Sedimentary Rock Textures, Structures, and Uses
Sedimentary Rocks
Texture
Sedimentary Rocks texture can be classified as:
Clastic Rocks (Detrital)
Grains of different sizes and material that fill the gaps can be of detrital origin (womb) or of chemical (cement).
Not Clastic Rocks (Crystalline)
- Amorphous: As the size grainy clay.
- Crystals: Of any size but uniform.
- Piroblástica: Very large crystals in a cryptocrystalline.
- Microcrystalline pasta: Crystals not visible to the naked eye, looks like the first and the second most earthy flint.
Structure
The incidence of stratification in a work could be very important. If the apparent dip is greater than the friction angle between the planes of the strata, there is a great probability of occurrence of landslides. In a playground or even in an open pit excavation, the axis of the structure should always be as normal as possible to the direction of stratification. The influence of stratification can be variable depending on the rock matrix and the thickness of the strata. If packets are metric powers, the possibility of their flat roofs and chimneys is much lower.
Uses
Gravel and Sand
Have been transported by water, wind, and ice on the funds drawn from rivers, lakes, and sea. In some cases, they have suffered little transport. They consist of quartz, and resist inalterable elements. Their size and shape depend on the duration and intensity of weathering. To manufacture mortars, they typically suffer if they are clean concrete. Extraction is done with retro. They can take advantage of alluvial fans of the torrents, although the material is more heterogeneous. Usual for the manufacture of macadam ballast, and clean sand is often used to filter and drain. Use of gravel for the construction of gabions, mesh boxes filled with gravel or crushed rock. Its carrying capacity is limited, and seats that are produced can cause the destruction of the structure.
Improvement methods for soil dynamics:
- Compaction: Dropping a weight on the sole large-tonnage.
- Vibroflotation: Going down to some depth and vibrating and injecting a filler for time.
- Solid compaction: Push mortar into the ground.
The tunnels and underground works are difficult to dig due to a lack of support, coming from water, lack of cohesion, high permeability problems for buildings near the area (parking the English court). To avoid this, continuous screens are used to isolate the area of drilling buildings. In a tunnel, grouting the presence of strong coverage can be a serious problem. Mild instability and collapse tunnels avoid false turn in the roof above us.
Limos
Come between 1-16mm grain composed mostly of quartz. Plasticity is little or no, low permeability, high capillarity, highly susceptible to liquefaction, are compacted easily, moderate deformity, sensitive to the action of vibration. Not suitable for mortar foundations, require special procedures. Difficulty and are injected with chemicals are needed for them to dig very shallow slopes require underground lines in excavation. Behaves very poorly in mud dug valleys are very wide major dams resulting in very open.
Clays
Grain size less than 4 microns is formed by clay minerals belonging to 3 main groups:
- Caolinite: Fairly stable in the presence of water.
- Illite
- Montmorillonite: Expansive clays.
They have large holes in the initial deposits can be 50%. Change shape when subjected to a force and maintain it (clay) is impervious to liquefaction susceptible, not easily eroded, often has some very low or zero cohesion and friction angle. In old buildings mixed with water and mud (adobe). Low bearing capacity requires the use of special foundations. Land Consolidation injections sometimes presents problems for grout rejected due to weak permeability. Reservoirs created on clay soils provide a guarantee of impermeability. In excavating sub depends on the compaction and the presence of water when dried are dug well. Mixed with cement can be used as injection material for building waterproof screens. Tendency to slide in the presence of water makes it advisable to avoid placing roads on clay slopes average less Ferrovial and channels. As a general rule, whenever working with clay, it is good to have good drainage.
Conglomerates
Rock fragments linked by a detrital or chemical binder as polygenic or monogenic nature as gaps form angular conglomerate. The rock is of high quality for building, used as decoration, not recommended as aggregate for concrete or for ballast or macadam is degradable and tidal waves do not breakwaters. They result in narrow valleys impermeable. Bearing capacity depends on open dug its matrix and binder in sub excavations of its homogeneity.
Sandstone Ortocuarcita
Formed almost all by quartz joined by siliceous cement, concrete good contributor to good adhesion and low resistance absorption indicated for ballast and macadam ideal for breakwaters waterproof. In admitted sub excavation parameter sub vertical and does not need support, abundant water in her little digs cost high due to hardness and dusting.
Sandstone Arches
Feldspathic sandstone (quartz + feldspar) comes from the decomposition or altered granite gneiss or schist. Supports vertical cliff if dry, wet changes. Used for cutting brick. Do not give advice as to dry cement roads or railways and jetties in ballasting.
Marga Formed by shale, limestone, or dolomite sand. Effervesces somewhat with HCl. “Vent” == flake disintegration due to desiccation. When subjected to the action of air, it affects fast. It would be better to cover them or leave a party without excavating and do just as concrete. Behavior similar to the highly erodible clays. Not for barren concrete and macadam ballast and jetties. Rock bonded if water reservoirs can be impermeable. It can be used to manufacture cement rock.
Carbonated
Limestone
Essential mineral calcite carbonate cap rock used in masonry and masonry because it is short and works easily, weather-resistant, used for concrete (strong adhesion for rough concrete), dams (good water density is not alterable by short-term), foundations (bearing structure to withstand any FILTRATION-screen Correction (cement injection Bore drillers), tapestry (the rock that comes into contact with water is covered with concrete or clay and clean mind later). The latter is used less than the screen. The existence of fractures causes spots that tend to roll road train disaster. It is to excavate sub behaves well. Can be used for concrete subjected to cooking with clay and then grinding.
Gypsum
Hydrated calcium sulfate. Quick solubility is it when this clay spread fast but less conspicuous karst gypsum and water slenitosas attack the cement and tricalcium aluminum requires special use as the high alumina cement and portland not NOT USED Concrete (for his aggressiveness with the cement, high solubility, and resist wear) ballast (rapid solubility) macadam (- resistance) cliffs … .. As resistance to dig foundation ACCEPT if this mass is cut well.