Architectural Technology: Heavy Timber, Metals, Concrete, Light Wood, and Masonry

Comprehensive practice flashcards covering vocabulary, structural systems, and material properties across heavy timber, metals, cast-in-place concrete, precast concrete, light wood framing, lumber milling, and masonry construction.

Charring

The fire-resistance mechanism in heavy timber where wood burns from the exterior inward, forming an insulating carbonaceous layer that protects the uncharred core and allows the structure to sustain loads long enough for occupant egress.

Braced Frame

The foundational structural concept in heavy timber construction consisting of an open framework of vertical, horizontal, and sloped members joined to resist lateral and moment forces without relying on sheathing diaphragms.

Flitch Beam

A compound structural member created by sandwiching a steel plate between timber pieces along their length, where the steel plate resists bending forces and the wood prevents the steel from twisting or buckling.

Firecut

An angular chamfer cut at the end of a timber beam bearing in a masonry wall pocket, designed to allow the beam to pivot and drop out freely during a fire failure without prying or destabilizing the masonry wall.

Cross-Laminated Timber (CLT)

An engineered mass timber product fabricated from dimensional solid lumber glued into large multi-layer structural panels, with adjacent layers oriented at right angles to provide two-way spanning strength and dimensional stability.

Mjøstårnet

An 18-story, 122,000-square-foot mass timber tower in Brumunddal, Norway, framed primarily with Glulam columns and beams and employing CLT for shear walls and stair cores.

Scope of Work (SOW)

The legally and practically binding sum of all responsibilities, protocols, and deliverables assigned to an entity in a design or construction contract.

Change Order (CO)

A written legal modification to the construction contract that documents revisions, additions, or deductions to the Scope of Work, requiring approval by the client and the design prime.

Substitutional Alloy

A metallic alloy formed when atoms of an alloying element replace some of the base metal's atoms directly within its regular crystal lattice pattern, as seen in brass and bronze.

Interstitial Alloy

A metallic alloy formed when additive atoms occupy the small spaces between the base metal's atoms without substituting them, as seen when carbon is added to iron to make steel.

Weathering Steel (COR-TEN)

An alloy of mild steel with copper, manganese, and chromium that produces an adherent, dense surface oxide layer that arrests further atmospheric corrosion, eliminating the need for protective paint finishes.

Hot-Rolling

An industrial forging method where heated, malleable metal blooms or ingots are repeatedly squeezed between steel rollers to produce long structural shapes with continuous cross-sections, such as wide-flange beams.

Galvanizing

A metal finishing method where steel is coated with a layer of metallic zinc, producing a characteristic crystalline spangled surface that provides sacrificial galvanic protection against corrosion.

Hydration (Concrete)

The exothermic chemical reaction between Portland cement and water that transforms the liquid slurry into a solid crystalline matrix of calcium hydroxide ($Ca(OH)_2$), achieving design strength at 28 days.

Slump Test

A standardized field test assessing the workability and consistency of fresh concrete by measuring the subsidence of a conical concrete sample after the mold is lifted away.

Concrete Admixture

Chemical substances added to concrete before or during mixing to alter properties such as workability, curing speed, air content, freeze resistance, or water demand.

Fly Ash

A supplementary cementitious pozzolan produced as a byproduct of coal combustion that can replace up to a substantial portion of Portland cement, reducing embodied carbon and improving workability.

Rebar (Reinforcing Bar)

Textured round steel bars with surface ribs cast into the tension zones of concrete elements to mechanically bond with the cured cement matrix and resist tensile forces.

Form Tie

A tensile metal connector assembly passing through concrete formwork to hold opposed form faces against the outward hydrostatic pressure of wet concrete while maintaining proper wall thickness.

Precast Concrete

A construction method where concrete members are cast, cured, and finished in reusable molds under controlled off-site conditions before being transported and erected on the job site.

Pre-tensioning

A prestressing process where high-strength steel strands are stressed between external anchors in a casting bed prior to pouring concrete, imparting an upward camber upon strand release to counteract future dead and live loads.

Hollow-Core Slab

A precast prestressed concrete spanning panel manufactured with continuous internal longitudinal voids to minimize dead weight while providing a load-bearing floor or roof deck.

Grout Sleeve

A cast-in duct embedded inside a precast concrete member designed to receive protruding rebar from an adjoining component, locked into an integrated connection by pumping in non-shrink cementitious grout.

Post-Tensioning (Cast-in-Place)

A method of reinforcing site-cast concrete slabs or beams using high-strength steel cables (tendons) laid in draped profiles within tubes, which are tensioned with hydraulic jacks after the concrete cures.

