Quick Notes Flashcards
When specifying lumber for use on a wooden deck, the lumber should always be
faced bark-side up
by orienting lumber bark-side up, cupping or warping of the deck lumber will be limited to the center of the wood, not the edges (i.e. where adjacent pieces of lumber sit parallel to one another along their long edge). Cupping at the edges of lumber creates a trip hazard that can easily be reduced or mitigated by placing deck lumber bark-side up.
Vegetated swales can be used to accommodate large storm events:
generally be designed to safely convey a 25-year storm event.
Note that they will often be designed to handle 2-year design storms without experiencing erosion.
Isolation or expansion joints
Are used in concrete to allow lateral movement between adjacent slabs or other fixed structures/surfaces, and as such, should be constructed to the full depth of the concrete slab.
Should also be placed at the interface between concrete and other fixed surfaces, for example, where a horizontal concrete surface meets a structure.
Stormwater infiltration rates are determined primarily by
Soil type
Infiltration
The movement of water through soil, rock or other material in the ground and, as such, infiltration rates are determined primarily by soil type.
Primary Purpose of Bid Form
Standardize all bids submitted so that they can be compared accurately to one another
In the absence of a bid form, contractors may format their bids in a variety of ways, making it difficult or impossible to accurately compare bids between contractors with the same scope of work.
Stabilized Inlet
Typically constructed with riprap - relatively large angular rocks that diffuse the velocity of water entering a stormwater treatment facility.
Silt Fences
Typically laid out along the contour of a slope to maintain water quality during construction activities.
Generally composed of a fine plastic mesh that retains and filters sediments from stormwater while also allowing water to pass through the plastic membrane.
To avoid or rehabilitate compacted soils, what measures should be taken during or after construction:
- Determine if compaction is located in the surface or in the subsoil
- Amend soils with organic matter
- Limit the use of heavy equipment during construction process
- Avoid use of heavy equipment during or directly after precipitation events, as wet soils are more readily compacted.
Site Protection Plan
a plan or plans that, in general, protect natural resources on a project site, sensitive areas adjacent and downstream of the project site and comply with local laws and codes.
Examples of content in a site protection plan include tree protection and salvage, site access, erosion control measures, and noise control.
Stormwater BMPs attempt to accomplish:
Aimed at infiltrating stormwater, thereby mimicking the natural hydrological regimen and recharging groundwater.
Also aim to reduce stormwater velocity and volume, as doing so improves water quality and reduces the potential for erosion during storm events.
In general, BMPs do not attempt to detain stormwater over long periods of time, although cistern structures and other rainwater harvesting devices would do so.
Likewise, BMPs do not channelize stormwater flows, as channelization results in high water velocities that will erode stream channels and reduce water quality when released into natural water systems.
Lower peak flow, not base flow.
Continuous Beam
Beam supported by at least three structural members (posts) on a wooden deck or other elevated structure.
Note that all beams are load bearing and that the portion of a beam overhanging a post could be referred to as “cantilevered”
Gravel Ballast
Recommended feature of green roofs along their perimeter to protect against wind shear.
What three materials are found in typical concrete mix?
Water
Aggregate
Cement
Under general conditions, properly constructed asphalt pavement requires surface maintenance or resurfacing every:
20 years
Bituminous Binder
Used to adhere a new coat of asphalt to an existing asphalt surface.
Mortar
Used to bond individual masonry units
Epoxy
a high-strength adhesive that is used to bond wood, concrete, metals and/or plastics in general construction
Asphalt Treated Base
An alternative to untreated base material and is typically used during construction in wet or freezing conditions
Plate Compactor
Used to compact an aggregate product during a construction process
The ratio of which two materials determines the compressive strength of concrete
Water and Cement
W/C Ratio
Reducing peak flows can help control:
- stream siltation
- soil erosion
- downstream scouring
- channel widening
- frequency of severe floods
Mitigating land subsidence
Usually achieved through groundwater recharge and stormwater infiltration
Proper dust control on a construction site has the primary benefits of
Reducing the volume of sediments produced by construction activities