Resistance of Natural Rubber Latex Modified Lightweight Concrete to Chloride Ingress

The aim of the study is to examine the chloride permeability characteristics of natural rubber latex (NRL) modified lightweight concretes (LWCs). The LWC was produced from lightweight fine and coarse aggregates (LWA) which were manufactured by cold bonding of class F fly ash. The NRL which is an elastic hydrocarbon polymer was used as an addition in the concrete production as 2% and 5% of the weight of total binder content (400 kg/m(3)), considering the solid polymer content. Chloride permeability of polymer modified concretes was tested in terms of rapid chloride permeability test (RCPT) and soaking test. The RCPT was carried out at the end of 28 days of curing. However, the specimens used for soaking test were immersed in NaCl solution after 28 days of initial curing and tested for chloride ion penetration at the end of 90 days of chloride exposure period. Furthermore, the cubic samples were tested in compression at 28 and 90 days to determine compressive strength development of the control and polymer modified lightweight concretes. The results indicated that the modification of the lightweight concretes with polymeric substance influenced considerably the strength and permeability characteristics of LWCs.