SECTION 4 Flashcards
aliquot
a portion of a larger whole, especially a sample taken for chemical analysis or other treatment. When soil sampling for contaminants, multiple aliquots are taken around the site for testing.
Rivet
A permanent mechanical fastener. On installation the rivet is placed in a punched or drilled hole, and the tail is upset, or ‘bucked’ by the rivet gun so that it expands to about 1.5 times the original shaft diameter, holding the rivet in place.
Bolts vs. Screws
The defining distinction is in their intended purpose: Bolts are for the assembly of two unthreaded components, with the aid of a nut. Screws in contrast are used with components that have at least one containing its own thread. Many screws and bolts can be either, depending on how they are used. Where a fastener is used with a nut, it is a bolt rather than a screw. Where a fastener forms its own thread in the component being fastened, it is a screw. Many bolts are held fixed in place during assembly, either by a tool or by a design of non-rotating bolt, such as a carriage bolt, and only their nut is turned.
Carriage Bolt Assembly
Threaded fasteners with a bolt that has a rounded, dome-shaped head. The bolt has a square neck that extends from the head towards the threads. A regular hex nut or wing nut allows the assembly to hold the components together. This assembly can be tightened with just one wrench.
Carriage bolt assemblies are commonly used in carpentry and construction; they are well-suited for fastening two structural wood pieces together, especially when extra strength is required. The square neck sinks into the wood as the fastener is tightened, preventing the bolt from turning and countersinking the bolt head at the same time.
Eye Bolt
An eye bolt is a screw with a loop on one end and threads on the other end. Eye bolts are commonly used to attach cables to objects, for instance attaching a string to the back of a painting to allow the painting to hang from a nail on a wall.
Eye bolts made by bending a rod or wire into a loop are only suitable for light duty applications, as heavy loads can cause the eye to open. For high loads, eye bolts with forged or welded loops should be chosen, as they can withstand loads up to the tensile strength of the material of which they are made.
J-Bolt Assembly
Usually sunk into concrete allowing it to be used as an anchor bolt
Anchor bolt
An anchor bolt is used to attach objects or structures to concrete. There are many types of anchor bolts, consisting of designs that are mostly proprietary to the manufacturing companies. All consist of a threaded end, to which a nut and washer can be attached for the external load.
Lag Bolt
Lag-bolt heads are meant to be driven with a wrench or a ratchet and socket. Before driving a lag bolt, pre-drill a pilot hole about two-thirds the bolt’s length using a drill bit that is 1/8 inch smaller than the lag bolt’s shank. Slide a washer onto the lag bolt before driving it in. used to secure load bearing materials together.
Lag Bolt with Expansion Shield
The term expansion shield is used to describe a masonry anchor that requires the use of a bolt, lag screw or setting tool to expand the anchor once it is placed in a hole in the base material. Other than epoxy type and concrete screws, all other concrete fasteners use expansion as a means by which their holding values are derived
Lag Bolt with Fiber Plug
The Fiberplug is a jute fiber screw style anchor designed for use in concrete, block, brick, and stone. The Fiberplug is an anchor designed for use with wood,
sheet metal, and lag screws. It is formed of braided jute fiber which is bound into a tubular shape. A lead lining on the sheet metal and wood screw sizes
makes it possible for the screw to reproduce its own thread, and keeps the jute fibers from being cut by the screw.
Lag Bolt with Lead Shield
Lag shields are medium-duty anchors which expand to fill the area of the pre-drilled hole when a lag screw is tightened into the shield. Extra-long sizes are for use in mortar or brick. Standard lengths are intended for use in concrete. They can be used in solid or hollow material and are more resistant to temperature fluctuations and rust than other light-duty anchors
Machine Bolt Assembly
A machine bolt, also known as a hex bolt, is a square or hexagonal head. The body or nut of the machine bolt consists of threading and a smooth shoulder; however, shorter bolts may be fully threaded. connects metal to metal
Toggle Bolt Assembly
A toggle bolt is a two-part fixture consisting of a bolt and spring-loaded “toggle wings” that pop open on the backside of the wall material, providing a sound anchor for tightening the bolt. Acts like a pin to join two element’s
Threaded Rod Assembly
A threaded rod, also known as a stud, is a relatively long rod that is threaded on both ends; the thread may extend along the complete length of the rod. They are designed to be used in tension.
Cement Nail
(Concrete Nail is more accurate name)
They are nails that are specifically designed to be driven into concrete. Because most nails are not strong enough to penetrate such a hard surface and would bend, there is a need for these types of nails for various applications. One of the common uses for cement nails is to tack down flooring materials installed on a concrete slab.
