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.
How to Acclimate Hardwood Flooring: Inside the Boxes. 1  Make sure the room or level where the flooring will be laid is an enclosed space. 2  Between 5 and 10 days ahead of time, check to see if the temperature and humidity of the space is at normal living conditions. In other words, let the heat or air run as it would normally for at least 5 days. Between 60 and 80 degrees Fahrenheit is a good range when it comes to the temperature.