Normal mortar

Abdelrazig et al. (1984) studied the commercial FEB SET-45 cements and mortars (Set Products Inc., Master Builders Division, Martin Marietta Corporation). Their hydration behaviour is similar to those described above. The mortars normally set in 15 minutes and hardened in 30 to 60... 

A solution of sulfur trioxide [7446-11-9] dissolved in chlorosulfonic acid [7990-94-5] CISO H, has been used as a smoke (U.S. designation FS) but it is not a U.S. standard agent (see Chlorosulfuric acid Sulfuric acid and sulfur trioxide). When FS is atomized in air, the sulfur trioxide evaporates from the small droplets and reacts with atmospheric moisture to form sulfuric acid vapor. This vapor condenses into minute droplets that form a dense white cloud. FS produces its effect almost instantaneously upon mechanical atomization into the atmosphere, except at very low temperatures. At such temperatures, the small amount of moisture normally present in the atmosphere, requires that FS be thermally generated with the addition of steam to be effective. FS can be used as a fill for artillery and mortar shells and bombs and can be effectively dispersed from low performance aircraft spray tanks. FS is both corrosive and toxic in the presence of moisture, which imposes limitations on its storage, handling, and use. 

Polymer-modified cementitious floor toppings are now widely used instead of separately laid granolithic toppings. The polymers used are normally supplied as milky white dispersions in water and are used to gauge a carefully selected sand/aggregate/cement mix as a whole or partial replacement of the gauging mortar. They must always be mixed in a forced-action mixer. 

Mortars of this system are prepared by blending ignited magnesium oxide, ADP and STPP with a filler, normally quartz sand. On mixing with water a cementitious mass is formed. The reaction has been studied by a number of workers Kato et al. (1976), Takeda et al. (1979), Neiman ... 

Quartz fine aggregates and normal Portland cement were used to prepare mortar at a w/c of 0.6. Mortar was cast into 30-mm diameter by 30-mm length cylinders and cured for 3 days. At the end of the curing period the specimens were oven dried at 105 °C until a constant mass was reached. Epoxy was then applied to the curved surface and the specimen was placed such that 1-2 mm of its height was immersed in a 20% NaCl solution. 

Quartz fine aggregate and normal Portland cement were used to prepare mortar with a w/c of 0.5. A cylindrical specimen, 43 mm in diameter and 50 mm long, was cast and cured under sealed conditions for 3 days at 23 °C. The specimen was then oven dried at 105 °C for 1 day prior to exposure to lithium nitrate solution. The specimen was then placed such that the bottom of the cylinder was submerged approximately 1-2 mm into a lithium nitrate solution with Teflon tape applied to the curved surface. 

Bury the exposed edges of the liner under soil, sod, or stones to protect it from the light, which degrades the butyl fabric, reducing its life span (normally about 20 years). You can mortar stones in place for stability, but do not let any mortar fall into the water. 

Accelerating admixtures reduce both the initial and final setting time of mortar sieved from concrete mixes, determined by ASTM C403 68 or BS 5075 (1975). Typical results are given in Table 5.1 for a 300 kg m cement content mix with a compacting factor of 0.85 0.02 [24] at normal ambient temperature. 

The effects on other properties of both plastic and hardened mortar or concrete have not been investigated. Furthermore, since the studies have been done on a laboratory scale, no information pertaining to effects of placing and curing under normal or varied environmental conditions is available. 

In order for normal set to occur in Portland cement paste, mortar, or concrete, calcium sulfate must be present in the cement-water system. In today s cements, most of the calcium sulfate introduced into the system as a component of the cement, can be present in one or more forms gypsum (CaS04.2H20), hemihydrate (CaS04.1/2... 

Microscopic Examination.—A few grams of the chocolate are freed from fat by extraction with carbon tetrachloride and from sugar by washing on a filter with a little alcohol and then with cold water. The residue, well mixed in a mortar, is examined with a magnification of 300-400 diameters, best in comparison with products of known origin. Such examination will show if the normal constituents of pure chocolate are accompanied by starch or flour of cereals, chestnuts (see Fig. 32 of Plate IV in the chapter on Flour) or oily seeds, or powdered cacao husks. 

Alumina has been used in a similar manner. Normally, alumina is added to an aqueous solution of PCC in water, prepared by mixing chromium trioxide, hydrochloric acid (6N) and pyridine. Removal of water leads to the formation of alumina particles covered by PCC, described as PCC on alumina, which is commercially available. Alternatively, it has been described that best results are obtained when alumina and PCC are finely ground in a mortar.231 The alumina not only helps in the work-up by allowing an easy filtering of the chromium-containing by-products, but also accelerates the oxidation with PCC.229a... 

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