Paddy Engineering Consultant

In large work or in major construction works, cement is generally stored at site. The cement must be stored in such a manner so that, it can be easily accessible for proper inspection. The building in which cement is stored should be water tight in order to prevent dampness. The guidelines given below should be observed while storing the cement. 1. Cement should not be stored for a long period. During rainy season, the storage time period of cement should be as minimal as possible. 2. Dampness in godowns must be avoided. 3. Cement should not be piled against the wall. A minimum space of 60 cm all –round should be left between the exterior walls and the stacks. The distance between two consecutive stacks should be minimum to reduce circulation of air. 4. Cement should not be piled directly on the floor; instead it should be piled off the floor on wooden planks/crates so as to be clear off the floor by at least 10 to 20 cm. 5. There should not be more than 15 bags in one pile. This...

ADVANTAGES OF PRECAST CONCRETE Following are the advantages of precast concrete: 1. The concrete of superior quality is produced as it is possible to have better technical control on the production of concrete in factory. 2. It is not necessary to provide joints in the precast construction. 3. The labour required in the manufacturing process of the precast units can easily be trained. 4. The moulds employed for preparing the precast units are of steel with exact dimension in all directions. These moulds are more durable and they can be used several times. 5. The precast articles may be given the desired shape and finish with accuracy. 6.The precast structures can be dismantled, when required and they can then be suitably used elsewhere. 7. The transport and storage of various components of concrete for cast in-situ work are eliminated when precast members are adopted. 8. The work can be completed in a short time, when precast units are adopted. 9. When precast structures are to be ins...

The following properties of soil are taken into consideration while dealing with soil as a construction material. Cohesion  Angle of internal friction  Capillarity  Permeability  Elasticity  Compressibility  1. COHESION It is the internal molecular attraction which resists the rupture or shear of a material. Cohesion is derived in the fine grained soils from the water films which bind together the individual particles in the soil mass. Cohesion is the property of the fine grained soil with particle size below 0.002 mm. cohesion of a soil decreases as the moisture content increases. Cohesion is greater in well compacted clays and it is independent of the external load applied. 2. ANGLE OF INTERNAL FRICTION The resistance in sliding of grain particles of a soil mass depends upon the angle of internal friction. It is usually considered that the value of the angle of internal friction is almost independent of the normal pressure but varies with the de...

The choice of whether a structure should be built of concrete, steel, masonry, or timber depends on the availability of materials and on a number of value decisions. 1. ECONOMY Frequently, the foremost consideration is the overall cost of the structure. This is, of course, a function of the costs of the materials and the labour and the time necessary to erect them. Concrete floor systems tend to be thinner than structural steel systems because the girders and beams or joists all fit within the same depth, or the floors are flat plates. This produces an overall reduction in the height of a building compared to a steel building, which leads to a; a. Lower wind loads because there is less area exposed to wind b. And savings in cladding and mechanical and electrical risers Frequently, however, the overall cost is affected as much or more by the overall construction time since the contractor and the owner must allocate money to carry out the construction and will not receive a retu...

SUITABILITY OF WATER FOR CONCRETE MIXING OBJECTIVE To assess suitability of water for use in concrete mix. EQUIPMENT Measuring cylinder Cube moulds Trowel Tamping rod Vibrating table Testing machine PROCEDURE Analyse water for its chemical compositions as per  IS 3025-1964  and compare these with permissible limits given in  IS: 456-2000 .In case water does not satisfy the permissible limits or it is not possible to obtain chemical analysis data readily, the suitability of water is tested by making concrete cubes. Concrete of desired grade is prepared with available water with designed proportions and cubes casted for testing. Prepare the same concrete mix with distilled water and cast the cubes in exactly the similar manner as with water of unknown nature. Cure both the sample in respective water under exactly the same conditions. Test both the cube specimens after 7 and 28 days in exactly the same manner. Compare the test results of strength and cond...

DURABILITY OF CONCRETE PILES Properly mixed concrete compacted to a dense impermeable mass is one of the most permanent of all constructional material and give little cause of concern about its long-term durability in a non aggressive environment. However, concrete can be  attacked by sulphate and sulfuric acid  occurring naturally in soils, by corrosive chemicals which may be present in industrial waste in fill materials and by organic acids and carbon dioxide present in ground water as a result of decaying vegetable matters. Attack by sulphates is a disruptive process whereas the action of organic acids or dissolved carbon dioxide is one of leaching. Attack by sulphuric acid combines features of both processes. The severity of attack by soluble sulphates must be assessed by determining the soluble sulphate content and the proportions of the various cat ions present in an aqueous extract of the soil. These determinations must be made in all cases where the concentration of s...

DURABILITY OF BUILDING FOUNDATION A foundation is that part of the structure which is in direct contact with ground. Therefore foundations are subjected to attack by chemicals present in soil, water and by mechanical abrasion and erosion. The extent of deterioration depends on the concentration of chemicals, the level of and fluctuations in the ground water table or the variation in tidal and river level or on climatic conditions. The only way to increase the durability of foundation is to protect the foundation material from the above mentioned attacks. There are 4 types of material commonly used as foundation material, such as Timber foundation Metal foundation Concrete foundation Brick work foundation Let us discuss methods of protecting different foundation material from deterioration. 1. PROTECTION OF TIMBER FOUNDATION Timber piles are liable to fungal attack and termites, if kept in moist conditions. The protection of timber is best achieved by pressure treatment w...