The influence of curing on OPC/PFA concrete for marine environments

Abstract

Pulverised -fuel ash (p.f.a.) , a by-product of coal--fired power stations has been successfully utilised in various ways all over the world for more than half a century. Local p.f.a. has been in production since 1985 and the disposal of the residual materials produced by the Marsa station has over these years developed into a serious environmental problem. The increased environmental awareness and the advent of a further possible coal firing station, inevitably stress the importance of research on local p.f.a. In this dissertation the properties of local p.f.a. are analyzed and the utilization of the material discussed. One particular field, where the author considers that p.f.a. can be used successfully, is marine construction. The development of strength of p.f.a. concrete and how this is influenced by curing is investigated; the properties of p.f.a. which affect durability in seawater are also discussed. This analysis is made with respect to current literature and investigations in this field of research, which is being developed in a number of countries. In the data presented in this work it is shown, that given suitable mix proportioning and, proper concrete requirements are followed, locally produced p.f.a., used as a partial replacement of both cement and sand in marine concrete, can achieve at least comparable strength to that of o.p.c. concrete, designed to achieve equal strength and workability.