Civilengineering Subjects tutorial | Learn civil Engineering online

## Civil engineering

Civilengineering Subjects tutorial : A branch of engineering that encompasses the conception, design, construction, and management of residential and commercial buildings and structures, water supply facilities, and transportation systems for goods and people, as well as control of the environment for the maintenance and improvement of the quality of life. Civil engineers include planning and design professionals in both the public and private sectors, contractors, builders, educators, and researchers.

Civil engineers play a major role in developing workable solutions to construct, renovate, repair, maintain, and upgrade infrastructure. The infrastructure includes roads, mass transit, railroads, bridges, airports, storage buildings, terminals, communication and control towers, water supply and treatment systems, storm water control systems, wastewater collection, treatment and disposal systems, as well as living and working areas, recreational buildings, and ancillary structures for civil and civic needs. Without a well-maintained and functioning infrastructure, the urban area cannot stay healthy, grow, and prosper.

Some of the subsets that civil engineers can specialize in include photogrammetry, surveying, mapping, community and urban planning, and waste management and risk assessment. Various engineering areas that civil engineers can specialize in include geotechnical, construction, structural, environmental, water resources, and transportation engineering. *See* Civil engineering, Coastal engineering, Construction engineering, Engineering, Environmental engineering, Highway engineering, River engineering, Surveying, Transportation engineering

Vertical Stirrups

Types of shear reinforcement : Vertical stirrups, Bent up bars along with stirrups, Inclined stirrups, contribution of bent up bars TYPES OF SHEAR REINFORCEMENT The following three types of shear reinforcement are used : Vertical stirrups. Bent up bars along with stirrups. Inclined stirrups. Vertical Stirrups These are the steel bars vertically placed around the tensile reinforcement at suitable spacing along the length of the beam. Their diameter varies from 6 mm to 16 mm. The free ends of the stirrups are anchored in the compression zone of the beam to the anchor bars (hanger bar) or the compressive reinforcement. Depending upon the magnitude of the shear force to be resisted the vertical stirrups may be one legged, two legged, four legged and so on as shown in Fig. 5.5. It is desirable to use closely spaced stirrups for better prevention of the diagonal cracks. The spacing of stirrups near the supports is less…

Continue Reading
Types of shear reinforcement
Effects of Shear Diagonal Tension, maximum bending tensile stress, tensile stress (σ) as well as shear stress (τ),

Learn : Effects of Shear Diagonal Tension, maximum bending tensile stress, tensile stress (σ) as well as shear stress (τ),crack pattern for a simply supported beam, The maximum bending moment in this beam will be at midspan and the maximum shear force, at the supports. EFFECTS OF SHEAR DIAGONAL TENSION Consider a beam AB subjected to transvers loads as shown in Fig. 5.3(a). The maximum bending moment in this beam will be at midspan and the maximum shear force, at the supports. The beam is subjected to bending and shear stresses across the cross-section. Let us consider a small element (1) from the tensile zone of the beam. It is subjected to bending tensile stress (σ) as well as shear stress (τ) as shown in Fig. 5.3. (b). At the midspan, the bending moment is maximum and the shear force is zero. So the element 2 is subjected to maximum…

Continue Reading
Effects of Shear Diagonal Tension
Shear Stresses in R.C.C. beam (Reinforced cement concrete beam), Stress Based Approach (Elastic Theory), IS Code Approach SHEAR STRESSES IN R.C.C. BEAMS Stress Based Approach (Elastic Theory) R.C.C. is a composite materials so the exact shear distribution as per elastic theory is very complex. It is shown in Fig. 5.2(b) by the hatched portion of the curve.It is parabolic in the compression zone with zero at the top and maximum at the neutral axis. The value of shear-stress is constant in the tensile zone and is equal to the maximum shear-stress (q) because the concrete, below the neutral axis (tensile zone) is assumed to be cracked and neglected. The maximum value of shear stress (q) as per elastic theory is given by \[q=\frac{V}{bjd}\] where V = shear force at the section b and d = dimensions of the section j = Lever arm depth factor IS Code Approach As per IS code…

Continue Reading
Shear Stresses in R.C.C. beams
Characteristic Strength of Materials

Learn : Characteristic Strength of Materials :Characteristic Strength of Concrete, Characteristic Strength of Steel. and Characteristic Load or ultimate load CHARACTERISTIC VALUES (REFER CLAUSE 36, IS CODE) Characteristic Strength of Materials The characteristic strength is based on the statistical analysis of the test results because there are variations in the strength of the material used. In order to simplify the analysis, it may be assumed that the variation in strength follows a normal distribution curve which is symmetric about the mean value as shown below in Fig. 3.1. Therefore, characteristic strength = Mean strength - k S where S is the standard deviation, k=1.64, corresponding to 5% probability \[\therefore f_{ck}=f_{m} - 1.64 S\] Characteristic Strength of Concrete The term characteristic strength means that value of strength of material below which not more than 5% of the test results are expected to fall. It is denoted by fck is N/mm2. The value…

