What is effect of specific gravity of aggregate on concrete?
Specific Gravity Affects Density of Concrete Aggregates with higher specific gravity implies higher strength. Higher dense concrete implies higher strength concrete.
What is specific gravity of aggregates?
Specific Gravity is the ratio of the weight of a given volume of aggregate to the weight of an equal volume of water. Water, at a temperature of 73.4°F (23°C) has a specific gravity of 1. Specific Gravity is important for several reasons. Some deleterious particles are lighter than the good aggregates.
Why is specific gravity significant for aggregates?
The specific gravity of an aggregate is considered to be a measure of strength or quality of the material. Aggregates having low specific gravity are generally weaker than those with high specific gravity. This property helps in a general identification of aggregates.
How do you calculate specific gravity of aggregates?
Procedure for Specific Gravity determination of Aggregate finer than 6.3mm
- A clean, dry pycnometer is taken and its empty weight is determined.
- About 1000g of clean sample is taken into the pycnometer, and it is weighed.
- Water at 270C is filled up in the pycnometer with aggregate sample, to just immerse sample.
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. Substances with a specific gravity of 1 are neutrally buoyant in water.
What is SSD condition of aggregate?
Saturated surface dry (SSD) is defined as the condition of an aggregate in which the surfaces of the particles are “dry” (i.e., surface adsorption would no longer take place), but the inter-particle voids are saturated with water.
What are the conditions in which specific gravity is increased or decreased?
Increases in specific gravity (hypersthenuria, i.e. increased concentration of solutes in the urine) may be associated with dehydration, diarrhea, emesis, excessive sweating, urinary tract/bladder infection, glucosuria, renal artery stenosis, hepatorenal syndrome, decreased blood flow to the kidney (especially as a …
What are the 4 major moisture conditions for aggregates?
There are four moisture states: Oven-dry (OD); all moisture removed. Air-dry (AD); surface moisture removed, internal pores partially full. Saturated-surface-dry (SSD); surface moisture removed, all internal pores full.
How is SSD weight calculated?
Simply stated, it is the unit weight of a saturated material divided by the unit weight of water and is computed as follows: Gs(ssd) = (1 + Absorption) x Gs(dry).
What is the relationship between density and specific gravity?
Density is defined as mass per unit volume. It has the SI unit kg m-3 or kg/m3 and is an absolute quantity. Specific gravity is the ratio of a material’s density with that of water at 4 °C (where it is most dense and is taken to have the value 999.974 kg m-3). It is therefore a relative quantity with no units.
What changes specific gravity?
Does the moisture affect the strength of aggregates?
Similarly, increased moisture levels reduce the concrete’s compressive strength and durability. As concrete’s surface area increases, particularly with the addition of fine aggregates, so does the demand for water. The increased water leads to a higher water-to-cement ratio.
Does specific gravity change with temperature?
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.
What is the purpose of specific gravity?
The specific gravity value of an object can be used to determine approximately where the object will float at the surface of the liquid. The SG is a percentage of an object’s volume that will be below the surface, and the remaining percentage is visible above.
Is specific gravity affected by temperature?
The temperature of measurement should be specified and controlled in all specific gravity measurements because the specific gravity of a solution is affected by temperature. Standards of specific gravity are set by analysing standard mixes at 27 degrees Celsius (80.6 Fahrenheit).