Mineral and Chemical Composition of Aggregates

Type of VMA Flow diameter cm T50S V-funneP S Remarks 

Modified cellulose 67 (3%) 3 9 Segregation after addition of water+ 101/m  

Polysaccharides 66 (150 g/m ) 4 26 Segregation after addition of water + 101/m flow diameter redueed at higher addition 

Xantane gum 68 3 28 Segregation and bleeding flow diameter reduced at higher addition 

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The part of Earth s geosphere that is accessible to humans is the crust, which, ranging from 5 to 40 km in thickness, is extremely thin compared to the diameter of the earth. Most of the solid earth crust consists of rocks. Rocks are composed of minerals, where a mineral is a naturally occurring inorganic solid with a definite internal crystal structure and chemical composition. A rock is a solid, cohesive mass of pure mineral or an aggregate of two or more minerals. 

Notice that meteorites are classified first of all into three large categories stony, iron, and stony-iron. As their name suggests, stony meteorites are similar in appearance and chemical composition to rocks found on the Earth s surface. Stony meteorites are divided into two major categories chondrites and achondrites. Chondrites are stony meteorites that contain small spheres, called chondrules, with diameters of about 1 mm, consisting of minerals that were once melted and that have now aggregated to form the meteorite. Stony meteorites lacking chondrules are called achondrites. 

In the concrete mix design relatively little attention is paid to the chemical and mineral composition of aggregate. Obvionsly, grading and physical properties, mainly the compressive strength, abrasion resistance, porosity and freeze-thaw resistance are of the highest importance [287,410]. Only in the case of potential risk of alkali... 

Solid solution theory The chemical theories of primary importance to understanding factors controlling carbonate mineral compositions in natural systems are associated with solid solutions. Carbonate minerals of less than pure composition can be viewed as mixtures of component minerals (e.g., SrCC>3 and CaSC>4 in CaCC>3). If the mixtures are of a simple mechanical type then the free energy of formation of the resulting solid will be directly proportional to the composition of the aggregate. Thus, for a two component, a and b, mixture ... 

Another argument that the 0-rich end-member was a ubiquitous component of primitive solids is that it is found in many different chemical forms (different minerals) in many classes of meteorites CAls and amoeboid olivine aggregates (AOAs) from Efremovka (CV3) (Aleon et al., 2002 Fagan et al., 2002), AOA from a CO chondrite, Y 81020 (Itoh et al, 2002), and CAl and AOA from CM and CR chondrites (Krot et al., 2002). This isotopic composition can also serve as an end-member for the chondrule mixing line in Figure 2. 

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