lacing—horizontal bracing between shoring members. lagging—heavy sheathing used as in underground work to withstand earth pressure. (See also sheathing.) laitance—a weak layer of cement and aggregate fines either: (1) carried by bleeding to the surface or…
kaolin—a rock, generally white, consisting primarily of clay minerals of the kaolinite group, composed principally of hydrous aluminum silicate of low iron content, used as raw material in the manufacture of white cement. kaolinite—a common clay…
ignition loss—see loss on ignition (preferred term). ilmenite—a mineral, iron titanate (FeTiO3), which in pure or impure form is commonly used as aggregate in high-density concrete. impact—instantaneous contact of a moving body with another body, either…
hacking—the roughening of a surface by striking with a tool. hairline crack—see crack, hairline. hairpin—the wedge used to tighten some types of form ties; a hairpin-shaped anchor set in place while concrete is unhardened; a light…
gage length—in cement testing, the nominal length between the innermost ends of metal studs that are molded into a test specimen with the axis of the stud in each end of the test specimen coincident with…
fabric, welded-wire—a series of longitudinal and transverse wires arranged approximately at right angles to each other and welded together at all points of intersection. fabric, woven-wire—a prefabricated steel reinforcement composed of cold-drawn steel wires mechanically twisted…
early ages (of concrete)—the period following the time of final setting during which properties are changing rapidly and heat evolution is important; for concrete made with Type I cement stored moist at 73 F (23 C),…
damage, abrasion—wearing away of a surface by rubbing and friction. (See also damage, cavitation and erosion.) damage, cavitation—pitting of concrete caused by implosion, that is, the collapse of vapor bubbles in flowing water which form in…
cabinet, moist—an upright and compartmented case having doors and shelves of moderate dimensions for storing and curing small test specimens of cement paste, mortar, and concrete in an atmosphere of approximately 73 F (23 C) and…
backer rod—a flexible, compressible rod placed in a joint to reduce the depth of sealant and improve its shape factor; it also serves to support the sealant against sagging and indentation. backpack grouting—see grouting, backpack. back…
abrasion damage—surface deterioration caused by rubbing and friction against the surface. abrasive—any hard, strong substance, such as rocks, sand, water, or minerals, that will cut, scour, pit, erode, or polish another substance. abrasive blasting—a process for…