Common Nail
Used for most medium to heavy construction work, this type of nail has a thick head and can be driven into tough materials. Common nails are made from wire and cut to the proper length and are available in sizes 2d through 60d. (60d nails are 9” long)
Machine Screw
These fasteners are often used with nuts as well as often driven into tapped holes. They might be considered a screw or a bolt based on the Machinery’s Handbook distinction. In practice, they tend to be mostly available in smaller sizes and the smaller sizes are referred to as screws or less ambiguously as machine screws, although some kinds of machine screws can be referred to as stove bolts. used to fasten machine components, appliances and more.
Plate Anchor
Anchors are designed to stabilize cracking and bowed foundation walls. Wall plate anchors secure basement and retaining walls that bowing, leaning or cracking due to excessive outside soil pressure. This hydrostatic pressure is the result of water buildup in the soils surrounding your home. Once the pressure has exceeded the original design strength of the wall you will see cracking followed by leaning or bowing of basement walls.
Construction Adhesive
Usually extruded out of a tube, used for big jobs like fastening plywood to floor joints or paneling to drywall.
Drive Anchor
Made of high-strength spring steel or of aluminum with a stainless steel pin for use in hard materials. The anchor is driven into a hole where it is compressed and forced against the walls of the hole. Permanent fastener good for indoor use.
Masonry Wall Tie
Used to tie the internal and external walls(or leafs) constructed of bricks or cementatious blocks together. It is placed in the cavity wall during construction and spans the cavity. The ends of the tie are designed to lock into the cement. Also incorporated into the design of the tie is means of preventing water transfer from the outer to the inner leafs. In flat ties this can be a twist. In wire ties this can be corrugations formed in the wire or again a twist.
Z-anchor
Z Anchors are the most conventional and common method of fixing systems used for natural stone installation. With their three-dimensional adjustability, Z anchors allow the quick and easy installation of natural stone slabs both at the horizontal and vertical joints.
Methods of estimating cut and fill
Average end area method
Contour method
Grid method
Grid method
Quick. Useful for estimating excavation of foundations and other square, level features. Each point on the grid is assigned a cut or fill depth based on existing contours and a proposed level elevation.
First calculate the volume of cut and fill separately (based on no cut no fill line, which is zero), helps to calculate cuyd for each square and add them up at the end.
Average end area method
Used to estimate volumes of cut/ fill on linear elements like roads. Cross sections are taken at intervals and average together, then multiplied by the total length.
Contour method
Most accurate method to calculate cut and fill.
- Delineate no cut no fill zones. No cut no fill lines delineate where cut stops and fill begins in some areas
- Meare surface area of each contour and enter it into supess
Erosion control strategies
- Minimize disturbed area and protect natural features and soil
- Phase construction activity
- Control stormwater flowing onto and through the project
- Stabilize soils promptly
- Protect slopes
Sediment control strategies
- Protect storm drain inlets
- Establish perimeter controls
- Retain sediment on-site and control dewatering practices
- Establish stabilized construction exits
- Inspect and maintain controls
Six Key Pollution Prevention Principles for Good Housekeeping during construction
- Provide for waste management
- Establish proper building material staging areas
- Designate paint and concrete washout areas
- Establish proper equipment/vehicle fueling and maintenance practices
- Control equipment/vehicle washing and allowable non-stormwater discharges
- Develop a spill prevention and response plan
Slope min/ max for Lawns & seeded areas
2% to 33% (1:3)
Slope min / max for pathways
. 5% to 10%
Slope min / max for paved or grass play or sitting areas
1% to 4%
Increase in volume of CUT materials (swell)
60% to 80% for solid rock
20% to 25% for soft earth
Settlement of fill materials (percent reduced volume)
8% to 20% where 8 is gravel and 20 is clay soil
traverse
A traverse is a series of points established on the job site connected through the measurement of angles and distances. These measurements are used in a process called traverse computations, which determine the relative location of the points to each other. In construction, traversing is used to establish control around a job site to lay out the structures.
Control point
A control point is a point on the ground or any permanent structure whose horizontal and vertical location/position is known. Control points are used as a starting point of the surveyor’s CAD.
Types of concrete joints
Isolation joint
Construction joint
Contraction joint
Isolation joint
Completely isolates a slab from something else, such as a building or column.
Isolation joints are formed by placing preformed joint material next to the column or wall or standpipe prior to pouring the slab. Isolation joint material is typically asphalt-impregnated fiberboard, although plastic, cork, rubber, and neoprene are also available.I olation joint material should go all the way through the slab, starting at the subbase, but should not extend above the top.
For a cleaner looking isolation joint, the top part of the preformed filler can be cut off and the space filled with elastomeric sealant. Some proprietary joints come with removable caps to form this sealant reservoir.
Construction joint
On many jobs there will be starting and stopping points—you won’t pour the entire slab or driveway all at once. That’s where you will place a construction joint.
