Development Of A New Slump Test Method To Measure The Rheological Properties Of Cement Paste

A new and cost effective technique is developed to measure the rheological properties of cement paste and is validated through experiment and analytical analysis with the use of flow table. Instead of conventional methods, such as free flow test and modified mini slump test without drops, the technique of slump test (ASTM C1437) with impact force was utilized. To date there has been no study to measure viscosity from mini slump test with impact force. The yield stress and the plastic viscosity of cement pastes were determined using AR-G2 rheometer. Rheology tests were conducted on more than twenty cement paste specimens with different proportions of cellulose nano fibrillated and sucrose producing different yield stress and viscosity. The correlation between the rheological parameters and mini slump tests were investigated from the experimental graphs of shear stress and viscosity versus shear rate. Plots of viscosity versus drop data were acquired through both experiment and analytical calculations. Based on our experiment, the formulas have been found, indicating the effectiveness of mini slump test instead of rheological analysis for the specific cement paste case.

This book presents the work of the RILEM TC 266-MRP, whose purpose was to enhance the reliability of rheological measurements performed on cement-based materials. It makes users more aware of potential sources of errors in the measurements, and provide guidelines on how to observe, counteract or eliminate the errors. Improving the reliability of rheological measurements will further enhance the use of rheology to investigate different aspects of the fresh properties of cement-based materials. After an introduction into mix design and applications, the book delivers a comprehensive overview of rheology definitions, behavior, and parameters; rheometers; measuring and analysis procedures; difficulties and challenges during measurements; relationships with specific empirical tests; and the behavior of concrete near a surface. This report on the measurement of rheological properties of complex materials such as concrete enables readers to understand the applicable concepts of rheology, and address the challenges on the measuring procedures, the rheological models and some errors and limitations of rheometers used.

Cementitious materials : historical notes / Waldemar A. Klemm / - Cement production and cement quality / Vagn Johansen / - Phase equilibria and cement hydration / Paul Wencil Brown / - Hydration mechanisms / E.M. Gartner and J.M. Gaidis / - The microstructure of concrete / Karen L. Scrivener / - Interfaces in concrete / S. Mindess / - Modeling of hydration reactions and concrete properties / L.J. Parrott / - Microsilica in concrete / L.R. Roberts / - Fiber-Reinforced cementitous materials / Arnon Bentur / - Mechanisms of corrosion of steel in concrete / Arnold Rosenberg / - Integrated knowledge systems for concrete science and technology / Geoffrey Frohnsdorff.

This book presents new information on concrete properties and production in the light of the widespread use of ready mixed concrete and new concreting materials. This book forms the Proceedings of the RILEM Colloquium held in Hanover, West Germany in October 1990. Papers from 18 countries in Europe, North America and the Far East are included.

Nonconventional Concrete Technologies: Renewal of the Highway Infrastructure identifies research and development opportunities in innovative, nonconventional materials and processes that have the potential to accelerate the construction process, improve the durability of highway pavement and bridges, and enhance the serviceability and longevity of new construction under adverse conditions.

The subjects of the symposia are on composite materials behaving as brittle, normal and special conditions of exploitation. Brittle matrix composites are applied in various domains and the series of symposia are closely related to their applications in civil engineering. In the last decades their importance is increasing along with their variety and the use of most advanced methods of testing. Papers include concretes, fibre concretes and ceramics, particularly their composition, microstructure and fracture processes. Various new and advanced engineering problems are presented in the papers.

The paper presents the methods of controlling sedimentation of cement mix using D-cube flow, slump, cone immersion and electrical resistance tests. These methods make it possible to control the sedimentation of aggregates and fibers, the optimization of different admixtures and additives and the rheological properties of cement mixes. The electrical resistance test for cement composites was modified. The cube (150x 150x 150mm) was equipped with two electrodes to measure the resistance of the mix. For sedimentation measurement electrodes were placed in the upper and bottom part of the mix. Measured changes of the resistance at different depths of the mix give the information about the sedimentation of components. The main advantage of the D-cube (150x150x150 mm) flow, slump and cone immersion tests is the ability to do it without advanced measuring devices and the fact that one method is sufficient to compare the rheological properties of cement pastes, mortars and concretes.