Flowability of fresh mortar in self-compacting concrete using fil ash

Title: Flowability of fresh mortar in self-compacting concrete using fil ash
Author(s): J. Wattanalamlerd
Paper category : conference
Book title: SCC'2005-China: 1st International Symposium on Design, Performance and Use of Self-Consolidating Concrete
Editor(s): Zhiwu Yu, Caijun Shi, Kamal Henri Khayat and Youjun Xie
Print-ISBN: 2-912143-61-6
e-ISBN: 2912143624
Publisher: RILEM Publications SARL
Publication year: 2005
Pages: 261 - 270
Total Pages: 10
Nb references: 4
Language: English

Abstract: Self-compacting concrete is concrete that can fill all corners of formwork by mean of its own self-weight and without segregation. In order to achieve that, concrete need to have proper combination of flowability and viscosity, called as self-compactability. It is well known that self-compactability of fresh concrete is mainly affected by the self-compactability of the fresh mortar. Self-compactability of fresh mortar usually depends on the physical properties of solid particles in mortar, and the chemical reaction between cement paste-superplasticizer which known as particle-dispersability of superplasticizer. Fly ash is one kind of pozzolan that widely used in concrete work. Usually, fly ash is not inert material; it can perform the chemical reactions, i.e. pozzolanic reaction and hydration reaction, when used in concrete. Existence of fly ash may influence to the efficiency of superplasticizer and this leads the difficulty to mix proportioning design. Flowability of fresh mortar containing ordinary Portland cement and polycarboxylate based superplasticizer was measured for several combinations of fly ash replacement ratio, superplasticizer dosage and water-powder ratio. The influence of fly ash on flowability was evaluated as functions of flow area and funnel speed. The relationships among superplasticizer dosage, water-powder ratio, and fly ash replacement ratio were investigated. Flowability chart (relative flow area versus relative funnel speed) for each type of powder was made by regard the blend of normal Portland cement and fly ash at different fly ash replacement ratio as different powder. Each flowability chart was simplified into two graphs, graph of relationship between water powder ratio and amount of free water, and graph of relationship between superplasticizer dosage and its dispersing effect. Within certain fly ash replacement ratio, the fly ash replacement ratio had linear relationships with: the inclination and interception of both simplified graphs.

Online publication: 2005-04-11
Publication type : full_text
Public price (Euros): 0.00
doi: 10.1617/2912143624.027