8/13/2019 Testing Limestone http://slidepdf.com/reader/full/testing-limestone 1/22 Testing limestone • A similar form may well be utilized for sand • and gravel or crushed rock analyses where the • geologist requires special test work on his or • her samples, such as size analysis, aggregate • crushing value (ACV), or polished stone value • (PSV) to name but a few. • Limestone rocks are sedimentary rocks that are made of mineral calcite which comes from the beds of evaporated seas, lakes and sea animal shells. This rock is used in concrete and is an excellent building stone for humid regions • The aggregate shall in general comply with M.S 7.5. All aggregate shall be hard, strong, durable, clean and free from adherent coating and shall not contain harmful materials in sufficient quantity to affect adversely the strength or durability of the concrete or to attack the reinforcement. Aggregate shall be store in such a manner as to prevent contamination by undesirable substance.
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her samples, such as size analysis, aggregate• crushing value (ACV), or polished stone value
• (PSV) to name but a few.
• Limestone rocks are sedimentary rocks that are made of mineral calcite whichcomes from the beds of evaporated seas, lakes and sea animal shells. This rock isused in concrete and is an excellent building stone for humid regions
• The aggregate shall in general comply with M.S 7.5. All aggregate shall be hard,
strong, durable, clean and free from adherent coating and shall not containharmful materials in sufficient quantity to affect adversely the strength ordurability of the concrete or to attack the reinforcement. Aggregate shall be storein such a manner as to prevent contamination by undesirable substance.
• Physical properties are more important if thelimestone is used for aggregate or buildingstone. Strength and durability are of primeimportance in the assessment of limestone foraggregate as well as other properties, such asporosity and water absorption.
• The density of a rock is one of its mostfundamental properties. It is principallyinfluenced by the mineral composition andthe amount of void space. Strength andhardness principally relate to density, porosity,moisture and homogeneity of a deposit.
• An assessment should begin with an initial fieldinvestigation involving field mapping, sectionmeasuring and sampling. Geological mappingaims to define the stratigraphical relationship andstructure of the limestone formations, as well as
determine lithologies. Further field investigationsmay include topographic and section surveys,sampling from exposures and drill core forsubsequent laboratory analysis
• In-situ mechanical strength of the rock mass oflimestone can be obtained with a handy Schmidthammer
• Hardness, lustre, and streak are aids toidentifying minerals. Limestone is composed
mainly of the mineral calcite. Calcite has a Mohshardness of '3', it's lustre is vitreous, and it has awhite streak.
• limestone is amorphous: it has no internal
structure, therefore no cleavage. So, it cannotbreak along cleavage lines. It can only fracture inrandom directions, along small cracks and areasof weakness present in the rocks.
• Limestone does not have a luster. It's mainconstituent, the mineral calcite, has a vitreous orglassy luster.
• Limestone can easily be dissolved by acids. If some vinegar is droppedonto a limestone, it will fizz Put a limestone rock into a plastic jar andcover it with vinegar. Cover the jar and watch the bubbling of the calciumcarbonate and also the disintegration of the rock over a few days,
• Carbonate Rocks.
• Limestone aggregate is one of carbonate rocks. Like other rocks, carbonaterocks are classified on the basis of their minerals and textures. The mineralcompositions are limited and the textures of carbonate rocks are assumedof added importance. Some carbonate rocks are crystalline, and the othersare clastic. Most rocks contain both crystalline and clastic elements
Limestone is composed predominantly of calcite, namely Magnesiumcalcite, aragonite and dolostones, dolostones consists primarily ofdolomite, aragonite and dolostones are the two main types of carbonaterocks.
• Magnesium calcite and aragonite are particularly subject to diageneticchange and therefore calcite and dolomite are the most common phases
in older carbonate rocks. Chemically, CaO, MgO and CO2
are leadcarbonate rocks and the content of oxygen and carbon are significant inthe analysis.
• Limestone is formed in various colour such as white, grey,cream or yellow. It’s texture is highly variable from very
fine-grained, and porcellaneous, to coarsely crystalline andof sugary appearance. Its structure bedding is usually formthe formation fossil layers.
• Usually limestone light is white or grey but can also beblack if many impurities are present. It’s grain is typically
fine, but it ranges from the microscopic to the size of acoral reef, which technically corresponds to one grain
• However, the formation of calcite or another carbonate cantherefore be identified by dropping dilute hydrochloric acidonto its surface.The calcite rock releases carbon dioxide,
and fizzes vigorously which indicates the presence of fossils• Calcium carbonate normally comprises 50% of calcite, and
the balanced are clay, sand, dolomite, carbon and ironoxides.
• In general, limestone is such as weathered rocks arecrinoidal limestone, chalk, shelly limestone andfossiliferous fresh water limestone. Weathering oftendevelops a thin white coating on pure limestone.
Commonly the appearance of the limestone pebblesare grey and it is compact at the rock center andporous at the surface. Since limestone is formed inseveral ways and contains numerous impurities, manyvariations are found. This is includes shaly orargillaceous limestone, sandy or arenaceous limestone,lime conglomerate, bituminous limestone andglauconitic limestone.
• The specific gravity of a mineral is the ratio of its
weight compared with the weight of an equal volumeof water.
• A calcite crystal laid upon a graph paper with blue linesshowing the double refraction