Title: Non-Expandable Perlite Powder as Pozzolanic Addition in Concrete
Author(s): Michal Bacuvcík, Ján Mendel, and Ivan Janotka
Publication: Materials Journal
Appears on pages(s): 3-14
Keywords: carbonation; durability; k-value; perlite; pozzolan; utility property
The main purpose of this research was to verify non-expandable powdered perlite (PP) for suitability as a Type II addition for use in concrete. The tests were carried out using CEM II/A-S 42.5 N. Pozzolanic reactivity was verified by the Frattini test. The suitability for use in concrete was assessed by considering the criteria of EN 450-1 as the limits of individual results necessary to be fulfilled for fly ash. If a standard is not issued for a pozzolan, it must be evaluated by the most closely related standard. Following this request, the k-value for PP required by EN 206+A2 and prescribed in TNI CEN/TR 16639 was determined. The k-value concept is based on the comparison of the durability performance for the relevant exposure class of a reference concrete with cement “A” against a test concrete, in which a part of cement “A” is replaced by an addition. This concept permits a defined range of combinations of cement conforming to EN 197-1 with a pozzolanic addition that may count fully toward requirements for the maximum water-cement ratio (w/c) and minimum cement content, which are specified for concrete. The TNI provides more detailed information on the principles of the equivalent performance concept and on the
application of this concept in 12 European Committee for Standardization (CEN) member countries. This paper reveals the methodological and experimental procedures for the k-value determination for PP as well as the resistance to carbonation, which includes one important aspect of durability related to the exposure class XC—corrosion induced by carbonation. The novelty of this investigation consists of the presentation of the Slovak national procedure for determination of the k-value and the resistance to carbonation alongside those elaborated by Technical Committee CEN/TC 104, Concrete and Related Products. The results point to the fact that the unexpanded PP is a Type II addition suitable for use in concrete.