Fresh concrete technology has progressed at a pace similar to many other aspects of concrete technology over the past three decades, and indeed many of these advances are interdependent. For example, the availability of super-plasticizers allows viable concrete to be produced with a lower water/binder ratio, thus increasing in situ strength.
In this chapter, we will first consider a characteristic called workability, including its definition and general measurement methods. We point out these limitations and show how this leads to the need for a more basic scientific description of the behavior of fresh cement paste and concrete. Next, we will explain how this was achieved by applying the principles of rheology, and discuss the development and use of test methods that will give a more complete understanding of the behavior.
Next, we will briefly examine the effects on the rheological properties of various constituent materials, including admixtures and cement substitutes, and how knowledge of these properties can be utilized. Next, we will briefly examine the factors that affect the loss of workability before setting up.
Description
This book is based on the syllabus and learning goals devised by the Concrete Technology Institute for Advanced Concrete Technology (ACT) courses. The first ACT course was held in 1968 at the Fulmer Grunge Training Centre of the Cement and Concrete Association (now the British Cement Association). Following there structuring of the BCA, the courses were presented at Imperial College London from 1982 to 1986 and at the University of Nottingham from 1996 to 2002.
With the advancement of computer-based communication technology, traditional housing courses now focus on self-learning rather than education, better access for participants outside the UK This book is not only a reference document in itself, but also provides the core material of the new ACT course and is divided into four volumes covering the following general areas:
- Constituent materials
- Properties and performance of concrete
- Types of concrete and the associated processes, plant and techniques for its use in construction
- Testing and quality control processes