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Slump Test

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Slump Test on Concrete Concept: Concrete slump test or slump cone test is to determine the workability or consistency of concrete mix prepared at the laboratory or the construction site during the progress of the work. Concrete slump test is carried out from batch to batch to check the uniform quality of concrete during construction. Description and procedures: Mold for slump test i.e. slump cone, non-porous base plate, measuring scale, temping rod. The mold for the test is in the form of the frustum of a cone having height 30 cm, bottom diameter 20 cm and top diameter 10 cm. The tamping rod is of steel 16 mm diameter and 60cm long and rounded at one end. Clean the internal surface of the mold and apply oil. Place the mold on a smooth horizontal non- porous base plate. Fill the mold with the prepared concrete mix in 4 approximately equal layers. Tamp each layer with 25 strokes of the rounded end of the tamping rod in a uniform manner over the...
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Basement Waterproofing

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Basement Waterproofing Basement waterproofing involves techniques and materials used to prevent water from penetrating the basement of a house or a building. Waterproofing a basement that is below ground level can require the application of sealant materials, the installation of drains and sump pumps, and more.  Waterproofing is usually required by building codes for structures that are built at or below ground level. Waterproofing and drainage considerations are especially important in cases where ground water is likely to build up in the soil or where there is a high water table.  Water in the soil causes hydrostatic pressure to be exerted underneath basement floors and walls. This hydrostatic pressure can force water in through cracks, which can cause major structural damage as well as mold, decay, and other moisture-related problems. Causes of water seepage and leaks Water seepage in basement and crawl spaces usually occurs over long periods of time and ...
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Basement Construction

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Basement Construction In the general context of building a basement can be defined as a storey which is below the ground storey and is there for constructed below ground level.  Basements are common in tall buildings as car parks, storage of services and underground shopping centres. The term “basement” has been regarded as synonymous to the term “deep pit”, which applies to excavations over 4.5 m deep. The main purpose of constructing basements are:  to provide additional space,  as a form of buoyancy raft,  in some cases, basements may be needed for reducing net bearing pressure by the removal of the soil. Basement can be classified into three groups: Types of basement Basement can be constructed by following method: Open cut method. Cut and cover method. Top down method. Open Cut Method This is the simplest and most straight forward technique of providing an excavation to the required depth. The sides of the excavation are ...
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Dewatering Methods - Groundwater Control

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Groundwater Control When rainwater collects in surface depressions, it is called surface water; when it percolates down into the permeable subsoil and collects in tiny soil voids, it is called groundwater; the upper surface of the groundwater is called the water table. Following some problems of water in the subsoil effect the construction work: A high water table could cause flooding during wet periods. Subsoil water can cause problems during excavation work by its natural tendency to flow into the voids create by the excavation activities. It can cause an unacceptable humidity level around finished buildings and structures. Civil engineers are must restrict the major problems of ground water and keep the excavation to safe. Therefore, they introduce many dewatering methods for controlling the ground water.These methods can be classified into two groups: Permanent exclusion of groundwater Temporary exclusion of groundwater Permanent Exclusion of Groundwater This c...
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Bentonite Slurry

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Bentonite Slurry in Civil Engineering Bentonite is a controlled mixture of fullers earth and water which produces a slurry or mud which has thixotrapic properties(ie. as the material is placed under stress to flow). When placed in the borehole it exerts a pressure in excess of earth and hydro-static pressure present on side of excavation. This also finds its application in the construction of special foundations for digging diaphragm walls and bored piles. Bentonite is implemented for self-hardening mixtures which are then resorted to build cut off walls, grouting mortars, and grouting. Finally, bentonite waterproofing properties are best exploited in environmental engineering, to seal off soil infiltration, and line the base of landfills. Bentonite is a kind of clay which has an ability to swell and gel when it is dispersed in water. This is used in construction mainly in excavation and foundation works. Bentonite contains more than 85% clay mineral, montmorillonite, a...
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Weathering - Formation of Soil

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Weathering Weathering is the breakdown of rocks at the Earth’s surface, by the action of rainwater, extremes of temperature, and biological activity. It does not involve the removal of rock material. or Weathering is the soil formation process. Soil Soil is major product of weathering processes. Soil is  combination of particles of Rock, Minerals, and Organic matters. Soil contains nutrition to growth of plant. Weathering Process Weathering processes are occurred in following major three ways or three types; Physical Weathering  Chemical  Weathering Biological Weathering 01.Physical (mechanical) weathering Physical weathering is the geological process of rocks breaking apart without changing their chemical composition.  or  Physical weathering is also refer to other things in the environment breaking down, like soil and minerals. Pressure, warm temperatures, water and ice can cause physical weathering.  Physical weather...
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Interior Structure of Earth

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Earth’s Profile Our planet Earth has an average radius of 6378 km and a mean mass density of 5.527 g/cm3 compared with a mean mass density of soil particles of 2.7 g/cm3 and water of 1 g/cm3. The earth has a  core  of heavy metals, mostly iron, of mass density 8 g/cm3 surrounded by a mantle. The  mantle  consists of two parts, upper mantle and lower mantle. The upper mantle is solid rock while the lower mantle is molten rock. Above the upper mantle is the  crust , which may be as much as 50 km thick in the continental areas and as little as 7 km thick in oceanic areas. Interior Structure of Earth according to Chemical properties   Crust: The outer most rock layer of the earth is called crust and it is divided into two parts 1.       Continental Crust (0-90 Km) 2.       Oceanic Crust (6-11 Km) Mainly this layer contain Silicon (Si), and Oxygen (O ₂ ) nearly 74% (Silicate-SiO ₂ ) and the tempera...
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