Self-compacting concrete: characterization of the evolution of mechanical properties and study of its deformability under mechanical load, shrinkage and creep.

Author(s)

Ana Carolina Marques

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Escola Politécnica (EP/BC)
• Defense date: 2011-04-29

Examining board members

Túlio Nogueira Bittencourt; Mônica Pinto Barbosa; Antonio Domingues de Figueiredo; Wellington Longuini Repette; Luiz Carlos Pinto da Silva Filho

• Advisor: Túlio Nogueira Bittencourt

Abstract

Self-compacting concrete (SCC) is a new material and its mechanical properties have yet to be studied. It has a higher amount of mortar and smaller coarse aggregates which make it more deformable. On the other hand, the packing of the particles in fresh SCC and its larger strength (at a constant water/cement ratio) may act in the opposite way. Besides, the prediction models provided by the Brazilian Code do not take special concretes into account. The main objective of this work is to verify if the creep and shrinkage prediction models available in the literature can predict those properties of a SCC. This study involves aspects of its characterization by tests in laboratory of creep, shrinkage and other mechanical properties, such as compressive strength, splitting tensile strength and modulus of elasticity. For the creep test, the influence of environmental conditions (for specimens kept in an environment with and without temperature and humidity controlled) and age at loading were evaluated. From the obtained experimental results, a comparison was made to the values obtained from the ACI, EC2, NBR, B3 and GL prediction models. The deformability of SCC was analyzed by monitoring a post-tensioned beam prototype followed by the comparison of the measured deflection and strain long the time to those obtained from a finite element model. From the obtained experimental results of creep and shrinkage, the most adequate prediction models are the ACI and GL models. The use of the ACI model with the finite element method produced good results when compared to the experimental measurements of deflection and strain of the prototype beam. With respect to the compliance creep function, it can be noticed that the model provided by the Brazilian Code is adequate to the studied SCC. (AU)