ABSTRACT
Mixing was carried out in a horizontal pan mixer and the following mixing procedure was followed for all concrete mixes. The coarse aggregate was mixed with about a third of the total water for approximately one minute, the sand was then added and mixed for about 30 seconds. The cement and the remaining water were then added and mixing was continued for a further three minutes. For the lightweight aggregates used in the as received moisture condition, an absorption equal to the 30 min value was allowed for in the calculations of total water. Presoaked Lytag aggregates were drained for about 20 min and the total mixing water was calculated taking into account the excess moisture content
of the aggregate. The mix proportions and properties of fresh concrete are given in Table 2.
