ABSTRACT

This chapter covers certain critical issues in the practical achievement of durability by focusing on aspects such as concrete manufacture, construction challenges and site practices, and quality control for durability. Concrete manufacture and construction are multistep processes. They involve materials selection and sampling, batching and mixing, and final finishing and protection afforded the freshly cast concrete structure. The chapter concentrates mainly on batching and mixing of concrete—whether on-site or in a ready-mix operation. Batching is the process of measuring the concrete ingredients accurately and consistently, to produce mixes that are consistent in quality and in properties related to processing or placing, such as workability. Control of mixing water content during the batching process is probably the single most important operation that influences consistent quality of concrete. Truck mixers are usually of the reversing drum type. Ready-mix concrete plants may have integral concrete mixers in their plant, or they may rely on the truck to effect the mixing.