User friendly self-compacting concrete in precast production

Title: User friendly self-compacting concrete in precast production
Author(s): M. Corradi, R. Khurana, R. Magarotto
Paper category : conference
Book title: International RILEM Symposium on Self-Compacting Concrete
Editor(s): O. Wallevik and I. Nielsson
Print-ISBN: 2-912143-42-X
e-ISBN: 2912143713
Publisher: RILEM Publications SARL
Publication year: 2003
Pages: 457 - 446
Total Pages: -10
Nb references: 4
Language: English

Abstract: Precast concrete production is growing rapidly all over the world. The main advantages of precast concrete constructions are the speed of production in a stable indoor and controlled working environment and economy. Thanks to the modern construction techniques, computer aided design and flexibility in production, combined with short delivery times, prefabrication has a major commercial advantage over in-situ concrete constructions. Higher structural performances and increased durability of precast structures derive from the optimal use of the materials. Self compacting concrete is a major step in this direction. This paper examines the flexibility of the combination type of self-compacting concrete using a viscosity modifying admixture in a water solution for controlling the plastic viscosity of the fresh concrete and a state of the art polycarboxylic ether (ACE) superplasticiser, designed to enhance the strengths at very early ages, for obtaining an appropriate yield stress. The combined use of this VMA and the superplasticiser, allows for the production of a self-compacting concrete which can accommodate the variations in the materials properties and the moisture content in the aggregates, making the concrete production easy and user friendly. The other very important advantage of this system is that it eliminates the need for all external energy for placing, compacting and heat curing of concrete to obtain high early strengths, as the ACE superplasticiser does not delay the hydration of cement. "Passive" curing may thus, be used effectively to obtain the required strengths for de-moulding, prestress transfer and handling in 8 to 16 hours that re normally required in the precast production process. The precast concrete elements production is thus, further rationalised. Applications in different concrete element in several precast plants are also presented in this paper.

Online publication: 2003-08-21
Publication type : abstract_only
Public price (Euros): 0.00