Phosphate-cement concrete

Compressive strength, flexural strength, and the elastic modulus of magnesia-phosphate cement products are affected by composition and water content. The compressive strength, at different times, for seven phosphate-cement concretes is plotted in Fig. 

Figure 8. Compressive strength vs time for seven phosphate cement concretes made with ammonium phosphate solution...

The compressive strength and setting time (Gillmore needle ASTM C266-74) for several phosphate-cement concretes containing different amounts of polyphosphate in ammonium phosphate solutions are plotted in Fig. 9. At 2 hours, 24 hours, and 7 days the compressive strength increases... 

Abdelrazig, B. E. I. Sharp, J. H. (1988). Phase changes on heating ammonium magnesium phosphate hydrates. Thermochimica Acta, 129, 197-215. Abdelrazig, B. E. I., Sharp, J. H. El-Jazairi, B. (1988). The chemical composition of mortars made from magnesia-phosphate cement. Cement Concrete Research, 18, 415-25. 

Sugama, T. Kukacka, L. E. (1983a). Magnesium monophosphate cements derived from diammonium phosphate solutions. Cement Concrete Research, 13, 407-16. 

In most applications, a small amount of binder powders is mixed with a large volume of inexpensive hllers and then the entire mixture is stirred in water to form the reaction slurry. For example, if the phosphate binders are used for manufacturing construction products, invariably the hllers are sand, gravel, ash, soil, or some mineral waste. The phosphate binders provide adhesion between the particles of these hllers and bind them into a solid object. Thus, these mixtures mimic conventional concrete mixmres in which Portland cement binder is mixed with large volume of sand and gravel to produce cement concrete. When phosphate binders are used, the products may be termed as phosphate concrete . In waste stabilization, the waste itself becomes the hller and the hnal product is termed as a waste form . 

Abdelrazig, B.E.I. (1988) The microstructure and mechanical properties of mortars made from magnesia-phosphate cement. Cement and Concrete Research 18,415-425. Abdelrazig, B.E.I. (1989) The microstracture and mechanical properties of mortars made from magnesia polyphosphate cement. Cement and Concrete Research 19, 147-158. Abdelrazig, B.E.I, et al. (1984) Chemical reactions in magnesium phosphate cements. 

El-Jazairi, B. (1987) The properties of magnesia phosphate cement based materials for rapid repair of concrete. Proceedings 3rd International Conference on Structural... 

Park, C.K., Silsbee, M.R., and Roy, D.M. (1998) Setting reaction and resultant structure of zinc phosphate cement in various orthophosphoric acid cement-forming liquids. Cement and Concrete Research 28,141-150. 

Seehra, S.S., Gupta, S., and Kumar, S. (1993) Rapid hardening magnesium phosphate cement for quick repair of concrete pavements characterization and durability aspects. Cement and Concrete Research 23,254-266. 

Sugama, T. et al. (1995) Mullite microsphere-filled lightweight calcium phosphate cement slurries for geothermal wells setting and Properties. Cement and Concrete Research 25, 1305-1310. 

Peru, J., and Ambroise, J. (1998) Fiber-reirrforced rrragnesia-phosphate cement composites for rapid repair. Cement and Concrete Composites 20,31-39. 

FIGURE 12.25 Comparison of cements (a) zinc phosphate dental cement and (b) Portland cement concrete. 

Typical strength development data of air cured silico-phosphate cement indicate that this system develops about 30% of its 28 day compressive strength in 2 hours. The tensile bond strength, compared with conventional concrete substrates, is very poor.I ]... 

Generally, a small amount of the binder is used in cement or phosphate concrete the major volume of the concrete is aggregates. The small amount of binder keeps the overall cost of the product low. The components of the aggregates, however, do not participate in the setting reaction. On the other hand, in the case of a CBPC the reaction of the aggregate will entirely depend on its solubility in the acidic phosphate solution. Since silica (Si02) is insoluble in an acid solution, it is safe to assume that it will not participate in any setting... 

Diethyl-1,2-dihydro-1-phenyl-2-propylpyridine accelerator, coatings Amyl acid phosphate accelerator, cold-cure cements Dibutyl xanthogen disulfide accelerator, composites 1-Phenyl-3,3-dimethyl urea accelerator, concrete setting Calcium formate accelerator, cosmetics Sodium persulfate accelerator, CR... 

Trimethylchlorosilane Zirconium oxychloride Zirconium oxychloride hexahydrate water repellent fabric finishing Nonoxynol-10 phosphate water repellent formulations, paper Ammonium zirconium carbonate water repellent ingredient Stearamide MEA-stearate water repellent treatment, cement Cocoyl hydroxyethyl imidazoline water repellent treatment, concrete Cocoyl hydroxyethyl imidazoline water repellent treatment, plaster Cocoyl hydroxyethyl imidazoline water repellent, adhesives Ammonium-12-molybdosilicate ... 

Ma, W., and Brown, P. (1992) Mechanical behaviour and microstractme development in phosphate modified high almnina cement. Cement and Concrete Research 22, 1092-1200. 

The aluminum phosphate binder consists of a combination of orthophosphoric acid (H3PO4) or monoaluminum phosphate [A1(H2P04)3] and aluminum oxide (fused alumina, AI2O3). Upon heating to elevated temperatures the two constituents interact, and aluminum orthophosphate (AIPO4) is formed as the final product of the reaction at temperatures above about 500 °C. This is a cementing process that results in the development of a hardened material. Aluminum phosphate binder is widely employed in refractory concrete applications, and is discussed in more detail in Chapter 23. 

Frantzis, P., and Baggott, R. (1996) Effect of vibration on the rheological characteristics of magnesia phosphate and ordinary Portland cemerrt sltrrries. Cement and Concrete Research 26,387-395. 

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