Hydraulic reactivity

Bohner M, Luginhuhl R, Reher C. A physical approach to modify the hydraulic reactivity of a-tricalcium phosphate powder. Acta Biomaterialia. 2009 5 3524-35. 

Effects of common minor and trace elements derived from recycling waste materials in fuels and as raw materials for clinker production, as well as cement hydration, are summarized by Uchikawa and Hanehara (1997). Crystal size and optical property variations in clinker phases (alite, belite, aluminates, and ferrite), and their hydraulic reactivities, are shown to be related to concentrations of sulphm, magnesium, phosphorous, fluorine, chlorine, chromium, manganese, zinc, and many other elements. The cement industry is based in crystal chemistry. 

Bei, R., and Ludwig, U. (1990) Hydraulic reactivity of belite-rich cements (in German). Zement-Kalk-Gips 43,506-510. 

Yang, N., Zhang, H., and Zhong, B. (1992) Study on hydraulic reactivity and stractural behavior of very active -C2S, in Proceedings 9th ICCC, New Delhi, Vol. 4, pp. 285-291. 

Alinite exhibits a high hydraulic reactivity, which is distinctly greater than that of tiicalcium silicate. The following degrees of hydration have been reported for both compounds (Boikova et al, 1986 Ji et al, 1997) ... 

Hydraulically reactive materials exhibit cementing properties if mixed just with plain water, without the presence of other constitnents to act as activators. Some fluidized-bed ashes or industrial slags (steelwork slag, for example) are examples of such materials. 

Galal, A.F. et al. (1990) Hydraulic reactivity and microstructure of artificial pozzolana-lime pastes, iaProceedings 12th International Conference on Cement Microscopy, Vancouver, pp. 135-153. 

HYDRAULICALLY REACTIVE CALCIUM GERMANATES, STANNATES, AND PLUMBATES... 

Dicalcium and tricalcium germanate have evoked scientific interest as their stmcture is isotypic with that of dicalcium and tricalcium silicate. Both compounds possess a distinct hydraulic reactivity. Tricalcium germanate exhibits a very fast initial hydration without any induction period, yielding, besides calcium hydroxide, three or more crystalline hydrate phases as prodncts of hydration. 

Calcium stannates and plumbates also exhibit hydraulic reactivity, but are of no practical interest. Calcium titanates are not hydraulically reactive. 

Hommertgen, C., and Odler, I. (1992) Investigations on hydraulically reactive glasses in the system CaO-Al203-Si02- Materials Research Society Symposium Proceedings 245, 165-172. 

Dopant—a foreign ion incorporated in small amounts into the ciystalline lattice of a hydraulically reactive phase to preserve at ambient temperature one of its high-temperature modifications and/or to increase its reactivity. 

The average phase composition of Portland cement (ASTM Type I, CSA 10) is -50% alite, C3S -25% belite, P-C2S -12% tricalcium aluminate, C3A -8% ferrite, C4AF > and -3.5% gypsum (Mindness, 1983). The structural order and crystallinity of the cement phases-and hence their hydraulic reactivities-are heavily dependent on the rate of cooling of the clinker ... 

FLUOROTRIAZINES Riag-fluoriaated triaziaes are used ia fiber-reactive dyes. Perfluoroalkyl triaziaes are offered commercially as mass spectral markers and have been iatensively evaluated for elastomer and hydraulic fluid appHcations. Physical properties of representative fluorotriaziaes are listed ia Table 13. Toxicity data are available. For cyanuric fluoride, LD g =3.1 ppm for 4 h (iahalatioa, rat) and 160 mg/kg (skin, rabbit) (127). 

Blended hydraulic cements are used to conserve energy. They are intimate and uniform blends of tine materials such as Pordand cement, ground blast furnace slag, dy ash, and other po22olans, ie, tine, reactive sUica sources. ASTM C595 Hsts five classes or types. 

Currently thousands of system combinations have been programmed on the ARRADCOM s CDC 6600 computer with additions and updates made as received. The program is being enlarged to include reactivity with hydraulic fluids, lubricants, metals, etc. Another data bank-maintained is a Hazard Failure program, which is aimed at warning users about potential problems... 

Homopolymers and copolymers from amido-sulfonic acid or salt containing monomers can be prepared by reactive extrusion, preferably in a twin screw extruder [1660]. The process produces a solid polymer. Copolymers of acrylamide, N-vinyl-2-pyrrolidone, and sodium-2-acrylamido-2-methyl-propane sulfonate have been proposed to be active as fluid loss agents. Another component of the formulations is the sodium salt of naphthalene formaldehyde sulfonate [207]. The fluid loss additive is mixed with hydraulic cements in suitable amounts. 

The last two applications, while convenient and initially appealing, require more maintenance and inspection than a simple, ground level monitor. Significant reactive forces can be generated and, therefore, the support structures must be properly engineered. Elevated monitors also require support and hydraulics to be protected by a water spray system if exposed to fires. An elevated monitor is shown in Eigure 7-12. 

Many factors affect the transport of contaminants in the subsurface, including the (spatially and temporally variable) hydraulic and physicochemical characteristics of the solid phase and the properties of water and the contaminants themselves. In this chapter, we focus on several specific, representative examples of reactive (nonconservative) contaminant transport. 

The toxicity of the degradation products may exceed the toxicity of the parent compounds. Heavy metals are converted to less soluble forms they are not removed from the subsurface. Heterogeneities in the subsurface may cause the uneven distribution of nutrients during direct-injection applications. Injection may be slower in formations with low hydraulic conductivities. Smaller reactive zones may also form in areas with low hydraulic conductivities. 

The vendor states that iron reactive walls installed by vertically oriented hydraulic fracture technology would have lower materials and installations costs than conventional funnel and gate systems (D176958, p. 7). 

Massachusetts Military Reservation, Falmouth, Massachusetts. Colder Associates Corporation is also involved in a full-scale pilot project at the Massachusetts Military Reservation (MMR), near Falmouth, Massachusetts. Two permeable barriers were emplaced at the site using hydraulic fracturing. Installation cost of the demonstration was estimated to be 160,000. This cost included design, construction, and the reactive media (D206235, p. 2). 

In 1988, FOREMOST Solutions installed a pilot-scale permeable reactive treatment (PeRT) wall at the U.S. Department of Defense s (DOD s) Maxwell Air Force Base in Montgomery, Alabama. Treatment wall panels were emplaced up to 75 ft below ground surface (bgs) using patented jet-assisted hydraulic fracturing. The project was designed and installed for 210,000 including the supplies and down-hole materials. Field installation was completed in 14 days (D213332, Appendix p. 74). 

---