Influence of aggregate type and gradation on the microstructure and durability properties of portland cement mortar and concrete

Title: Influence of aggregate type and gradation on the microstructure and durability properties of portland cement mortar and concrete
Author(s): A. Elsharief
Paper category : conference
Book title: International RILEM Symposium on Concrete Science and Engineering: A Tribute to Arnon Bentur
Editor(s): K. Kovler, J. Marchand, S. Mindess and J. Weiss
Print-ISBN: 2-912143-46-2
e-ISBN: 2912143586
Publisher: RILEM Publications SARL
Publication year: 2004
Pages: 213 - 222
Total Pages: 10
Nb references: 14
Language: English

Abstract: This paper presents the results of an investigation on the influence of aggregate type and gradation on the microstructure and durability of portland cement mortar and concrete. The objective of this study was to investigate the relationship between experimental parameters used in mixture proportioning and the microstructure and performance of mortar and concrete. Two sizes of fine aggregate gradations were used to prepare the specimens. The results indicate that increase in the aggregate size would increase the porosity and thickness of the interfacial transition zone surrounding the aggregate. The effect of aggregate gradation on the durability of cementitious materials was investigated by comparing the results of absorption, sorptivity, electrical conductivity, and resistance to sodium sulfate solution attack. The results indicate that decrease in the aggregate size leads to increase in the electrical conductivity and porosity and decrease in sorptivity of the paste. The resistance to sulfate attack depends on the mode of transportation of the sulfate-ions within the paste and the aggregate size. Similar durability investigation was carried on concrete specimens with fine and coarse sand gradations. The results appear to be consistent with those obtained for mortar. The effect of aggregate type on microstructure durability of mortar was examined by comparing mortars prepared with normal and lightweight aggregate. The results indicated that lightweight aggregate mortar had better durability than normal aggregate mortar. The improvement in durability was linked to the dense paste surrounding lightweight aggregate.

Online publication: 2004-02-04
Publication type : full_text
Public price (Euros): 0.00
doi: 10.1617/2912143586.019