Term
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Definition
| Distribution of particle size |
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Term
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Definition
| (sieve weight/total weight) x 100 |
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Term
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Definition
For filtering; Large % of the same size particle
(NOT subbase because their will be a lot of voids and won't compact well)
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Term
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Definition
For strong compaction; distribution of particle size is approximately equal throughout
(for use with roads/subbase) |
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Term
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Definition
| Uneconomical to use (both a large % of coarse aggregate and a large % of fine aggregate) |
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Term
D with a subscript
(for example D(sub)20=½″) |
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Definition
| Shows aggregate size; (the example would show that 20% of the sample is more fine than the ½″) |
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Term
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Definition
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Term
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Definition
Mathematical indication of how uniform an aggregate is; it is determined by D(sub)60/D(sub)10
(Smaller coefficient=higher uniformity)
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Term
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Definition
| It is the next sieve higher, in the column, above the first sieve to have cumulative percent retained >15% |
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Term
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Definition
Average size of sample; add cumulative percent retained column and then divide the total by 100)
Ex) (10.9+26.1+42.4+67.485.1+93.8)/100
FM=3.26
**Note: FM > 3.1 then unworkable mix
FM < 2.3 then uneconomical |
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Term
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Definition
- Multiply the %passing of each aggregate to the respective porportion
- Plot the gradation curve with the specification envelope
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Term
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Definition
Avoid segregation
Can use a Riffle Sample Splitter for fine
or use Quatering for coarse (dump into a cone shape, mix completely then flatten the cone, "cut" into quarters and use two quarters diagonal from eachother, discarding the other two). |
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Term
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Definition
Aggregate can be used for filtering, large surface area is needed.
The more surface area in contact with the water, the more effective the aggregate is.
**Irregular shaped aggregate can have a higher surface area then round aggregate of approx. the same size. |
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Term
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Definition
| The spaces between individual aggregates. |
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Term
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Definition
The open spaces on the surface of an individual aggregate.
**Can also be found on the inside of an individual aggregate. |
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Term
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Definition
Includes the solids, pores and voids.
Vbulk=vs+vp+va
vs: volume of solids
vp: volume of pores
va: volume of voids
**Generally inside a box of 1 cubic foot |
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Term
| Surface Saturated Dry Volume (SSD) |
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Definition
Volume of solids including the pores.
Vssd=vs+vp
vs: solid volume, excludes pores |
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Term
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Definition
Weight of the solid plus the weight of absorbed water filling the pores on the surface plus some free water on the particle surface.
Ww=Ws+Wp+Wfree
**Wfree=Wsub-Wssd |
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Term
| Surface Saturated Dry Weight (SSD) |
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Definition
The weight of the solid material plus the weight of the pores.
Wssd=Ws+Wp |
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Term
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Definition
| Weight of the solid material only (Ws). |
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Term
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Definition
Wet weight of aggregate per unit of volume.
gamma=Ww/Vbulk |
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Term
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Definition
Weight of dry aggregate per unit volume.
gamma(dry)= gamma/(1+mc)
**mc= moisture content |
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Term
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Definition
Ratio of weight of water in sample divided by weight of solids in sample.
%MC=[(Ww-Ws)/Ws] x 100 |
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Term
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Definition
Amount of water needed to fill the pores.
%ABS=[(Wssd-Ws)/Ws] x 100 |
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Term
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Definition
Ratio of unit weight of aggregate to the unit weight of water.
SG=gamma/gamma(water)
**gamma(water):
62.4 lbs/cf
1 g/cubic centimeter
1000 kg/cubic meter |
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Term
Bulk Specific Gravity (BSG)
(For Coarse) |
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Definition
Based on oven dry weight, ssd weight and submerged weight of the aggregate.
BSG=Ws/(Wssd-Wsub) |
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Term
Apparent Specific Gravity (ASG)
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Definition
Based on oven dry weight and submerged weight of the aggregate.
ASG=Ws/(Ws-Wsub) |
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Term
Bulk Specific Gravity
(For Fine) |
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Definition
BSG=Ws/(Wssd+Wfw-Wfwa)
Wfw: weight of flask and water
Wfwa: weight of flask, water and aggregate |
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Term
Apparent Specific Gravity
(For Fine) |
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Definition
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Term
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Definition
Dry weight per cubic foot divided by the SG*unit weight of water.
Vs=(Ws/cf)/(SG*gamma(water)) |
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Term
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Definition
Portion of total volume that is occupied by voids.
