Portland cement mortar

Lead is relatively easily corroded where acetic acid fumes are present and under such conditions it either should not be used or should be efficiently protected. Generally, any contact between lead and organic material containing or developing acids will cause corrosion for instance, unseasoned wood may be detrimental. Trouble from this cause may be prevented by using well-seasoned timber, by maintaining dry conditions, or by separating the lead from the timber by bitumen felt or paint. Lead is also subject to attack by lime and particularly by Portland cement, mortar and concrete, but can be protected by a heavy coat of bitumen. A lead damp-proof course laid without protection in the mortar joint of a brick wall may become severely corroded, especially where the brickwork is in an exposed condition and is excessively damp. 

S. Chandra and J. Aavik, Influence of proteins on some properties of portland cement mortar, Int. J. Cement Compos. Lightweight Concrete, 9, 91 94 (1987). 

Acrylic emulsions (or acrylic latices) are characterised as high-solids polymers having a film-forming temperature at or below room temperature (Lavelle, 1986). They have excellent hydrolysis resistance compared with other resins and are well suited as modifiers for portland cement mortars. Studies have shown that certain acrylic latices impart excellent workability at lower water demand, thin section adhesion and toughness, improved flexural strength and tensile strength and outstanding adhesion (Lavelle, 1983). 

Another version of Portland cement mortar or concrete is the replacement of some of the Portland cement with rice hull ash. This ash additive markedly improves the resistance of the mortar or concrete to food acids and similar chemicals. Flyash (pozzolanic admixture) meeting ASTM C618 has also been widely used to improve the properties and sulfate resistance of Portland cement... 

In this instance, brick was also used as a protective layer to shield the structural shell from the effects of heat. The flue itself was designed to stand alone against the forces of gravity and earthquake. An airspace was provided ranging from a few inches to a few feet, so that access could be provided to the exterior surface of the brick liner, a maintenance advantage not possible with the corbel supported brick lining. The structure itself was laid up in either acid resistant silicate or common Portland cement mortars, as previously described. It was basically unreinforced axially, but was corsetted with steel tension bands cir-... 

Routine lining inspection and maintenance procedures must be followed to obtain suitable lining life. Maintenance procedures described for acid sulfite digesters apply here with one addition, replacement of brick "fall-outs." This problem can be caused by movements of the lining and the steel shell, low compression in the lining, and the low bond strength between the Portland cement mortar and the carbon brick. Proper design considerations will normally reduce or eliminate this problem. 

Occasional repointing of the mortar joints is normally the only maintenance required. In the dilution zone, where attack of the Portland cement mortar may occur, repointing with a polyester or vinyl ester mortar will usually solve the problem. If voids are detected in the wall, these can be filled by pumping a port-land cement mix or a catalyzed resin into the wall by the technique described for filling voids in a digester lining. The service and maintenance history of these vessels has generally been excellent. 

The chlorination tower lining is tile set in a polyester or vinyl ester mortar with a Portland cement grout backing. The hypochlorite and peroxide units do not need the resistance of the resin mortar, therefore, Portland cement mortar can be used. Caustic extraction towers are occasionally lined with tile set in Portland cement mortar even though the alkaline operating conditions may soften the tile. To minimize the softening effect, the tile should have an extremely tight, well fired body. 

Structural tile construction is commonly used in these units. The wall of the unit is thus a concrete wall with tile faces. The tile has traditionally been set with Portland cement mortar but modern bleach plant operations with closed loop recycling of chemicals has resulted in the increased use of resin mortars with their broader chemical resistance. 

Structural tile construction and tile lined steel construction are commonly used in the paper mill to handle the pulp and to handle the paper mill chemicals. The tile affords a relatively smooth surface, it will not contaminate the pulp, and is resistant to chemical corrosion. The tile can be set in Portland cement mortar, however, a resin mortar is frequently preferred since it will be more resistant to a broader range of chemicals. Resin cements also have greater strength and are somewhat more resistant to erosion. 

Although ordinary Portland cement mortars (or concretes) can be used as materials for conventional repair, different types of additions or admixtures may improve their performance [8,9]. The water/cement ratio is usually low (e. g. 0.4 or even... 

J. M. Geist, S. V. Amagna and B. B. Mellor Improved portland cement mortars with polyvinyl acetate emulsions. Industrial and Engineering Chemistry Vol.45, No.4 (1953), pp.759-767. 

Fig. 7.8 Flexural strength of mortar from slag cement (SC) with the fineness 350 m /kg (SC-2) and 630 m /kg (SC-1) respectively, in comparison to the strength of Portland cement mortar (PC) (according to [72])...

Ono, Y. Hidaka, T. and Shirasaka, M., "On the Influence of Na O, K O, and MgO on the Development of Strength of Portland Cement Mortar," Reviews, 23rd General Meeting of the Cement Association... 

It has been known since the 1950 s that the incorporation of various polymers into portland cement mortars and concretes can considerably improve many physical and chemical properties (American Chemical Society, 1973 American Concrete Institute, 1972, 1973a, 1975 Auskem and Horn, 1971 Coughlin et a/., 1970 Dikeou et a/., 1969,1971,1972 Dow Chemical... 

Variation of Compressive and Tensile Strength of Portland Cement Mortars with Polymer Latex Modification"... 

Fig. 6.3. Free shrinkage strains in repair mortars, (a) Epoxy mortar, (b) Styrene Butadiene Rubber modified mortar, (c) Magnesium phosphate modified mortar, (d) Ordinary Portland cement mortar.

Kostogloudis, G.C. et al. (1998) Comparative investigation of corrosion resistance of steel reinforcement of alinite and Portland cement mortars. Cement and Concrete Research 28,995-1010. 

Portland cement mortar droppings tend to adhere strongly to zinc and when fully hardened are often difficult to remove completely without damaging the metal. 

Fibres may also prevent the occurrence of large cracks, thus preventing percolation of water and contaminants into ceramic materials such as Portland cement mortars and concretes. So, corrosion of steel reinforcement or potential deterioration of concrete may be reduced with the addition of a variety of fibres to the Portland cement matrices. In addition, other enhanced... 

Portland cement mortar is a mixture of Portland cement, sand and water,... 

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