Compressive strength and drying shrinkage of HySSIL cellular lightweight concrete under different exposure conditions

Lee, H 2010, Compressive strength and drying shrinkage of HySSIL cellular lightweight concrete under different exposure conditions, Masters by Research, Civil, Environmental and Chemical Engineering, RMIT University.


Document type: Thesis
Collection: Theses

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Title Compressive strength and drying shrinkage of HySSIL cellular lightweight concrete under different exposure conditions
Author(s) Lee, H
Year 2010
Abstract An innovative cellular lightweight concrete has the potential to offer significant environmental benefits to the Australian construction sector. It has the potential to reduce the self weight of normal concrete structures by up to 50% and to offer environmental advantages with its superior insulation properties. The porous microstructure of the material provides better sound and temperature insulation than normal concrete.

Initial studies have shown that the strength of this cellular concrete changes significantly with the moisture content of the material itself. Concern has therefore been raised about the possible changes in moisture content during in-service conditions and the resultant effect on compressive strength. Therefore, it is vital to understand the equilibrium moisture content of the material under standard exposure conditions according to Australian Standards. The structural application of cellular concrete also requires a sound understanding of the drying shrinkage of the material, since differential shrinkage could cause warping and cracking of the structures. In calculating the drying shrinkage of normal concrete, the basic shrinkage strain is determined using standard specimens and then modified to allow for the size effect. This method requires some validation/modification prior to application to cellular concrete.

The research work presented here has addressed the above gaps in knowledge through a comprehensive experimental program covering moisture content, compressive strength and drying shrinkage of cellular light weight concrete under different exposure conditions. Compressive strength, moisture content, and exposure relationships have been established by means of the exposure of 100 mm cubes cut from panels to six different service exposure conditions, preceded by the conditioning methods adopted in the normal manufacturing process for panels. It is observed that exposure to different environments with a range of relative humidity from 30% to 80% changed the equilibrium moisture content of the material by between 4% and 8%. This change led to a 33% change in compressive strength, which indicates that care should be taken in electing surface coatings if the material is used in load- bearing structures.
The drying shrinkage of the cellular lightweight concrete has been examined through the design of an experimental program covering age, dimensions of specimens and the exposed environment as major variables. The current AS3600 drying shrinkage model has been modified to predict the drying shrinkage of the cellular lightweight concrete studied here.
Degree Masters by Research
Institution RMIT University
School, Department or Centre Civil, Environmental and Chemical Engineering
Keyword(s) Cellular Lightweight Concrete
Drying Shrinkage
Compressive Strength
Relative Humidity
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Created: Fri, 06 Jun 2014, 14:43:07 EST by Keely Chapman
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