What is Alkali-Aggregate Reaction (AAR). Alkali-aggregate reaction (AAR) is a chemical reaction between the alkali in Portland cement and reactive minerals in aggregate and additives that takes place when moisture is present.herefore with aggregates falling in deleterious zone, Use of low alkali cement is recommended to prevent any chances of ASR occurrence. 1  Alkali-silica, a reaction between the alkali hydroxides in concrete and reactive forms of silica in aggregate (e.g., chert, quartzite, opal, strained quartz crystals); 2  Alkali-silicate, a reaction between the ....
For solid hardwood flooring, both unfinished and prefinished, acclimation is a must. The same thing for laminate flooring. Keep it in the house for at least 48 hours prior to installation. The negative effects of not acclimating your hardwood floors before installation can be either buckling or gaps between the boards.
All hardwood products are affected by environmental conditions. Acclimate the new flooring in the areas to be installed to normal lived-in conditions while in the boxes. If products are protected in plastic open the ends of the boxes. Length of time is not the determining factor.