sentences:  The alkaline route is the most important in terms of research and development and commercial applications and is described below.The acidic route is discussed elsewhere.In the 1950s, Viktor Glukovsky, of Kiev, USSR, developed concrete materials originally known under the names "soil silicate concretes" and "soil cements", but since the introduction of the geopolymer concept by Joseph Davidovits, the terminology and definitions of 'geopolymer' have become more diverse and often conflicting.