Cement reference compounds

Cement Clinker Compounds Ca-Ca Distance, Mean Distance <4 A (this Work) Ca-Ca Distance, Mean Distance <4 A (Jost Reference) Ca-Ca Distance, Shortest Distance <4 A (this Work) Ca-Ca Distance, Shortest Distance <4 A (jost Reference)... 

Portland cement is classified as a hydrauHc cement, ie, it sets or cures in the presence of water. The term Portland comes from its inventor, Joseph Aspdin, who in 1824 obtained a patent for the combination of materials referred to today as Portland cement. He named it after a grayish colored, natural limestone quarried on the Isle of Portland, which his cured mixture resembled. Other types of hydrauHc cements based on calcium materials were known for many centuries before this, going back to Roman times. Portland cement is not an exact composition but rather a range of compositions, which obtain the desired final properties. The compounds that make up Portland cements are calcium siHcates, calcium aluminates, and calcium aluminoferrites (see ). 

It is therefore the conviction of the author that the high humidity, the relatively long lasting alkalinity of the cement plaster used in these mortuaries of crematoria II and III, in combination with the realistic homicidal gassing scenarios (high HCN concentrations, slow ventilation process) would have led to the formation of long-term stable cyanide compounds in an amount that should be easily detectable still today. Not at least because the conditions of these mortuaries are very similar to those described in the construction damage case referred to before,102 which is quoted entirely and henceforth analyzed in Appendix 1 of this volume. 

Cement is a binder that sets and hardens by itself or binds other materials together. The most widely known application of cements is in construction a second one is the area of bone cements. Cements used in construction are characterized as hydraulic or nonhydraulic and mostly for the production of mortars and concrete. Hydraulic cements set and harden after combining with water. Most construction cements are hydraulic and based on Portland cement, which consists of calcium silicates (at least 2/3 by weight). Nonhydraulic cements include the use of nonhydraulic materials such as lime and gypsum plasters. Bone cements and bone cement composites refer to compounds that have a polymer matrix with a dispersed phase of particles. For instance, polymethylmethacrylate (PMMA) is reinforced with barium sulphate crystals (for radio-opacity) or with hydroxyapatite... 

The cement chemical notation refers to C = CaO, P = P2Os, H = H20 (see Figure 6.4). In addition to compounds occurring in the water-free binary Ca0-P205 phase diagram shown in Figure 6.4, the table lists also hydrated compounds. 

Contact-Bond Adhesives. Another group of glues, referred to collectively as contact cements or contact-bond adhesives, bear some similarities to the pressure-sensitive adhesives in that they do not rapidly achieve full hardening. Until a few years ago, contact-bond formulations were mainly organic solvent solutions of elastomers, compounded with tackilying resins and antioxidants. However, with recent concerns over energy, environmental, and fire safety questions, interest has turned to water-based systems. 

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