Construction joints are formed using some sort of bulkhead, made of wood, steel, plastic, or precast concrete. These bulkheads are often used as screed rails during placement and finishing of the slab.
Construction joints should be worked into the overall joint plan, where they can also function as contraction joints.
A construction joint should also be used in cases of equipment breakdown, an unexpected shortage of materials, or bad weather, although the joint should still be worked into the jointing pattern—placed where a contraction joint was planned. If that’s not possible, the odd section may later have to be removed.
If the slab will have no significant traffic crossing the joint, a plain butt joint, with no reinforcement crossing the joint, is acceptable. If there is to be traffic other than foot traffic, you will need to use some sort of load transfer device.
Contraction joint
After concerts is poured, it shrinks. Contraction joints are formed by saw cutting, by tooling a joint with a grooving tool, or by inserting a plastic strip into the concrete during finishing (zip-strip). Proper timing and depth of cut are essential. If you wait too long, the slab will crack where it wants to rather than where you want it to. And if the joint is not cut deep enough it will not create the plane of weakness needed to guide the crack.
There are several methods for tooling a joint into a concrete slab during the finishing operations, but as with a saw cut, the depth of the groove needs to be at least one-quarter the slab thickness to weaken the slab enough to get the crack to follow
Types of permeable pavement
Modular Interlocking Concrete Block Pavement consists of impervious concrete blocks that allow water to infiltrate into a reservoir through inter-block or intra-block voids. These voids may be filled with gravel or soil and grass. Gravel is the most common filler as it is less susceptible to clogging.
Porous Asphalt or Porous Concrete consists of standard asphalt or concrete mixes from which the finer aggregates have been removed. Removal of these fine materials results in a pavement with a matrix of pores that allows water to permeate through the surface.
Plastic Grid Systems consist of plastic interlocking units with virtually no impervious surface area. Grid spaces may be planted with grass or left unplanted and filled with gravel. The grids provide structural stability and prevent settling while allowing a large amount of void space for infiltration of stormwater.
Benefits of permeable pavement
reduction of runoff, which reduces flood risk, stream erosion and damage to downstream infrastructure;
removal of contaminants from infiltrated stormwater
Soil density testing
Soil density testing is used to determine the soil compaction level necessary to withstand a building, road or other structure. It is typically done in a laboratory setting using proctor tests to establish the optimal moisture content for a soil’s compaction. On-site compaction testing on-site involves determining the maximum dry density of the soil through moisture density testing and then measuring it based on the relation between field density values and laboratory values using nuclear meters and sand cones.
Components of grout and motar
Grout is generally a mixture of water, cement and sand, and is employed in pressure grouting, embedding rebar in masonry walls, connecting sections of pre-cast concrete, filling voids, and sealing joints such as those between tiles. Common uses for grout in the household include filling in tiles of shower floors and kitchen tiles.
Masonry mortar, a mixture of coarse sand, Portland cement, and lime,1 is used for laying brick and stone.
Soil proctor test
The Proctor Soil Compaction Test is used to understand compaction characteristics of different soils with change in moisture content.0 It consists of a cylindrical mold placed and compacted in three layers by dropping 25 times a 2,5 kg weight falling from an elevation of 30 centimeters. The type of compaction and the provided energy for a given soil volume are standard for this test
control points vs benchmarks
Control points provide information for the location and elevation of established monuments. Control points that provide vertical datum are also known as benchmarks.
slump test
The concrete slump test measures the consistency of fresh concrete before it sets. It is performed to check the workability of freshly made concrete
definition of Phytoexraction
Phytoexraction is a form of phytoremediation that uses the plants natural ability to absorb contaminants and store them as part of their natural metabolism. Certain plants are used for certain chemicals. Over time, the plants are harvested and burned or recycled to further remove the chemicals from the land.
definition of phytodegradation
Phytodegradation uses plants that naturally break down the chemicals they absorb and therefore do not need to be harvested.
definition of bioremediation
Bioremediation uses the micro flora and fauna that are present on the site already and breaking down the contaminants. The organisms are identified and the site conditions where they were found are replicated throughout the site.
definition of phytovolatization
Phytovolatization refers to the process of a plant absorbing a chemical that is present in the water and through the plant’s natural processes; the chemical is broken down and released into the atmosphere through transpiration.
components of the contract documents
drawings, specifications, general conditions, agreement
sequence of site construction
- site clearing / demo
- all organic matter cleared and grubbed from the construction zone
- topsoil typically stripped and stockpiled
- cut & fill operations
- drainage and utilities
- grading
- structures and paving
- furnishings and planting
infiltration trench
a gravel-filled trench that allows stormwater to soak into the ground.
may include an overflow, an underdrain or vegetation. To
reduce clogging, use settling basins or other pretreatment components in conjunction with the infiltration trench. Site-specific conditions—such as soil type, water table, drainage area and slope—may restrict
their use.
