: bluntness. The new image analysis method is then approved to be efficient for the shape characterization of fine aggregate in concrete.

scholarly journals Flexural Performance of Self Consolidating, Self Cured Concrete Beams -Incorporating Sap

2019 ◽  
Vol 8 (12) ◽  
pp. 1812-1816
Keyword(s):  
Internal Curing ◽  
Flexural Behavior ◽  
Crushed Rock ◽  
Fine Aggregate ◽  
Flow Properties ◽  
Self Compacting Concrete ◽  
Conventional Concrete ◽  
Ambient Temperatures ◽  
Flexural Performance ◽  
Passing Ability

Self- Compacting Concrete (SCC) is a sort of Concrete that possesses high flowing, passing ability, which can be placed and compacted due to its own weight without any peripheral compaction effort, at the same time it is cohesive enough to be handled without any segregation or bleeding distinctiveness. This Research Study presents an experimental exploration Flexural behavior of Internal cured Self Compacting Concrete (ICSCC) with fine aggregate substitution by Crushed Rock Fines (CRF) at 0%& 30%, with silica fume as supplementary for cementitious material. Mix Proportions for ICSCC, controlled specimens SCC and Normal Conventional Concrete (NCC) M40 grade is arrived. For each concrete mixes 150mm X 150mm x150mm cubes and 100 X230 X 1500mm beams were casted and exposed to internal curing at ambient temperatures for 7 and 28 days. The results arrived for ICSCC mixes were paralleled with controlled specimens of SCC and NCC. Appropriate materials were selected to have a better performance to ensure efficient internal curing in the concrete mass. The Flow Properties of SCC, ICSCC mixes have been performed as per EFNARC Stds and results of flow properties were within limits. Analysis made from the experimental exploration is accomplished that the Flexural characteristics for ICSCC mixes curried at ambient temperature found acceptable

scholarly journals Durability studies on ready mix concrete using mineral admixtures and manufactured sand

2021 ◽  
Author(s):  
Jagadish Vengala ◽  
◽  
K Ramesh ◽  
Manjunath M ◽  
Manish S Dharek ◽  
...  
Keyword(s):  
Fast Track ◽  
Chloride Ions ◽  
Experimental Results ◽  
Mineral Admixtures ◽  
Crushed Rock ◽  
Fine Aggregate ◽  
River Sand ◽  
Manufactured Sand ◽  
Strength And Durability ◽  
Ready Mix Concrete

To meet the intensifying demand of fine aggregate in construction sector, manufactured sand has become a viable alternative to the river sand. Ready mix concrete (RMC) is playing vital role in fast-track construction particularly in Tire-II cities in India. The strength and durability concerns about using 100% manufactured sand along with mineral admixtures in RMC plant needs to be addressed through suitable experimental demonstrations. This research gives the experimental results on strength and durability studies of concrete carried out on samples obtained from RMC Plant by making use of manufactured sand containing (50% of crushed sand and 50% of the crushed rock fines) as replacement for natural sand. Trials on partial replacing cement with fly ash content of 33% and GGBS of 40% has also been carried out. Compressive and split-tensile strength studies were conducted on cubes (150mmx150mmx150mm) and cylinders (150mmx300mm) at 7, 14 & 28 days of curing. Non-Destructive tests such as Ultra Sonic Pulse Velocity (UPV) and rebound hammer tests were conducted to assess the quality of these mixes. Durability tests were conducted and comparison of the % of loss in mass and % of loss in strength for concrete samples subjected to acid attack, sulphate attack, alkaline attack tests were also carried out. Rapid chloride permeability test (RCPT) was conducted to check the concrete resistance against chloride ions penetration. The experimental results revealed that the use of 100% manufactured sand along with mineral admixtures in producing ready mix concrete is a good choice in view of the non-availability of river sand to meet the demands of fast-track construction projects.

scholarly journals An Investigation to Replace sand with Kunkur Quarry dust as fine Aggregates in Concrete

2020 ◽  
Vol 10 (2) ◽  
pp. 5-9
Keyword(s):  
Construction Industry ◽  
Structural Strength ◽  
Raw Materials ◽  
Crushed Rock ◽  
Hardened Concrete ◽  
Fine Aggregate ◽  
Design Strength ◽  
Manufactured Sand ◽  
Fine Aggregates ◽  
Drying Up

