What is SSD condition of aggregates?
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 is SSD condition in concrete mix design?
SSD stands for saturated surface-dry and it describes a condition that a concrete surface must be brought to when a cement product is to be applied to it. The surface is SSD when the substrate is saturated with water, filling the voids in the substrate’s aggregate, but the outer surface is devoid of free water.
Why is the SSD condition of aggregates the best choice especially in the proportioning of materials of a concrete mix design?
The SSD state is the best choice as a reference state for the following reasons: … The moisture content of aggregates in the field is much closer to the SSD state than the OD state. The bulk specific gravity (BSG) of aggregates is more accurately determined by the displacement method in the SSD condition.
How can you determine if the coarse aggregate is in SSD condition?
The coarse aggregate specific gravity test (Figure 1) is used to calculate the specific gravity of a coarse aggregate sample by determining the ratio of the weight of a given volume of aggregate to the weight of an equal volume of water. It is similar in nature to the fine aggregate specific gravity test.
What is the full form of SSD?
Solid state drives (SSDs) and hard disk drives (HDDs) are the two main storage options to consider.
How do you correct moisture in concrete?
The moisture correction is made by multiplying the aggregate weight shown by 100 plus the percentage of moisture in the material. If a moisture determination shows that the sand has 5% total moisture, multiply the sand weight shown by 105%.
What is saturated concrete?
Water-saturated concrete is typically concrete that is damp to the touch with no standing water in the hole. Keep in mind, water-saturated concrete may affect the adhesive’s cure time.
What are the four conditions of moisture in aggregate?
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.
Which type of aggregate gives maximum strength?
Cubical aggregate has maximum strength in concrete as it has good packing and strength in all direction. Rounded aggregate is not suitable for concrete.
What are the different sizes of aggregate?
|Medium gravel||Ad 8mm – 16mm|
|Coarse gravel||16mm – 64mm|
|Cobbles||Ad 64mm – 256mm|