ON LINE COURSE
THE NEW CONCRETE
This book is entitled “The New Concrete”. What is “new”? There are many reasons why I have used this term . Some are related to the material. Others belong to the book.First of all, during the last 30 years concrete is changed in composition and perfor-mance: only a minor part of cement is still Portland cement. In Europe about 90% of the cement adopted in modern concretes is in form of blended cements where Portland cement is replaced by fly ash, granulated ground blast furnace slag, natural or industrial pozzolan, silica fume and other components including ground limestone. The use of chemical admixtures, and particularly of superplasticizers, has revolutionized the technology of concrete in terms of water-cement – which can be as low as 0.30 to manufacture High Strength Concrete - or in terms of workability to manufacture Self-Compacting Concrete. More recently, the use of shrinkage-reducing admixtures (SRA), particularly in combination with polymer macro-fibers or CaO-based expansive agents, allows to manufacture crack-free concrete even in the absence of wet curing. Secondly, this book is devoted to Architects and Building or Civil Engineers who are interested in essential information about concrete and its performance, together with standard prescriptions to be adopted by contractors, pre-cast concrete and ready-mixed manufacturers. Other excellent books like “Properties of Concrete” by A.M. Neville, ”High-Performance Concretes” by P.C. Aïtcin, “Concrete. Microstructure, Properties an Materials” by P. K. Mehta and P. J. M Monteiro, are available and more devoted to scien-tists, students or concrete specialists, but they do not offer any helpful and practical support especially to European people concerned with concrete.The third reason why the concrete presented in this book is new is that it is based on the European Standard (EN) specially for the cements and the concrete properties dea-ling with characteristic strength, permeability and durability. No other book is so devo-ted to the European Standards. However, the technical literature available in America (ACI,CANMET) or in Japan (specially in chemical admixtures) is taken in great account in this book.Moreover, attached to the book is the “Easy & Quick” software to support and help readers to establish technical prescriptions about concrete strength, durability, placement, compaction and curing according to European Standards.
CONCRETE MID DESIGN
CONCRETE MIX DESIGN
Concrete mix-design is the method to transform the required engineering properties into the composition of the concrete mixture in terms of kg/m3 of cement, water, sand and coarse aggregate.
The concrete mix design elaborated in this handbook is based on the EN 197-1 for the cements to be adopted, and the EN 206-1 for the required exposure and consistency classes
This handbook takes into account two types of mix-design depending on the complexity of the required performances: simple or complex mix design.
Simple mix-design is based on the relationships between the concrete properties, on one hand, and the composition of the mixture, on the other, when the concrete properties are the 28-day characteristic strength in the hardened state, and the workability in the fresh state. These relationships depend on the cement strength class and the maximum size of the aggregate.
Complex mix-design is based on the relationships between properties and concrete composition when the properties include durability, permeability, early strength, flexural or tensile strength, besides the 28-day compressive strength. Complex mix-design also includes the calculation of the slump loss depending on the time and temperature transportation, as well as the presence of chemical admixtures.
This handbook also takes into account how to predict drying shrinkage, creep and thermal heating in concrete structures on the basis of the concrete composition elaborated from the mix design.
A special software called CMD (Computerized Mix Design) is available to elaborate automatically simple and complex mix designs.
THE NEW CONCRETE
CONCRETE MIX DESIGN
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