stormwater sand filter
Sand filter systems temporarily store stormwater runoff to filter and remove pollutants before it reaches natural water sources, such as creeks, streams, and rivers. Stormwater is filtered through a natural, or an engineered filter media, and systems are commonly designed with two chambers. The first is a sediment chamber, or forebay, where larger particles deposit before the runoff water is filtered in a filtration bed of sand where fine particles are removed. Afterward, the filtered water is typically collected in an underdrain and then conveyed to the storm drainage system. Sand filter applications can be on the surface, below the surface, or within a cartridge configuration.
topsoiling
Preserving and using topsoil to provide a suitable growth medium and enhance final site stabilization with vegetation.
Use Where slopes are 2:1 or flatter and Where the subsoil or areas of existing surface soil have problems like structure, pH, or nutrient balance, too shallow, or contains toxic components.
Advantages of topsoil include higher organic matter and greater available water- holding capacity and nutrient content.
Stripping, stockpiling, and re-applying topsoil, or importing topsoil may not always be cost-effective. It may also create an erosion problem if improperly secured.
aeolian soils
Sand dunes. Aeolian processes are those processes of erosion, transport, and deposition of sediments that are caused by wind at or near the surface of the earth.
vertisols
clay-rich soils that shrink and swell with changes in moisture content. During dry periods, the soil volume shrinks and deep wide cracks form. The soil volume then expands as it wets up.
colluvial soils
a general name for loose, unconsolidated sediments that have been deposited at the base of hillslopes by either rainwash, sheetwash, slow continuous downslope creep, or a variable combination of these processes.
alluvial soils
loose clay, silt, sand, or gravel that has been deposited by running water in a stream bed, on a floodplain, in an alluvial fan or beach, or in similar settings. Alluvium is also sometimes called alluvial deposit. Alluvium is typically geologically young and is not consolidated into solid rock.
lumber nominal sizing
the size before shrinkage and planing, rather than the actual size. nominal sizing used in specifications. does not apply to the length of the board.
actual dimensions of 1x lumber (1-12)
Nominal Size Actual Size
1x4 3/4 x 3-1/2
1x6 3/4 x 5-1/2
1x8 3/4 x 7-1/4
1x10 3/4 x 9-1/4
1x12 3/4 x 11-1/4
brush layering
Brush layering is a revegetation technique, which combines layers of dormant or rooted cuttings (see Dormant Cuttings under Plant Care and Preparation section) with soil to revegetate and stabilize both streambanks and slopes.
knox box
fire / emergency access box opened with PIN or common key. contains keys to locked gates or doors. does not require electric or data or phone for operation. suited for rural locations
depth of drainage lines
below frost line
ADA height for table
28”-34”
albedo
Albedo is the fraction of light that a surface reflects. If it is all reflected, the albedo is equal to 1. If 30% is reflected, the albedo is 0.3. The albedo of Earth’s surface (atmosphere, ocean, land surfaces) determines how much incoming solar energy, or light, is immediately reflected back to space.
invert elevation
measured from the bottom of the interior of the pipe to finish grade
Point of Vertical Intersection (PVI)
The point where two adjacent tangents would cross (whether they actually cross or not) is called the “point of vertical intersection”, or “PVI.” This location can be useful for editing the geometry of a profile because this one point controls the slopes of both tangents and any curve connecting them.
Point of Vertical Tangency (PVT)
The VPT serves as the end of the vertical curve and is located at the point where the vertical curve connects with the departing roadway segment. In other words, the VPC and VPT are the points along the roadway where the vertical curve begins and ends.
successful stormwater management will….
increase time in the treatment train, reduce peak flows, aid reduction of downstream flooding, improve public safety during storms, improve wildlife habitat, increase recreation potential, create more consistent soil moisture, and result in lower site maintenance costs.
term for the distance between point of curvature (PC) and point of tangency (PT)
chord
difference between unit price and fixed price contracts
fixed price contracts do not require precise measurements of in price quantities to determine payment. lump sum contract reduces the potential for cost overruns because all parties have agreed to a budget for a scope of services.
how to measure the height of a retaining wall
measure from the top of the wall to the bottom of the footer. (think about how much material would be needed to construct the wall)
single greatest source of water polution
sediments
max height of stockpiled soil on a job site
4 feet
principal difference between mortar and grout
the amount of water in the mix.
both mortar and grout are portland cement-based products containing cement, water, and sand. the purpose of mortar is to make things stick to each other (ie CMU wall), while grout is a filler material (ie tiles)
reference specifications
well vetted spec developed by professionals or associations. the reference to the spec is included in the spec instead of inventing a new one. A specification that calls out a material, product or method based on the requirements of testing standards written by organizations such as ASTM, UL, ASHRAE, etc.
