Aggregate Moisture Content Testing
If using a microwave oven or an oven to dry the sample, it may be helpful to use a wide, shallow sample container (like a heat-proof baking dish) that will allow the aggregate to lay in a thin layer. Only use non-metallic sample containers and equipment inside a microwave.
WhatsApp: +86 18221755073
Moisture Content
In general, there are four aggregate moisture conditions: Oven-dry (OD). All moisture is removed by heating the aggregate in an oven at 105 ° C (221 ° F) to constant weight (this usually constitutes heating it overnight). All pores connected to the surface are empty and the aggregate is fully absorbent. Airdry (AD). All moisture is removed ...
WhatsApp: +86 18221755073
Aggregate Moisture in Concrete
While this will potentially increase strengths and even durability if not accounted for, placing these dry aggregates into the wet concrete mixture will allow the aggregates to take up water from the paste, filling their pore spaces but decreasing the amount of water available to allow the particles to slip by one another during pumping ...
WhatsApp: +86 18221755073
Rodded Unit Weight of Coarse Aggregates Test (ASTM C29)
Astm C29: Determination of the unit weight of coarse aggregates in a compacted condition. This test method is applicable to aggregates not exceeding 15 cm in nominal size. The unit weight so determined is necessary for the design of a concretemixture by the absolute value methodز
WhatsApp: +86 18221755073
Concrete Property Test
based on inaccurate aggregate moisture contents can impact workability, strength development, air entrainment, permeability, and shrinkage of the concrete mixture.
WhatsApp: +86 18221755073
Adjusting for Aggregate Moisture Contents
Aggregates are subject to four moisture conditions, depending on the amount of water in the pores or on the surface of the aggregate particles. Aggregate that contains no water in the pores or on the surface is oven-dry. Aggregate that has a dry surface but contains some water in the pores is air-dry.
WhatsApp: +86 18221755073
Coarse Aggregate Specific Gravity
If the aggregate is not oven-dry to start, the existing water in the aggregate pore structrure may be able to penetrate further into the pores (AASHTO, 2000c [1]). 3. Dry the sample to a saturated suface dry (SSD) condition. Rolling up the aggregate into the towel and then shaking and rolling the aggregate from side to side is usually effective ...
WhatsApp: +86 18221755073
Aggregate Moisture in Concrete
While this will potentially increase strengths and even durability if not accounted for, placing these dry aggregates into the wet concrete mixture will allow the aggregates to …
WhatsApp: +86 18221755073
What is Specific Gravity of Aggregate?
The method is gravimetric and is calculated from determinations of the aggregate sample mass in oven-dry (OD), saturated, surface-dry SSD, and immersed conditions. Specific gravity determinations can be made on the full range of particle sizes of the coarse aggregate portion, or on individual size fractions. Average relative density values can ...
WhatsApp: +86 18221755073
Concrete Property Test
Aggregates can be found in four moisture conditions: Oven dry—aggregate particles are completely dry and able to absorb water from the mixture. Air dry—aggregates are partially dry and able to absorb water from the mixture. Saturated surface dry (SSD)—aggregates have absorbed all of the water that they potentially can and are dry on the ...
WhatsApp: +86 18221755073
Water to Cement Ratio and Aggregate Moisture …
proper adjustments are made to the aggregate and water batch weights. Aggregate mixture proportions are developed using either the oven-dry or saturated surface-dry condition. It is important to know this information when adjusting mix designs to account for actual aggregate moisture contents.
WhatsApp: +86 18221755073
Rodded Unit Weight of Coarse Aggregates Test (ASTM C29)
Rodding the aggregates: Fill the bucket one third full and rod the aggregate layer with 25 strokes of the tamping rod, evenly distributed over the surface. Add another layer of aggregates so that the bucket is approximately two thirds full and repeat the rodding procedure.
WhatsApp: +86 18221755073
Aggregate Gradation: Testing Tips and Tricks
Oven-drying the aggregate sample. ... Smaller volumes of samples dry faster and are more convenient to handle. ASTM C702 allows fine aggregate to be divided with a mechanical splitter if the material is drier than saturated surface-dry (SSD). For non-specification testing of some free-flowing aggregates with low fines content, you could ...
WhatsApp: +86 18221755073
Full article: Modified pycnometer method to measure the …
The water absorption of aggregates is calculated as the ratio of the difference between the weight of the aggregates in saturated surface dry (SSD) condition and oven-dry condition to the weight of oven dry aggregates. The aggregates are in SSD condition when they are saturated with water fromwithin, while dry on the surface.
