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.
We know you're excited to install your new hardwood, but you could miss a very important step: Acclimation. Acclimation allows the moisture in the wood to adjust to the normal conditions it will be installed in.owever, you must be sure of and record that the site is stable and in the target humidity range or you will have problems and your warranty will not cover it. Well controlled and stabilized means that the heating and air conditioning have been running for a week and the humidity has stabilized between 45% and 60%.