Cement price in Kerala

Raw Mix Proportioning and Raw Mix Design of cement The raw materials mixture is called raw mix or raw meal or kiln feed, The continuous production of high-quality cement is possible only if the raw mix possesses optimum composition, The purpose of calculating the composition of the raw mix is to determine the quantitative proportions of the components of the raw materials to give clinker the desired chemical and mineralogical composition and for smooth kiln operation.    Main Parameters for Raw Mix Design,    The raw mix composition is usually characterized by certain ratios called moduli. They are proportioning formulas in which percentages of various oxides as determined by chemical analysis are included., The three important moduli are lime saturation factor (LSF), silica modulus (SM), and alumina modulus (AM). Lime Saturation Factor (LSF), LSF represents the ratio of the actual amount of lime (CaO) to the theoretical lime required by other major oxides in raw mix/clinker., It is the ratio of CaO to the other three main oxides.   A clinker with a higher LSF will have a higher proportion of elite than a clinker with a low LSF., Limiting the range of LSF in clinker is 0.66 – 1.02 and the preferable range is 0.92 – 0.96. Silica Modulus (SM), SM represents the proportion of SiO2 to the total of Al2O3 and Fe2O3., It is the ratio of SiO2 to the sum of Al2O3 and Fe2O3. SiO2 SM = Al2O3 + Fe2O3,    A high SM means that more calcium silicates (C3S + C2S) and less aluminate (C3A) and ferrite (C4AF) are present in the clinker., In addition, it characterizes the ratio of solid/liquid and the amount of liquid phase in the clinker., Kiln process (coatings, rings, dusty clinker) is sensitive to SM changes., The limiting range of SM in clinker is 1.9 – 3.2 and the preferable range is 2.1 – 2.7. Alumina Modulus (AM), AM characterizes the raw meal/clinker by the proportion of alumina to iron oxide., It is the ratio of Al2O3 to Fe2O3. Al2O3 AM = Fe2O3, AM determines the potential proportions of aluminate (C3A) and ferrite phase (C4AF) in the clinker., In addition, it characterizes the composition of the liquid phase in the clinker,    Alumina and iron oxide have flux effect., The liquid phase promotes the C3S formation., Higher iron oxide decreases the viscosity of the melt, increasing the speed of reaction between CaO and SiO2., Low alumina modulus = Easier burning due to low viscosity., Limiting the range of AM in clinker is 1.2 – 2.5 and a preferable range is 1.3 – 1.6 Raw Mix Design Calculation Prerequisites for Raw Mix Design Calculation, Raw Materials 1. Chemistry 2. Materials cost,    There are many methods of calculation: from the simplest to more complicated ones., The basis for calculation is the chemical composition of the raw materials. Generally, data of chemical analysis should be accurate to two places of decimals. Results of the analysis are more than 100%, each constituent being proportionally reduced. If on the other hand, the total of constituents is less than 100 the constituents are not proportionally increased to 100. In this case, the difference from 100 is denoted as ‘rest’, so that the total of all constituents is then 100. Ingredients and properties of cement compounds Ingredients:     1. Lime (CaO):, This is the important ingredient of cement  and its proportion is to be carefully maintained.,A sufficient quantity of lime forms tricalcium  silicate (C3S) and dicalcium silicate (C2S),   The lime in excess makes the cement unsound and causes the expansion and disintegration of the cement. , On the other hand, if the lime is deficient, it will decrease the strength of the cement and will cause it to set quickly.    2. Silica (SiO2):, It imparts strength to the cement due to the formation of dicalcium silicate and tricalcium  silicate.,If silica is present in excess quantity

Workability of concrete workability is one of the physical parameters of concrete which affects the strength and durability, as well as the cost of labor and appearance of the finished product, workability of concrete is defined as the ease with which concrete can be mixed placed compacted and finished, concrete is said to be workable when it is easily placed and compacted homogeneously that is without bleeding or segregation,  Technically speaking workability of concrete is the amount of useful internal work necessary to produce 100 compactions it is said that wet concrete is more workable than dry concrete workability is described as very low, medium, high, and variable  types of workability   There are three types number one is unworkable concrete also called harsh concrete, it is concrete with very less amount of water content, hand mixing of this type of concrete is not so easy, these types of concrete have high segregation of aggregates as cement paste is not lubricated properly we stick to aggregates in this type of concrete, it is very difficult to maintain homogeneity of concrete mix and compaction requires more effort water-cement ratio for this type of concrete is below 0.4 unworkable concrete needs more work or effort to be compacted    Second is medium workable, this type of concrete is used in most of the construction work this type of concrete is comparatively easy to mix transport pour, and compact without any segregation and loss of homogeneity, the water-cement ratio of medium workable concrete is 0.42 0.55, this type of concrete is used in construction with light reinforcement, generally, a spacing of reinforcement allows concrete to compact effectively    Third one is highly workable this type of concrete is relatively very easy to mix transport or this type of concrete is used where effective compaction is not possible or in mass highly workable concrete flow easily and settle down without any effort but there are very higher chances of segregation and loss of homogeneity in this case such concrete is used where heavy reinforcement is used and where the vibration of concrete is not possible highly workable concrete is self-compacting water symmetry issue for this type of concrete is more than 0.5  Fractural strength concrete The fracture strength of the concrete, is the ability of an unreinforced beam or slab to resist failure in bending, that is bending moment flexible strength is one measure of the tensile strength of concrete, the ideal method for determination of the tensile occurs in bending when the tensile strength at the bottom of the beam exceeds the tensile capacity of the concrete, which is called the modulus of rupture that is extreme fiber stress in bending, the stress can be calculated as modulus of rupture  Compressive streangth of concrete compressive strength of concrete  is a measure of the concrete’s ability to resist loads that tend to compress heat a force is applied to the top and bottom of a test sample until the sample fractures or is deformed, the compressive strength is determined by loading the molded concrete specimen specimens either cubes or cylinders in uniaxial compression until ultimate failure, normally a strength of cylinder specimen is taken as 0.8 times the strength of q,  compressive strength depends on several factors like water symmetry, cement contained, characteristics of cement, type and properties of aggregate, degree of compaction, curing aid at the time of testing, testing conditions, ambient conditions, specimen geometry rate of loading, etc Determining compressive streangth of concrete and testing procedure the compressive strength of concrete is given in terms of the characteristic, compressive strength of 150 mm size cubes tested at 28 days, as per Indian standards, the correct characteristic compressive strength is defined as the strength of the concrete below which not more than five percent of the test results are expected to fail    The dry proportion of ingredients that is cement sand and coarse aggregate, as