Product description

Basic Use
CEMEX’s Plastic Cement is specially formulated and manufactured to produce masonry mortar for use in brick, block and stone construction.

Composition and Materials
CEMEX’s Plastic Cement consists of a mixture of Portland Cement and plasticizing materials (such as limestone, hydrated or hydraulic lime) together with other materials introduced to enhance one or more properties. These components are proportioned at the cement plant under controlled conditions to assure product consistency.

Types
CEMEX’s Plastic Cement meets the physical requirements of ASTM C-91 for Type N, S and Type M Masonry Cements for use in preparation of ASTM Specification C-270 Type S, or M mortar, respectively, without any further additions.

Limitations
CEMEX’s Plastic Cement is designed to be mixed with sand and water. The addition of hydrated lime or any other materials to a plastic cement mortar at the job site is not required or recommended.

Plastic Cement is not approved for use in load-bearing structural masonry construction in seismic zones 2, 3 and 4.

Technical data

Applicable Standards
Related Standards: The following standards are related to the use of CEMEX’s Plastic Cements:

ASTM C-91 Standard Specification for Masonry Cements

ASTM C-144 (Standard Specification for Aggregates for Masonry Mortar)

ASTM C-270 (Standard Specification for Mortar)

ASTM C-780 (Standard Specification for Pre-construction and Construction Evaluation of Mortar for Plain and Reinforced Unit Masonry)

Water
All water should be clean and free from organic material and deleterious amounts of dissolved acids, alkalies and salts.

Physical Properties
CEMEX’s Plastic Cement provides consistent workability, strength and durability (See Table 1).

Durability
Properties of masonry mortar related to its durability include:

• Drying shrinkage characteristics. Results of laboratory test shown in Figure I indicate that the drying shrinkage of Plastic Cement Mortars is about half that of Portland Cement-Lime Mortars (See Figure I).
• Resistance to sulfate attack. Plastic Cement Mortars also demonstrate significantly greater sulfate resistance than Portland Cement-Lime Mortars (See Figure II).
• Water permeance. The properties of Plastic Cement Mortars when combined assure that the designer’s and masons’ needs are met. Laboratory research3 has confirmed the excellent performance of Masonry Cement Mortars in water permeance tests (See Figure III).

Installation

Preparation
CEMEX’s Plastic Cement proportioned with sand meeting ASTM C-144, according to Table 2, will produce mortar meeting the requirements of ASTM C-270 under the proportion specifications. Under the property requirements of ASTM C-270, however, cement-to-sand proportions for the job mixed mortar are to be in the range of 1:2¼ to 1:3½, and the mortar must be pre-tested in the laboratory before the job begins.

Machine mixing should be used whenever possible. First, with mixer running, add most of the water and half the sand. Next, add the Plastic Cement and the rest of the sand. After one minute of continuous mixing, slowly add the rest of the water. Mixing should continue for at least three minutes; extending mixing up to five minutes improves mortar.

Application
Good workmanship practices are required for successful application, including proper filling of head and bed joints, careful placement of units, appropriate tooling of the joint, modification of construction procedures and/or schedules to adapt to extreme weather conditions4,5 and proper cleaning procedures.

Masonry joints should be tooled at the same degree of stiffness and moisture. If joints are tooled too early, excess water will be drawn to the surface, producing lighter joints. The joints will appear dark and discolored if tooling is done after stiffening has started.

Hot Weather and Retempering
Mortars exposed to hot winds and full sun will tend to lose workability due to the evaporation of water. Common sense precautions should be taken to protect the mortar such as shading the mixer, wetting mortar boards, covering wheelbarrows and tubs, and balancing mortar production to meet demand.

If it is necessary to restore workability, mortar may be retempered by adding water and remixing. No mortar should be used or retempered beyond 2½ hours after the initial mixing. (ASTM C-270, Section 6.3)

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.

Availability

CEMEX’s Plastic Cement, available in the western United States under the brand name Victor Plastic® can be ordered by contacting the California sales office. A complete listing of CEMEX sales offices are:

Maintenance
Avoid use of harsh chemical cleaners or strong acid solutions in cleaning masonry.

Technical services
CEMEX personnel are available to provide technical assistance by contacting any of the offices previously listed.

1. Dubovoy, V.S., and Ribar, J.W., “Masonry Cement Mortars – A Laboratory Investigation”, Research and Development Bulletin RD0095, PCA Skokie, IL, 1990, 26pp.
2. Zematis, W.L., "Factors Affecting Performance of Unit Masonry Mortar", ACI Journal, Proc. Vol. 56, No. 6, American Concrete Institute, Detroit, MI 1959.
3. Ribar, J.W., "Water Permeance of Masonry, a Laboratory Study", ASTM STP 778, ASTM 1982, pp 200-220.
4. "Cold Weather Construction" and "Hot Weather Construction", ACI 530.1/95, Section 1.8, pp. 5-12, ACI, 38800 Country Club Drive, Farmington Hills, MI 48331.
5. "Recommended Practices and Guide Specifications for Cold Weather Masonry Construction", International Masonry All Weather Council, 823 Fifteenth Street, NW, Washington, DC 20005.

Filing systems

• Electronic SPEC-DATA*
• SPEC-DATA*

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.

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 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.

U.S. Operations Headquarters
920 Memorial City Way, Suite 100
Houston, TX 77024
(713) 650-6200