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.
A floor that is not acclimated to its environment is more likely to experience problems such as expansion, tenting, squeaking and buckling after installation. When you are not sure if your laminate flooring needs to be acclimatized, play it safe and take a couple extra days for acclimation of laminate flooring.