dc.description.abstract
Steadily improved compaction techniques in earthworks and ground engineering over the course of time, require the use of adequate test equipment to assess the achieved compaction success. For this purpose, conventional and spot like compaction testing methods, especially at large construction sites, are outdated and don't represent the state of the art anymore. In this master thesis "Continuous Compaction Control" (CCC) is considered in connection with rollers equipped with vibratory exciters. CCC is, as the name suggests, a roller integrated compaction measurement method with dynamically excited rollers, that allows to measure the success of compaction immediately, continuously and to document the results already during the compaction process. This is accomplished by analyzing the motion behavior of the vibratory excited roller drum. Therefore dynamic compaction values, which indicate soil stiffness properties, are calculated from consequently measured drum accelerations. Generally spoken, CCC is based on the measurement of the dynamic interaction between soil and roller. This novel approach of work-integrated compaction control is, due to his numerous advantages (totality of all the benefits arising from them), able to significantly increase the quality, uniformity and durability of earthworks. After a short introduction into the topic, Chapter 2 describes the theoretical basics of surface near compaction. At first targets, respectively methods of soil compaction, and their essential influencing factors on the compactability of soils, are explained. Methods of surface compaction, with the main focus on vibrating rollers, and the different types of roller with regard to principle, structure and modes of operation are described. Specific methods of compaction tests form the conclusion of the chapter and represent the seamless transition to chapter 3, which is exclusively dedicated to CCC. At the beginning of Chapter 3, principle of operation, effectiveness, advantages and disadvantages, as well as components of CCC systems are presented, to subsequently introduce the leading systems on the market (Compactometer, Terrameter, ACE). Their structure, measurement principle as well as respective formulas for determining the individual measure values are presented. Furthermore, the calibration of CCC measurement values and parameters influencing them are discussed. Chapter 4 describes the procedure, setup and structure of done experimental large scale in situ tests and therefore introduces to the following section 5, which deals with the evaluation of the data and signals, measured and memorized during the roller test passes. These recordings, describing the kinematic roller behavior, are evaluated, determined and graphically shown, with the overall goal to analyze, discuss, interpret and compare the different resulting CCC values. The sixth and final chapter contains a brief summary of the obtained findings, as well as a status - quo report, that includes and provides views on possible further research activities in this field.
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