M 201 SPECIFICATIONS FOR MATERIALS

Standard Specification for

Moist Cabinets, Moist Rooms, and Water Storage Tanks Used in the Testing of Hydraulic
Cements and Concretes

AASHTO DESIGNATION: M 201-94

1. SCOPE with recording thermometers. The use of satisfactory results have not been
humidity recording devices is optional. obtained with other devices.
Shelves on which fresh specimens are 4.3.2 Moist Rooms Used in Cement
1.1 This specification covers placed shall be level.
requirements for moist cabinets, moist Testing-Durable shelving that is properly
rooms, and water storage tanks used for 4.1.1 The air in a moist storage unit shielded to prevent droplets of water
storage of paste, mortar and concrete test must be nearly saturated with moisture in from falling on the surfaces of freshly
specimens. order to provide specified storage molded specimens shall be available
conditions. In many cases, saturation is within each room.
1.2 This standard does not purport to below optimum during periods when
address all of the safety problems, if any, 4.3.3 Moist Rooms Used in Concrete
specimens are being placed in or Testing-Atmospheric conditions withn
associated with its use. It is the removed from storage. Measurements of
responsibility of the user of this standard each room shall be such that test
relative humidity should not be made at specimens in storage shall have free
to establish appropriate safety and health such obviously inopportune times.
practices and determine the applicability water maintained on the entire surface
of regulatory limitations prior to use. 4.1.2 The recordings from the area at all times. Specimens shall not be
recording thermometers can be audited in exposed to dripping or running water.
order to ascertain the adequacy of the 4.4 Water Storage Tanks:
2. REFERENCED DOCUMENTS mechanisms used to control the moist
room air temperature. 4.4.1 General-Tanks shall be
constructed of noncorroding materials.
2.1 ASTM Standard: 4.2 Moist Cabinets-A moist cabinet shall Provisions for automatic control of water
be constructed of durable materials and temperature to 23.0 ± 1.7°C shall be
C 911 Specification for Quicklime,
the doors shall be tightfitting. The made where a tank is located in a room
Hydrated Lime, and
specified relative humidity shall be not having temperature controlled within
Limestone for Chemical Use
maintained by the use of one or more fog that range and in any other instance
sprays, water sprays, or "curtains" of where difficulty in maintaining
3. DEFINITIONS water on the inner walls that are so temperatures within the specified range is
directed that the discharge will collect in encountered. Each tank located in a space
a pool at or near the bottom of the moist not controlled to 23.0 ± 1.7°C shall be
3.1 Moist Cabinet-a compartmented storage section. Provision for automatic
storage facility of moderate dimensions equipped with a recording thermometer
control of air temperature shall be made with its sensing element in the storage
with controlled temperature and relative where a cabinet is located in a
humidity. water. The water in a storage tank shall
nonconditioned work room and in any be clean, and shall be saturated with lime.
3.2 Moist Room-a "walk-in" type storage other instance where difficulty in Continuous running water or
facility with controlled temperature and maintaining temperatures within the demineralized water may affect test
relative humidity. Commonly called a fog specified range is encountered. results due to excessive leaching and
room when the prescribed relative 4.3 Moist Rooms: should not be used in storage tanks.
humidity is achieved by the atomization
of fresh water. 4.3.1 General-The walls of a moist 4.4.2 Continuous, fresh running water
room shall be constructed of durable or demineralized water shall not be used
materials, and all openings shall be in storage tanks. A closed system,
4. REQUIREMENTS provided with tight-fitting doors or circulating the saturated lime water
windows. The temperature of the air in between or among storage tanks, may be
the room shall be thermostatically used.
4.1 General-The atmosphere in a moist
controlled, with provisions being made
cabinet or room shall have a temperature
for heating or cooling, or both, as may be
of 23.0 ± 1.7°C and a relative humidity of 5. KEYWORDS
necessary. The sensing element shall be
not less than 95 percent. The moisture in
located in the moist room. The specified
the atmosphere shall be saturated to the
relative humidity may be maintained in 5.1 Cement paste; concrete; moist
degree needed to ensure the exposed
any convenient and suitable manner; cabinets; moist rooms; mortar; water
surfaces of all specimens in storage will
however, air-water type sprays with storage tanks.
both look moist and feel moist at all
abrasion-resistant orifices shall be
times. All storage units shall be equipped
employed in all instances where

249