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 process of batching and mixing of concrete. Batching of Concrete: The correct measurement of the various materials used in the concrete mix is called batching. It has been observed that batching errors are partly responsible for the variation in the quality of concrete. This operation can be properly and better controlled than [...]
In this article we will discuss about the methods of transportation and placement of concrete. Transportation of Concrete: After mixing, concrete should be transported and placed at site as quickly as possible without segregation, drying, etc. Hence transportation of fresh concrete is very important operation. Depending upon the type of work and equipment available various methods of transporting of concrete [...]
In this article we will discuss about:- 1. Introduction to Compaction of Concrete 2. Voids in Concrete 3. Methods 4. Types of Vibrators. Introduction to Compaction of Concrete: The process of compaction of concrete consists essentially of the elimination of entrapped air from the concrete. The oldest means of achieving this aim is by punning with a rod, or by [...]
In this article we will discuss about:- 1. Process of Hydration for Concrete 2. Objects of Concrete Curing 3. Necessity 4. Methods 5. Period of Concrete Curing 6. Maturity of Cured Concrete. Process of Hydration for Concrete: Concrete derives its strength by the hydration of cement particles. The process of hydration is not a momentary action, it continues for long. [...]
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 [...]
Factors that affect the grading of aggregate are: 1. Surface Area of the Aggregate 2. Relative Volume Occupied by the Aggregate 3. Workability of the Mix 4. Segregation. Factor # 1. Surface Area of the Aggregate: For a given maximum size of aggregate, larger the size of aggregate particles, lesser the surface area of aggregate in a given mix, which [...]
The strength can be defined as the ability to resist force. With-regard to concrete for structural purposes it can be defined as the unit force required to cause rupture. Strength is a good index of most of the other properties of practical importance. In general stronger concretes are stiffer, more water tight and more resistant to weathering etc. Nature of [...]
In this article we will discuss about:- 1. Tensile Strength of Concrete 2. Flexure Strength 3. Impact Strength 4. Resistance to Abrasion of Concrete 5. Fatigue Strength. Tensile Strength of Concrete: The actual tensile strength of cement paste or similar brittle material as that of stone is very much lower than the theoretical strength estimated on the basis of molecular [...]