Study of the Behaviour of Different Mineral and Pozzolanic Admixtures in Conventional and Roller-Compacted Concretes with Respect to their Microstructure and Durability

Title: Study of the Behaviour of Different Mineral and Pozzolanic Admixtures in Conventional and Roller-Compacted Concretes with Respect to their Microstructure and Durability
Author(s): Hasparyk
Paper category : conference
Book title: International RILEM Conference on the Use of Recycled Materials in Building and Structures
Editor(s): E. Vázquez, Ch. F. Hendriks and G.M.T. Janssen
Print-ISBN: 2-912143-52-7
e-ISBN: 2912143756
Publisher: RILEM Publications SARL
Publication year: 2004
Pages: 1035 - 1044
Total Pages: 10
Nb references: 9
Language: English

Abstract: The use of mineral and pozzolanic admixtures in concrete may contribute to the improvement
of its properties such as workability, permeability loss with resulting increase in durability
and, in general, increase in mechanical strength. Several of the admixtures generally
employed in conventional concrete (CVC), such as fly ash, blast- furnace slag and silica fume,
have been used in roller compacted concrete (RCC). However, other materials like powdered
aggregate, rice husk-ash and metakaolin are under study with a view to improving the
properties of both CVC and RCC, with considerable cost effectiveness. In this paper, the
focus is on assessing, by means of laboratory tests, the influence of different admixtures in the
durability and microstructure of CVC and RCC.
The experimental program comprised the study of seven different types of admixture, as
follows: powdered aggregate, ground blast furnace slag, calcined clay pozzolan, silica fume,
fly-ash, metakaolin and rice husk-ash, totaling 15 combinations for CVC and 26 for RCC.
Water permeability tests under pressure were performed, along with compressive strength
tests in concrete test specimens and accelerated reactivity tests on mortar bars featuring the
different admixtures. Microstructural observations of the concrete samples with the various
admixtures were performed after 90 days of curing, by using a scanning electron microscope.
The results obtained indicate that the admixtures analyzed display differing behaviors and
may have a considerably positive influence on the durability and on the microstructures of
conventional and roller compacted concrete, provided the former are employed in adequate
proportions.

Online publication: 2004-09-29
Publication type : full_text
Public price (Euros): 0.00
doi: 10.1617/2912143756.114