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.
When a person travels to a location that is greater than 8,000 feet, they must do so at a speed that allows their body to acclimatize to certain changes, such as decreased air pressure, low humidity, and greater exposure to ultraviolet rays. Typically, full acclimatization can take as much as five days. If a person does not fully acclimatize to the higher altitude, it may cause a condition known as altitude sickness. The three forms of altitude sickness are acute mountain sickness, high altitude pulmonary edema, and high-altitude cerebral edema.