دانلود کتاب CS TR 71 Concrete Petrography

Concrete petrography is an effective technique for investigating the quality, workmanship, durability and defects of concrete. It involves the microscopic examination and description of hardened concrete in the laboratory, using specialised petrological techniques that have been adapted from those used for the study of rocks. One of the benefits of petrography is that the careful examination of a few well-chosen and representative samples can reduce or remove the need for other more expensive test procedures. Many kinds of materials, such as those resulting from the hydration of cement or from deleterious reactions and internal features can be identified by petrography. The proportions of the original ingredients of the concrete can be estimated to a good order of accuracy. The technique can also be used to assess the effectiveness of some concrete repair techniques; an example is the degree of crack filling by resin injection.Investigations involving concrete petrography are commissioned by a wide range of clients who usually know little about the procedures involved and often find the petrographer's reports difficult to interpret. The published literature regarding concrete petrography proves equally difficult to understand as practically all of it is intended to be read by petrographers. W i th this in mind, The Concrete Society formed a working party with the intention of providing this introductory guide to concrete petrography that is aimed squarely at non-specialists. Whether you are commissioning, conducting or interpreting concrete petrography this report provides a clear and concise account of the state of practice. It was written by working party members comprising concrete petrography experts and engineers experienced in the investigation of concrete structures. This report draws on a wide range of case study examples and explains all of the latest techniques and interpretative guidance. Colour pictures of microscopical features are included that illustrate typical concrete compositions, unusual ingredients, workmanship defects and a wide range of types of damage and deleterious reactions. A glossary of terms is included for easy reference.