project manual includes
bidding documents, general conditions, sample forms, scheudle of drawings, supplementary provisions, technical specifications,
whats included in an invitation to bid
project description. project title, time and place bids are due, and type of contract
what contributes to slope failure
altering surface drainage, increasing grade of a slope, remove vegetation, increased loads, altering subsurface drainage
groundwater recharge
primary method for which groundwater enters an aquifer
dimension accuracy is determined by
the expressed value of a dimension is considered accurate to 1/2 the smallest unit indicated. for example a dim of 1’-0” is accurate to the nearest 1/2”
tensile strength
the ability of a material to withstand forces parallel to the surface of the material
extensive green roof
planting medium ranges from 1.6 to 6 inches deep and shallow rooted plants are used. more often used for sustainability or building performance rather than gathering
intensive green roof
planting medium depth over 6 inches, and a variety of larger plants are used. often used in areas enjoyed by people.
types of retaining wall failure
overturning, buckling, sliding
types of layout systems
coordinate system
architectural grid system
stationing system
baseline system
components of all contract documents
drawings
specifications
addenda
agreement
modifications
conditions of the contract
nails vs screws when fastening wood
nails = lower cost
nails = faster installation
screws = more durable
screws = stronger
low impact development (LID) benefits
reduced stormwater volume and velocity (more infiltration)
less cost on underground piping etc.
more potential green space
design element with largest impact on wayfinding
plantings
3 part specs
general
product
execution
rebar sizing
numbers in rebar correspond to the diameter measured in 1/8” increments. for example #4 rebar is 1/8” x 4, or 1/2” diameter.
level spreader
used to control stormwater flows and improve water quality. distribute flow over a large area to minimize erosion and maximize infiltration by adjacent vegetated surfaces
goal of a site protection plan
protect natural resources on and adjacent to the site
ways to reduce/avoid soil compaction on site
avoid operating heavy machinery during or after precipitation events
add wood chips and top with plywood where machinery will operate
limit cut and fill to previously disturbed areas
don’t operate machinery on frozen soils
under typical conditions, how long does it take for concrete to cure to full strength?
28 days
vent line / pipe
used to aerate fill soil over an existing tree roots
always shown on a tree protection plan
survey base
reference notes
tree protection fencing
limits of work
areas of vegetation to be protected
vegetation to be transplanted or removed
keynotes
stationing layout system
used to layout linear elements on site
Construction sequence for grading
Site prep
Rough grading
Fine grading
Finish surfacing
Aspects of site prep before grading
Tree Protection
Topsoil removal
Erosion and sediment control
Clearing and demo
Place grade stakes
Topsoil stockpiling
Store stripped soil for 6 months max
4 ft high max piles
Purpose of soil compaction
Increase bearing capacity and shear strength
Ratio when balancing cut and fill
1.1 to 1.2 cu ft of cut to 1 cut ft of fill to accommodate shrinkage
Potential negative impacts due to changing storm drainage patterns
Increase flood potential due to increase peak flow rates
Decreased groundwater supply due to reduced infiltration
Increased soil erosion and sedimentation due to greater volume and velocity
increased petrochemical pollution from streets
contamination of winter runoff with salt and sand
degradation of water quality happens at what percentage of impervious cover?
20%
above that, stream bank erosion, loss of habitat, and decreased biodiversity may occur
ways to reduce impervious surface in design
parking stall dims
road widths
cluster development
BMP
best management practices
measures that have been developed to control store and treat storm water runoff from developed areas for the purpose of reducing flooding or removing pollutants while maintaining or enhancing environmental quality
SWPPP
storm water pollution prevention plan.
a site-specific, written document that Identifies potential sources of
stormwater pollution at the construction site
Check dam
a temporary structure to control concentrated stormwater flows in
channels
Permanent downdrain
a concrete or half-pipe sectional flume to conduct flows
safety down slopes
silt fence installation
parallel to existing contours or constructed level
alignments. Ends of the fence must be extended 10ft, tracing up slope at 45 degrees to alignment of the main fencing section.
three main causes of tree damage during construction
- Equipment driving too near the tree,
- Root damage caused by adding or removing soil
- Severing of roots caused by trenching.
root growth pattern of large woody trees
a diameter of 1 to 2 times the height of the tree
primarily in top 12” of soil
not deeper than 3-7 ft
mitigation plan
includes avoidance/preventative measures, minimization/limiting impacts, and compensation/offset/restoration
Hazard mitigation is any cost-effective and sustained action taken to reduce the long-term risk to human life, property, and infrastructure from hazards
3 docs used in the solicitation of bids
bid form
invitation to bid
instructions to bidders
rational method
Q=CiA
Q is rate of runoff in cubic feet per second
C is a coefficient
A is the area is acres
i is intensity in inches per hour
with sites that have many coeffients, start by calculating each area with its coefficient, then multiply by the intensity
wet ponds (retention ponds)
Design and uses
basins that contain a permanent pool of water
used for stormwater management, pollutant removal, habitat improvement, aesthetics.