One-Way Concrete Joist System

A cast-in-place concrete spanning system consisting of closely spaced parallel ribs cast monolithically with a thin top slab, transferring loads across a bay in one direction to primary girders or bearing walls.

Waffle Slab

A two-way cast-in-place concrete slab system formed over a modular grid of square dome pans, creating an underside coffer of intersecting ribs that reduces mass while resisting multi-directional moments.

Flat Slab (Concrete)

A two-way reinforced concrete floor or roof system of uniform slab thickness supported directly on columns without dropped beams, facilitating low structural depth and flexible open plans.

Cold Joint

A distinct discontinuity plane created when freshly placed concrete is poured against an earlier lift that has already set, often detailed with a decorative reveal to conceal cracking.

Diaphragm Principle

The structural mechanism in light wood framing wherein rigid planar sheathing locks studs or joists together, transferring shear and lateral loads across the assembly rather than through individual pinned connections.

Platform Framing

A light wood framing system where studs extend only one story tall between horizontal subfloor platforms, providing an automatic fireblock and work surface at each consecutive floor.

Sill Plate

The horizontal wood member anchored to a concrete or masonry foundation wall with anchor bolts, constructed from pressure-treated lumber to resist rot from moisture wicking.

Bridging (Floor Joists)

Diagonal cross-bracing or solid wood blocks placed mid-span between adjacent floor joists to hold them vertical and prevent rotational rolling or twisting under live loads.

Birdsmouth Cut

An angled notch cut into the lower bearing end of a wood roof rafter consisting of a horizontal seat cut and a vertical plumb cut, seating the sloping rafter securely on the wall top plate.

Heartwood

The dense, inactive central wood of a tree trunk that no longer transports sap or nutrients, providing the hardest and most dimensionally stable wood in the tree.

Janka Hardness Scale

A standardized rating scale quantifying wood density and hardness based on the force required to embed an 0.444-inch steel ball halfway into a timber sample.

Quarter Sawing

A method of converting a log into boards by sawing radially perpendicular to the growth rings, creating straight face grain, minimal runout, and high resistance to warping.

Seasoning (Lumber)

The controlled drying of milled lumber through air or kiln drying until structural framing members reach a moisture content of $19\%$ or less of their total weight.

Board Foot

A standard unit of measurement for rough or surfaced lumber equal to a nominal volume of 144 cubic inches (equivalent to a board 12 inches wide, 12 inches long, and 1 inch thick).

Glued-Laminated Timber (GluLam)

An engineered structural wood product made by gluing individual pieces of end-jointed and planed lumber together with their grain running parallel to the longitudinal axis.

Book Matching (Veneers)

A veneer layup pattern where consecutive sliced leaves from a wood flitch are alternately folded out side-by-side like the pages of a book, creating mirror-image symmetrical grain figures.

Concrete Masonry Unit (CMU)

A modular hollow or solid structural masonry block made of molded, steam-cured concrete, standardly manufactured on an 8-inch cubic modular grid.

Modular Brick

A standardized clay brick with nominal modular dimensions of 4 inches by 8 inches by 2 2/3 inches, allowing three vertical courses with standard 3/8-inch mortar joints to equal one 8-inch CMU module.

Repointing

The masonry restoration process of raking out weathered, damaged sacrificial mortar from bed and head joints to a set depth and packing fresh mortar into the joints.

Type N Mortar

A general-purpose cement-lime mortar mix providing a balance of bond strength and workability, used primarily for exterior veneers, non-load-bearing exterior walls, and interior walls.

Firebrick

A specialized refractory ceramic brick made of fireclay that withstands high service temperatures without decomposing, used to line fireplaces, kilns, and combustion chambers.

Wythe

A single continuous vertical thickness of masonry units, exactly one masonry unit wide.

Stretcher (Masonry)

A masonry unit laid flat in a wall course with its longest face exposed parallel to the wall plane, remaining entirely within a single wythe.

Common Bond (Brick)

A traditional structural brick pattern where five continuous courses of stretchers are tied across wythes by a sixth header course composed entirely of headers.

Jointer (Tooling Tool)

A curved or shaped steel hand tool dragged along fresh mortar joints to compact the mortar against masonry units and form water-shedding joint profiles.

Masonry Lintel

A horizontal spanning element of steel, reinforced concrete, or bond-beam CMU placed over a wall opening to carry the triangular zone of uncorbelled masonry load directly above.

Cavity Wall

A multi-layered exterior wall system consisting of an outer masonry veneer separated by a continuous air space and drainage plane from an inner structural backup wall, connected by metal ties.

Shelf Angle

A continuous steel angle fastened to a building's perimeter floor slab edges at multi-story increments to transfer the dead weight of exterior brick veneer back to the primary structural frame.