Following a national outcry by environment management organizations both governmental and non-governmental to preserve rivers it’s seen to be strongly backed by political leaders which is posing a great threat to the future of construction industry. This therefore calls for thorough investigations on alternative materials which can potentially be used to replace sand either partially or fully to help preserve rivers which are the major source of sand. Sand harvesting is associated with drying up of rivers which causes water problems to the communities during the dry period. At present, the identified alternative sources are manufactured sand (mechanically crushed rock sand).This source proves to be expensive as machinery must be purchased purposely for crushing the aggregates and extra cost must be incorporated with this process. The alternative sought should therefore be of a lower cost compared to what is currently in use. The research examined the use of Kunkur fines to test its potential for use as an alternative to preserve the drying rivers. The research used quantitative design to examine its variables which extend from the raw materials, fresh and the hardened concrete. Kunkur fines from EAPCC quarry is a potential material for partially replacing sand up to 50% for fine aggregates in concrete as it qualifies the tests which are required to regard a material as having sufficient structural strength and suitable for use as fine aggregate. An increase of Kunkur fines in the blend slightly reduces the strength of concrete. Up to 50% replacement the blend gives sufficient structural strength of 20N/mm 2 and above with further increase of Kunkur recording lower values than the design strength. Kunkur has low silt content which is slightly higher than that of sand by 0.91% but below the maximum required percentage by BS 812 of 5%. The research recommends the use of Kunkur fines as it will help reduce the amount of sand harvested in the rivers annually by half and this will reduce the effect of water scarcity in the affected areas. Its use will also solve the problem of heap disposal by the EAPCC in the mines as the waste will be appropriately used in the construction industry

Effect of Copper Slag as a Fine Aggregate on the Durability Characteristics of High-Performance Concrete (HPC) Containing Silica Fume

2020 ◽  
Vol 07 (02) ◽  
pp. 1-10
Author(s):  
Rizwan Ahmad Khan ◽  
Keyword(s):  
Silica Fume ◽  
High Performance ◽  
High Performance Concrete ◽  
Copper Slag ◽  
Chloride Penetration ◽  
Interfacial Transition Zone ◽  
Fine Aggregate ◽  
Fresh Properties ◽  
Fine Aggregates ◽  
Effect Of Copper

This paper investigates the fresh and durability properties of the high-performance concrete by replacing cement with 15% Silica fume and simultaneously replacing fine aggregates with 25%, 50%, 75% and 100% copper slag at w/b ratio of 0.23. Five mixes were analysed and compared with the standard concrete mix. Fresh properties show an increase in the slump with the increase in the quantity of copper slag to the mix. Sorptivity, chloride penetration, UPV and carbonation results were very encouraging at 50% copper slag replacement levels. Microstructure analysis of these mixes shows the emergence of C-S-H gel for nearly all mixes indicating densification of the interfacial transition zone of the concrete.

scholarly journals Sodium Metasilicate Cemented Analogue Material and Its Mechanical Properties

2016 ◽  
Vol 2016 ◽  
pp. 1-17 ◽  
Author(s):  
Songlin Yue ◽  
Yanyu Qiu ◽  
Pengxian Fan ◽  
Pin Zhang ◽  
Ning Zhang
Keyword(s):  
Complex Geometry ◽  
Sodium Metasilicate ◽  
Raw Material ◽  
Fine Aggregate ◽  
Regression Equations ◽  
Deformation And Failure ◽  
Orthogonal Experiments ◽  
Low Modulus ◽  
New Type ◽  
The Relationship

Analogue material with appropriate properties is of great importance to the reliability of geomechanical model test, which is one of the mostly used approaches in field of geotechnical research. In this paper, a new type of analogue material is developed, which is composed of coarse aggregate (quartz sand and/or barite sand), fine aggregate (barite powder), and cementitious material (anhydrous sodium silicate). The components of each raw material are the key influencing factors, which significantly affect the physical and mechanical parameters of analogue materials. In order to establish the relationship between parameters and factors, the material properties including density, Young’s modulus, uniaxial compressive strength, and tensile strength were investigated by a series of orthogonal experiments with hundreds of samples. By orthogonal regression analysis, the regression equations of each parameter were obtained based on experimental data, which can predict the properties of the developed analogue materials according to proportions. The experiments and applications indicate that sodium metasilicate cemented analogue material is a type of low-strength and low-modulus material with designable density, which is insensitive to humidity and temperature and satisfies mechanical scaling criteria for weak rock or soft geological materials. Moreover, the developed material can be easily cast into structures with complex geometry shapes and simulate the deformation and failure processes of prototype rocks.

Sign in / Sign up

Export Citation Format

Share Document