Assessing the freeze-thaw durability of surface treated concrete
Title: Assessing the freeze-thaw durability of surface treated concrete
Author(s): D.J. Cleland, L. Basheer
Paper category : conference
Book title: International RILEM Workshop on Frost Resistance of Concrete
Editor(s): M. J. Setzer, R. Auberg and H. - J. Keck
Publisher: RILEM Publications SARL
Publication year: 2002
Pages: 359 - 366
Total Pages: 8
Nb references: 9
Abstract: Pore liners such as silanes and siloxanes are used as surface treatments for concrete to reduce the ingress of water and water born ions. These pore liners react with hydrated cement particles and form a hydrophobic lining on the pore walls. Unlike other coatings these water repellents will not block the pores and hence will allow evaporation of moisture from the concrete, helping it to dry out. However the surface moisture of the concrete at the time of application of the treatment affects the depth of penetration of the treatment and it is believed that it will in turn affect the longer term performance of the treated concrete.
The water movement in the treated concrete is reduced due to the water repellent nature of the pore liner. However the high pressure water movement generated during freezing and thawing may overcome the hydrophobic effect of the treatment which may not provide sufficient protection against moisture movement. Many structures treated with pore liners may be exposed to freezing and thawing conditions during their service life. Hence it is important to assess the freeze-thaw durability of surface treated concrete. This paper describes a laboratory study carried out using the RILEM test, which was developed for untreated concrete.
Concrete specimens with three different water cement ratios were used to study the performance of concrete with varying pore structure. Three different pore liners were used for the investigation. To study the effect of the surface moisture condition of the concrete at the time of application of the treatment the concretes were exposed to two different moisture conditions before applying the treatments. The performance of freezing media, saline water and tap water, is reported in the paper. Results indicate that the surface treatment improves the freeze thaw resistance even in the case of the most porous concrete used in the study. However the surface moisture condition of the concrete at the time of application of the treatment influences the extent of the improvement in durability in the case of salt scaling resistance.
Online publication: 2010-06-28
Publication type : full_text
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