Flashcards in Soils and Aggregates Deck (52)
Loading flashcards...
1
What are the Soil properties that help determine the spatial allocation of land-uses, the design and construction of structures, and the selection and installation of plant materials
Physical and Chemical Properties
2
Aggregates
Crushed rock or gravel
3
What are the 3 characteristics that define a Soil Profile?
textures, mineral contents, and chemical makeup
4
What are the soil Horizons
O, A, B, C, D
5
O/A Horizon (Organic Horizon) (2"-2')
Surface Layer
6
B Horizon (Subsoil) (4"-8')
Horizons of Maximum Accumulation
Clay
7
C Horizon (Substratum) (Parent Material)
Weathered parent material
8
D Horizon (Underlying Stratum)
BedRock
9
Soil Particle Sizes
(1) Clay (2) Silt (3)Sand (4) Gravel (5)Cobbles
10
Residual Soils
Remains above its parent rock
11
Transported Soils
Materials that have been moved from another place by glaciation, wind, water, or gravity
12
What was the USDA Classification System developed for?
Agriculture
13
USDA Classification System
Describes the relative proportion of clay, silt, and sand particles
14
What are the 11 Basic Soil Orders of the USDA Classification System based on?
Climate, Parent Material, Vegetation
15
What was the AASHTO Classification System developed for?
Devised for highway construction suitability
Engineering Properties of Soils
16
What are the 2 major soil groups in the AASHTO Classification System?
Granular Materials & Silt-Clay Materials
17
What were the Unified Systems developed for?
Devised for highway engineering
18
What are the 3 soil categories in the Unified Systems?
Coarse-grained Soils, Fine-grained Soils, Organic Soils
19
Order Coarse-grained, Fine-grained, Organic Soils from Excellent to Not Suitable, for use as Foundation Material.
Coarse-Grained: Excellent to Fair
Fine-Grained: Fair to Poor
Organic Soil: Not Suitable
20
Cumulose Soil
Organic
21
What are the Physical Properties of Soil?
Texture, Color, Density, Capillarity, Permeability, Shrinkage and Swell, Cohesion
22
How to obtain information about soil texture?
Soil Survey Report
23
What is Soil Density?
The Total Volume of Solids and Voids in Soil
24
Capillarity
Upward movement of moisture or water above the water table as a function of fine-textured soil
25
What are Clay & Silts and Coarse-textured soils capillary action?
Clay & Silts have High Capillary action
Coarse-textured soils have a lower capillary action
26
Permeability
The ability of soil to transmit water downward due to gravity Pore space
27
Shrinkage and Swell
Buildup and release of capillary tensile stresses within soil due to water
28
Cohesion
The ability of a soil sample to bind together when moderately dry
29
Elasticity
The ability of soil to return to its original shape after being deformed by a load. Compatibility of a soil
30
Plasticity
Refers to the ability of soil to be deformed under pressure without cracking or crumbling and to maintain a deformed shape after pressure is released
31
Liquid Limit
The liquid limit refers to the moisture content at which soil passes from a liquid to a plastic state as moisture is removed
32
Plastic Limit
Plastic Limit refers to the moisture content at which soil passes from a plastic to a semisolid state as water is removed
33
Frost Susceptibility
The relative tendency of some soil to swell due to frost when the moisture in the soil freezes
34
Are Fine-Grained or Coarse-Grained soils more susceptible to frost-action?
Fine-grained are more susceptible to freeze than coarse-grained
35
Compressibility and Compaction
Compact soil to increase its ability to support the weight
36
Bearing Strength
The ability of a soil to support a load without failure
37
What 3 factors affect Bearing Strength?
Water Content, Rate and time of loading, Confining pressure
38
What are the 3 components of Drainage?
Runoff, Internal Drainage, Permeability or porosity
39
Erodibility
The extent to which a soil mass can withstand the forces of wind or water erosion
40
Spatial Variability
Most urban sites consist of more than one soil type but are seldom mapped
41
Available Moisture and Adequate Drainage
Ideal Ratio Airspace to Water 1:1
42
Soil pH
Acidity or alkalinity of a Soil
43
What are the soil pH levels for acidic soil? For alkaline soil?
Acid is 0-6.5
Neutral is 6.6 - 7.3
Alkaline is 7.4 - highest
44
Colloidal Content
Refers to the number of clay particles in a soil sample
45
Depth
Depth to Bedrock, to water table or to unweathered parent materials
46
At what depth should plants be installed?
Between 18" - 36"
47
Issues with Urban Soils
Compaction, Increased runoff, Oxygen deficient environment, severely inhibited root growth, Increased thermal conductivity, Limited nutrient availability
48
Natural Granular Materials
Sand, gravel, crushed stone
49
Manufactured Granular Materials
Slag, vermiculite, pumice, and crushed brick
50
Relevant Properties of Aggregates
Cleanliness, Soundness, Gradation
51
Common Applications of Aggregates
Foundations, Finished Surfaces, Vehicular Roads and Parking Areas
52
