Physical Properties
CEMEX’s Victor Plastic Cement provides consistent workability, strength, durability, appearance and meets UBC and ASTM physical requirements for plastic cements. (See Table 1).
| Table 1 Uniform Building Code, Physical Requirements for Plastic Cements | |
|---|---|
| Fineness, residue ona No. 325 sieve (45*m), maximum, percentage | 24 |
| Soundness: Autoclave expansion, maximum, percentage |
1.0 |
| Time of setting, Gilmore method: Initial set, minimum, hour Final set, maximum, hour |
1-1/2 24 |
| Compressive Strength (average of three cubes): Initial compressive strength of mortar cubes, composed of one part cement and three parts blended sand (half graded Ottawa sand, and half Standard 20-30 Ottawa sand) bye volume, prepared and tested in accordance with this specification shall be equal to or higher than the values specified for the ages indicated below: | 7 days, psi (kPa) 1,800(12 402 kPa) 28 days, psi (kPa) 2,900 (19 981 kPa) |
| Air content of mortar Minimum percentage by volume |
8 |
| Maximum percentage by volume | 20 |
| Water retention, minimum flow after suction, percentahe of original flow | 70 |
Durability
Properties of plastic cement plaster related to its durability include:
- Drying shrinkage characteristics. Results of laboratory test shown in Figure I indicate that the drying shrinkage of plastic cement plaster is about half that of Portland Cement-Lime Plaster (See Figure 1).
- Resistance to sulfate attack. Plastic Cement Plaster also demonstrates significantly greater sulfate resistance than Portland Cement-Lime Plaster (See Figure II).
- Water permeance. Laboratory research has confirmed the excellent performance of plastic cement plaster in water permeance tests (See Figure III).
Preparation
CEMEX’s Victor Plastic Cement proportioned with sand meeting ASTM C-897 will produce plaster meeting the requirements of ASTM C-926. Under the requirements of ASTM C-926 (Table 3, Base Coat Proportions), cement-to-sand proportions for job mixed plaster are to be in the range of 1:2½ to 1:4 for the Scratch coat and 1:3 to 1:5 for the Brown coat.
In accordance with ASTM C 926 - All plasters shall be prepared in a mechanical mixer, using sufficient water to produce a workable consistency and uniform color.
Hot Weather and Retempering
Plaster exposed to hot winds and full sun will tend to lose workability due to the evaporation of water. Common sense precautions such as shading the mixer, covering wheelbarrows and tubs, and balancing plaster production to meet demand should be taken to protect the plaster. If it is necessary to restore workability, plaster may be retempered by adding water and remixing. No plaster mix should be used or retempered beyond one hour after the initial mixing.
Cold Water Precautions
Mortar should be maintained at a minimum temperature of 40° F as prescribed by standard cold weather masonry specifications. Cold weather admixtures should be approved by the architect.
Sand should be protected and/or heated to prevent ice from forming. The fresh work should be protected at a minimum temperature of 40°F (6°C) for a least three days to provide proper curing for the plaster.
Availability
CEMEX’s Portland Cements can be ordered by contacting at CEMEX Customer Care at:
Customer Care | 1-800-992-3639
Maintenance
Avoid use of harsh chemical cleaners or strong acid solutions in cleaning plaster.
Technical Services Personnel
CEMEX personnel are available to provide technical assistance by contacting Customer Care at: 1-800-992-3639
Warranty
CEMEX warrants that the products identified are in accordance with the appropriate current ASTM and Federal Specifications. No one is authorized to make any modifications or addition to this warranty. CEMEX makes no warranty or representation, either expressed or implied, with respect to this product, and disclaims any implied warranty of merchantability or fitness for a particular purpose.
CEMEX warrants that the products identified are in accordance with the appropriate current ASTM and Federal Specifications. No one is authorized to make any modifications or addition to this warranty. CEMEX makes no warranty or representation, either expressed or implied with respect to this product, and disclaims any implied warranty of merchantability or fitness for a particular purpose.
As CEMEX has no control over the other ingredients mixed with this product or the final application, CEMEX does not and cannot warrant the finished work.
In no event shall CEMEX be liable for direct, indirect, special, incidental or consequential damages arising out of the use of this product, even if advised of the possibility of such damages. In no case shall CEMEX’s liability exceed the purchase price of this product.