Cement Energy and Environment

~~ty & Standards EVALUATION OF CEMENT CLINKER GRINDABILITY THROUGH SINGLE PARTICLE IMPACT BREAKAGE DISTRIBUTIONS bmurden Gen9 Mug/a University, Faculty of Engineering, Dept. of Mining Engineering, 48170, Kotekli, Mug/a, Turkey Ahmet Hakan Benzer Hacettepe University, Faculty of Engineering, Dept. of Mining Engineering, 06800, Beytepe, Ankara, Turkey Abstract The drop weight breakage technique is proposed to determine grindability of clinker as a material property on the basis of single particle breakage data. Single particle impact breakage data was evaluated in relation to the detailed chemical and mineralogical composition data determined by X-ray powder diffraction method using X-ray diffractometer on the basis of particle size. Test samples were provided from two different clinkering rotary kilns. Clinkers were stored in the same silo without any blending process and then fed to three different grinding lines. JK prior art breakage model parameters determined for clinker breakage demonstrated that, grindability could be characterized by the value of single particle impact breakage parameter A.b. However, as different particle sizes will have different breakage functions depending on the energy consumption level, an average A.b value should be determined to obtain an representative grindability value. This value is proposed to be determined through JK prior art breakage model which could be established for different size fractions. Evaluations highlight the importance of blending of different clinkers in the storage silo to maintain minimization of variations in grindability. For further details you log on to: mro@tC'!_ _1a org. tr "'~~' tcma.grg. tr Courtesy: Cement and Concrete World, May-June 2011, P69. NEW PARADIGMS OF QUALITY IN CONCRETE ~oN~T-· · ~-·~ r~s (Based on Dr. M. Ramiah Endowment Lecture delivered at 27th AGM, ICI, Hyderabad, 18 Sep\ember 2010.) Prof. Dr. A. K. Mu/lick, Former Director General, NCBM, Introduction Quality like beauty, is difficult to define; although we can discern a quality construction just as we notice a beautiful flower or admire melodious music, whenever we come across one. In all such cases, our judgment is based on the final product. However, the present day tendency is to define quality in terms of 'what is to be done to achieve quality' - a series of do's and don'ts. It is a 'prescriptive' approach. This straightjacket approach helps to carry on with the task at hand, but do not yield a holistic solution . This approach is best embodied in the concepts of Quality Assurance (QA) and Quality Control (QC). Quality Assurance (QA) is the process of planning or forward thinking necessary to ensure that the specified quality will be obtained. Quality control (QC) is the activity which is carried out to verify such compliance with the specified requirements. The emphasis is on 'specified' quality and 'specified' requirements. That is why, Abdun-Nur said 'Quality control is conformity to specifications, no more, no less'. QAand QC Quality assurance in construction activity, which is both technical and organizational , relates to; • Proper design, • Use of adequate materials and components to be . supplied by the producers, • Proper workmanship in the execution of works by the contractor, and • Proper care during the use of structure including periodic inspection and timely maintenance and repair by the owner. Quality control in concrete constructions relies heavily on adequate workmanship in production of concrete. It emphasis: • Proper storage of materials, • Proper batching of ingredients, • Proper mixing, • Due care in transportation of fresh concrete to the site of placement, • Proper placing of concrete in the forms, • Thorough compaction, • Adequate curing, • Special precautions during extreme weather concreting. These necessary sufficient wholesome below. are steps, for quality, no doubt, but not achieving as defined 5