shape should be long 3:1 ratio to increase time for settling, irregular shape shore, 4-8 foot depth
detention facilities (dry basins)
used to control peak discharge rates with temporary storage
reduces downstream flooding and stream bank erosion
does not improve water quality
can be above or below ground
ponds looks similar to wet ponds, but have a flow channel and positive drainage (2%min) toward an outlet to fully drain, no hooded riser.
side slopes 3:1 max
infiltration basins
reduce runoff and replenish groundwater (reduce downstream peak flows)
filters runoff through the soil, but should not used to remove sediment - sediment will eventually clog it. remove sediment before using filter strips or sediment traps
limited based on soil type, depth to groundwater
may allow contaminants to enter groundwater
rain garden is a type of infiltration basin, also infiltration trenches and porous pavement
porous pavements
suitable for low volume roads, driveways, parking lots, bikeways
only where subgrade allows for permeability, appropriate depth to groundwater
sand and deicing salts cannot be used
filter strips
placed adjacent to impervious surfaces to intercept overland sheet flow.
lowers runoff velocity, increase time of concentration, improve infiltration, contribute to groundwater recharge
bioretention
use of plant material to collect, filter, and retain stormwater in parking lot islands, swales, etc.
rainwater harvesting system components
- catchment area
- conveyance system to connect to storage
- storage area or cistern
optional: roof wash system, delivery system, water treatment system
3 types of green roofs
extensive - 2-6 inches of lightweight growing medium with shallow rooted plants subsisting solely on rainwater
intensive - deeper soil, wide range of plants, more weight limited by structure. irrigation is required.
modular - plants in trays or pots
components of green roof system
waterproof membrane
roof barrier
protection board (optional, protection during construction)
insulation
drainage and retention layer - corrugated plastic with absorptive quality below
filter fabric
growing medium
plantings
mulch
NDS
Natural Drainage System
program/initiative to improve stormwater management and visual and social environment of communities
uses many design approaches including interconnected swales instead of curb and gutter system
SEA Street
street edge alternative design
swales, sidewalks, plantings
compost blanket
1-3” layer of compost applied to disturbed soils
enhances soil stability
prevents concentrated stormwater flows
promotes vegetative growth
should not be used to slow down high velocity runoff, but can prevent it
contributing factors of soil erosion
precipitation intensity, duration
soil particle size, permeability
vegetation type/amount
slope/topo length gradient and orentation
erodible soil types
silt/ fine sand - highly erosive
clay - not easily, but once in suspension does not settle easily
5 ways to minimize site disturbance
work with existing topo
restrict area of disturbance
develop compactly (cluster development)
manage site construction
preserve existing vegetation
soil bioengineering
the use of live, woody, and herbaceous plants to stabilize or protect stream banks, shorelines, drainage ways and upland slopes
examples: live staking, live fascines, brushlayering, branchpacking, live cribwall, fiber rolls, log terraces,
deconstruction plan
identify all site and building components that can be removed, reused, or recycled. meant to supplement conventional demolition to reduce construction related waste, and manage hazardous materials. Costs more than demo but has potential to generate additional income.
how to increase compressive strength of concrete
alter the ratio of water to cement in the mix. less water = more compressive strength
as compressive strength increases, tensile strength decreases and so does durability
EVA routes
emergency vehicle access routes
soil surface albedo
Land surface albedo is the ratio of reflected to incident solar radiation. It is a function of several surface parameters including soil color, moisture, roughness and vegetation cover.
rational method
q = Cia
computing peak rate of runoff for drainage areas less than 200 acres
i = inches per hour
a = acres
C = coeficient defined by characteristics of the land (0-1)
hydraulics vs hydrology
hydraulics - study of channelized water through pipes, weirs, etc.
hydrology - study of the flow of water over land (cannot be replicated in a lab, therefore less exact)
strategies for wind erosion control on construction site
temp seeding of soil
erosion control blankets
mulching with wood chips
what affects the holding power of a nail?
length
material
diameter
shape of point
most common cause of retaining wall failure
improper drainage
porous concrete is made of..
