Guidelines for Concrete Mixtures Containing Supplementary Cementitious Materials to Enhance Durability of Bridge Decks


Book Description

NCHRP Report 566 is designed to help facilitate the use of supplementary cementitious materials to enhance durability of concrete used in highway construction, especially bridge decks. The report includes a methodology for selecting optimum concrete mixture proportions that focuses on durability aspects of concrete and the performance requirements for specific environmental conditions. The methodology is presented in a text format and as a computational tool, in the form of a Visual Basic?driven Microsoft Excel spreadsheet. Background information and a hypothetical case study was published as NCHRP Web-Only Document 110: Supplementary Cementitious Materials to Enhance Durability of Concrete Bridge Decks. The Statistical Experimental Design for Optimizing Concrete (SEDOC), the computational tool for the concrete mixture optimization methodology, and the user?s guide are available in a ZIP format for download.




Properties of Fresh and Hardened Concrete Containing Supplementary Cementitious Materials


Book Description

This volume represents the current knowledge on the effect of SCMs (slag, fly ash, silica fume, limestone powder, metakaolin, natural pozzolans, rice husk ash, special SCMs, ternary blends) on the properties of fresh and hardened concrete (e.g. early strength development, workability, shrinkage) and curing requirements. Other topics treated in the book are postblending vs preblending, implications of SCM variability, interaction between SCM and commonly used admixtures (e.g. superplasticizers, air entrainers).




Computer Aided Optimum Design in Engineering XII


Book Description

Presenting the latest research discussed at the Twelfth International Conference on Computer Aided Optimum Design in Engineering, this book contains papers describing case studies in engineering; considering static, dynamic analysis and damage tolerance. Manufacturing and structural protection issues are discussed as well as emergent applications in fields such as biomechanics. Contributions also include numerical methods and different optimisation techniques.Nowadays, it is widely accepted that optimisation techniques have much to offer to those involved in the design of new industrial products. The formulation of optimum design has evolved from the time it was purely an academic topic, unable now to satisfy the requirements of real life prototypes. The development of new algorithms, the improvement of others, the appearance of powerful commercial computer codes with easy to use graphical interfaces and the revolution in the speed of computers has created a fertile field for the incorporation of optimisation in the design process in different engineering disciplines Topics covered include: Structural optimisation, Optimisation in biomechanics, Shape and topology optimisation, Industrial design optimisation cases, Evolutionary methods in design optimisation, Multi-level optimisation, Multidisciplinary optimisation, Reliability based optimisation, Material optimisation, Aerospace structures, Applications in mechanical and car engineering, New and enhanced formulations, Optimisation under extreme forces, Optimisation in aerodynamics, Optimisation in civil engineering, Life cost optimisation, Education issues in design optimisation, Commercial software for design optimisation.




TR News


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Optimization of Concrete Mixtures for Use in Structural Elements


Book Description

Portland cement is an essential ingredient in concrete. The use of cement is to enhance the strength as well as other hardened properties of concrete mixtures. Determining the accurate amount of cement is important because the required strength may not be achieved if not enough cement is used. By contrast, when using too much cement, concrete cracking may occur that leads to reducing durability. Researchers at the University of Arkansas (UA) have shown that many bridge decks achieve their 28 day design strength of 4000 psi by 7 days of age. Bridge decks having high strength may experience cracking, which affects the durability. The Arkansas State Highway and Transportation Department (AHTD) classifies two types of concrete mixtures that can be used in bridges. The first is Class S concrete, and the second is Class S(AE). Class S is used for the structural components and does not contain air entrainment while Class S (AE) is mainly used for bridge decks and contains air entrainment. AHTD requires the same minimum cementitious material content for both classes of concrete. The purpose of this research is to determine if the cementitious material content of Class S mixtures can be reduced while still meeting AHTD specifications. The research program examined cementitious material content, Class C fly ash content, and water to cementitious material ratio (w/cm) . For all mixtures, selected fresh and hardened concrete properties were measured to ensure that they complied with AHTD requirements.







Brittle Matrix Composites 9


Book Description

The subjects of the symposia are on composite materials with matrices behaving as brittle in normal or special conditions. Brittle matrix composites are applied in various domains (civil engineering, mechanical equipment and machinery, vehicles, etc.) and in the last decades their importance is increasing together with their variety. Papers include: aggregate-binder composites (concretes, fibre concretes, rocks); sintered materials (ceramics); high strength composites with brittle matrices. In principle, the general problems of structures made of composite materials are not included in the papers. Various approaches to the material engineering problems are presented in the papers.










Progress Report


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