Continue Reading
Characteristic Strength of Materials Characteristic Load or ultimate load
Learn : comparison of working stress method and limit state method, working stress method,Drawbacks of the working stress method, Limit state method : Limit state of collapse, Limit state of serviceability. COMPARISON OF WORKING STRESS METHOD AND LIMIT STATE METHOD Working Stress method and Drawbacks of the working stress method Working Stress method This method of design was the oldest one. It is based on the elastic theory and assumes that both steel and concrete and elastic and obey Hook's law. It means that the stress is directly proportional to strain up to the point of collapse. Based on the elastic theory, and assuming that the bond between steel and concrete is perfect, permissible stresses of the materials are obtained. The basis of this method is that the permissible stresses are not exceeded any where in the structure when it is subjected to worst combination of working loads. In this method, the…

Continue Reading
comparison of working stress method and limit state method
Limit state concept

Learn : Limit state concept,Limit State of Collapse,Limit State of Serviceability Limit state is the acceptable limit of safety,serviceability requ.before failure. Limit state concept The aim of this method is that the structure should be able to withstand safely all the load that are liable to act on it throughout its life and it should also satisfy the serviceability requirements of limiting deflection and cracking. Limit state is defined as the acceptable limit of safety and serviceability requirements before failure. The most important limit states which are considered in design as are follows: (i) Limit state of collapse. (ii) Limit state of serviceability Limit State of Collapse This limit state is also called as strength limit state as it corresponds to the maximum load carrying capacity i.e., the safety requirements of the structure. The limit state of collapse is assessed from collapse of the whole or part of the structure.…

Continue Reading
Limit state concept
Types of problem in T Beam

Learn : Types of problem in T Beam : Procedure for Determining the Moment of Resistance of the Given Section in T beam,Find Stresses in Steel and Concrete in T beam,To design the section for given loads.Design of T beam TYPES OF PROBLEM IN T BEAM To determine the moment of resistance of the given section in T beam. To Find Stresses in Steel and Concrete in T beam. To design of T beam. Procedure for Determining the Moment of Resistance of the Given Section in T beam Given : Dimensions of the section i.e., bw, bf, Df, d. Area of steel Ast Material - grade of concrete and steel (i) Determine σcbc and σst from the Tables 2.1 and 2.2 for given grades of concrete and steel Calculater modular ratio (m) \[m=\frac{280}{3\sigma_{cbc}}\] (ii) Determine critical neutral axis (nc) \[\frac{m.\sigma_{cbc}}{\sigma_{st}}=\frac{n_{c}}{d-n_{c}}\] (iii) Determine actual neutral axis (n) : To reduce the trial…

Continue Reading
Types of problem in T Beam | Working Stress Method
Repainting Doors

Learn : Repainting wood work,Repainting Wood Furniture,Repainting Doors,Repainting Cabinetry,wood floors Repainting wood work (i) If the old paint be unsightly, unsound, blistering or flaking off then it should be removed by the application of some paint remover, by scrapping or by burning the paint with a blow lamp. (ii) On surface disfigured by smoke a coat of one kilogram glue and 60 gms of unslaked lime in four kilograms of water should first be given. (iii) The surface should be thoroughly cleaned by washing it with soap and water. All greasy spots should be painted with turpentine oil and washed with soap and water. A solution of washing soda in water is used for cleaning the surface of all greasy spots. (iv) All holes and cracks etc. should be filled up with putty i.e. stopping should be done. (v) Before the application of each coat the surface should be rubbed smooth…

Continue Reading
Repainting wood work
New plastered surfaces

Learn : Painting plastered surfaces,New plastered surfaces Painting plastered surfaces (i) A plastered surface should be painted only after it has thoroughly dried, otherwise the paint would get spoil. (ii) To avoid sucking of paint by plaster soak the surface with a pore filling solution which will dry off leaving an impervious surface. A wash of 1 kg of size, 500 gm of soft soap and 9 liters of creamy lime wash is recommended. (iii) Cracks or holes, if any, should be filled in with glaziers putty and the surface sand papered on its drying. (iv) First two coats should consists of white lead and boiled linseed oil. (v) Third coat should consist of white lead, linseed oil, desired pigment and a little turpentine oil. This coat is applied after the surface has been rubbed smooth. Finishing coat having the same composition as the third coat but having more of…

Continue Reading
Painting plastered surfaces
Painting new wood work

Learn : Painting new wood work : Knotting or killing the knot, Application of priming coat, Stopping, Application of finishing coats. Painting new wood work Following points should be attended to before painting new wood work: (i) Only well seasoned timber should be painted otherwise not only shall the paint be spoilt but also due to dry rot the timber is likely to decay early. Also the paint surface will otherwise crack due to uneven shrinkage (ii) It is advisable not to paint excessively dry wood. (iii) Paint should be applied to only dry surface. (iv) The surface to be painted should be rendered smooth, clean and free from rust or dirt. (v) All nails should be punched in 1/2 cm below the surface. (vi) Large and loose knots should be cut out and filled tightly with correctly fitting wooden pieces. (vii) The surface should be…

Continue Reading
Painting new wood work