WhatsApp: +86 18221755073
Moisture Content
Oven-dry (OD). All moisture is removed by heating the aggregate in an oven at 105 ° C (221 ° F) to constant weight (this usually constitutes heating it overnight). All pores connected to the surface are empty and the aggregate is fully absorbent.
WhatsApp: +86 18221755073
Water to Cement Ratio and Aggregate Moisture …
Oven-dry (OD): This is achieved under laboratory conditions when the aggregate is heated to 220 F (105 C) for an extended period. Under this condition, all moisture is removed from the …
WhatsApp: +86 18221755073
Moisture Content Test — Material Testing Expert
There are a few ways to perform a moisture content test on aggregate. One of the most common methods is called the oven-dry method, which involves taking a sample of the aggregate, drying it in an oven at a specific temperature and weight it …
WhatsApp: +86 18221755073
DETERMINATION OF RODDED UNIT WEIGHT OF COARSE AGGREGATE …
M SSD = the rodded unit weight of the saturated surface dry aggregate, kg/m3 (lb/ft3) G = combined mass of the oven-dry aggregate and the bucket, kg (lb) T = mass of the bucket alone, kg (lb/f) V = volume of the bucket, m3 (ft 3) A = % absorption, determined by ASTM Method C 127. Calculate the rodded unit weight to the nearest 10 kg/m 3 (1 lb ...
WhatsApp: +86 18221755073
Moisture Content
Oven-dry (OD): All moisture is removed from the aggregate by heating in an oven at 105 C to constant weight (overnight heating usually is sufficient). All pores are empty. Air-dry (AD): All moisture removed from surface, but internal pores partially full.
WhatsApp: +86 18221755073
Coarse Aggregate Specific Gravity
Remove the aggregate from the water and dry it until it maintains a constant mass. This indicates that all the water has left the sample. Drying should occur in an oven regulated at 230°F (110°C).
WhatsApp: +86 18221755073
CIVL 1101
Therefore, ASTM has set a standard oven-dry moisture content and a rodding method for compaction. The maximum unit weight of a blend of two aggregates is about 40% fine aggregate by weight. Therefore, this is the most economical concrete aggregate since it will require the least amount of cement.
WhatsApp: +86 18221755073
Rodded Unit Weight of Coarse Aggregates Test (ASTM C29)
Quantity of oven-dry aggregate sample should be at least 125% of the quantity required to fill the metal pail; TEST PROCEDURE of Rodded Unit Weight of Coarse Aggregates. Calibrate the metal bucket to determine its volume by determining the net weight of water required to fill it and dividing it by the density of water.
WhatsApp: +86 18221755073
Concrete Property Test
Aggregates can be found in four moisture conditions: • Oven dry—aggregate particles are completely dry and able to absorb water from the mixture. • Air dry—aggregates are partially …
WhatsApp: +86 18221755073
Water to Cement Ratio and Aggregate Moisture …
occur naturally on a daily basis in aggregate stockpiles. Oven-dry (OD): This is achieved under laboratory conditions when the aggregate is heated to 220 F (105 C) for an extended period. Under this condition, all moisture is removed from the aggregate's pores. Air-dry (AD): The surface of the aggregate is dry and the internal pores may be
WhatsApp: +86 18221755073
Moisture Content
Oven-dry (OD): All moisture is removed from the aggregate by heating in an oven at 105 C to constant weight (overnight heating usually is sufficient). All pores are empty. Air-dry (AD): All …
WhatsApp: +86 18221755073
Specific Gravity Formulas
water (C) is equal to their oven‐dry mass in air (A) less the mass of water they displace when submerged. The latter is the product of the mass density of water ( w) and the net volume of the aggregate particles (i.e., the volume of the aggregate particles excluding their permeable pores), so
WhatsApp: +86 18221755073
Moisture Content
Oven-dry (OD). All moisture is removed by heating the aggregate in an oven at 105 ° C (221 ° F) to constant weight (this usually constitutes heating it overnight). All pores connected to the …
WhatsApp: +86 18221755073
How to measure free or surface aggregate moisture
The other common mistake is to bake the aggregate to bone dry before weighing. This drives off the internal moisture as well as the surface moisture. Both approaches are wrong. During tests at a concrete plant we found an expert in oven-dry testing who had an ingenious way to check the progress of the bake-out.
WhatsApp: +86 18221755073
Moisture Content Test — Material Testing Expert
There are a few ways to perform a moisture content test on aggregate. One of the most common methods is called the oven-dry method, which involves taking a sample of the …
WhatsApp: +86 18221755073
TIP 6
aggregates needs to be accounted for by adding additional water to the mixture. Therefore the aggregate moisture has to be measured and the amount of batch water adjusted accordingly.
WhatsApp: +86 18221755073