The use of admixtures in high alumina cement mortar for the marine environment

High-alumina cement (HAC) mortars, made at 5, 20, and 40 C, were mixed using seawater, deionized water, and reconstituted seawater. The admixtures used were an accelerator, superplasticizer, antiwashout, air-entraining and waterproofing admixtures, and an ethylene-vinyl acetate (EVA) polymer latex dispersion. Results on short-term (1 year) durability against freezing and thawing and wetting and drying in all three waters are presented and compared to the performance of the same combination over 3 years at a maritime exposure site. The samples with polymer latex performed poorly in most tests, while the control and samples with accelerator and superplasticizer performed well in both laboratory exposure conditions and on the maritime site. Temperature of mixing and curing is very important in both the early and long-term performance of HAC, but the interactions between the effects of admixtures and conditions mean that it is obligatory to carry out durability tests on any proposed combination before a decision is made regarding materials selection.