portland cement
water
single sized aggregate
deck bracing type X
used for elevated decks with long posts, and long beam spans
minimum height clearance of a trail for visually impaired
80”
type of bond when blocks are adhered with mortar
tensile
failure type: sliding
occurs when the wall starts to move forward because it does not have the proper footing to withstand the force of the soil it’s retaining
failure type: overturning
occurs when a wall begins to rotate forward about the toe of the footing because it is not able to handle the forces at the top of the wall
failure type: breaking
the result of improper construction techniques or materials
failure type: crushing / settling
occurs when there is an excessive amount of force applied to the toe of a footing in an attempt to overturn the wall. it is the result of the soils beneath the footing being unable to handle the forces exerted
live load
a load produced by the use and occupancy of the building or other structure that does not include construction or environmental loads such as wind load, snow load, rain load, earthquake load, flood load, or dead load
characteristics of urban soils
variety in soil horizons due to cutting and filling
compaction
varying levels of pH due to contamination
higher fluctuations of soil temperature
lack of topsoil
minimum distance a screw must embed into receiving piece of wood
2/3 the length of the screw
max stair run without handrail
2
pocket wetland
small area, which will not have water in it most of the time, therefore will not have plant diversity
when can tree stakes be removed
after 2 growing seasons
benefits of a green roof
thermal insulation
slows runoff
reduces heat island effect
types of soil horizon layers
A - topsoil
O - organic matter on top of topsoil (not soil)
B - subsoil below A
C - subsoil below B
lumber grading stamp
defined by American Lumber Standard Committee, lumber stamp includes name of mill, species of wood, grade of lumber, moisture content, condition of seasoning
catch basin invert heights
invert out is lower than invert in (up to 1 ft)
deck post footing
always use an anchor or dowel, dont bury direct into concrete
crib wall
a wall made of stacked concrete pieces that form boxes that are then filled
how to prevent splitting or cracking in a piece of wood
nail away from the edge of the board
select material with consistent grains
make sure wood was dried properly
best type of light bulb for outdoor security lighting
low pressure sodium (produce only yellow light, highly efficient)
subgrade material suitable for direct pouring concrete
loam
azimuth
the measure of the line from the north in a clockwise pattern
north is azimuth of 0 and 360
bearing
survey bearing, tells which direction the line is taking. always starts with north or south not east or west
keyed concrete joiny
used to prevent the movement of two slabs of concrete by having the two pieces fit together in unison
metes and bounds
used to describe the lands shape and boundary
geodetic vs cadastral survey
geodetic takes the curve of the earth into account, cadastral does not (uses plane surveying)
strongest wood for use as a post
douglas fir
best type of nail for framing a structure
a sinker nail is thick and has a low profile head
casing nail
used to attach molding to a wall
box nail
small nail used in non structural applications
best type of light bulb for color rendering
incandescent lights are best
florescent and mercury are not as good
high pressure sodium is poor
tensile strength
Ultimate tensile strength is the maximum stress that a material can withstand while being stretched or pulled before breaking. In brittle materials the ultimate tensile strength is close to the yield point, whereas in ductile materials the ultimate tensile strength can be higher.
stormwater structure best for 20 plus year storms
concrete channel because they can withstand erosion, unlike vegetated swale
max gap between deck boards
1/8”
tooled vs troweled joints
applies to mortar.
In the tooled joint a special tool is used to compress and shape the mortar in the joint (vee, concave). In the troweled joint excess mortar is cut off (struck) with the trowel with no further finishing (struck, weathered, flush).
schmidt hammer test
A plunger rod is pressed against the concrete surface until a spring-loaded mass releases, causing an impact. The degree that the mass bounces back is registered as the “rebound number” and used to evaluate the hardness properties of the concrete. (compressive strength)
curing time for concrete
28 days
types of Palustrine wetlands
marshes
swamps
bogs
fens
wetland salinity
Freshwater wetlands typically have a salinity measure of less than 0.5 ppt, but sometimes nearby land uses increase the salinity, which is destructive to plants
marshes
Marshes are defined as wetlands frequently or continually inundated with water, characterized by emergent soft-stemmed vegetation (no woody veg) adapted to saturated soil conditions. There are many different kinds of marshes, ranging from the prairie potholes to the Everglades, coastal to inland, freshwater to saltwater. All types receive most of their water from surface water, and many marshes are also fed by groundwater. Nutrients are plentiful and the pH is usually neutral leading to an abundance of plant and animal life. We have divided marshes into two primary categories: non-tidal and tidal.
examples of non tidal marshes
Examples of non-tidal marshes are: Prairie potholes, playa lakes, vernal pools and wet meadows.
bogs
Bogs are one of North America’s most distinctive kinds of wetlands. They are characterized by spongy peat deposits, acidic waters and a floor covered by a thick carpet of sphagnum moss. Bogs receive all or most of their water from precipitation rather than from runoff, groundwater or streams. As a result, bogs are low in the nutrients needed for plant growth, a condition that is enhanced by acid forming peat mosses. has shrubs and herbaceous plants, very few trees.
