There are currently 9 names in this directory beginning with the letter H.
H
Hardener (Curing Agent)
A catalytic or reactive agent used to promote, enhance or control the curing reaction and aid in property development. The addition of a curing agent to an epoxy resin causes polymerization.
Hardness
A measure of the resistance of a material to surface indentation or abrasion; a function of the stress required to produce some specified type of surface deformation. It is measured in Shore A (soft types) and Shore D (rigid types)
Haze
The cloudy or turbid appearance of an otherwise transparent specimen caused by light scattered from within the specimen or from its surfaces.
High solids
A general term used to denote the presence of a higher than average percentage of solid ingredients and thus a lower percentage of solvents.
Holidays
A coating application defect where there is complete absence of coating on random areas of substrate. This is detected by holiday detector.
Hydration
The chemical reaction between water and Portland cement, which causes the concrete to attain its ultimate compressive strength.
Hydrostatic pressure
Pressure which forces water up through a below-grade slab, generally causing installation problems due to moisture. This occurs when water table is higher than the slab. Hydrostatic pressure is caused by the weight of the water pressing down on itself.
Hygrometer
An instrument for measuring the degree of humidity or relative humidity of the atmosphere.
Hygroscopic
a. A substance that can absorb and retain moisture, or lose or throw off moisture. Wood and wood products are hygroscopic. They expand with absorption of moisture and their dimensions become smaller when moisture is lost or thrown off.
b. The ability to lose or gain moisture relative to the atmospheric humidity and temperature