%Voids=[(SG*gamma(water))-gamma(dry)]/(SG*gamma(water) |
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Term
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Definition
| Mostly retained on the No. 4 sieve |
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Term
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Definition
| Passes the 3/8" sieve, almost entirely passing the No. 4 sieve, but is retained on the No. 200 sieve |
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Term
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Definition
- Concrete
- Asphalt
- Pipe Bedding
- Filtering (around drain pipes)
- Rip Rap
- Gabions
- Road Base
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Term
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Definition
When we create a later of stone/aggregate we provide a strong base.
Angular Aggregate: Many contact points, increased friction, increased shear strength. |
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Term
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Definition
| Area that a load acts over is dependent on the size of the load at the top, thickness of the aggregate, and the angle of friction between aggregates. |
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Term
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Definition
P=Force/Area
Area=π(tanθ*h)² |
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Term
| Pressure for Uniform Loads |
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Definition
P=Force/Area
Area=(width of footing+2*h*tanθ) x (width of footing+2*h*tanθ) |
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Term
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Definition
Densification of material resulting in increase of weight per unit volume.
**Well-graded aggregate creates a natural filling of voids and produces better compaction. |
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Term
| Optimum Moisture Content (OMC) |
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Definition
Moisture content at which the greatest compact can be achieved.
Too dry or too wet then it won't compact well. |
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Term
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Definition
Surface: 1 ½″
Base: 4-6″
Subbase: 6-12″
Compacted Natural Soil: 12″ |
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Term
| Flexible Pavement (Asphalt) |
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Definition
| Used mainly for roadways and parking lots that endure "reasonable" loads. |
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Term
| Rigid Pavement (Portland Cement Concrete) |
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Definition
| Used mainly for roadways, turning areas, loading docks, airport runways; or areas that are subjected to heavy loads. |
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Term
Failure Mechanisms
(Flexible Pavement) |
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Definition
| Water in base couse, under load, is forced into the subgrade. Leads to subgrade collapse, creating voids and potholes. |
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Term
Failure Mechanisms
(Rigid Pavement) |
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Definition
| Water in base course, under load, is forced out. It carries fines, which creates voids, offering no support. Ultimately can lead to collapse. |
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Term
| General Failure Mechanisms |
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Definition
Pumping: Pressure from traffic loads forces water to openings.
Frost Action: Water undergoes expansion when it freezes, heaving pavement up and washing materials away when it thaws.
Ice Lenses: Mass of frozen ice in pavement-indicates void has been created. |
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Term
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Definition
| Natural process where water is lifted above its normal level due to surface tension with the surrounding solids. |
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Term
| Stabilizing/Strengthening Aggregate |
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Definition
Clay: Adds cohesion(sticks better)
Salts: Forms brine, which forms a film that keeps the OMC (better compaction)
Lime: Clumps the fines together
Portland and Asphalt Cement: Small amounts mixed with aggregate for cohesion |
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Term
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Definition
Measures of the ease with which water flows through a material.
Represented by variable "k" in cm/sec
k=[D(sub)10]² |
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Term
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Definition
Openings too small then it clogs
Openings too big then its not effective |
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Term
| Durability and "Soundness" of Aggregate |
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Definition
| Ability to resist weathering, especially repetitive freezing and thawing. |
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Term
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Definition
Ability to transmit force
Resistance to crushing
Resistance to wear |
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Term
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Definition
| Harmful or injurious to the aggregate. |
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Term
| Deleterious- Friable Particles |
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Definition
| Easily crumbled (such as clay), this can affect gradation results (excessive fines). |
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Term
| Deleterious- Material Finer than No. 200 Sieve |
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Definition
| Creates a coating on coarse aggregate that absorbs the water. |
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Term
| Deleterious- Soft Particles |
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Definition
| Can be scratched easily, can be crushed easily and does not resist abrasion well. |
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Term
| Deleterious- Lightweight Particles |
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Definition
| Low specific gravity, usually soft/weak. |
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Term
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Definition
| Slows hardening of cement, may deteriorate and leave voids, can react with aggregate(chemical reaction), causes excessive expansion and early concrete breakdown. |
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Term
| Special Aggregate- Lightweight |
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Definition
Low specific gravity, reduces final weight of product.
Used to produce lightweight structural concrete. |
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Term
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Definition
| High specific gravity, no clear-cut unit weight, used in structures to resist flow of water, used as counterbalance, and used for nuclear radiation shielding(in nuclear power plants, or hospital radiation rooms). |
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