Publisher's Synopsis
Basically, the problem of designing a concrete mix consists of selecting the correct proportions of cement, fine and coarse aggregate and water to produce concrete having the specified properties. Sometimes additional ingredients such as ground granulated blastfurnace slag (ggbfs), pulverized-fuel ash (pfa), or admixtures are used. There are many properties of concrete that can be specified, e.g. workability, strength, density, thermal characteristics, elastic modulus, and durability requirements. The properties most usually specified are: the workability of the fresh concrete; the compressive strength at a specified age; and the durability, by means of specifying the minimum cement content and/or the maximum free-water/cement ratio, and in some cases requiring the use of selected types of materials.;The mix design process must take account of those factors that have a major effect on the characteristics of the concrete, but can, at least at the first stage, ignore those which only have a minor effect on the concrete. There is little point in devising a complex method of mix design which takes into account factors which are difficult to measure or which are unlikely to remain constant during the progress of the job. The effects of various factors on the properties of concrete are described in sections 2 and 3 of this book.;The principle behind the method described in this publication is that from the restricted data usually available at the mix design stage, mix proportions are derived in an attempt to produce a concrete having the required workability and strength. Typical data are given in part 2 but where there is more appropriate information available related to local materials, this can be used instead. A trial mix is then made, but because of the assumptions made at this stage in the design it is probable that this trial mix will not completely comply with the requirements. If necessary it is possible from the trial mix results and information given in this publication, to adjust the mix proportions and to use these for actual production or to prepare a revised trial mix.
