Technological properties are those qualities which give information regarding the suitability of metals for various technological operations or processes. Such properties are highly desirable in shaping, forming and fabrication of materials. The following technological properties will be discussed: 1. Machinability 2. Weldability 3. Castability 4. Formability 5. Malleability. 1. Machinability: It is defined as the ease with which a given [...]
By thermal properties of material, we mean those properties or characteristics of materials which are the functions of temperature or heat. We are here concerned with the thermal behaviour of solids i.e., the response of solid material to thermal change, i.e., increase or decrease of heat or temperature. Thermal properties of engineering materials comprise the following: 1. Specific heat. 2. [...]
The factors have been found to influence the test results to a great extent are: 1. Effect of Size and Shape of Specimen 2. Effect of Conditions of Casting 3. Effect of Moisture Content of Specimen 4. Effect of Temperature of Specimen at Test 5. Effect of Bearing Conditions 6. Effect of Rate of Loading. Factor # 1. Effect of [...]
In this article we will discuss about:- 1. Introduction to Workability of Fresh Concrete 2. Factors Affecting the Workability of Fresh Concrete 3. Measuring the Workability 4. Effect 5. Segregation 6. Bleeding. Introduction to Workability of Fresh Concrete: The strength of concrete of a given proportion is affected very much by the degree of its compaction. Therefore it is desirable [...]
Usually the tests that can be adopted to determine the workability of concrete are: 1. Slump Test 2. K. Slump Test 3. Kelly Ball Test 4. Compacting Factor Test 5. Flow Test. 1. Slump Test: This test is used extensively at the site of Work all over the world. Actually this test does not measure the workability of concrete but [...]
Generally the factors that affect the strength of concrete are: 1. Age of Concrete 2. Coarse Aggregate 3. Richness of the Mix 4. Curing of Concrete 5. Temperature of Concrete. Factor # 1. Age of Concrete: The relation between the water/cement ratio and strength of concrete applies to one type of cement at one age only. Different types of cements [...]
In this article we will discuss about the relation between compressive and tensile strength of concrete. The theoretical compressive strength of concrete is eight times larger than its tensile strength. This implies a fixed relation between the compressive and tensile strength of concrete. In fact there is a close relation but not a direct proportionality. The ratio of tensile to [...]
In this article we will discuss about the behaviour of concrete when compressive stress varies. When the compressive stress alternates between zero and a certain fraction of short term static strength the behaviour of concrete is very significant. As the stress increases from zero to a certain value of about 20 MPa, the strain also increases. On decreasing the load [...]
In this article we will discuss about:- 1. Definition of Creep 2. Factors Influencing the Creep of Concrete 3. Measurement 4. Magnitude 5. Effects. Definition of Creep: Creep can be defined as the increase in strain under a sustained constant stress, taking into account other time dependent deformations not associated with stress viz., shrinkage, swelling and thermal deformations. Thus creep [...]
Shrinkage of concrete can be classified into the following categories: 1. Plastic Shrinkage 2. Drying Shrinkage 3. Autogeneous Shrinkage 4. Carbonation Shrinkage. 1. Plastic Shrinkage: Plastic shrinkage takes place, soon after the concrete is placed in the form work, while the concrete is still in plastic stage. The cement paste at this stage un-goes a volumetric contraction. The magnitude of [...]