Durability of High Alumina Cement mortars for the marine environment

High Alumina Cement (HAC) mortars, made at 5, 20 and 40 degC, were mixed using seawater, de-ionised water and reconstituted seawater. The admixtures used were: an accelerator, a superplasticiser, anti-washout, air-entraining and water-proofing admixtures and an ethylene vinyl acetate (EVA) polymer latex dispersion. Results on short-term (one year) durability against freezing and thawing and wetting and drying in all three waters are presented and compared to the performance of the same combinations over three years at a marine exposure site. The samples with polymer latex performed poorly in most tests, while the control and samples with accelerator and superplasticiser performed well in both laboratory exposure conditions and on the marine 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 taken regarding materials selection.