Mix design of concrete cannot be carried out without specific gravity of fine aggregate, and higher specific gravity produced stronger concrete. Finally, the presence of silt in sand would increase water demand in concrete mixture and may reduce concrete strength.
What is the effect relation of the specific gravity of aggregate in a concrete?
The experimental results showed that there was a quantifiable relationship between the specific gravity of the aggregate and the water/cement ratio: the properties of the interface and the strength of the concrete were best when the specific gravity of the coarse aggregate was higher than that of the water and lower ...
What is the purpose of determining the specific gravity of the aggregates used in the design of concrete mix?
Specific gravity is used to separate deleterious particles, lighter than other particles, from good aggregates . It is used in calculating the solid volume of aggregates in concrete mix. The materials used in this investigation are cement, gavel and water.
How does fine aggregate affect concrete?
The shape and texture of aggregate affects the properties of fresh concrete more than hardened concrete. ... Crushed stone produces much more angular and elongated aggregates, which have a higher surface-to-volume ratio, better bond characteristics but require more cement paste to produce a workable mixture.
How the specific gravity of fine aggregate is important?
Specific Gravity is important for several reasons. Some deleterious particles are lighter than the “good” aggregates . ... Specific gravity is critical information for the Hot Mix Asphalt Design Engineer. This value is used in calculating air voids, voids in mineral aggregate (VMA), and voids filled by asphalt (VFA).
What are the 4 main properties of concrete?
- Mechanical strength, in particular compressive strength. The strength of normal concrete varies between 25 and 40 MPa. ...
- Durability. ...
- Porosity and density. ...
- Fire resistance.
- Thermal and acoustic insulation properties.
- Impact resistance.
What are the different sizes of aggregate?
| Coarse aggregate Size | Medium gravel Ad 8mm – 16mm | Coarse gravel 16mm – 64mm | Cobbles Ad 64mm – 256mm | Boulders >256mm |
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How does the size of aggregate affect concrete?
The tensile strength of the concrete is severely affected by increasing the size of the aggregate. On increasing the maximum grain size to 120–180 mm, the reduction in tensile strength is 30–50% as compared with concretes with maximum aggregate size 20 mm.
What is the size of fine aggregate?
– Fine aggregates are usually sand or crushed stone that are less than 9.55mm in diameter . Typically the most common size of aggregate used in construction is 20mm. A larger size, 40mm, is more common in mass concrete. Larger aggregate diameters reduce the quantity of cement and water needed.
What is the best aggregate for concrete?
Gravel or broken stone aggregates with rough and non-glassy texture are the best aggregates because they create a good bond with the cement paste. Aggregates need to be hard, strong, chemically inert, and non-porous. Organic substances and dirt coating compromise the strength and durability of concrete.
What is the importance of specific gravity?
4.1 Specific gravity is an important property of fluids being related to density and viscosity . Knowing the specific gravity will allow determination of a fluid’s characteristics compared to a standard, usually water, at a specified temperature.
What are the factors affecting specific gravity test?
Specific gravity varies with temperature and pressure ; reference and sample must be compared at the same temperature and pressure or be corrected to a standard reference temperature and pressure.
How do you calculate specific gravity?
The density of the object (x) divided by the density of water (1) gives us the specific gravity 0.8.
What is the most important property of concrete?
The compressive strength of concrete is considered one of the most important structural properties it has. As an industrial standard, concrete is classified by different grades. These grades are based on the compressive strength of the material when a specimen of it is made into a cube or a cylinder.
What are the properties of fresh concrete?
- Consistency.
- Workability.
- Settlement & Bleeding.
- Plastic shrinkage.
- Loss of consistency.
What is the properties of hardened concrete?
Characteristic strength, drying shrinkage, creep, modulus of elasticity, permeability and resistance to chemical attack are hardened and time-dependent properties of concrete that may influence structural performance.
