A Capillary Suction Model for Concrete Masonry and Its Application to Integral Water-Repellent Masonry

2009 ◽  
pp. 116-116-21
Author(s):  
MV Karkare ◽  
CT Walloch
Keyword(s):  
Water Repellent ◽  
Capillary Suction ◽  
Concrete Masonry

scholarly journals The Effect of Water Repellent Surface Impregnation on Durability of Cement-Based Materials

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Peng Zhang ◽  
Huaishuai Shang ◽  
Dongshuai Hou ◽  
Siyao Guo ◽  
Tiejun Zhao
Keyword(s):  
Reinforced Concrete ◽  
Service Life ◽  
Concrete Structures ◽  
Chloride Penetration ◽  
Water Repellent ◽  
Reinforced Concrete Structures ◽  
Capillary Suction ◽  
Surface Impregnation ◽  
Cement Based Materials ◽  
Ft Ir

In many cases, service life of reinforced concrete structures is severely limited by chloride penetration until the steel reinforcement or by carbonation of the covercrete. Water repellent treatment on the surfaces of cement-based materials has often been considered to protect concrete from these deteriorations. In this paper, three types of water repellent agents have been applied on the surface of concrete specimens. Penetration profiles of silicon resin in treated concrete have been determined by FT-IR spectroscopy. Water capillary suction, chloride penetration, carbonation, and reinforcement corrosion in both surface impregnated and untreated specimens have been measured. Results indicate that surface impregnation reduced the coefficient of capillary suction of concrete substantially. An efficient chloride barrier can be established by deep impregnation. Water repellent surface impregnation by silanes also can make the process of carbonation action slow. In addition, it also has been concluded that surface impregnation can provide effective corrosion protection to reinforcing steel in concrete with migrating chloride. The improvement of durability and extension of service life for reinforced concrete structures, therefore, can be expected through the applications of appropriate water repellent surface impregnation.

Evaluation of the Effectiveness of Clear Water Repellent Coatings on Partially Grouted Single-Wythe Concrete Masonry Walls

2007 ◽  
Vol 4 (8) ◽  
pp. 100629
Author(s):  
Jeffrey H. Greenwald ◽  
Thomas C. Young ◽  
B. Trimble ◽  
J. Brisch ◽  
S. W. Dean
Keyword(s):  
Water Repellent ◽  
Masonry Walls ◽  
Clear Water ◽  
Concrete Masonry ◽  
Concrete Masonry Walls

Eindringtiefe eines Hydrophobierungsmittels als Funktion der Qualität, des Feuchtigkeitsgehaltes und des Alters des Betons / Penetration depth of a water repellent agent as a function of quality, humidity and age of concrete

1999 ◽  
Vol 5 (3) ◽  
pp. 289-306
Author(s):  
H.A. Moetsch ◽  
St. Meier ◽  
A. Gerdes ◽  
F.H. Wittmann
Keyword(s):  
Building Materials ◽  
Concrete Surface ◽  
Water Repellent ◽  
Protective Measures ◽  
Capillary Suction ◽  
Treatment Need ◽  
Measuring Cell ◽  
National Highway ◽  
Different Types ◽  
Concrete Elements

Abstract Service life and lifetime of a concrete structure are not only depending on mechanical but also on chemical loads. Therefore precautions are often taken into account already in the planning- or construction phase. Certain protective measures such as water repellent treatment need preliminary tests on the finished concrete surface, in order to be applied in an optimal way . The present paper describes the preliminary tests performed on three tunnels of the second section of the Swiss National Highway N5 (Grenchen - Zuchwil) in the area of Solothurn. For the construction of the three tunnels different qualities of concrete and different types of form work were used. Furthermore the selected sections of the tunnels differ also from age and environmental conditions. A new two-chamber measuring cell developped at the Institute for Building Materials of ΕΤΗ-Zurich was applied to determine the capillary suction capacity of selected tunnel sections. Values measured on concrete elements in practice with this new cell are much more reliable than those measured with the traditional Karsten-cell.

scholarly journals Carbonation of Water Repellent-Treated Concrete

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Peng Zhang ◽  
Peibing Li ◽  
Hong Fan ◽  
Huaishuai Shang ◽  
Siyao Guo ◽  
...  
Keyword(s):  
Concrete Structures ◽  
Hyperbolic Function ◽  
Water Repellent ◽  
Water Penetration ◽  
Carbonation Depth ◽  
Carbonation Reaction ◽  
Capillary Suction ◽  
Time Treatment ◽  
Surface Impregnation ◽  
Preventive Method

Water repellent treatment has been considered an effective preventive method against water and aggressive ions penetration into concrete and consequently can improve the durability of concrete structures. In reality, many concrete structures are exposed to conditions with high risk of carbonation. In this contribution, one type of ordinary concrete had been prepared and surface impregnated by 400 g/m2silane cream and 100 g/m2and 400 g/m2silane gel. In addition, integral water repellent concrete was produced by adding 2% silane emulsion. Then, the specimens were exposed to accelerated carbonation for 7, 28, and 72 days. The effect of water repellent treatment on carbonation of concrete has been investigated. The results indicate that surface impregnation reduced carbonation depth of concrete under RH 70%, but integral water repellent concrete increased carbonation. Carbonation reaction started behind the hydrophobic layer in the surface-impregnated concrete. The coefficient of carbonation can be described better by a hyperbolic function of time. Treatment by 400 g/m2silane gel and silane cream showed better efficiency on reducing carbonation than usage of 100 g/m2. Coefficient of water capillary suction was decreased significantly by both surface impregnation and integral water repellent treatment. It is an effective method to protect concrete from water penetration into the material.

Preparation and Characteristics of Integral Water Repellent Cement-Based Materials

2011 ◽  
Vol 675-677 ◽  
pp. 1189-1192 ◽  
Author(s):  
Peng Zhang ◽  
Tie Jun Zhao ◽  
F.H. Wittmann ◽  
Shao Chun Li
Keyword(s):  
Compressive Strength ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Reduction Rate ◽  
Chloride Penetration ◽  
Water Repellent ◽  
Entire Volume ◽  
Capillary Suction ◽  
Cement Based Materials

Polymers are often applied in concrete for multiple purposes and aims. For instance, surface impregnation of concrete with silanes is a reliable technology to protect cement-based materials from ingress of aggressive solutions into the materials. An alternative method is to add silane emulsion into fresh concrete or mortar to produce integral water repellent materials. In this contribution integral water repellent concrete was prepared by adding 1 %, 2 %, 3 %, 4 % and 6 % of silane emulsion. The influence of silane emulsion on the compressive strength, porosity and pore size distribution, water capillary suction and chloride penetration have been investigated. The results indicate that addition of silane emulsion moderately reduced compressive strength of concrete. With 3 % of silane emulsion the reduction is about 10 %. The addition of silane emulsion hardly has influence on pore size distribution. Silane does not block the capillary pores, but only forms a hydrophobic film on the walls of capillary pores. Addition of silane emulsion reduces water capillary suction significantly. The reduction rate is higher than 89 %. Even the surface of integral water repellent concrete is abraded off 7 mm, the material still demonstrates high water repellency because the entire volume is hydrophobic. In addition, chloride penetration also can be reduced substantially.

Water repellent also absorbs

Nature ◽  
2003 ◽  
Author(s):  
Philip Ball
Keyword(s):  
Water Repellent
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