Masonry Cements

A second form of limestone is finely pulverized limestone for masonry cement. This form is achieved by intergrinding roughly equal parts of limestone and cement clinker in a bad mill to which an air-entraining agent is added. 

Barium carbonate prevents formation of scum and efflorescence in brick, tile, masonry cement, terra cotta, and sewer pipe by insolubilizing the soluble sulfates contained in many of the otherwise unsuitable clays. At the same time, it aids other deflocculants by precipitating calcium and magnesium as the carbonates. This reaction is relatively slow and normally requites several days to mature even when very fine powder is used. Consequentiy, often a barium carbonate emulsion in water is prepared with carbonic acid to further increase the solubiUty and speed the reaction. 

Most masonry cements are finely iaterground mixtures where Portland cement is a principal constituent. These cements also iaclude finely grouad limestones, hydrated lime, aatural cement, po22olans, clays, or air-entraining ageats. Secoadary materials are used to impart the required water reteatioa and plasticity to mortars. 

Masonry cements (80) are cements for use in mortars for masonry constmction. They are formulated to yield easily workable mortars and contain special additives that reduce the loss of water from the mortar to the porous masonry units. 

Masonry cements, 5 493, 500t, 502 Masonry coatings, 18 68 Masons lime, 15 28 Mass... 

Air-Plas . [Westvaco] Amine tallate air entraining agent for masonry cement syrplics. 

Vinsoi . [Hercules] I wood resin derivs. thermoidastic resin fev lacquers, adhesives, elec, insulation, floor coverings, foundry molds as extender for latmces water rqtdlent, air entrainment aid fOT masonry cements asi t emulsifier. 

Polytard . [Westvaco] lignin sulfomc acid derivs. additive to masonry cement... 

Masonry cement [9.4, 9.5] is a traditional product which consists of Portland cement as the primary strength-developing constituent and an inorganic component which may be ground limestone. 

Masonry cement was developed to overcome the above problems. It is specified in ENV 413-1 [9.4]. Essentially it consists of Portland cement (at least 25 % in Type MC 5 and at least 40 % in the other Types) and an inorganic material (such as limestone), finely ground to more than 85 % passing 90 microns. Two of the four Types contain an air-entraining agent, while the other Types do not. The Standard specifies the characteristics of the cement, the fresh mortar and the compressive strengths. The limestone content of masonry cement can be over 70 % in Type MC 5 and over 55 % in the other Types. 

It should be noted that mortars using masonry cement compete with cement-lime mortars. Their relative merits are discussed further in section 26.5. 

Masonry cements were developed in the 1930s in the U.S.A. They consisted of cement blended with an inert void filler and an air-entraining agent to give the required soft properties and controlled strength. 

Cement lime sand Masonry cement sand Cement sand with plasticizer ... 

The resistance to frost attack increases in the sequence cement-lime-sand, masonry cement-sand, cement-sand with plasticiser, while adhesion and resistance to rain penetration increases in the sequence cement-sand with plasticiser, masonry cement-sand, cement-lime-sand [26.24],... 

Shibazaki, T., Properties of Masonry Cement Modified with Water-Soluble Polymers (in Japanese), Semento-Gijutsu-Nempo 17, pp. 194-199 (Jan. 1964)... 

Figure 4. PJ gives the polymer-cement ratio vs. water retention of latex-modified mortars, measured according to JIS A 6908 (Finish Coatings and Wall Coverings for Decorative Use) and ASTM C 91 (Standard Specification for Masonry Cement). The water retention nerally increases with rising polymer-cement ratio, and becomes nearly constant at a polymer-cement ratio of 5 to 10%. Such excellent water retention of the latex-modified mortars is most helpful or effective to inhibit dry-out phenomena (the lack of cement hydration due to water loss in the mortar or concrete) in thin layer linings or coatings on highly water-absorbable substrates such as dried cement mortars and ceramic tiles.

Chem. Descrip. Low-rosin grade fatty acid derived from tall oil Uses Surfactant raw material for mfg. of emulsifiers used in disinfectants, cleaners, detergents, air-drying and baking alkyds, gloss oils and varnishes, toy enamels, metallic driers, core oils, masonry cements, flotation reagents, metal cleaners Regulatory FDA approved... 

Bhatty, J.l. et al. (1996) Stabilization of heavy metals in Portland cement, silica fumel Portland cement and masonry cement matrices. PCA R P No 2067, Portland Cement Association, Skokie, IL, USA. 

Masonry cements These are used for preparing bricklaying mortars and stuccos, and must not be used in concrete. They are usually complex proprietary formulations containing Portland clinker and a number of other ingredients that may include limestone, hydrated lime, air entrainers, retarders, water proofers and colouring agents. 

J. T. UWG and H. TOFFER, "Safety Review-Shipping Masonry Cement Billets Containing Scrap Uranium in NIO Boxes," DUN-7654, Douglas United Nuclear (August 1971). 

Mortar may be classified into five general types, on the basis of composition straight lime, straight cement, cement lime, masonry cement, or lime pozzolan. 

As modern admixtures for portland cement entered the marketplace in the 1960s, demand for natural cement in concrete construction waned, and what was left of the industry refocused its efforts on the masonry cement market. The final, or more accurately, the last 20" century revision of ASTM CIO does not reflect this change, as by 1970 the last of the original natural cement producers had closed its doors. In 1979, the standard was withdrawn due to disuse. 

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