BDCS 1 (conc & masonry)

chalky white surface deposite of low strength

• compression
• weak in tension

chemical reaction, rather than drying out of the mix, that causes hardening of concrete

• standard concrete
• for general all-purpose use

• modified concrete
• for slow setting and less heat

• high early strength concrete
• for quick setting and early strength

• low heat concrete
• for very slow setting (little heat)

• sulfate resisting concrete
• for alkaline water and soils

• accelerators
• air-entraining agents
• retarders
• waterproofing
• water-reducing
• workability agents

• calcium chloride
• speed up setting time

• resins, fats, and oils
• resist freezing action

• starches, sugars, and acids
• slow down setting time

• stearate compounds
• decrease permeability

• organic compounds
• reduce water content
• decrease the permeability of the concrete

• powdered silicas and lime
• improve workability

mixed completed at a central mixing plant and transported to the site in a agitator truck with revolving chamber

completed in the truck mixer

• #3 (3/8" dia) thru #11 (1-3/4" dia)
• and #18 (2-1/2" dia)

billet steel

rail steel

axle steel

low-alloy steel

ASTM A615 Grade 60

• grade 40, 50, 60, and 75
• min specified yeild strength 40,000, 50,000, 60,000, and 75,000

welded wire fabric with wires at 6" on center in each direction, with each wire havign a cross-sectional area of 2.9/100 or 0.029 square inches (which is 6 gauge wire)

90 to 115lbs per cubic foot

measures consistency and workability

measures compressive strength of concrete and utilizes standard test cylinders 6" in dia and 12" long

uses molds into which moist clay is pressed by hand or machine into rectangular molds

• widely used
• forces the mixture through a die, extruding a clay ribbon that is cut into bricks by tightly stretched wires

• severe weathering
• used in areas of heavy rain, snow, or continual freezing

• moderate weathering
• used in areas of average rain and moderate freezing

• no weathering
• used in areas of minimal rain and no freezing, as in sheltered or indoor locations

• face brick
• high degree of mechanical perfection, narrow color range, and min size variations

• face brick
• greater size variation and wide color range

• face brick
• nonuniform in size, color, and texture

• hollow brick
• high dregree of mechanical perfection, min size variation, and narrow color range

• hollow brick
• greater size variation and wide color range

• hollow brick
• nonuniform in size, color and texture

inferior brick used behind face brick

very hard and dense brick used in pavements

brick made with greater resistance to high temperatures, as in a fireplace

brick made from a mixture of natural clay and straw, placed in molds, and dried in the sun. requires protection from rain and subsurface moisture

flat brick generally used on interiors where solid masonry cannot be structurally suported

brick whose net cross-sectional area is at least 60% of its gross cross-sectional area

top of a brick

end of the brick

• gypsum tiles
• solid or cored units manufactured from gypsum plaster
• avialable in 2 to 6 inches, in standard panels 12x30 inches in size

• fieldstone
• natural stone used decoratively

irregular stone with at least one good face used for ashlar veneers, copings, sills, curbs, etc

cut stone, used for surface veneers, toilet partitions, flooring, stair treads, etc.

thin slabs used for paving, treads, countertops, etc.

used for sculpture, monuments, gravestones, etc.

used as aggregate for concrete, asphaltic concrete, terrazzo, built-up roof surfacing, etc. as well as granular fill

used as filler in asphalt flooring, shingles, paints, etc.

• binding agent of concrete
• made from lime, silica, iron oxide, and alumina

• waste material obtained from coal-fired power plants
• used in concrete to increase strength, decrease permeability, reduce temperature rise, increase sulfate resistance, and improve workability
• can also be used to decrease the amout of cement needed

• precast concrete product manufactured by adding aluminum powder to concrete, hardening it in molds and then curing the molds in a pressurized steam chamber (autoclave)
• typ in blocks of 10in high by 25in long and 4in,8in,10in thick
• laid with thin mortar

• concrete mixture that can be placed purely by means of its own weight without the use of vibration
• made possible by use of a superplasticizer admixture called a polycarboxlylate polymer

• uses epoxy-coated carbon fiber mesh in place of standard steel mesh for secondary steel reinforcement
• used for precast panels, to make them thinner and lighter
• less concrete is required because carbon fiber is noncorrosive

• aka moisture dome test
• most common tests for moisture in concrete and is inexpensive and easy to complete

• aka relative humidity test
• determines the moisture emission by measuring the relative humidity of the atmosphere confined adjacent to the concrete floor

• qualitative test conducted by sealing an 18inX18in sheet of plastic to the floor to trap excessive moisture for 16hrs
• visually inspected

• similar to poythylene sheet test
• uses 24inX24in sheet for 72hrs

• uses proprietary meters to determine the moisture content of the concrete by measuring conductance and capacitance
• probes of the meter are placed on the concrete and percentage of moisture content in the slab is read out directly

• from 0 to 14, below 7 is acidic
• concrete should be tested for pH levels

• process strongly alkaline cement begins to dissolve sand and rock within the concrete
• chemical reaction produces a gel-like material that creates tremendous pressures in the pores of the concrete surface
• pressure can buckle or blister the floor finish
• can be avoided by using aggregates not susceptible to ASR, by using low-lime cement, by prorper curing, or by not finishing the concrete with a hard trowl surface

used to determine the level of alkalinity in concrete

occurs wherever there are 2 successive pours; that is, wherever there is a new pour against a cured section of concrete

mixture of cement, lime, sand and water

prepared mixture of portland cement and pulverized limestone

M, S, N and O

• white, crysalline deposit of water-soluble salts on the surface of brick masonry
• caused when water seeps into the masonry and dissolves soluble salts present in the masonry, backup wall, mortar or anything in contact with the wall