Creep and shrinkage behavior of selfconsolidating concrete

1
Creep and shrinkage behavior of
self-consolidating concrete
Advisor David J. Mukai, Ph.D. Benoit Cordoba,
Masters candidate University of Wyoming
2
Introduction

• Self-Consolidating Concrete (SCC) was developed
  in Japan starting in the mid 1980s by professor
  Hajime Okamura to improve the durability of
  buildings in Japan. In the summer of 1988
  Kazumasa Ozawa was able to create the first SCC.
• Because of its many advantages SCC is starting to
  be used in the U.S.

3
What is SCC?

• Concrete that can be placed in the form and go
  through obstructions by its own weight and
  without the need of vibration.
• Typical characteristics
• Low coarse aggregate (CA) content.
• High cement content (typically).
• Cement replacement with fly ash or slag cement.
• High range water reducer and plasticizers.

4
Flowing ability and passing ability

• Since the quality of the concrete depends on its
  ability to flow and clear obstacles, they need to
  be verified on site.
• Flowing ability is measured with a slump cone
  pancake.
• Passing ability is measured by the ability of
  concrete to go through obstructions.
• depends on low CA content
• Experiment being conducted at the University of
  Wyoming.

5
Passing Ability of SCC
John McBrides Research at the University of
Wyoming
6
Literature review

• According to Neville1 the factors that affect
  creep and shrinkage predictions are shown at
  right.
• Predictions that use slump will not be applicable
  to SCC.

1 Creep of plain and structural concrete
Neville, Dilger, Brooks. Construction Press,
1983.
7
Examples
8
Experiment

• Measure creep and shrinkage of three SCC mixtures
  (Shah, Miura, Khayat)
• Measure creep and shrinkage of three non-SCC
  mixtures (proportioned according to Portland
  Cement Association guidelines) with same w/c as
  SCC mixtures.
• Creep tests based on ASTM C512-87.

9
Testing frame
Applied force 35000 lb/156 kN
Cylinders are 4 diameter x 8
There is a spherical washer Under the bottom
plate to align the header plates.
10

• Questions?