fens
Fens, are peat-forming wetlands that receive nutrients from sources other than precipitation: usually from upslope sources through drainage from surrounding mineral soils and from groundwater movement. Fens differ from bogs because they are less acidic and have higher nutrient levels. Therefore, they are able to support a much more diverse plant and animal community. These systems are often covered by grasses, sedges, rushes and wildflowers. Some fens are characterized by parallel ridges of vegetation separated by less productive hollows. The ridges of these patterned fens form perpendicular to the downslope direction of water movement. Over time, peat may build up and separate the fen from its groundwater supply. When this happens, the fen receives fewer nutrients and may become a bog.
five classes of wetland systems
marine, estuarine, riverine, lacustrine, and palustrine
estuarine wetland
similar to a marine wetland, but access to the open ocean is much more limited and its waters are at least somewhat diluted by freshwater. They are partially enclosed by land, and salinity can range between .5 and less than 30 ppt depending on distance from the ocean, time of day, and season. Examples of estuarine wetlands include estuaries (as the name implies), lagoons, and mangrove swamps (technically called “mangrove forest wetlands”).
Riverine wetlands
wetlands contained within a river system, channel, or river basin. The exception here is if the wetland is heavily dominated by trees, shrubs, and other terrestrial plant life (making it a forested wetland), or if salinity is greater than .5 ppt (making it a coastal wetland).
Lacustrine wetlands
“situated in a topographic depression or a dammed river channel,” have trees or shrubs with less than 30% canopy coverage (meaning they’re either well-spaced apart or not mature), and in most cases must have an area greater than 8 hectares or 20 acres. In most cases, there is a noticeable amount of wave action. Additionally, they can be fed by either fresh or saltwater, but salinity must be less than .5 ppt. They can often be found along the outskirts of lakes.
Palustrine wetlands
can either be tidal or nontidal so long as salinity is less than .5 ppt, and are dominated by trees, shrubs, and other emergent vegetation (including certain species of lichen and mosses). The latter can be lacking, but only if the wetland is less than 8 hectares, it does not have a bedrock shoreline or one formed by waves, and its deepest part is less than 2.5 meters at low water. Examples of palustrine wetlands include some of the most widely known wetlands: bogs, fens, swamps, and marshes.
types of mortar
type M - high compressive strength, low workability (below ground applications)
Type O - used on interiors
Type S - structural applications
Type N - works well outdoors, good bonding strength, most common for landscapes
types of bolts, where they are used
anchor bolt - best for fastening something to a foundation in decking design
through bolt - used in wall systems
lag bolt - not used to attach things to a footing, used to fasten two items together needing high stength
J bolt - embedded in concrete, used to receive something on top like a sign
swamp
any wetland that is dominated by trees and shrubs. There are many types of swamps, including mangrove swamps, northern hardwood swamps, lowland swamps, and shrub swamps, among others.
ways for a construction surveyor to lay out a site
metes and bounds - identifies objects from a known meridian
Coordinates - uses a grid
Station offsets - uses a reference line, then locates objects using the line with perpendicular measurements
dimensions - using sets of measurements from know objects
examples of sediment control devices
silt fence
silt sacks
hay bales
filter strips
tack coat
used to bind two layers of asphalt together
how to deal with cracking concrete
fill cracks with epoxy
what to use when compacting clay soil
sheepsfoot roller
shoreline erosion management techniques
vertical revetments
breakwaters
slope revetments
beach renourishment
composite deck board spacing
1/8 to 1/4
asphalt treated base (ATB)
A water resistant barrier to prevent fines infiltration into the subgrade and pavement structure. If water accumulates in the subgrade, the repetition of pavement loading can cause subgrade fines to migrate into the base and pavement structure. This can clog the base layer, which impedes drainage and create voids in the subgrade into which the pavement may settle.
An alternative to untreated base material. Structurally, ATB is about three times as strong as an untreated granular base (such as crushed rock). Therefore, it is possible to use thinner layers for the same structural support, which can save on excavation costs. In some cases a layer of aggregate base is still needed to provide material to fine grade and to provide a smooth surface on which to pave.
heat of hydration
chemical process that happens when you mix cement and water (particles expand, creating heat)
forebay
located upstream of a stormwater wetland or infiltration device to intercept and reduce the velocity of flow entering the wetland and to settle sediments and other solids. improves water quality within the wetland, improves efficiency and lifespan
depth of a wet pond
4-8 feet
vegetative swales handle what level of storm event
25 yr storm
general conditions
The general conditions, often referred to as the boilerplate, augment the construction contract and outline the rules under which the project will be built. They establish the rights, authority, and obligations of the contracting parties: the owner, the owner’s representative, and the contractor.
project manual
The project manual consists of the bidding documents, general conditions, supplementary provisions, and the technical specifications. These documents are often contained within a single binder or “book.”
contract documents
construction agreement, drawings, general conditions, supplementary provisions, technical specifications, addenda, and changes.
