Durability of Lightweight Concrete. Phase II. Wetting and Drying Tests of Lightweight Concrete

摘要

The report covers tests performed to evaluate the durability of lightweight concrete subjected to cycles of wetting and drying. The tests described are one phase of a 3-phase project dealing with durability of lightweight concrete. The results of these tests warrant the following conclusions: (1) Concrete containing lightweight aggregate from one source was more durable than normal sand and gravel concrete, and the other two sources produced slightly less durable concrete. (2) There was no apparent difference in durability between the 5.5 and 6.0-bag mixes for lightweight aggregate concrete. (3) Mixes containing lightweight fine aggregate with 25 percent passing the No. 100 sieve were less durable than those containing 15 percent passing the No. 100 sieve. (4) The higher the initial moisture content of the lightweight aggregate, the less is the wetting and drying durability of the concrete. (5) Concrete sand used to replace lightweight fine aggregates improved the durability of lightweight concrete. (Author)